Retained in vitro infectivity and cytopathogenicity of HIV-1 despite truncation of the C-terminal tail of the env gene product

Transfer of endoplasmic reticulum and Golgi retention signals to human immunodeficiency virus type 1 gp160 inhibits intracellular transport and proteolytic processing of viral glycoprotein but does not influence the cellular site of virus particle budding.

“…Immunoprecipitation with a chimeric soluble CD4 molecule and with a monoclonal antibody against the immunodominant hypervariable domain of gp120, both of which require correct conformation for recognition, confirmed that the recombinant glycoproteins were correctly folded. It is very unlikely that the changes introduced into Env-TM\Golgi and Env856ER have resulted in these molecules no longer being substrates for the processing enzyme, since HIV-1 glycoproteins with significantly greater alterations than those in Env-TM\Golgi and Env856ER can still be proteolytically processed and induce syncytium formation (Wilk et al, 1992(Wilk et al, , 1996. These results together point to the recombinant molecules having a native conformation, but being retained within the Golgi and ER due to the presence of the retention signals.…”

“…PNL4-3 BH"!env (Bosch & Pawlita, 1990 ;Wilk et al, 1992), a derivative of pNL4-3 (Adachi et al, 1986), is the wildtype construct used in these analyses and will be referred to as pNL-Wt. The nucleotide numbering employed is that of the BH10 strain (Myers et al, 1995).…”

“…For initial analysis of antibody specificities, lysates from HeLa cells infected with recombinant vaccinia virus expressing the HIV-1 Env gene product (Owens & Compans, 1989) were employed. Infection of MT-4 cells with cell-free supernatants from transfected COS-7 cells and analysis of infected cells by indirect immunofluorescence were performed as previously described (Wilk et al, 1992).…”

“…The cell lysates were incubated for 10 min on ice before clarification in a bench centrifuge. In order to concentrate virus particles, clarified culture supernatants were precipitated with polyethylene glycol as described by Wilk et al (1992) and subsequently taken up in sample buffer for Western blot analysis. Western blot analyses of viral proteins in cell and virus lysates were performed employing rabbit anti-gp120 and anti-p24 sera as previously described (Kra$ usslich et al, 1993).…”

Human retroviruses and AIDS 1997

“…The results of these experiments indicate that the cytoplasmic domain is dispensable for HIV or STV Env-mediated cell-cell fusion. In the case of HIV-1, however, truncation of the cytoplasmic domain by as few as 20 amino acids results in significantly decreased virus replication in most cell types, although the virus is still viable in the highly permissive MT4 cell line Freed and Martin, 1995;Gabuzda et al, 1992;Wilk et al, 1992). SIV replication, in contrast, appears to have no requirement for the cytoplasmic domain of Env Zingler and Littman, 1993).…”