title: ATP-coupled transport of vesicular stomatitis virus G protein. Functional boundaries of secretory compartments.
abstract: The oligosaccharide processing intermediates of the vesicular stomatitis virus strain ts045 G protein were used to identify ATP- and temperature-sensitive steps in the constitutive pathway of protein transfer to the cell surface. In addition to the initial ATP-sensitive step required for export from the endoplasmic reticulum (Balch, W. E., Elliott, M. M., and Keller, D. S. (1986) J. Biol. Chem. 261, 14681-14689), two distinct ATP-sensitive steps functionally dissect the Golgi into at least 3 compartments: a cis compartment containing the trimming enzyme mannosidase I, a medial compartment conferring resistance to endoglycosidase H, and a trans compartment containing terminal glycosyl transferases. A fourth ATP-sensitive step is required for export of G protein from the trans Golgi to the cell surface. A high threshold of cellular ATP (70% of the control) was required for maximal rates of transport between Golgi compartments. Transport between compartments is inhibited at 40% of the normal cellular ATP pool. Only a single temperature-sensitive step localized to the endoplasmic reticulum inhibited transport of ts045 G protein to the cell surface. The data suggest that ATP-sensitive steps punctuate transport of protein between compartmental boundaries of the secretory pathway.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002472:Cell Transformation, Viral; D006224:Cricetinae; D003412:Cricetulus; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005260:Female; D006056:Golgi Apparatus / Q000378:metabolism*; D008562:Membrane Glycoproteins; D008954:Models, Biological; D010053:Ovary; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics / Q000378:metabolism*; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: C028391:G protein, vesicular stomatitis virus; D008562:Membrane Glycoproteins; D014759:Viral Envelope Proteins; D014764:Viral Proteins; D000255:Adenosine Triphosphate