title: The p115-interactive proteins GM130 and giantin participate in endoplasmic reticulum-Golgi traffic.
abstract: The transport factor p115 is essential for endoplasmic reticulum (ER) to Golgi traffic. P115 interacts with two Golgi proteins, GM130 and giantin, suggesting that they might also participate in ER-Golgi traffic. Here, we show that peptides containing the GM130 or the giantin p115 binding domain and anti-GM130 and anti-giantin antibodies inhibit transport of vesicular stomatitis virus (VSV)-G protein to a mannosidase II-containing Golgi compartment. To determine whether p115, GM130, and giantin act together or sequentially during transport, we compared kinetics of traffic inhibition. Anti-p115, anti-GM130, and anti-giantin antibodies inhibited transport at temporally distinct steps, with the p115-requiring step before the GM130-requiring stage, and both preceding the giantin-requiring stage. Examination of the distribution of the arrested VSV-G protein showed that anti-p115 antibodies inhibited transport at the level of vesicular-tubular clusters, whereas anti-GM130 and anti-giantin antibodies inhibited after the VSV-G protein moved to the Golgi complex. Our results provide the first evidence that GM130 and giantin are required for the delivery of a cargo protein to the mannosidase II-containing Golgi compartment. These data are most consistent with a model where transport from the ER to the cis/medial-Golgi compartments requires the action of p115, GM130, and giantin in a sequential rather than coordinate mechanism.
authors.affiliation: Department of Cell Biology, University of Alabama, Birmingham 35294, USA.
authors.forename: C
authors.initials: C
authors.lastname: Alvarez
authors.forename: R
authors.initials: R
authors.lastname: Garcia-Mata
authors.forename: H P
authors.initials: HP
authors.lastname: Hauri
authors.forename: E
authors.initials: E
authors.lastname: Sztul
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D001324:Autoantigens; D002352:Carrier Proteins / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D000077614:Golgi Matrix Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000276:immunology / Q000378:metabolism*; D010446:Peptide Fragments / Q000276:immunology / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport / Q000187:drug effects; D033921:Vesicular Transport Proteins; D014759:Viral Envelope Proteins / Q000378:metabolism*
chemical_list: D000906:Antibodies; D001324:Autoantigens; D002352:Carrier Proteins; C028391:G protein, vesicular stomatitis virus; D000077614:Golgi Matrix Proteins; C097741:Golgin subfamily A member 2; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D010446:Peptide Fragments; D033921:Vesicular Transport Proteins; D014759:Viral Envelope Proteins; C087574:macrogolgin; C091580:vesicular transport factor p115