Phosphorylation of the herpes simplex virus type 1 tegument protein VP22.
Phosphorylation of the herpes simplex virus type 1 tegument protein VP22.
复制标题
单纯疱疹病毒 1 型外皮蛋白 VP22 的磷酸化。
作者：
G. Elliott;Dawn O’Reilly;P. O’Hare
已知单纯疱疹病毒1型被膜蛋白VP 22在感染期间高度磷酸化。在这里，我们表明，两种电泳形式的VP 22可以确定在感染的细胞提取物，这种异质性是由磷酸化。此外，VP 22的非磷酸化形式似乎特异性地掺入病毒体中。我们还表明，VP 22的磷酸化形式是在瞬时转染过程中检测到的唯一形式，因此VP 22可以作为细胞激酶的底物。利用体内标记的VP 22的磷酸化氨基酸和磷酸化肽分析来证明在转染和感染期间合成的VP 22的磷酸化概况是相同的。在这两种情况下，VP 22仅在位于蛋白质的N-末端120个残基中的丝氨酸残基上进行修饰。此外，在体外磷酸化被用来显示，组成型细胞激酶，酪蛋白激酶II，其中有四个丝氨酸共识识别位点在N-末端的VP 22，磷酸化VP 22在体内观察到的相同的方式。该激酶还在完整的帽-被膜结构中的N-末端磷酸化VP 22。因此，酪蛋白激酶II可能是感染期间VP 22的主要激酶。
The herpes simplex virus type 1 tegument protein VP22 is known to be highly phosphorylated during infection. Here we show that two electrophoretic forms of VP22 can be identified in infected cell extracts and that this heterogeneity is accounted for by phosphorylation. Furthermore, the nonphosphorylated form of VP22 appears to be specifically incorporated into virions. We also show that the phosphorylated form of VP22 is the only form detected during transient transfection and as such that VP22 can act as a substrate for a cellular kinase. Phospho-amino acid and phospho-peptide analyses of in vivo labeled VP22 were utilized to demonstrate that the phosphorylation profiles of VP22 synthesized during transfection and infection are the same. In both cases VP22 was modified solely on serine residues located in the N-terminal 120 residues of the protein. Moreover, in vitro phosphorylation was utilized to show that the constitutive cellular kinase, casein kinase II, which has four serine consensus recognition sites at the N-terminus of VP22, phosphorylates VP22 in the same manner as observed in vivo. This kinase also phosphorylates VP22 at the N-terminus in intact capsid-tegument structures. Casein kinase II is therefore likely to be the major kinase of VP22 during infection.