Membrane association of functional vesicular stomatitis virus matrix protein in vivo

Abstract

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. * Corresponding author. described (49). Plasmid construction. The DNAs encoding the M, G, and N proteins of VSV (Indiana serotype, San Juan strain) were obtained from the plasmids pMZ10 (17a), pARG (49), and

Intracellular Behavior of Rabies Virus Matrix Protein (M) Is Determined by the Viral Glycoprotein (G)

“…The transfection of VSV M cDNA alone to HeLa cells resulted in, although most M proteins remained in the cytoplasm as a soluble form, tight association of about 10% of M proteins with the cell membrane even in the absence of other viral proteins (7). Soluble M proteins may interact with the cytoskeletons (e.g., tubulin ; 23a), causing the alteration of cell shape, and may also enter the nucleus where it would inhibit host-directed gene expression (2a) .…”

Preformed cytoplasmic nucleocapsids are not necessary for alphavirus budding.

“…For homogenization, cells were collected by scraping in an ice-cold homogenization buffer [10 mM Tris-HCl pH 7.4, 1 mM EDTA, 2.5 mM PMSF/ml, 10% (w/w) sucrose] (Chong and Rose, 1993). Cells were disrupted by 20 strokes in a 23-gauge needle.…”

Generation of Marburg virus-like particles by co-expression of glycoprotein and matrix protein

“…In many enveloped viruses, virally encoded cytoplasmic proteins called matrix proteins play an important role in virus assembly and budding. The matrix protein of vesicular stomatitis virus (VSV) drives the formation of virion particles by interacting with both the plasma membrane as well as the nucleocapsid [3]. Formation of virus-like particles (VLPs) has been reported for several viruses [4].…”