Temperature-sensitive mutants with lesions in the vaccinia virus F10 kinase undergo arrest at the earliest stage of virion morphogenesis.
Vaccinia virus encodes two protein kinases; the B1 kinase is expressed early and appears to play a role during DNA replication, whereas the F10 kinase is expressed late and is encapsidated in virions. Here we report that the F10 kinase gene is the locus affected in a complementation group of temperature-sensitive mutants composed of ts15, ts28, ts54, and ts61. Although these mutants have a biochemically normal phenotype at the nonpermissive temperature, directing the full program of viral gene expression, they fail to form mature virions. Electron microscopic analysis indicates that morphogenesis undergoes arrest at a very early stage, prior to the formation of membrane crescents or immature virions. An essential role for the F10 protein kinase in orchestrating the onset of virion assembly is implied.
Traktman
P
P
Department of Cell Biology, Cornell University Medical College, New York, NY 10021, USA.
Caligiuri
A
A
Jesty
S A
SA
Liu
K
K
Sankar
U
U
D000818:Animals; D002460:Cell Line; D015870:Gene Expression; D005814:Genes, Viral; D005816:Genetic Complementation Test; D008854:Microscopy, Electron; D009024:Morphogenesis; D009154:Mutation; D016366:Open Reading Frames; D010641:Phenotype; D016133:Polymerase Chain Reaction; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D015183:Restriction Mapping; D013696:Temperature; D014616:Vaccinia virus / Q000201:enzymology / Q000235:genetics / Q000254:growth & development*; D014764:Viral Proteins / Q000235:genetics*
D014764:Viral Proteins; C095546:protein kinase 2, Vaccinia virus; D017346:Protein Serine-Threonine Kinases