it is also indistinguishable from the unphosphorylated viral pp12 protein in its migration on sds-polyacrylamide gels , reactivity with rabbit antisera directed against purified viral pp12 , low rna-binding affinity , and ability to serve as a substrate for in vitro phosphorylation at serine-40 by protease-activated kinase i .
C0031715
phosphorylation
C0031727
kinase