title: Behavior of a transitional tubulovesicular compartment at the cis side of the Golgi apparatus in in vivo fusion studies of mammalian cells.
abstract: We have investigated the behavior in in vivo cell fusion experiments of a transitional compartment lying between the endoplasmic reticulum and Golgi apparatus to determine if the compartment, as recognized by the antibody G1/93, might congregate in a similar manner to Golgi apparatus [W. C. Ho et al. (1990) Eur. J. Cell Biol. 52, 315-327]. The distributions of the transitional tubulovesicular compartment, endoplasmic reticulum, and Golgi apparatus in HeLa cells were assessed by immunofluorescent staining using mouse monoclonal antibody G1/93, mouse monoclonal antibody HP 24, and rabbit anti-galactosyltransferase, respectively. In agreement with previous results [W. C. Ho et al. (1990) Eur. J. Cell Biol. 52, 315-327], the Golgi apparatus was observed to congregate gradually over a 3- to 6-h period, forming a large, extended, central Golgi complex in uv-inactivated Sindbis virus-fused HeLa cells. Concomitant with this was a marked congregation of the transitional tubulovesicular compartment. Congregation of the tubulovesicular compartment was not affected by cycloheximide. The endoplasmic reticulum retained its web-like distribution throughout the syncytoplasm and rimmed the nuclear periphery. Treatment of HeLa cells with nocodazole prior to fusion followed by incubation of the syncytia in drug-containing media blocked congregation of the G1/93-positive compartment. With this long-term nocodazole treatment, Golgi apparatus was dispersed into scattered Golgi elements and the G1/93 distribution was endoplasmic reticulum-like. These results suggest that the transitional tubulovesicular compartment recognized by G1/93 is normally structured on microtubules and microtubule organizing centers and may be considered to be a subcompartment of a greater, perinuclear, Golgi complex.
authors.affiliation: Department of Biochemistry and Nutrition, Virginia Polytechnic Institute and State University, Blacksburg 24061.
authors.forename: L
authors.initials: L
authors.lastname: Xiao
authors.forename: B
authors.initials: B
authors.lastname: Storrie
mesh_terms: D000911:Antibodies, Monoclonal; D002459:Cell Fusion; D003593:Cytoplasm / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000502:physiology / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D008970:Molecular Weight; D015739:Nocodazole / Q000494:pharmacology; D009685:Nuclear Envelope / Q000648:ultrastructure; D015388:Organelles / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D012845:Sindbis Virus
chemical_list: D000911:Antibodies, Monoclonal; D015739:Nocodazole