mVps45 knockdown selectively modulates VAMP expression in 3T3-L1 adipocytes

Jessica B A Sadler, Jennifer Roccisana, Minttu Virolainen, Nia J. Bryant, Gwyn W. Gould

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Insulin stimulates the delivery of glucose transporter-4 (GLUT4)-containing vesicles to the surface of adipocytes. Depletion of the Sec1/Munc18 protein mVps45 significantly abrogates insulin-stimulated glucose transport and GLUT4 translocation. Here we show that depletion of mVps45 selectively reduced expression of VAMPs 2 and 4, but not other VAMP isoforms. Although we did not observe direct interaction of mVps45 with any VAMP isoform; we found that the cognate binding partner of mVps45, Syntaxin 16 associates with VAMPs 2, 4, 7 and 8 in vitro. Co-immunoprecipitation experiments in 3T3-L1 adipocytes revealed an interaction between Syntaxin 16 and only VAMP4. We suggest GLUT4 trafficking is controlled by the coordinated expression of mVps45/Syntaxin 16/VAMP4, and that depletion of mVps45 regulates VAMP2 levels indirectly, perhaps via reduced trafficking into specialized subcellular compartments.

Original languageEnglish
JournalCommunicative and Integrative Biology
Volume8
Issue number3
Early online date24 Jun 2015
DOIs
Publication statusE-pub ahead of print - 24 Jun 2015

Keywords

  • adipocyte
  • biochemistry
  • cell biology
  • glucose transport
  • hormones
  • insulin
  • intracellular membranes
  • membrane protein trafficking
  • membrane trafficking
  • SNARE proteins
  • VAMP

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