title: Vesicular stomatitis virus matrix protein mutations that affect association with host membranes and viral nucleocapsids.
abstract: Viral matrix (M) proteins bind the nucleoprotein core (nucleocapsid) to host membranes during the process of virus assembly by budding. Previous studies using truncated M proteins had implicated the N-terminal 50 amino acids of the vesicular stomatitis virus M protein in binding both membranes and nucleocapsids and a sequence from amino acids 75-106 as an additional membrane binding region. Structure-based mutations were introduced into these two regions, and their effects on membrane association and incorporation into nucleocapsid-M protein complexes were determined using quantitative assays. The results confirmed that the N terminus of M protein is involved in association with plasma membranes as well as nucleocapsids, although these two activities were differentially affected by individual mutations. Mutations in the 75-106 region affected incorporation into nucleocapsid-M complexes but had only minor effects on association with membranes. The ability of site-specific mutant M proteins to complement growth of temperature-sensitive M mutant virus did not correlate well with the ability to associate with membranes or nucleocapsids, suggesting that complementation involves an additional activity of M protein. Mutants with similar abilities to associate with membranes and nucleocapsids but differing in complementation activity were incorporated into infectious cDNA clones. Infectious virus was repeatedly recovered containing mutant M proteins capable of complementation but was never recovered with mutant M proteins that lacked complementation activity, providing further evidence for a separate activity of M protein that is essential for virus replication.
authors.affiliation: Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157.
authors.forename: Brooke
authors.initials: B
authors.lastname: Dancho
authors.forename: Margie O
authors.initials: MO
authors.lastname: McKenzie
authors.forename: John H
authors.initials: JH
authors.lastname: Connor
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Lyles
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism* / Q000821:virology; D006224:Cricetinae; D009154:Mutation; D019251:Nucleocapsid / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000502:physiology; D018116:Vesiculovirus / Q000502:physiology*; D014763:Viral Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication / Q000502:physiology*
chemical_list: C094460:M protein, Vesicular stomatitis virus; D014763:Viral Matrix Proteins