Temperature-dependent phosphorylation state of the H5R protein synthesised at the early stage of infection in cells infected with vaccinia virus ts mutants of the B1R and F10L protein kinases.

The phosphorylation state of H5R protein was investigated by two-dimensional gel electrophoresis of proteins of BSC-40 cells infected at 32 degrees or 39.5 degrees with vaccinia virus ts mutants of the viral B1R or F10L protein kinase genes. A temperature-dependent increase of underphosphorylated H5R protein (pI 6.8) was demonstrated in the case of the B1R, but not of the F10L gene. The temperature-dependent cytoplasmic location of underphosphorylated H5R protein after infection with the ts mutants of the B1R gene was the consequence of the associated viral DNA replication block. These results show that the B1R protein kinase controls the phosphorylation state of the H5R protein synthesised at the early stage in vaccinia-virus-infected cells. Copyright 2000 S. Karger AG, Basel.