title: Specific in vitro cleavage of Mason-Pfizer monkey virus capsid protein: evidence for a potential role of retroviral protease in early stages of infection.
abstract: Processing of Gag polyproteins by viral protease (PR) leads to reorganization of immature retroviral particles and formation of a ribonucleoprotein core. In some retroviruses, such as HIV and RSV, cleavage of a spacer peptide separating capsid and nucleocapsid proteins is essential for the core formation. We show here that no similar spacer peptide is present in the capsid-nucleocapsid (CA-NC) region of Mason-Pfizer monkey virus (M-PMV) and that the CA protein is cleaved in vitro by the PR within the major homology region (MHR) and the NC protein in several sites at the N-terminus. The CA cleavage product was also identified shortly after penetration of M-PMV into COS cells, suggesting that the protease-catalyzed cleavage is involved in core disintegration.
authors.affiliation: Department of Protein Biochemistry, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
authors.forename: Michaela
authors.initials: M
authors.lastname: Rumlová
authors.forename: Tomás
authors.initials: T
authors.lastname: Ruml
authors.forename: Jan
authors.initials: J
authors.lastname: Pohl
authors.forename: Iva
authors.initials: I
authors.lastname: Pichová
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D015683:Gene Products, gag / Q000378:metabolism; D016333:HIV Protease / Q000378:metabolism; D015497:HIV-1 / Q000378:metabolism; D016093:Mason-Pfizer monkey virus / Q000378:metabolism / Q000502:physiology*; D019251:Nucleocapsid / Q000737:chemistry / Q000378:metabolism; D014779:Virus Replication
chemical_list: D036022:Capsid Proteins; D015683:Gene Products, gag; D010450:Endopeptidases; D016333:HIV Protease