Beta-COP is essential for biosynthetic membrane transport from the endoplasmic reticulum to the Golgi complex in vivo.
Microinjection of antibodies against a synthetic peptide of a non-clathrin-coated vesicle-associated coat protein, beta-COP, blocks transport of a temperature-sensitive vesicular stomatitis virus glycoprotein (ts-O45-G) to the cell surface. Transport is inhibited upon release of the viral glycoprotein from temperature blocks at 39.5 degrees C (endoplasmic reticulum [ER]) and 15 degrees C (intermediate compartment), but not at 20 degrees C (trans-Golgi network). Ts-O45-G is arrested in tubular membrane structures containing p53 at the interface of the ER and the Golgi stack. This is consistent with inhibition of acquisition of endoglycosidase H resistance of ts-O45-G in injected cells. Secretion of endogenous proteins and maturation of cathepsin D are also inhibited. These data provide in vivo evidence that beta-COP has an important function in biosynthetic membrane traffic in mammalian cells.
Pepperkok
R
R
European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
Scheel
J
J
Horstmann
H
H
Hauri
H P
HP
Griffiths
G
G
Kreis
T E
TE
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002402:Cathepsin D / Q000378:metabolism; D020756:Coatomer Protein; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism*; D008845:Microinjections; D008869:Microtubule-Associated Proteins / Q000502:physiology*; D013696:Temperature; D014709:Vero Cells / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism
D000906:Antibodies; D020756:Coatomer Protein; D008869:Microtubule-Associated Proteins; D014764:Viral Proteins; D002402:Cathepsin D