title: Varying effects of temperature, Ca(2+) and cytochalasin on fusion activity mediated by human immunodeficiency virus type 1 and type 2 glycoproteins.
abstract: We examined fusion mediated by the human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) envelope glycoproteins under various experimental conditions. Incubation of HeLa cells expressing HIV-2(ROD) and HIV-2(SBL/ISY) envelope glycoproteins with HeLa-CD4 target cells resulted in fusion at temperatures >/=25 degrees C whereas fusion with cells expressing HIV-1(Lai) occurred only at >/=31 degrees C. HIV-2 envelope glycoprotein-mediated fusion proceeded in the absence of Ca(2+) in the culture medium, whereas HIV-1 fusion required Ca(2+) ions for fusion. In contrast to HIV-2 envelope glycoprotein fusion, incubations in the presence of the 0.5 microM cytochalasin B completely inhibited HIV-1 envelope glycoprotein-mediated fusion. Our results suggest that in contrast to HIV-2, HIV-1 fusion is dependent on dynamic processes in the target membrane.
authors.affiliation: LECB, Division of Basic Sciences, NCI-FCRDC, National Institutes of Health, P.O. Box B, Bldg. 469, Rm. 211, Miller Drive, 21702-1201, Frederick, MD, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Jernigan
authors.forename: R
authors.initials: R
authors.lastname: Blumenthal
authors.forename: A
authors.initials: A
authors.lastname: Puri
mesh_terms: D000199:Actins / Q000378:metabolism; D001704:Biopolymers / Q000378:metabolism; D015704:CD4 Antigens / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology*; D002459:Cell Fusion / Q000187:drug effects; D003571:Cytochalasin B / Q000494:pharmacology*; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D015686:Gene Products, env / Q000378:metabolism*; D015726:Giant Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D015498:HIV-2 / Q000145:classification / Q000187:drug effects / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D013696:Temperature; D013997:Time Factors
chemical_list: D000199:Actins; D001704:Biopolymers; D015704:CD4 Antigens; D015686:Gene Products, env; D003571:Cytochalasin B; D002118:Calcium