The exocyst complex regulates free fatty acid uptake by adipocytes

PloS One
Mayumi InoueTae-Hwa Chun

Abstract

The exocyst is an octameric molecular complex that drives vesicle trafficking in adipocytes, a rate-limiting step in insulin-dependent glucose uptake. This study assessed the role of the exocyst complex in regulating free fatty acid (FFA) uptake by adipocytes. Upon differentiating into adipocytes, 3T3-L1 cells acquire the ability to incorporate extracellular FFAs in an insulin-dependent manner. A kinetic assay using fluoresceinated FFA (C12 dodecanoic acid) uptake allows the real-time monitoring of FFA internalization by adipocytes. The insulin-dependent uptake of C12 dodecanoic acid by 3T3-L1 adipocytes is mediated by Akt and phosphatidylinositol 3 (PI3)-kinase. Gene silencing of the exocyst components Exo70 and Sec8 significantly reduced insulin-dependent FFA uptake by adipocytes. Consistent with the roles played by Exo70 and Sec8 in FFA uptake, mCherry-tagged Exo70 and HA-tagged Sec8 partially colocalize with lipid droplets within adipocytes, suggesting their active roles in the development of lipid droplets. Tubulin polymerization was also found to regulate FFA uptake in collaboration with the exocyst complex. This study demonstrates a novel role played by the exocyst complex in the regulation of FFA uptake by adipocytes.

References

Oct 15, 1996·Proceedings of the National Academy of Sciences of the United States of America·N ShakibaiS Eisenberg
Jul 1, 1997·Journal of the American Dietetic Association·J H Weisburger
Jul 22, 1998·Proceedings of the National Academy of Sciences of the United States of America·D HirschH F Lodish
Jan 23, 1999·The Journal of Clinical Investigation·A DresnerG I Shulman
Dec 25, 2002·The Journal of Biological Chemistry·Frits KampJames A Hamilton
May 10, 2003·Nature Cell Biology·Nathalie SansRobert J Wenthold
Nov 5, 2003·The Journal of Biological Chemistry·Pingsheng LiuRichard G W Anderson
Aug 6, 2004·The Proceedings of the Nutrition Society·Jürgen PohlWolfgang Stremmel
Oct 22, 2004·Molecular Biology of the Cell·Jürgen PohlWolfgang Stremmel
Nov 18, 2004·Journal of Lipid Research·Jinfang LiaoAndreas Stahl
Nov 20, 2004·The Journal of Biological Chemistry·Marie-Ann EwartGwyn W Gould
May 4, 2005·The Journal of Cell Biology·Vladimir A LizunovVadim A Frolov
May 10, 2005·The Journal of Biological Chemistry·Takashi TsuboiGuy A Rutter
Mar 10, 2006·Molecular Biology of the Cell·Mayumi InoueAlan R Saltiel
Apr 14, 2006·Molecular and Cellular Biology·Qiwei WuAndreas Stahl
Aug 17, 2006·Nature Reviews. Molecular Cell Biology·Reinhard Jahn, Richard H Scheller
Sep 19, 2006·Current Biology : CB·Silvia CermelliMichael A Welte
Aug 23, 2007·American Journal of Physiology. Endocrinology and Metabolism·J Patrick KampfAlan M Kleinfeld
Oct 20, 2007·The Journal of Biological Chemistry·Yiqun BaoWalter Hunziker
Jun 11, 2008·The Journal of Cell Biology·Mika Sakurai-YagetaPhilippe Chavrier
Nov 14, 2008·Bioscience Reports·Patrick D LyonsGustav E Lienhard
Apr 26, 2011·Nature Cell Biology·Xiao-Wei ChenAlan R Saltiel
Apr 21, 2012·Advances in Nutrition·Anastasia Georgiadi, Sander Kersten
Jan 16, 2013·Molecular & Cellular Proteomics : MCP·Natalie KrahmerTobias C Walther
Feb 18, 2014·Methods in Enzymology·Tae-Hwa Chun, Mayumi Inoue
Mar 1, 1993·Journal of Microscopy·E M M MandersJ A Aten

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Citations

Dec 31, 2019·Communications Biology·Katharine R GrabekCarlos D Bustamante
Sep 27, 2016·Journal of Cellular Physiology·Toshiaki TanakaMitsuyoshi Iino
Nov 20, 2019·The Journal of Biological Chemistry·Shifeng WangJingshi Shen

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Methods Mentioned

BETA
Assay
transfection
GTPases
confocal microscopy

Software Mentioned

ImageJ

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