ARF-GAP-mediated interaction between the ER-Golgi v-SNAREs and the COPI coat.
In eukaryotic cells, secretion is achieved by vesicular transport. Fusion of such vesicles with the correct target compartment relies on SNARE proteins on both vesicle (v-SNARE) and the target membranes (t-SNARE). At present it is not clear how v-SNAREs are incorporated into transport vesicles. Here, we show that binding of ADP-ribosylation factor (ARF)-GTPase-activating protein (GAP) to ER-Golgi v-SNAREs is an essential step for recruitment of Arf1p and coatomer, proteins that together form the COPI coat. ARF-GAP acts catalytically to recruit COPI components. Inclusion of v-SNAREs into COPI vesicles could be mediated by direct interaction with the coat. The mechanisms by which v-SNAREs interact with COPI and COPII coat proteins seem to be different and may play a key role in determining specificity in vesicle budding.
Rein
Ulrike
U
Friedrich Miescher Laboratory, Max Planck Society, D-72076 Tübingen, Germany.
Andag
Uwe
U
Duden
Rainer
R
Schmitt
Hans Dieter
HD
Spang
Anne
A
D020823:ADP-Ribosylation Factor 1 / Q000378:metabolism; D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D022181:COP-Coated Vesicles / Q000378:metabolism; D020755:Coat Protein Complex I / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D020690:GTPase-Activating Proteins / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D050600:SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins
D020755:Coat Protein Complex I; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C089147:GCS1 protein, S cerevisiae; D020690:GTPase-Activating Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D050600:SNARE Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors