Assembly of HIV GAG-B-Galactosidase Fusion Proteins into Virus Particles

Coding Sequences Upstream of the Human Immunodeficiency Virus Type 1 Reverse Transcriptase Domain in Gag-Pol Are Not Essential for Incorporation of the Pr160 gag-pol into Virus Particles

“…Perhaps the HIV Pol possesses some uncharacterized property distinct from that of the ␤-Gal. In support of this hypothesis, it has been demonstrated clearly that the HIV GBG (32), not HIV Pr160 gag-pol , is severely impaired in its incorporation into virions upon removal of the N-terminal myristylation signal. Thus, it is conceivable that HIV Pol may have as-yet-undefined functions associated with it which are involved in the process of Gag-Pol transport and incorporation.…”

“…It is possible that the Nterminal 15 residues may be responsible for rescue of the mutant [⌬GAG or ⌬(GAGϩPR)] into particles via putative interactions with the Pr55 gag . This is unlikely, however, because HIV Gag-␤-galactosidase (HIV GBG) fusion proteins, constructed by fusion of the ␤-Gal gene to HIV gag at the Nterminal 15th codon or at the C terminus of MA, were excluded from HIV particles (32), suggesting that the N-terminal 15 residues are not involved in the incorporation of Gag-Pol into virus particles. In contrast, HIV GBG (analogous to the HIV Gag-Pol) fused at the end of the NC domain was efficiently incorporated into virus particles (32).…”

Association of Human Immunodeficiency Virus Type 1 Gag with Membrane Does Not Require Highly Basic Sequences in the Nucleocapsid: Use of a Novel Gag Multimerization Assay

“…Structural studies and protein-protein interaction analyses have demonstrated that CA and SP1 likely contribute to Gag multimerization by facilitating direct interactions between Gag molecules (24, 29, 31, 33, 59-61, 67, 96). Mutations and deletions in the C-terminal domain of CA (12,21,42,50,56,58,76,82,87,88,90) and SP1 (1,45,49,93) cause defects in virus particle production, indicating that the Gag-Gag interaction mediated by this region is physiologically important for virus assembly. Unlike CA and SP1, NC is thought to promote Gag multimerization primarily through interaction with RNA.…”

Analysis of Mason-Pfizer Monkey Virus Gag Domains Required for Capsid Assembly in Bacteria: Role of the N-Terminal Proline Residue of CA in Directing Particle Shape

“…In vivo studies with both RSV and HIV have shown that the bulk of MA and the N terminus of CA are dispensable for capsid assembly and budding as long as a membrane-targeting domain is located at the N terminus and the NC domain is intact (13,35,37). In general, the NC domain or an equivalent region C terminal of CA that can mediate the association of Gag molecules appears to be critical for the assembly of capsids with a density resembling that of wild-type virus (2,23,36,38,39,40). Similar conclusions were drawn from in vitro binding experiments with HIV type 1 Gag deletion mutants (3).…”