TRAPP I implicated in the specificity of tethering in ER-to-Golgi transport.
TRAPP is a conserved protein complex required early in the secretory pathway. Here, we report two forms of TRAPP, TRAPP I and TRAPP II, that mediate different transport events. Using chemically pure TRAPP I and COPII vesicles, we have reconstituted vesicle targeting in vitro. The binding of COPII vesicles to TRAPP I is specific, blocked by GTPgammaS, and, surprisingly, does not require other tethering factors. Our findings imply that TRAPP I is the receptor on the Golgi for COPII vesicles. Once the vesicle binds to TRAPP I, the small GTP binding protein Ypt1p is activated and other tethering factors are recruited.
Sacher
M
M
Department of Cell Biology, Yale University, New Haven, CT 06520, USA.
Barrowman
J
J
Wang
W
W
Horecka
J
J
Zhang
Y
Y
Pypaert
M
M
Ferro-Novick
S
S
D022181:COP-Coated Vesicles / Q000378:metabolism; D002268:Carboxypeptidases / Q000378:metabolism; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D043402:Cathepsin A; D002499:Centrifugation, Density Gradient; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D011485:Protein Binding / Q000187:drug effects; D020033:Protein Isoforms / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D013379:Substrate Specificity; D013696:Temperature; D033921:Vesicular Transport Proteins; D043324:beta-Fructofuranosidase; D020691:rab GTP-Binding Proteins / Q000378:metabolism
D002352:Carrier Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D020033:Protein Isoforms; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; C406327:transport protein particle, TRAPP; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; D002268:Carboxypeptidases; D043402:Cathepsin A; C060755:YPT1 protein, S cerevisiae; D020691:rab GTP-Binding Proteins