Measles virus matrix protein is not cotransported with the viral glycoproteins but requires virus infection for efficient surface targeting.
As we have shown earlier, the measles virus (MV) glycoproteins H and F are expressed on both, the apical and the basolateral membrane of polarized Madin-Darby canine kidney cells. In contrast to the glycoproteins, we found the viral matrix protein (M) to accumulate selectively at the apical plasma membrane of MV-infected cells. M did not colocalize with the glycoproteins at basolateral membranes of polarized cells indicating an independent surface transport mechanism. Analysis of infected cells treated with monensin supported this view. When H and F were retained in the medial Golgi by monensin treatment, M did not accumulate in this cellular compartment. To elucidate the subcellular transport mechanism of the cytosolic M protein, M was expressed in the absence of other viral proteins. Flotation analysis demonstrated that most of the M protein coflotated in infected or in M-transfected cells with cellular membranes. Thus, the M protein possesses the intrinsic ability to bind to lipid membranes. Unexpectedly, plasmid-encoded M protein was rarely found to accumulate at surface membranes. Although cotransport with the viral glycoproteins was not needed, M transport to the plasma membrane required a component only provided in MV-infected cells.
Riedl
Petra
P
Institute of Virology, Philipps University of Marburg, Robert-Koch-Strasse 17, 35037 Marburg, Germany.
Moll
Markus
M
Klenk
Hans-Dieter
HD
Maisner
Andrea
A
D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004285:Dogs; D006023:Glycoproteins / Q000378:metabolism*; D008459:Measles virus / Q000378:metabolism* / Q000502:physiology; D014760:Viral Fusion Proteins / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000378:metabolism*
D006023:Glycoproteins; D014760:Viral Fusion Proteins; D014763:Viral Matrix Proteins