Monoclonal antibody-mediated inhibition of RNA binding and annealing activities of HIV type 1 nucleocapsid protein.
Retroviral nucleocapsid (NC) proteins are highly basic, with one or two zinc fingers, and are required for virion formation, genomic RNA dimerization and packaging, and replication primer tRNA annealing to the viral RNA. We report here the first characterization of monoclonal antibodies directed against a retroviral nucleocapsid protein and their use to study the structure-function relationships of the nucleocapsid protein NCp7 of HIV-1. Four anti-NCp7 monoclonal antibodies (MAbs) have been generated by using NCp7 of HIV-1. The epitope targets of these MAbs were mapped using ELISA and BIAcore techniques. Whereas three of them are specific for epitopes located in the N and C termini of NCp7, the fourth one appears to be conformation specific. Interestingly, only two of these MAbs, the conformation-specific one and the MAb recognizing an N-terminal epitope are able to inhibit the RNA-binding and annealing activities of NCp7 as well as strong-stop DNA synthesis in vitro. The binding of the two other MAbs onto NCp7 either has no effect or enhances the NCp7-RNA interactions. These MAbs also display a differential recognition of the Gag polyprotein precursor, which makes them useful tools for studying NC protein maturation in the course of virion morphogenesis.
Tanchou
V
V
U332 INSERM, Institut Cochin de Génétique Moléculaire, Université René Descartes, Paris, France.
Delaunay
T
T
De Rocquigny
H
H
Bodeus
M
M
Darlix
J L
JL
Roques
B
B
Benarous
R
R
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D002213:Capsid / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D036022:Capsid Proteins; D004279:DNA, Viral / Q000096:biosynthesis; D018604:Epitope Mapping; D015683:Gene Products, gag / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D015483:HIV Antibodies / Q000276:immunology*; D054303:HIV Reverse Transcriptase; D015497:HIV-1 / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D011487:Protein Conformation; D011498:Protein Precursors / Q000378:metabolism; D012357:RNA, Transfer, Lys / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry / Q000378:metabolism*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D014764:Viral Proteins; D016335:Zinc Fingers; D054301:gag Gene Products, Human Immunodeficiency Virus
D000911:Antibodies, Monoclonal; D036022:Capsid Proteins; D004279:DNA, Viral; D015683:Gene Products, gag; D015483:HIV Antibodies; C071884:NCP7 protein, Human immunodeficiency virus 1; D010455:Peptides; D011498:Protein Precursors; D012357:RNA, Transfer, Lys; D012367:RNA, Viral; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; D054303:HIV Reverse Transcriptase; D012194:RNA-Directed DNA Polymerase