Membrane association of functional vesicular stomatitis virus matrix protein in vivo.
The matrix (M) protein of vesicular stomatitis virus (VSV) is a major structural component of the virion which is generally believed to bridge between the membrane envelope and the ribonucleocapsid (RNP) core. To investigate the interaction of M protein with cellular membranes in the absence of other VSV proteins, we examined its distribution by subcellular fractionation after expression in HeLa cells. Approximately 90% of M protein, expressed without other viral proteins, was soluble, whereas the remaining 10% was tightly associated with membranes. A similar distribution in VSV-infected cells has been observed previously. Conditions known to release peripherally associated membrane proteins did not detach M protein from isolated membranes. Membrane-associated M protein was soluble in the detergent Triton X-114, whereas soluble M protein was not, suggesting a chemical or conformational difference between the two forms. Membranes containing associated M protein were able to bind RNP cores, whereas membranes lacking M protein were not. We suggest that this membrane-bound M fraction constitutes a functional subset of M protein molecules required for the attachment of RNP cores to membranes during normal virus budding.
Chong
L D
LD
Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06510-8023.
Rose
J K
JK
D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000378:metabolism*; D008954:Models, Biological; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D012995:Solubility; D013347:Subcellular Fractions / Q000737:chemistry; D014721:Vesicular stomatitis Indiana virus / Q000254:growth & development / Q000378:metabolism*; D014758:Viral Core Proteins / Q000378:metabolism; D014763:Viral Matrix Proteins / Q000302:isolation & purification / Q000378:metabolism*
D046911:Macromolecular Substances; D008565:Membrane Proteins; D011994:Recombinant Proteins; D012261:Ribonucleoproteins; D014758:Viral Core Proteins; D014763:Viral Matrix Proteins; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40