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© The Rockefeller University Press,
0021-9525/1999//301 $5.00
The Journal of Cell Biology, Volume 146, Number 2,
, 1999 301-312
Original Article |
Erg30, a Vap-33–Related Protein, Functions in Protein Transport Mediated by Copi Vesicles
bmzevi{at}weizmann.weizmann.ac.il
Intracellular transport of newly synthesized and mature proteins via vesicles is controlled by a large group of proteins. Here we describe a ubiquitous rat protein—endoplasmic reticulum (ER) and Golgi 30-kD protein (ERG30)—which shares structural characteristics with VAP-33, a 33-kD protein from Aplysia californica which was shown to interact with the synaptic protein VAMP. The transmembrane topology of the 30-kD ERG30 corresponds to a type II integral membrane protein, whose cytoplasmic NH2 terminus contains a predicted coiled-coil motif. We localized ERG30 to the ER and to pre-Golgi intermediates by biochemical and immunocytochemical methods. Consistent with a role in vesicular transport, anti-ERG30 antibodies specifically inhibit intra-Golgi transport in vitro, leading to significant accumulation of COPI-coated vesicles. It appears that ERG30 functions early in the secretory pathway, probably within the Golgi and between the Golgi and the ER.
Key Words: endoplasmic reticulum Golgi coated vesicles secretion transport intermediates
© 1999 The Rockefeller University Press
1.used in this paper: βCOP, β subunit of COPI; BFA, brefeldin A; COP, cytosolic coat protein; ERG30, ER and Golgi 30-kD protein; MBP, maltose binding protein; NSF, NEM-sensitive fusion protein; PDI, protein disulfide isomerase; SNAP, soluble NSF attachment protein; VAMP, vesicle-associated membrane protein; VAP-33, VAMP-associated protein of 33 kD; VSVG, vesicular stomatitis virus G protein
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