title: Generation of infectious virus particles by transient co-expression of human immunodeficiency virus type 1 gag mutants.
abstract: We have demonstrated that COS7 cells transiently co-expressing myristylation-defective (Myr-) and protease-defective (PR-) human immunodeficiency virus (HIV) mutants can release infectious virions when co-transfected with an amphotropic murine leukaemia virus envelope protein expression plasmid (SV-A-MLV-env). In contrast, no infectious virions were detected when a PR-, noninfectious HIV gag mutant was co-expressed with the Myr- mutant, although the Myr- mutant could still process the immature core particles in trans. This result indicates that generation of functionally normal Gag proteins is required for virus infectivity in our complementation system. A mutant with a 56-amino-acid deletion in the N-terminal region of the capsid (CA) domain could still complement the PR- mutant to generate infectious virions, suggesting that the deletion mutant could provide a functional protease for processing in the PR- mutant. This result is consistent with the concept that mutations within the N-terminal region of the CA domain have no major effects on Gag-Pol incorporation into particles.
authors.affiliation: Institute of Clinical Medicine, National Yang-Ming University, and Department of Medical Research and Education, Veterans General Hospital-Taipei, Taiwan, Republic of China.
authors.forename: Y L
authors.initials: YL
authors.lastname: Chen
authors.forename: P W
authors.initials: PW
authors.lastname: Ts'ai
authors.forename: C C
authors.initials: CC
authors.lastname: Yang
authors.forename: C T
authors.initials: CT
authors.lastname: Wang
mesh_terms: D000818:Animals; D019556:COS Cells; D015683:Gene Products, gag / Q000235:genetics / Q000378:metabolism*; D015750:Genes, gag; D005816:Genetic Complementation Test; D016333:HIV Protease / Q000502:physiology; D015497:HIV-1 / Q000235:genetics / Q000254:growth & development*; D009052:Leukemia Virus, Murine; D009154:Mutation; D009227:Myristic Acids / Q000378:metabolism; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D014162:Transfection; D014771:Virion / Q000648:ultrastructure
chemical_list: D015683:Gene Products, gag; D009227:Myristic Acids; D011498:Protein Precursors; C059767:p55 gag precursor protein, Human immunodeficiency virus 1; D016333:HIV Protease