title: Mammalian Erv46 localizes to the endoplasmic reticulum-Golgi intermediate compartment and to cis-Golgi cisternae.
abstract: Yeast endoplasmic reticulum (ER) vesicle protein Erv46p is a novel membrane protein involved in transport through the early secretory pathway. Investigation of mammalian Erv46 (mErv46) reveals that it is broadly expressed in tissues and protein-secreting cells. By immunofluorescence microscopy, mErv46 displays a crescent-shaped perinuclear staining pattern that is characteristic of the Golgi complex. Quantitative immunoelectron microscopy indicates that mErv46 is restricted to the cis face of the Golgi apparatus and to vesicular tubular structures between the transitional ER and cis-Golgi. Minor amounts of mErv46 reside in ER membranes and later Golgi cisternae. On Brefeldin A treatment, mErv46 redistributes to punctate structures that costain for ERGIC53. Depletion of mErv46 protein by RNA interference caused no apparent structural changes in the intermediate compartment or Golgi complex. These findings place mErv46 in a group of itinerant proteins that cycle between the ER and Golgi compartments such as ERGIC53 and the p24 proteins.
authors.affiliation: Department of Morphology, University Medical Center, 1211 Geneva 4, Switzerland.
authors.forename: Lelio
authors.initials: L
authors.lastname: Orci
authors.forename: Mariella
authors.initials: M
authors.lastname: Ravazzola
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Mack
authors.forename: Charles
authors.initials: C
authors.lastname: Barlowe
authors.forename: Stefan
authors.initials: S
authors.lastname: Otte
mesh_terms: D000818:Animals; D001483:Base Sequence; D001693:Biological Transport, Active / Q000187:drug effects; D020126:Brefeldin A / Q000494:pharmacology; D019556:COS Cells; D002460:Cell Line; D018076:DNA, Complementary / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D037241:Mannose-Binding Lectins / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D016253:Microscopy, Immunoelectron; D034622:RNA Interference
chemical_list: D018076:DNA, Complementary; C084004:LMAN1 protein, human; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins; D020126:Brefeldin A