Article:Spatiotemporal Regulators for Insulin-Stimulated GLUT4 Vesicle Exocytosis. (5424486)

From ScienceSource
Jump to: navigation, search

This page is the ScienceSource HTML version of the scholarly article described at https://www.wikidata.org/wiki/Q33655562. Its title is Spatiotemporal Regulators for Insulin-Stimulated GLUT4 Vesicle Exocytosis. and the publication date was 2017-04-25. The initial author is Xiaoxu Zhou.

Fuller metadata can be found in the Wikidata link, which lists all authors, and may have detailed items for some or all of them. There is further information on the article in the footer below. This page is a reference version, and is protected against editing.



Converted JATS paper:

Journal Information

Title: Journal of Diabetes Research

Spatiotemporal Regulators for Insulin-Stimulated GLUT4 Vesicle Exocytosis

  • Xiaoxu Zhou
  • Ping Shentu
  • Yingke Xu

Department of Biomedical Engineering, Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou 310027, China

Publication date (ppub): /2017

Publication date (epub): 4/2017

Abstract

Insulin increases glucose uptake and storage in muscle and adipose cells, which is accomplished through the mobilization of intracellular GLUT4 storage vesicles (GSVs) to the cell surface upon stimulation. Importantly, the dysfunction of insulin-regulated GLUT4 trafficking is strongly linked with peripheral insulin resistance and type 2 diabetes in human. The insulin signaling pathway, key signaling molecules involved, and precise trafficking itinerary of GSVs are largely identified. Understanding the interaction between insulin signaling molecules and key regulatory proteins that are involved in spatiotemporal regulation of GLUT4 vesicle exocytosis is of great importance to explain the pathogenesis of diabetes and may provide new potential therapeutic targets.

Paper

1. Introduction

GLUT4 is a 12-transmembrane facilitative glucose transporter that is primarily expressed in muscle and adipose tissues, where it is responsible for insulin-stimulated glucose disposal and for the entry of glucose to muscles during contraction and exercise (see latest reviews in [[1][3]]). The indispensible role of GLUT4 in regulation of glucose hemostasis has been well documented in the previous animal studies, in which genetic ablation of the GLUT4 gene specifically in mice muscle or adipose tissues results in impaired glucose uptake, hyperinsulinemia, and peripheral insulin resistance [[4], [5]]. The major physiological action of insulin is to increase the glucose uptake and storage in muscle and adipose tissues, which is accomplished through the mobilization of intracellular GLUT4 storage vesicles (GSVs) to the cell surface upon stimulation. In the basal state, approximately 5–10% of the GLUT4 is located at the cell surface and >90% in intracellular membrane compartments. Insulin stimulation shifts the steady-state distribution of GLUT4 towards the plasma membrane. The dysfunction of insulin-stimulated GLUT4 translocation is highly related to peripheral insulin resistance and non-insulin-dependent diabetes mellitus in human beings [[2]].

Multiple insulin signaling pathways have been implicated in GLUT4 regulation, which may impinge on one or numerous steps along the intracellular itinerary of GLUT4 trafficking [[6]]. Although the insulin signal transduction network that controls GLUT4 translocation has been largely discovered (reviewed in [[2], [7]]), the mechanism of spatiotemporal coupling between the signaling and intracellular vesicle trafficking is still not fully understood. Insulin regulates GLUT4 vesicle exocytosis in a temporal and spatial manner. Insulin initiates rapid signaling transduction cascades that propagate into the cell to mobilize GLUT4 vesicle release. In addition, insulin promotes the spatial compartmentalization of signaling and protein machinery that play an important role in insuring the fidelity and specificity of its action on GLUT4 vesicle exocytosis. Here, we focus on the current understanding and recent work that have led to improved knowledge of how insulin signaling and key regulatory proteins are involved in spatiotemporal regulation of GLUT4 vesicle exocytosis.

2. Temporal Regulators of Insulin-Stimulated GLUT4 Translocation

Insulin stimulates the surface accumulation of GLUT4 with a half time of 2–5 minutes, which reaches a plateau after 12 minutes [[8]]. In this process, multiple trafficking steps of GLUT4 are potentially regulated by insulin signaling, including GSV release and trafficking [[9]], vesicle tethering/docking [[10][12]], and ultimately fusion [[13][15]].

Insulin signaling is initiated through binding and activation of its surface receptor. Activation of the insulin receptor triggers a cascade of phosphorylation events that ultimately promote GLUT4 vesicle exocytosis. The canonical insulin signaling pathway involves docking of the insulin receptor substrate (IRS) to the activated insulin receptor, which then subsequently activates phosphoinositide 3-kinase (PI3K). Activated PI3K increases the conversion of phosphatidylinositol 4,5-bisphosphate (PIP2) to phosphatidylinositol 3,4,5-trisphosphate (PIP3) at the plasma membrane, which activates Akt and atypical protein kinase C (aPKC) and subsequently phosphorylation of AS160 (Akt substrate of 160 kDa) by Akt (see reviews in [[1], [7], [16]]). In addition, a PI3K-independent pathway that is involved with c-CBL, c-CBL-associated protein (CAP), and the small GTPase TC10 may also regulate insulin-stimulated GLUT4 translocation in adipocytes (see reviews in [[1], [17]]). Together, these signaling pathways ensure the efficient delivery of GLUT4 to the cell surface by properly orchestrating lipids, protein kinases, small GTPase, and adaptor proteins at the plasma membrane (Figure 1).

2.1. PI3K

The PI3K-dependent insulin signaling plays a pivotal role in regulation of GLUT4 translocation in both muscle and adipose cells. There is a lot of evidence showing that PI3K activity is essential for insulin-stimulated GLUT4 translocation. Inhibition of PI3K activity with specific inhibitors, such as wortmannin and LY294002, or expression of dominant-negative mutants of PI3K and microinjection of blocking antibodies to PI3K can completely abolish insulin-stimulated GLUT4 translocation [[18][20]]. In contrast, overexpression of constitutively active form of PI3K [[21][23]] or exogenous addition of cell-permeable derivatives of PIP3 induces insulin-independent GLUT4 translocation [[24]]. Furthermore, a recent work from our group by using optogenetic approach (light-induced protein heterodimerization between CIBN-CAAX and CRY2-iSH2) to rapidly activate PI3K in adipocytes shows that light-activated PI3K fully mimics the effect of insulin on promoting GSV exocytosis [[25]]. Together, these studies demonstrate the central role of PI3K as a major effector in connecting insulin signaling with vesicle trafficking.

2.2. Akt/PKB

Akt/PKB, a serine-/threonine-specific protein kinase downstream of PI3K, is another crucial node in insulin signaling. There are three existing Akt isoforms (Akt1–3) in mammalian cells, and knockout and knockdown studies have identified Akt2 as the relevant isoform required for insulin-stimulated GLUT4 trafficking and glucose uptake [[26][29]]. Microinjection of Akt substrate peptide or antibody specific to Akt inhibits insulin-stimulated GLUT4 translocation to the plasma membrane by 66% and 56%, respectively, in 3T3-L1 adipocytes [[30]]. In L6 muscle cells, overexpression of Akt dominant-negative mutations decreases insulin-stimulated GLUT4 translocation by approximately 60% [[31]]. In addition, the drug inhibitor for Akt activation, Akti, does not fully abolish insulin-stimulated GLUT4 translocation in adipocytes [[25], [32]]. Using an optogenetic approach to control Akt activation, a study from our group has demonstrated that Akt only accounts for about two-third of a maximal insulin effect on GLUT4 translocation [[25]], which disagrees with the previous studies that claim Akt is sufficient for insulin-stimulated GLUT4 translocation [[33][35]]. Whether Akt and PI3K play equivalent roles in GLUT4 translocation needs to be further tested in other cell types or compared in a more physiological condition. However, it has been suggested that other PI3K signaling pathways, for instance, PI3K-activated Rac1 and aPKC pathways, are required together with Akt to promote GLUT4 translocation in muscle and adipose cells [[36], [37]].

2.3. AS160 and TBC1D1

AS160 (also known as TBC1D4) is a downstream effector of Akt/PKB, which has been shown to be a key modulator of intracellular GLUT4 translocation [[38], [39]]. AS160 is a Rab GTPase-activating protein (Rab-GAP), which is present on GLUT4 vesicles. Insulin causes the phosphorylation of AS160 at multiple serine/threonine residues, which inactivate its GAP activity. The current understanding is that in the basal state, the Rab-GAP function of AS160 promotes the inactive GDP-bound state of Rabs. However, in the presence of insulin stimulation, phosphorylation of AS160 shuts off its GAP activity, shifting the equilibrium of its target Rabs to an active GTP-bound state, which releases GLUT4 from intracellular retention mechanisms [[38][40]]. Indeed, studies have shown that knockdown of AS160 increases the localization of GLUT4 at the PM of unstimulated cells, which impairs insulin-stimulated GLUT4 translocation [[38], [40]]. Similarly, overexpression of Akt/PKB phosphorylation-deficient mutant of AS160, that is, constitutively active GAP, induces a reduction in Rab activity and insulin-stimulated GLUT4 translocation in both 3T3-L1 adipocytes and muscle cells [[41], [42]]. TBC1D1, another Rab-GAP protein that is highly homologous with AS160/TBC1D4, has shown to display similar regulation of GLUT4 in 3T3-L1 adipocytes and muscle cells [[43], [44]]. TBC1D1 is most abundant in the skeletal muscle and only has a very low abundance in adipocytes. Knockdown of endogenous TBC1D1 in 3T3-L1 adipocytes has no effect on insulin-stimulated GLUT4 translocation, whereas its overexpression diminishes the effect of insulin on GLUT4 translocation [[43], [45]]. Knockout of TBC1D1 protein expression in mice impairs exercise-mediated glucose uptake in muscle fibers and lowers GLUT4 expression but does not affect the fold change of insulin-stimulated glucose uptake in muscle [[46], [47]]. The latest animal studies by generating TBC1D1 Ser231Ala-knockin mice that are abortive of AMP-activated protein kinase- (AMPK-) induced phosphorylation show that TBC1D1 is more involved in AICAR-induced muscle glucose uptake and only partially mediates AMPK-regulated glucose homeostasis in muscle [[48]]. Nevertheless, this study has not measured phosphorylation of AS160 or TBC1D1 in response to exercise or AICAR on other sites besides Ser231, nor did it assess other means of Rab-GAP regulation by phosphorylation. Thus, the role of these two Rab-GAPs in different cells and in different stimulus conditions still deserves further studies in the field.

The identification and characterization of the downstream Rabs of AS160 and TBC1D1 have been an intense area of research. The previous in vitro experiments show that AS160 has Rab-GAP activity against Rabs 2, 8, 10, 13, and 14 [[49], [50]]. In adipocytes, the Rab proteins that are currently considered to be the main targets of AS160 are Rab10 and Rab14 [[49], [51]]. Studies show that knockdown of Rab10 diminishes insulin-stimulated GLUT4 translocation in 3T3-L1 adipocytes, whereas the surface recycling of a transferrin receptor is unaffected, suggesting that Rab10 can act specifically at the GSVs [[51], [52]]. To support this, knockdown of Dennd4C, the guanine nucleotide exchange factor (GEF) for Rab10, inhibits insulin-stimulated GLUT4 translocation in adipocytes [[53]]. On the contrary, studies suggest that Rab14 is involved in the endosomal recycling of GLUT4, probably engaging in intracellular sorting of GLUT4 into GSVs [[51], [54], [55]]. In muscle cells, it has been shown that Rab8 and Rab13 are the major targets of AS160, whose downregulation profoundly inhibits insulin-stimulated GLUT4 translocation [[56][59]]. In addition, other Rabs that are implicated in intracellular GLUT4 traffic include Rab4 [[60]], Rab5 [[61]], Rab11 [[62]], Rab28 [[63]], and Rab31 [[64]]. On the other hand, the Rabs associated with exercise-stimulated GLUT4 traffic are still unknown. The Rabs may work collectively to ensure the proper traffic of GLUT4 through the intracellular compartments to the PM.

2.4. aPKC

Atypical PKCs (including protein kinase ζ and ι/λ isoforms), which belong to the PKC family, require neither calcium nor diacylglycerol for activation. Blocking the activation of PKCλ partly inhibits GLUT4 trafficking [[65], [66]]. Overexpression of dominant-negative mutants of PKCλ inhibit insulin-stimulated glucose uptake by ~60%, and these mutants do not inhibit insulin-induced activation of Akt [[65]]. In addition, muscle-specific knockout of PKCλ has shown to induce systemic insulin resistance and diabetes in mice, which further demonstrates the importance of aPKC in insulin-stimulated glucose transport [[67]]. On the contrary, overexpression of constitutively active PKCλ or PKCζ isoforms have been demonstrated to promote GLUT4 translocation in 3T3-L1 adipocytes [[65]], rat skeletal muscle cells [[68]], and primary rat adipocytes [[69]]. Interestingly, studies in muscle cells show that activation of PKC induces serine phosphorylation of VAMP2 in the GLUT4 compartment, which subsequently increases glucose transport [[70]]. Another research in adipocytes indicates that aPKCζ/λ is a convergent downstream target of the insulin-stimulated PI3K and TC10 signaling pathways [[36]]. Furthermore, the exocyst subunit Sec5 has shown to be regulated by PKC signaling, which modulates the stability of exocyst complex through phosphorylation modification [[71]]. However, the downstream effectors of PKC and the underlying mechanism of regulation in GLUT4 translocation are still needed in the field. The connection of aPKC signal to GLUT4 vesicle trafficking appears to involve the actin cytoskeleton, Rabs, and molecular motors, as PKCλ/ζ can impinge on Rac-mediated actin dynamics and can also regulate the interaction between Rab4 and kinesin motors [[72], [73]].

2.5. Rac and TC10

Insulin-stimulated GLUT4 translocation requires dynamic changes in the actin cytoskeleton or called actin remodeling. Remodeled actin may serve as a scaffold that directs selective signaling molecules for proper signal transduction or alternatively may serve as tracks for motor proteins to move GLUT4 vesicles to the PM. These functions of regulation appear to be engaged with small G protein activity: Rac1 in muscle cells and TC10 in adipocytes.

Rac is one of the Rho GTPase family members. Rac1 is the only isoform that is shown to be involved in insulin-stimulated GLUT4 translocation in muscle cells [[74]]. In muscle-specific Rac1 knockout mice, both insulin- and exercise-stimulated GLUT4 translocations and glucose uptake are markedly impaired [[74], [75]]. Similarly, in L6 cells with Rac1 knockdown or overexpression of dominant-negative mutant of Rac1, the increase in insulin-stimulated GLUT4 translocation is fully abolished [[76], [77]]. Under these circumstances, insulin-stimulated actin remodeling is affected, presumably through the downregulation of Rac1 activity. In muscle cells, it has been suggested that Akt and Rac1 are two parallel signaling pathways under the regulation of PI3K [[74], [77][79]]. Rac1 knockdown or constitutive activation has no effect on insulin-stimulated Akt phosphorylation [[77], [79]]. On the contrary, some other studies suggest that Akt signaling is an upstream of Rac1 in skeletal muscle cells [[80], [81]]. These studies show that insulin-induced Rac1 activation is completely inhibited by Akt inhibitors or with Akt2 knockdown in muscle cells [[80], [81]]. Thus, the mechanism of Rac1 activation and its potential role in regulation of GLUT4 trafficking in adipose cells are yet to be established.

TC10 is a member of the Rho small GTPase known to regulate cortical actin dynamics and contribute to GLUT4 exocytosis [[82], [83]]. In adipocytes, TC10 becomes activated in response to insulin stimulation, and this activation appears to be PI3K-independent, under the regulation of the CAP/Cbl/C3G cascade of the signaling pathway (see reviews in [[2], [17], [84]]). TC10 has homology sequence with Cdc42 and Rac and binds to effectors having a Cdc42-/Rac-interactive binding domain, such as p21-activated protein kinase, the neural Wiscott-Aldrich syndrome protein (N-WASP) [[85]], and also proteins without these domains, for instance, Exo70 [[86]], PIST [[87]], and CIP4 [[88]]. In 3T3-L1 adipocytes, overexpression of dominant-interfering TC10alpha mutant inhibits insulin-stimulated glucose uptake and GLUT4 translocation [[82], [89]], suggesting the importance of GTPase activity in its function. On the contrary, another study shows that overexpression of TC10alpha or other chimeras with lipid raft-targeting motifs in adipocytes inhibits insulin-stimulated GLUT4 translocation, and these effects are independent of its GTPase activity but dependent on its membrane localization [[90]]. Furthermore, although siRNA-mediated TC10 knockdown was reported to effect insulin-simulated GLUT4 translocation, no other lab has reported the same findings and no mouse knockout models have corroborated these findings found in 3T3-L1 adipocytes. In addition, in muscle cells, TC10 mutations are shown to fail to prevent insulin-stimulated GLUT4 translocation [[76]]. Thus, additional studies are needed to elucidate the role of TC10 in regulation of the trafficking of GLUT4, especially in muscle systems, and how these intracellular effectors of TC10 regulate discrete steps of GLUT4 trafficking in cells.

3. Spatial Determinants of Insulin-Regulated GLUT4 Translocation

The spatial aspects of insulin signal transduction and distribution of regulatory proteins play a crucial role in determining the specificity of insulin action. So far, lots of insulin signaling molecules, such as insulin receptor [[91]], CAP, and its interacting proteins [[89], [92]], have been found to associate with or reside on the subdomain of the plasma membrane lipid raft structure. The role of lipid rafts in insulin signaling has been reviewed elsewhere [[17], [93]]. Here, we mainly focus on the description of membrane traffic regulatory proteins in spatial regulation of GLUT4 vesicle exocytosis.

3.1. Exocyst Complex

An exocyst is an evolutionarily conserved octameric protein complex consisting of Sec3, Sec5, Sec6, Sec8, Sec10, Sec15, Exo70, and Exo84 (see reviews in [[94], [95]]). The exocyst components were originally identified in a genetic screen for temperature-sensitive secretory mutants of yeast Saccharomyces cerevisiae [[96]]. The exocyst complex plays a crucial role in the targeting of vesicles to the plasma membrane during exocytosis, and it has been shown to be involved in diverse cellular processes, such as yeast budding, cell polarity, ciliogenesis, and neurite outgrowth (see reviews in [[94], [95]]). The exocyst has been demonstrated to play a pivotal role in insulin-stimulated GLUT4 trafficking, presumed by facilitating the tethering/docking of GLUT4 vesicles to the plasma membrane [[86], [97]]. It has been shown that the GTPase TC10 interacts with Exo70 and recruits Exo70 and Sec6/Sec8 subcomplex components to the cell surface after insulin stimulation [[86]]. Overexpression of dominant-negative mutant of Exo70 blocks insulin-stimulated GLUT4 vesicle fusion with the plasma membrane but not the redistribution of vesicles to the periphery of cells [[86]]. In 3T3-L1 adipocytes, studies have shown that insulin stimulation promotes the redistribution of Sec6 and Sec8 to the cell surface, and overexpression of Sec6/Sec8 exocyst subunits augments insulin-stimulated GLUT4 translocation [[97]]. In addition, Sec8 interacts with synapse-associated protein 97 (SAP97) in lipid rafts, which anchors the exocyst complex in the subdomain of the plasma membrane [[98]]. Besides, both Sec3 and Exo70 can interact with PIP2, the phospholipid present in lipid rafts through PH domain-like structure [[99], [100]]. Thus, it is conceivable that exocyst complex assembles in subdomains at the plasma membrane, which regulates the spatial localization and fusion of GLUT4 with the plasma membrane. Indeed, the previous work has shown that the exocytic sites of insulin-stimulated GLUT4 vesicle exocytosis are spatially clustered on the plasma membrane, which are disrupted and become randomized after Sec8 knockdown [[101]]. Together, these studies suggested that the exocyst might serve as a spatial landmark for GLUT4 vesicle exocytosis at the plasma membrane. In the future, direct visualization of exocyst dynamics and GLUT4 vesicle exocytosis is needed to better illustrate this point.

3.2. SNARE Proteins

The primary role of SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) is to bridge two membranes and drive membrane fusion events, which control the membrane traffic in all eukaryotic cells [[102]]. The interaction between SNARE proteins from the vesicle (v-SNAREs) and those from the target membrane (t-SNAREs) is essential for membrane fusion. The SNARE proteins involved in the fusion of GLUT4 vesicles with the plasma membrane are syntaxin 4, SNAP23, and VAMP2 [[103], [104]]. The t-SNAREs syntaxin 4 and SANP23 are located on the plasma membrane, which mark the exocytic sites where GLUT4 vesicles fuse. It has been reported that syntaxin 4 and SNAP23 are not uniformly distributed on the cell surface. Syntaxin 4 and SNAP23 reside on cholesterol-enriched lipid raft structure which occupies discrete areas on the plasma membrane [[105], [106]]. It has been generally accepted that VAMP2 is the v-SNARE present on GSVs, although other v-SNAREs, such as VAMP3, VAMP7, and VAMP8, have also been suggested to be present on GLUT4 vesicles and implicated in vesicle exocytosis [[14], [107], [108]]. Similar to syntaxin 4 and SNAP23, VAMP2 has also been demonstrated to localize in lipid rafts [[106]]. Together, these studies strongly suggest the lipid rafts play an important role in the process of insulin-stimulated GLUT4 vesicle exocytosis at the plasma membrane.

In addition, proteins that can regulate SNARE function may engage in spatial regulation of vesicle exocytosis. One particular interesting protein is Munc18c, which is a member of Sec1/Munc18 (SM) family proteins. SM proteins are essential regulators of SNARE-mediated vesicle fusion events, initially identified as high-affinity binding partners for syntaxin proteins on the plasma membrane and, more recently, in a binding mode with the SNARE core complex [[109]]. In adipocytes, Munc18c interacts with syntaxin 4. Overexpression of Munc18c has shown to inhibit insulin-stimulated GLUT4 translocation, but in adipocytes derived from MEFs with Munc18c knockout, it shows enhanced GLUT4 translocation [[110], [111]]. These studies suggest that disruption of the interaction between syntaxin4 and Munc18c might serve another function of insulin regulation. Indeed, researches have demonstrated that insulin signaling through the insulin receptor kinase regulates the assembly of SNARE complexes by controlling the phosphorylation of Munc18c [[112], [113]]. In the basal state, Munc18c interacts with syntaxin 4, which blocks the availability of syntaxin 4 to interact with VAMP2 and t-SNAREs. Whereas in the presence of insulin, insulin receptor tyrosine kinase phosphorylates Munc18c on Tyr219 and Tyr521 sites, which release Munc18c from syntaxin4, thus promotes the SNARE complex formation, and increases insulin-stimulated GLUT4 vesicle exocytosis [[112], [113]].

4. Perspectives

To dissect the spatiotemporal relationship between insulin signaling, protein dynamics, and GLUT4 vesicle trafficking, new techniques are greatly needed in this field. For instance, new approaches to perturb insulin signaling in a rapid and specific manner, our group has recently applied an optogenetic system to control the activation of PI3K and Akt both spatially and temporally and dissect the role of individual of them in insulin-stimulated GLUT4 vesicle exocytosis [[25]]. Integration of optogenetics with high-resolution light microscope imaging and the dynamic function of signaling nodes in vesicle trafficking that is not easily targetable with drugs can be visualized and analyzed. In addition, a large-scale and high-throughput proteomics study is needed. Although the insulin signaling pathway and key molecular players have been identified and characterized, the intersection of different signaling pathways and new components that are potentially involved in regulation of vesicle trafficking remains to be discovered.

Acknowledgements

Acknowledgments

This work was supported by the National Natural Science Foundation of China (31571480, 31301176, and 61427818), the National Key Research and Development Program of China (2016YFF0101406), and the National Basic Research Program of China (2015CB352003).

References

  1. D. LetoA. R. SaltielRegulation of glucose transport by insulin: traffic control of GLUT4Nature Reviews. Molecular Cell Biology201213638339610.1038/nrm33512-s2.0-848614448598486144485922617471
  2. J. S. BoganRegulation of glucose transporter translocation in health and diabetesAnnual Review of Biochemistry20128150753210.1146/annurev-biochem-060109-0942462-s2.0-848618900858486189008522482906
  3. L. SylowM. KleinertE. A. RichterT. E. JensenExercise-stimulated glucose uptake - regulation and implications for glycaemic controlNature Reviews. Endocrinology201713313314810.1038/nrendo.2016.16227739515
  4. A. ZismanO. D. PeroniE. D. AbelTargeted disruption of the glucose transporter 4 selectively in muscle causes insulin resistance and glucose intoleranceNature Medicine20006892492810.1038/786932-s2.0-003383424810932232
  5. E. D. AbelO. PeroniJ. K. KimAdipose-selective targeting of the GLUT4 gene impairs insulin action in muscle and liverNature2001409682172973310.1038/350555752-s2.0-0035825643003582564311217863
  6. H. ZaidC. N. AntonescuV. K. RandhawaA. KlipInsulin action on glucose transporters through molecular switches, tracks and tethersThe Biochemical Journal2008413220121510.1042/BJ200807232-s2.0-481491009864814910098618570632
  7. J. StockliD. J. FazakerleyD. E. JamesGLUT4 exocytosisJournal of Cell Science2011124Part 244147415910.1242/jcs.0970632-s2.0-8485690048022247191
  8. R. GoversA. C. CosterD. E. JamesInsulin increases cell surface GLUT4 levels by dose dependently discharging GLUT4 into a cell surface recycling pathwayMolecular and Cellular Biology200424146456646610.1128/MCB.24.14.6456-6466.20042-s2.0-3042841303304284130315226445
  9. J. S. BoganN. HendonA. E. McKeeT.-S. TsaoH. F. LodishFunctional cloning of TUG as a regulator of GLUT4 glucose transporter traffickingNature2003425695972773310.1038/nature019892-s2.0-0142184334014218433414562105
  10. S. H. HuangL. M. LifshitzC. JonesInsulin stimulates membrane fusion and GLUT4 accumulation in clathrin coats on adipocyte plasma membranesMolecular and Cellular Biology20072793456346910.1128/MCB.01719-062-s2.0-339476063343394760633417339344
  11. L. BaiY. WangJ. FanDissecting multiple steps of GLUT4 trafficking and identifying the sites of insulin actionCell Metabolism200751475710.1016/j.cmet.2006.11.0132-s2.0-338456665933384566659317189206
  12. V. A. LizunovH. MatsumotoJ. ZimmerbergS. W. CushmanV. A. FrolovInsulin stimulates the halting, tethering, and fusion of mobile GLUT4 vesicles in rat adipose cellsThe Journal of Cell Biology2005169348148910.1083/jcb.2004120692-s2.0-188444054371884440543715866888
  13. F. KoumanovB. JinJ. YangG. D. HolmanInsulin signaling meets vesicle traffic of GLUT4 at a plasma-membrane-activated fusion stepCell Metabolism20052317918910.1016/j.cmet.2005.08.0072-s2.0-277445846592774458465916154100
  14. Y. XuB. R. RubinC. M. OrmeDual-mode of insulin action controls GLUT4 vesicle exocytosisThe Journal of Cell Biology2011193464365310.1083/jcb.2010081352-s2.0-799582368577995823685721555461
  15. K. G. StenkulaV. A. LizunovS. W. CushmanJ. ZimmerbergInsulin controls the spatial distribution of GLUT4 on the cell surface through regulation of its postfusion dispersalCell Metabolism201012325025910.1016/j.cmet.2010.08.0052-s2.0-779562986097795629860920816091
  16. S. HuangM. P. CzechThe GLUT4 glucose transporterCell Metabolism20075423725210.1016/j.cmet.2007.03.0062-s2.0-339475966793394759667917403369
  17. A. R. SaltielJ. E. PessinInsulin signaling in microdomains of the plasma membraneTraffic200341171171610.1034/j.1600-0854.2003.00119.x2-s2.0-0242268533024226853314617354
  18. B. CheathamC. J. VlahosL. CheathamL. WangJ. BlenisC. R. KahnPhosphatidylinositol 3-kinase activation is required for insulin stimulation of pp70 S6 kinase, DNA synthesis, and glucose transporter translocationMolecular and Cellular Biology19941474902491110.1128/MCB.14.7.490200283084128007986
  19. J. F. ClarkeP. W. YoungK. YonezawaM. KasugaG. D. HolmanInhibition of the translocation of GLUT1 and GLUT4 in 3T3-L1 cells by the phosphatidylinositol 3-kinase inhibitor, wortmanninThe Biochemical Journal1994300Part 363163510.1042/bj300063100282602808010944
  20. P. M. SharmaK. EgawaY. HuangInhibition of phosphatidylinositol 3-kinase activity by adenovirus-mediated gene transfer and its effect on insulin actionThe Journal of Biological Chemistry199827329185281853710.1074/jbc.273.29.185282-s2.0-003254094400325409449660823
  21. H. KatagiriT. AsanoH. IshiharaOverexpression of catalytic subunit p110alpha of phosphatidylinositol 3-kinase increases glucose transport activity with translocation of glucose transporters in 3T3-L1 adipocytesThe Journal of Biological Chemistry199627129169871699010.1074/jbc.271.29.169872-s2.0-003005439800300543988663584
  22. S. S. MartinT. HarutaA. J. MorrisA. KlippelL. T. WilliamsJ. M. OlefskyActivated phosphatidylinositol 3-kinase is sufficient to mediate actin rearrangement and GLUT4 translocation in 3T3-L1 adipocytesThe Journal of Biological Chemistry199627130176051760810.1074/jbc.271.30.176052-s2.0-002997313500299731358663595
  23. J. F. TantiT. GrémeauxS. GrilloOverexpression of a constitutively active form of phosphatidylinositol 3-kinase is sufficient to promote Glut4 translocation in adipocytesThe Journal of Biological Chemistry199627141252272523210.1074/jbc.271.41.252272-s2.0-002979517800297951788810283
  24. G. SweeneyR. R. GargR. B. CeddiaIntracellular delivery of phosphatidylinositol (3,4,5)-trisphosphate causes incorporation of glucose transporter 4 into the plasma membrane of muscle and fat cells without increasing glucose uptakeThe Journal of Biological Chemistry200427931322333224210.1074/jbc.M4028972002-s2.0-3543017307354301730715166230
  25. Y. XuD. NanJ. FanJ. S. BoganD. ToomreOptogenetic activation reveals distinct roles of PIP3 and Akt in adipocyte insulin actionJournal of Cell Science2016129102085209510.1242/jcs.1748052-s2.0-849709481428497094814227076519
  26. H. ChoJ. L. ThorvaldsenQ. ChuF. FengM. J. BirnbaumAkt1/PKBalpha is required for normal growth but dispensable for maintenance of glucose homeostasis in miceThe Journal of Biological Chemistry200127642383493835210.1074/jbc.C1004622002-s2.0-0035914388003591438811533044
  27. H. ChoJ. MuJ. K. KimInsulin resistance and a diabetes mellitus-like syndrome in mice lacking the protein kinase Akt2 (PKB beta)Science200129255221728173110.1126/science.292.5522.17282-s2.0-0035368548003536854811387480
  28. Z. Y. JiangQ. L. ZhouK. A. ColemanM. ChouinardQ. BoeseM. P. CzechInsulin signaling through Akt/protein kinase B analyzed by small interfering RNA-mediated gene silencingProceedings of the National Academy of Sciences of the United States of America2003100137569757410.1073/pnas.13326331002-s2.0-003793465012808134
  29. C. E. McCurdyG. D. CarteeAkt2 is essential for the full effect of calorie restriction on insulin-stimulated glucose uptake in skeletal muscleDiabetes20055451349135610.2337/diabetes.54.5.13492-s2.0-178444012691784440126915855319
  30. M. M. HillS. F. ClarkD. F. TuckerM. J. BirnbaumD. E. JamesS. L. MacaulayA role for protein kinase Bbeta/Akt2 in insulin-stimulated GLUT4 translocation in adipocytesMolecular and Cellular Biology199919117771778110.1128/MCB.19.11.7771003269552910523666
  31. Q. WangR. SomwarP. J. BilanProtein kinase B/Akt participates in GLUT4 translocation by insulin in L6 myoblastsMolecular and Cellular Biology19991964008401810.1128/MCB.19.6.4008003304942210330141
  32. E. GonzalezT. E. McGrawInsulin signaling diverges into Akt-dependent and -independent signals to regulate the recruitment/docking and the fusion of GLUT4 vesicles to the plasma membraneMolecular Biology of the Cell200617104484449310.1091/mbc.E06-07-05852-s2.0-3374948951116914513
  33. Y. NgG. RammJ. A. LopezD. E. JamesRapid activation of Akt2 is sufficient to stimulate GLUT4 translocation in 3T3-L1 adipocytesCell Metabolism20087434835610.1016/j.cmet.2008.02.0082-s2.0-414490878114144908781118396141
  34. Y. NgG. RammD. E. JamesDissecting the mechanism of insulin resistance using a novel heterodimerization strategy to activate AktThe Journal of Biological Chemistry201028585232523910.1074/jbc.M109.0606322-s2.0-779493212357794932123520022950
  35. A. D. KohnS. A. SummersM. J. BirnbaumR. A. RothExpression of a constitutively active Akt Ser/Thr kinase in 3T3-L1 adipocytes stimulates glucose uptake and glucose transporter 4 translocationThe Journal of Biological Chemistry199627149313723137810.1074/jbc.271.49.313722-s2.0-002990801600299080168940145
  36. M. KanzakiS. MoraJ. B. HwangA. R. SaltielJ. E. PessinAtypical protein kinase C (PKCzeta/lambda) is a convergent downstream target of the insulin-stimulated phosphatidylinositol 3-kinase and TC10 signaling pathwaysThe Journal of Cell Biology2004164227929010.1083/jcb.2003061522-s2.0-1642458098164245809814734537
  37. L. SylowM. KleinertC. PehmøllerAkt and Rac1 signaling are jointly required for insulin-stimulated glucose uptake in skeletal muscle and downregulated in insulin resistanceCellular Signalling201426232333110.1016/j.cellsig.2013.11.0072-s2.0-848900360708489003607024216610
  38. M. LaranceG. RammJ. StockliCharacterization of the role of the Rab GTPase-activating protein AS160 in insulin-regulated GLUT4 traffickingThe Journal of Biological Chemistry200528045378033781310.1074/jbc.M5038972002-s2.0-278445288702784452887016154996
  39. A. ZeigererM. K. McBrayerT. E. McGrawInsulin stimulation of GLUT4 exocytosis, but not its inhibition of endocytosis, is dependent on RabGAP AS160Molecular Biology of the Cell200415104406441510.1091/mbc.E04-04-03332-s2.0-464430028715254270
  40. L. EguezA. LeeJ. A. ChavezFull intracellular retention of GLUT4 requires AS160 Rab GTPase activating proteinCell Metabolism20052426327210.1016/j.cmet.2005.09.0052-s2.0-285444352052854443520516213228
  41. H. SanoS. KaneE. SanoInsulin-stimulated phosphorylation of a Rab GTPase-activating protein regulates GLUT4 translocationThe Journal of Biological Chemistry200327817145991460210.1074/jbc.C3000632002-s2.0-0037677096003767709612637568
  42. F. S. ThongP. J. BilanA. KlipThe Rab GTPase-activating protein AS160 integrates Akt, protein kinase C, and AMP-activated protein kinase signals regulating GLUT4 trafficDiabetes200756210.2337/db06-09002-s2.0-338470628453384706284517259386
  43. W. G. RoachJ. A. ChavezC. P. MiineaG. E. LienhardSubstrate specificity and effect on GLUT4 translocation of the Rab GTPase-activating protein Tbc1d1The Biochemical Journal2007403235335810.1042/BJ200617982-s2.0-342471484303424714843017274760
  44. D. AnT. ToyodaE. B. TaylorTBC1D1 regulates insulin- and contraction-induced glucose transport in mouse skeletal muscleDiabetes20105961358136510.2337/db09-12662-s2.0-779531956227795319562220299473
  45. J. A. ChavezW. G. RoachS. R. KellerW. S. LaneG. E. LienhardInhibition of GLUT4 translocation by Tbc1d1, a Rab GTPase-activating protein abundant in skeletal muscle, is partially relieved by AMP-activated protein kinase activationThe Journal of Biological Chemistry2008283149187919510.1074/jbc.M7089342002-s2.0-440490875314404908753118258599
  46. J. StockliC. C. MeoliN. J. HoffmanThe RabGAP TBC1D1 plays a central role in exercise-regulated glucose metabolism in skeletal muscleDiabetes20156461914192210.2337/db13-14892-s2.0-849815437858498154378525576050
  47. S. R. HargettN. N. WalkerS. S. HussainK. L. HoehnS. R. KellerDeletion of the Rab GAP Tbc1d1 modifies glucose, lipid, and energy homeostasis in miceAmerican Journal of Physiology. Endocrinology and Metabolism20153093E233E24510.1152/ajpendo.00007.20152-s2.0-849386745458493867454526015432
  48. Q. ChenB. XieS. ZhuA Tbc1d1 Ser231Ala-knockin mutation partially impairs AICAR- but not exercise-induced muscle glucose uptake in miceDiabetologia201760233634510.1007/s00125-016-4151-98499446214727826658
  49. H. SanoL. EguezM. N. TeruelRab10, a target of the AS160 Rab GAP, is required for insulin-stimulated translocation of GLUT4 to the adipocyte plasma membraneCell Metabolism20075429330310.1016/j.cmet.2007.03.0012-s2.0-339475780853394757808517403373
  50. S. IshikuraP. J. BilanA. KlipRabs 8A and 14 are targets of the insulin-regulated Rab-GAP AS160 regulating GLUT4 traffic in muscle cellsBiochemical and Biophysical Research Communications200735341074107910.1016/j.bbrc.2006.12.1402-s2.0-338461781853384617818517208202
  51. Y. ChenY. WangJ. ZhangRab10 and myosin-Va mediate insulin-stimulated GLUT4 storage vesicle translocation in adipocytesThe Journal of Cell Biology2012198454556010.1083/jcb.2011110912-s2.0-848663471078486634710722908308
  52. L. A. SadaccaJ. BrunoJ. WenW. XiongT. E. McGrawSpecialized sorting of GLUT4 and its recruitment to the cell surface are independently regulated by distinct RabsMolecular Biology of the Cell201324162544255710.1091/mbc.E13-02-01032-s2.0-8488276245923804653
  53. H. SanoG. R. PeckA. N. KettenbachS. A. GerberG. E. LienhardInsulin-stimulated GLUT4 protein translocation in adipocytes requires the Rab10 guanine nucleotide exchange factor Dennd4CThe Journal of Biological Chemistry201128619165411654510.1074/jbc.C111.2289082-s2.0-799557668727995576687221454697
  54. P. D. BrewerE. N. HabtemichaelI. RomenskaiaA. C. CosterC. C. MastickRab14 limits the sorting of Glut4 from endosomes into insulin-sensitive regulated secretory compartments in adipocytesThe Biochemical Journal2016473101315132710.1042/BCJ201600202-s2.0-849751290948497512909426936971
  55. S. E. ReedL. R. HodgsonS. SongA role for Rab14 in the endocytic trafficking of GLUT4 in 3T3-L1 adipocytesJournal of Cell Science2013126Part 91931194110.1242/jcs.1043072-s2.0-848786664148487866641423444368
  56. H. LiL. OuJ. FanRab8A regulates insulin-stimulated GLUT4 trafficking in C2C12 myoblastsFEBS Letters2017591349149910.1002/1873-3468.125558501109467828079283
  57. Y. SunT. T. ChiuK. P. FoleyP. J. BilanA. KlipMyosin Va mediates Rab8A-regulated GLUT4 vesicle exocytosis in insulin-stimulated muscle cellsMolecular Biology of the Cell20142571159117010.1091/mbc.E13-08-04932-s2.0-8489875871724478457
  58. Y. SunP. J. BilanZ. LiuA. KlipRab8A and Rab13 are activated by insulin and regulate GLUT4 translocation in muscle cellsProceedings of the National Academy of Sciences of the United States of America201010746199091991410.1073/pnas.10095231072-s2.0-7865054955221041651
  59. V. K. RandhawaS. IshikuraI. Talior-VolodarskyGLUT4 vesicle recruitment and fusion are differentially regulated by Rac, AS160, and Rab8A in muscle cellsThe Journal of Biological Chemistry200828340272082721910.1074/jbc.M8042822002-s2.0-552490981265524909812618650435
  60. M. CormontM. N. BortoluzziN. GautierM. MariE. van ObberghenY. Le Marchand-BrustelPotential role of Rab4 in the regulation of subcellular localization of Glut4 in adipocytesMolecular and Cellular Biology199616126879688610.1128/MCB.16.12.687900299239808943343
  61. K. L. TessneerR. M. JacksonB. A. GrieselA. L. OlsonRab5 activity regulates GLUT4 sorting into insulin-responsive and non-insulin-responsive endosomal compartments: a potential mechanism for development of insulin resistanceEndocrinology201415593315332810.1210/en.2013-21482-s2.0-849070427628490704276224932807
  62. A. KesslerE. TomasD. ImmlerH. E. MeyerA. ZorzanoJ. EckelRab11 is associated with GLUT4-containing vesicles and redistributes in response to insulinDiabetologia200043121518152710.1007/s0012500515632-s2.0-0034435239003443523911151761
  63. Z. ZhouF. MenzelT. BenninghoffRab28 is a TBC1D1/TBC1D4 substrate involved in GLUT4 traffickingFEBS Letters20175911889610.1002/1873-3468.1250927929607
  64. I. J. LodhiS. H. ChiangL. ChangGapex-5, a Rab31 guanine nucleotide exchange factor that regulates Glut4 trafficking in adipocytesCell Metabolism200751597210.1016/j.cmet.2006.12.0062-s2.0-338455728273384557282717189207
  65. K. KotaniW. OgawaM. MatsumotoRequirement of atypical protein kinase cλ for insulin-stimulation of glucose uptake but not for akt activation in 3T3-L1 adipocytesMolecular and Cellular Biology199818126971698210.1128/MCB.18.12.697100317245909819385
  66. C. YangR. T. WatsonJ. S. ElmendorfD. B. SacksJ. E. PessinCalmodulin antagonists inhibit insulin-stimulated GLUT4 (glucose transporter 4) translocation by preventing the formation of phosphatidylinositol 3,4,5-trisphosphate in 3T3-L1 adipocytesMolecular Endocrinology200014231732610.1210/mend.14.2.0425003445674010674403
  67. R. V. FareseM. P. SajanH. YangP. LiS. MastoridesW. R. Gower JrS. NimalC. S. ChoiS. KimMuscle-specific knockout of PKC-lambda impairs glucose transport and induces metabolic and diabetic syndromesThe Journal of Clinical Investigation200711782289230110.1172/JCI314082-s2.0-345476635203454766352017641777
  68. G. J. EtgenK. M. ValasekC. L. BroderickA. R. MillerIn vivo adenoviral delivery of recombinant human protein kinase C-zeta stimulates glucose transport activity in rat skeletal muscleThe Journal of Biological Chemistry199927432221392214210.1074/jbc.274.32.221392-s2.0-0033529546003352954610428775
  69. G. BandyopadhyayM. L. StandaertU. KikkawaY. OnoJ. MoscatR. V. FareseEffects of transiently expressed atypical (zeta, lambda), conventional (alpha, beta) and novel (delta, epsilon) protein kinase C isoforms on insulin-stimulated translocation of epitope-tagged GLUT4 glucose transporters in rat adipocytes: specific interchangeable effects of protein kinases C-zeta and C-lambdaThe Biochemical Journal1999337Part 34614709895289
  70. L. BraimanA. AltT. KurokiActivation of protein kinase C zeta induces serine phosphorylation of VAMP2 in the GLUT4 compartment and increases glucose transport in skeletal muscleMolecular and Cellular Biology200121227852786110.1128/MCB.21.22.7852-7861.20012-s2.0-0034774069003477406911604519
  71. X. W. ChenD. LetoJ. XiaoExocyst function is regulated by effector phosphorylationNature Cell Biology201113558058810.1038/ncb22262-s2.0-799556265957995562659521516108
  72. T. ImamuraJ. HuangI. UsuiH. SatohJ. BeverJ. M. OlefskyInsulin-induced GLUT4 translocation involves protein kinase C-λ-mediated functional coupling between Rab4 and the motor protein kinesinMolecular and Cellular Biology200323144892490010.1128/MCB.23.14.4892-4900.20032-s2.0-0038451252003845125212832475
  73. L. Z. LiuH. L. ZhaoJ. ZuoProtein kinase Czeta mediates insulin-induced glucose transport through actin remodeling in L6 muscle cellsMolecular Biology of the Cell20061752322233010.1091/mbc.E05-10-09692-s2.0-3374574634616525020
  74. S. UedaS. KitazawaK. IshidaCrucial role of the small GTPase Rac1 in insulin-stimulated translocation of glucose transporter 4 to the mouse skeletal muscle sarcolemmaThe FASEB Journal20102472254226110.1096/fj.09-1373802-s2.0-779544471117795444711120203090
  75. L. SylowI. L. NielsenM. KleinertRac1 governs exercise-stimulated glucose uptake in skeletal muscle through regulation of GLUT4 translocation in miceThe Journal of Physiology2016594174997500810.1113/JP2720392-s2.0-849765315108498633404327061726
  76. L. JeBaileyA. RudichX. HuangC. Di Ciano-OliveiraA. KapusA. KlipSkeletal muscle cells and adipocytes differ in their reliance on TC10 and Rac for insulin-induced actin remodelingMolecular Endocrinology200418235937210.1210/me.2003-02942-s2.0-0842312945084231294514615606
  77. L. JeBaileyO. WanonoW. NiuJ. RoesslerA. RudichA. KlipCeramide- and oxidant-induced insulin resistance involve loss of insulin-dependent Rac-activation and actin remodeling in muscle cellsDiabetes200756239440310.2337/db06-08232-s2.0-338470268013384702680117259384
  78. F. S. ThongP. J. BilanA. KlipThe Rab GTPase-activating protein AS160 integrates Akt, protein kinase C, and AMP-activated protein kinase signals regulating GLUT4 trafficDiabetes200756241442310.2337/db06-09002-s2.0-338470628453384706284517259386
  79. S. UedaT. KataokaT. SatohActivation of the small GTPase Rac1 by a specific guanine-nucleotide-exchange factor suffices to induce glucose uptake into skeletal-muscle cellsBiology of the Cell20081001164565710.1042/BC200701602-s2.0-5614912223618482007
  80. T. KwonD. Y. KwonJ. ChunJ. H. KimS. S. KangAkt protein kinase inhibits Rac1-GTP binding through phosphorylation at serine 71 of Rac1The Journal of Biological Chemistry2000275142342810.1074/jbc.275.1.4232-s2.0-0034614606003461460610617634
  81. S. NozakiT. TakedaT. KitauraN. TakenakaT. KataokaT. SatohAkt2 regulates Rac1 activity in the insulin-dependent signaling pathway leading to GLUT4 translocation to the plasma membrane in skeletal muscle cellsCellular Signalling20132561361137110.1016/j.cellsig.2013.02.0232-s2.0-848763345078487633450723499910
  82. L. ChangS. H. ChiangA. R. SaltielTC10alpha is required for insulin-stimulated glucose uptake in adipocytesEndocrinology20071481273310.1210/en.2006-11672-s2.0-338458680113384586801117008399
  83. M. KanzakiR. T. WatsonJ. C. HouM. StamnesA. R. SaltielJ. E. PessinSmall GTP-binding protein TC10 differentially regulates two distinct populations of filamentous actin in 3T3L1 adipocytesMolecular Biology of the Cell20021372334234610.1091/mbc.01-10-04902-s2.0-003632022312134073
  84. N. J. HoffmanJ. S. ElmendorfSignaling, cytoskeletal and membrane mechanisms regulating GLUT4 exocytosisTrends in Endocrinology and Metabolism201122311011610.1016/j.tem.2010.12.0012-s2.0-799521078407995210784021216617
  85. C. L. NeudauerG. JobertyN. TatsisI. G. MacaraDistinct cellular effects and interactions of the Rho-family GTPase TC10Current Biology19988211151116010.1016/S0960-9822(07)00486-100325586969799731
  86. M. InoueL. ChangJ. HwangS.-H. ChiangA. R. SaltielThe exocyst complex is required for targeting of Glut4 to the plasma membrane by insulinNature2003422693262963310.1038/nature015332-s2.0-003743132912687004
  87. C. L. NeudauerG. JobertyI. G. MacaraPIST: a novel PDZ/coiled-coil domain binding partner for the rho-family GTPase TC10Biochemical and Biophysical Research Communications2001280254154710.1006/bbrc.2000.41602-s2.0-0034806856003480685611162552
  88. L. ChangR. D. AdamsA. R. SaltielThe TC10-interacting protein CIP4/2 is required for insulin-stimulated Glut4 translocation in 3T3L1 adipocytesProceedings of the National Academy of Sciences of the United States of America20029920128351284010.1073/pnas.2024955992-s2.0-003679097612242347
  89. S. H. ChiangC. A. BaumannM. KanzakiInsulin-stimulated GLUT4 translocation requires the CAP-dependent activation of TC10Nature2001410683194494810.1038/350736082-s2.0-0035912228003591222811309621
  90. J. Chunqiu HouJ. E. PessinLipid raft targeting of the TC10 amino terminal domain is responsible for disruption of adipocyte cortical actinMolecular Biology of the Cell20031493578359110.1091/mbc.E03-01-00122-s2.0-014152165412972548
  91. J. GustavssonS. ParpalM. KarlssonLocalization of the insulin receptor in caveolae of adipocyte plasma membraneThe FASEB Journal199913141961197110544179
  92. C. A. BaumannV. RibonM. KanzakiCAP defines a second signalling pathway required for insulin-stimulated glucose transportNature2000407680120220710.1038/350250892-s2.0-003464879411001060
  93. P. E. BickelLipid rafts and insulin signalingAmerican Journal of Physiology. Endocrinology and Metabolism20022821E1E1011739076
  94. B. HeW. GuoThe exocyst complex in polarized exocytosisCurrent Opinion in Cell Biology200921453754210.1016/j.ceb.2009.04.0072-s2.0-679491066166794910661619473826
  95. M. MunsonP. NovickThe exocyst defrocked, a framework of rods revealedNature Structural & Molecular Biology200613757758110.1038/nsmb10972-s2.0-337458413643374584136416826234
  96. P. NovickC. FieldR. SchekmanIdentification of 23 complementation groups required for post-translational events in the yeast secretory pathwayCell198021120521510.1016/0092-8674(80)90128-200189300466996832
  97. M.-A. EwartM. ClarkeS. KaneL. H. ChamberlainG. W. GouldEvidence for a role of the exocyst in insulin-stimulated Glut4 trafficking in 3T3-L1 adipocytesThe Journal of Biological Chemistry200528053812381610.1074/jbc.M4099282002-s2.0-135442720491354427204915550383
  98. M. InoueS. H. ChiangL. ChangX. W. ChenA. R. SaltielCompartmentalization of the exocyst complex in lipid rafts controls GLUT4 vesicle tetheringMolecular Biology of the Cell20061752303231110.1091/mbc.E06-01-00302-s2.0-3374574618816525015
  99. B. HeF. XiX. ZhangJ. ZhangW. GuoExo70 interacts with phospholipids and mediates the targeting of the exocyst to the plasma membraneThe EMBO Journal200726184053406510.1038/sj.emboj.76018342-s2.0-346488231133464882311317717527
  100. X. ZhangK. OrlandoB. HeMembrane association and functional regulation of Sec3 by phospholipids and Cdc42The Journal of Cell Biology2008180114515810.1083/jcb.2007041282-s2.0-383490306513834903065118195105
  101. K. LetinicR. SebastianA. BarthelD. ToomreDeciphering subcellular processes in live imaging datasets via dynamic probabilistic networksBioinformatics201026162029203610.1093/bioinformatics/btq3312-s2.0-779554054767795540547620581401
  102. J. E. RothmanMechanisms of intracellular protein transportNature19943726501556310.1038/372055a000281436987969419
  103. B. CheathamA. VolchukC. R. KahnL. WangC. J. RhodesA. KlipInsulin-stimulated translocation of GLUT4 glucose transporters requires SNARE-complex proteinsProceedings of the National Academy of Sciences of the United States of America19969326151691517310.1073/pnas.93.26.151692-s2.0-00304649978986782
  104. S. L. MacaulayD. R. HewishK. H. GoughFunctional studies in 3T3L1 cells support a role for SNARE proteins in insulin stimulation of GLUT4 translocationThe Biochemical Journal1997324Part 121722410.1042/bj324021700309176789164859
  105. S. A. PredescuD. N. PredescuK. ShimizuI. K. KleinA. B. MalikCholesterol-dependent syntaxin-4 and SNAP-23 clustering regulates caveolar fusion with the endothelial plasma membraneThe Journal of Biological Chemistry200528044371303713810.1074/jbc.M5056592002-s2.0-277445284612774452846116118213
  106. L. H. ChamberlainG. W. GouldThe vesicle- and target-SNARE proteins that mediate Glut4 vesicle fusion are localized in detergent-insoluble lipid rafts present on distinct intracellular membranesThe Journal of Biological Chemistry200227751497504975410.1074/jbc.M2069362002-s2.0-0037147217003714721712376543
  107. D. WilliamsJ. E. PessinMapping of R-SNARE function at distinct intracellular GLUT4 trafficking steps in adipocytesThe Journal of Cell Biology2008180237538710.1083/jcb.2007091082-s2.0-387491050503874910505018227281
  108. P. ZhaoL. YangJ. A. LopezVariations in the requirement for v-SNAREs in GLUT4 trafficking in adipocytesJournal of Cell Science2009112Part 193472348010.1242/jcs.0474492-s2.0-7035038958619759285
  109. N. J. BryantG. W. GouldSNARE proteins underpin insulin-regulated GLUT4 trafficTraffic201112665766410.1111/j.1600-0854.2011.01163.x2-s2.0-799557173167995571731621226814
  110. H. KandaY. TamoriH. ShinodaAdipocytes from Munc18c-null mice show increased sensitivity to insulin-stimulated GLUT4 externalizationThe Journal of Clinical Investigation2005115229130110.1172/JCI226812014437698415690082
  111. D. C. ThurmondB. P. CeresaS. OkadaJ. S. ElmendorfK. CokerJ. E. PessinRegulation of insulin-stimulated GLUT4 translocation by Munc18c in 3T3L1 adipocytesThe Journal of Biological Chemistry199827350338763388310.1074/jbc.273.50.338762-s2.0-003250921400325092149837979
  112. J. L. JewellE. OhL. RamalingamMunc18c phosphorylation by the insulin receptor links cell signaling directly to SNARE exocytosisThe Journal of Cell Biology2011193118519910.1083/jcb.2010071762-s2.0-799555172157995551721521444687
  113. V. AranN. J. BryantG. W. GouldTyrosine phosphorylation of Munc18c on residue 521 abrogates binding to syntaxin 4BMC Biochemistry2011121p. 1910.1186/1471-2091-12-192-s2.0-799556711597995567115921548926
The underlying source XML for this text is taken from https://www.ebi.ac.uk/europepmc/webservices/rest/PMC5424486/fullTextXML. The license for the article is Creative Commons Attribution 4.0 International. The main subject has been identified as maturity-onset diabetes of the young.