Distinct signals in the GLUT4 glucose transporter for internalization and for targeting to an insulin-responsive compartment
- PMID: 7657693
- PMCID: PMC2120561
- DOI: 10.1083/jcb.130.5.1071
Distinct signals in the GLUT4 glucose transporter for internalization and for targeting to an insulin-responsive compartment
Abstract
In adipose and muscle cells, insulin stimulates a rapid and dramatic increase in glucose uptake, primarily by promoting the redistribution of the GLUT4 glucose transporter from its intracellular storage site to the plasma membrane. In contrast, the more ubiquitously expressed isoform GLUT1 is localized at the cell surface in the basal state, and shows a less dramatic translocation in response to insulin. To identify sequences involved in the differential subcellular localization and hormone-responsiveness of these isoforms, chimeric GLUT1/GLUT4 transporters were stably expressed in mouse 3T3-L1 adipocytes. The NH2 terminus of GLUT4 contains sequences capable of sequestering the transporter inside the cell, although not in an insulin-sensitive pool. In contrast, the COOH-terminal 30 amino acids of GLUT4 are sufficient for its correct localization to an intracellular storage pool which translocates to the cell surface in response to insulin. The dileucine motif within this domain, which is required for intracellular sequestration of chimeric transporters in fibroblasts, is not critical for targeting to the hormone-responsive compartment in adipocytes. Analysis of rates of internalization of chimeric transporter after the removal of insulin from cells, as well as the subcellular distribution of transporters in cells unexposed to or treated with insulin, leads to a three-pool model which can account for the data.
Similar articles
-
Insulin-sensitive targeting of the GLUT4 glucose transporter in L6 myoblasts is conferred by its COOH-terminal cytoplasmic tail.J Cell Biol. 1995 May;129(3):641-58. doi: 10.1083/jcb.129.3.641. J Cell Biol. 1995. PMID: 7730401 Free PMC article.
-
Trafficking of Glut4-green fluorescent protein chimaeras in 3T3-L1 adipocytes suggests distinct internalization mechanisms regulating cell surface glut4 levels.Biochem J. 1999 Dec 1;344 Pt 2(Pt 2):535-43. Biochem J. 1999. PMID: 10567238 Free PMC article.
-
Intracellular targeting of the insulin-regulatable glucose transporter (GLUT4) is isoform specific and independent of cell type.J Cell Biol. 1991 Aug;114(4):689-99. doi: 10.1083/jcb.114.4.689. J Cell Biol. 1991. PMID: 1651337 Free PMC article.
-
Intracellular organization of insulin signaling and GLUT4 translocation.Recent Prog Horm Res. 2001;56:175-93. doi: 10.1210/rp.56.1.175. Recent Prog Horm Res. 2001. PMID: 11237212 Review.
-
Molecular mechanisms of insulin-stimulated glucose uptake in adipocytes.Diabetes Metab. 2002 Apr;28(2):85-92. Diabetes Metab. 2002. PMID: 11976560 Review.
Cited by
-
GLUT4 recycles via a trans-Golgi network (TGN) subdomain enriched in Syntaxins 6 and 16 but not TGN38: involvement of an acidic targeting motif.Mol Biol Cell. 2003 Mar;14(3):973-86. doi: 10.1091/mbc.e02-06-0315. Mol Biol Cell. 2003. PMID: 12631717 Free PMC article.
-
The sentrin-conjugating enzyme mUbc9 interacts with GLUT4 and GLUT1 glucose transporters and regulates transporter levels in skeletal muscle cells.Proc Natl Acad Sci U S A. 2000 Feb 1;97(3):1125-30. doi: 10.1073/pnas.97.3.1125. Proc Natl Acad Sci U S A. 2000. PMID: 10655495 Free PMC article.
-
GLUT4 is retained by an intracellular cycle of vesicle formation and fusion with endosomes.Mol Biol Cell. 2004 Feb;15(2):870-82. doi: 10.1091/mbc.e03-07-0517. Epub 2003 Oct 31. Mol Biol Cell. 2004. PMID: 14595108 Free PMC article.
-
The cytosolic C-terminus of the glucose transporter GLUT4 contains an acidic cluster endosomal targeting motif distal to the dileucine signal.Biochem J. 2000 Aug 15;350 Pt 1(Pt 1):99-107. Biochem J. 2000. PMID: 10926832 Free PMC article.
-
The GLUT4 code.Mol Endocrinol. 2008 Feb;22(2):226-33. doi: 10.1210/me.2007-0282. Epub 2007 Aug 23. Mol Endocrinol. 2008. PMID: 17717074 Free PMC article. Review.
References
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Other Literature Sources
Medical
Miscellaneous