Interactions of normal and mutant vesicular stomatitis virus matrix proteins with the plasma membrane and nucleocapsids.
We demonstrated recently that a fraction of the matrix (M) protein of vesicular stomatitis virus (VSV) binds tightly to cellular membranes in vivo when expressed in the absence of other VSV proteins. This membrane-associated M protein was functional in binding purified VSV nucleocapsids in vitro. Here we show that the membrane-associated M protein is largely associated with a membrane fraction having the density of plasma membranes, indicating membrane specificity in the binding. In addition, we analyzed truncated forms of M protein to identify regions responsible for membrane association and nucleocapsid binding. Truncated M protein lacking the amino-terminal basic domain still associated with cellular membranes, although not as tightly as wild-type M protein, and could not bind nucleocapsids. In contrast, deletion of the carboxy-terminal 14 amino acids did not disrupt stable membrane association or nucleocapsid interaction. These results suggest that the amino terminus of M protein either interacts directly with membranes and nucleocapsids or stabilizes a conformation that is required for M protein to mediate both of these interactions.
Chong
L D
LD
Department of Pathology and Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510.
Rose
J K
JK
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002213:Capsid / Q000378:metabolism*; D002458:Cell Fractionation; D002462:Cell Membrane / Q000378:metabolism*; D002478:Cells, Cultured; D006224:Cricetinae; D008969:Molecular Sequence Data; D009154:Mutation; D011994:Recombinant Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D017384:Sequence Deletion; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics / Q000378:metabolism*; D014758:Viral Core Proteins / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000235:genetics / Q000378:metabolism*
D011994:Recombinant Proteins; D012261:Ribonucleoproteins; D014758:Viral Core Proteins; D014763:Viral Matrix Proteins