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Organization and Assembly of the TRAPPII Complex
Author(s) -
Choi Catherine,
Davey Michael,
Schluter Cayetana,
Pandher Preet,
Fang Yuan,
Foster Leonard J.,
Conibear Elizabeth
Publication year - 2011
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.1600-0854.2011.01181.x
Subject(s) - biology , golgi apparatus , protein subunit , microbiology and biotechnology , vesicular transport proteins , yeast , tethering , saccharomyces cerevisiae , endoplasmic reticulum , biochemistry , gene , vacuolar protein sorting
Current models suggest that TRAPP tethering complexes exist in two forms. Whereas the seven‐subunit TRAPPI complex mediates ER‐to‐Golgi transport, TRAPPII contains three additional subunits (Trs65, Trs120 and Trs130) and is required for distinct tethering events at Golgi membranes. It is not clear how TRAPPII assembly is regulated. Here, we show that Tca17 is a fourth TRAPPII‐specific component, and that Trs65 and Tca17 interact with distinct domains of Trs130 and make different contributions to complex assembly. Whereas Tca17 promotes the stable association of TRAPPII‐specific subunits with the core complex, Trs65 stabilizes TRAPPII in an oligomeric form. We show that Trs85, which was previously reported to be a subunit of both TRAPPI and TRAPPII, is not associated with the TRAPPII complex in yeast. However, we find that proteins related to Trs85, Trs65 and Tca17 are part of the same TRAPP complex in mammalian cells. These findings have implications for models of TRAPP complex formation and suggest that TRAPP complexes may be organized differently in yeast and mammals.