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STAM Adaptor Proteins Interact with COPII Complexes and Function in ER‐to‐Golgi Trafficking
Author(s) -
Rismanchi Neggy,
Puertollano Rosa,
Blackstone Craig
Publication year - 2009
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2008.00856.x
Subject(s) - copii , golgi apparatus , microbiology and biotechnology , endoplasmic reticulum , brefeldin a , copi , biology , signal transducing adaptor protein , endocytic cycle , secretory pathway , endocytosis , transport protein , endosome , vesicular stomatitis virus , signal transduction , receptor , biochemistry , cell culture , genetics , intracellular
Signal‐transducing adaptor molecules (STAMs) are involved in growth factor and cytokine signaling as well as receptor degradation, and they form complexes with a number of endocytic proteins, including Hrs and Eps15. In this study, we demonstrate that STAM proteins also localize prominently to early exocytic compartments and profoundly regulate Golgi morphology. Upon STAM overexpression in cells, the Golgi apparatus becomes extensively fragmented and dispersed, but when STAMs are depleted, the Golgi becomes highly condensed. Under both scenarios, vesicular stomatitis virus G protein–green fluorescent protein trafficking to the plasma membrane is markedly inhibited, and recovery of Golgi morphology after Brefeldin A treatment is substantially impaired in STAM‐depleted cells. Furthermore, STAM proteins interact with coat protein II (COPII) proteins, probably at endoplasmic reticulum (ER) exit sites, and Sar1 activity is required to maintain the localization of STAMs at discrete sites. Thus, in addition to their roles in signaling and endocytosis, STAMs function prominently in ER‐to‐Golgi trafficking, most likely through direct interactions with the COPII complex.