The exocytotic trafficking of TC10 occurs through both classical and nonclassical secretory transport pathways in 3T3L1 adipocytes

Robert T. Watson, Megumi Furukawa, Shian Huey Chiang, Diana Boeglin, Makoto Kanzaki, Alan R. Saltiel, Jeffrey E. Pessin

Research output: Contribution to journalArticle

34 Scopus citations

Abstract

To examine the structural determinants necessary for TC10 trafficking, localization, and function in adipocytes, we generated a series of point mutations in the carboxyl-terminal targeting domain of TC10. Wild-type TC10 (TC10/WT) localized to secretory membrane compartments and caveolin-positive lipid raft microdomains at the plasma membrane. Expression of a TC10/C206S point mutant resulted in a trafficking and localization pattern that was indistinguishable from that of TC10/WT. In contrast, although TC10/C209S or the double TC10/C206,209S mutant was plasma membrane localized, it was excluded from both the secretory membrane system and the lipid raft compartments. Surprisingly, inhibition of Golgi membrane transport with brefeldin A did not prevent plasma membrane localization of TC10 or H-Ras. Moreover, inhibition of transGolgi network exit with a 19°C temperature block did not prevent the trafficking of TC10 or H-Ras to the plasma membrane. These data demonstrate that TC10 and H-Ras can both traffic to the plasma membrane by at least two distinct transport mechanisms in adipocytes, one dependent upon intracellular membrane transport and another independent of the classical secretory membrane system. Moreover, the transport through the secretory pathway is necessary for the localization of TC10 to lipid raft microdomains at the plasma membrane.

Original languageEnglish (US)
Pages (from-to)961-974
Number of pages14
JournalMolecular and cellular biology
Volume23
Issue number3
DOIs
Publication statusPublished - Feb 1 2003
Externally publishedYes

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ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

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