Comparative study of the protein kinase associated with animal viruses

Viral Aspects of Protein Phosphorylation

“…Because many of the known viral phosphoproteins reside in the virion, it was natural to examine virions for protein kinase activities, and when such were found there was a general tendency to assume that these were most probably viral gene products, like the major virion proteins. If this argument were valid, however, one would have to conclude that almost all classes of animal viruses encode protein kinases, as the range of viruses for which virion protein kinases have been reported (see Tan, 1975, for a selection) is as wide as that for which it has been established that there are viral phosphoproteins.…”

Vesicular stomatitis virus deficient in protein kinase is infectious

“…However, we found that virions purified from turtle heart (TH-1) cells had a 30-fold lower protein kinase activity compared with virions purified from BHK-21 cells (table 1). Previously we had shown that phosvitin added as a phosphate acceptor greatly increased the sensitivity of the protein-kinase assay [9]. The incorporation of [32p].…”

“…The acidinsoluble radioactivity (1990 cpm) of a sample taken just before incubation at 28°C was subtracted from the rest of the samples. a Protein kinase activity was assayed as described in Materials and methods b Virus grown in BHK-21 or TH-1 cells was purified as described previously [9]. Confluent monolayer cultures were mock-infected and incubated at 33°C for 18 h in medium containing 0.2% bovine serum albumin instead of serum [5].…”

“…and 20/ag of virus or 30/ag of cell extract in a final volume of 200/ul. After incubation at 33°C for 30 min, acid-insoluble radioactivity was determined as described previously [9].…”

“…Little is known about the other virionassociated enzymes. However, protein kinase has been the subject of numerous studies recently [5][6][7][8][9]. This enzyme is located within the virion and can be activated by mild disruption of the virion with nonionic detergents, to phosphorylate the L, NS and M proteins in a cell-free system [6,7].…”