摘要
As one of the immediate-early(IE)proteins of herpes simplex virus type 1(HSV-1),ICP22 is a multifunctional viral regulator that localizes in the nucleus of infected cells.It is required in experimental animal systems and some nonhuman cell lines,but not in Vero or HEp-2 cells.ICP22 is extensively phosphorylated by viral and cellular kinases and nucleotidylylated by casein kinase Ⅱ.It has been shown to be required for efficient expression of early(E)genes and a subset of late(L)genes.ICP22,in conjunction with the UL13 kinase,mediates the phosphorylation of RNA polymerase Ⅱ.Both ICP22 and UL13 are required for the activation of cdc2,the degradation of cyclins A and B and the acquisition of a new cdc2 partner,the UL42 DNA polymerase processivity factor.The cdc2-UL42 complex mediates postranscriptional modification of topoisomerase Ⅱα in an ICP22-dependent manner to promote L gene expression.In addition,ICP22 interacts with cdk9 in a Us3 kinase dependent fashion to phosphorylate RNA polymerase Ⅱ.
As one of the immediate-early （IE） proteins of herpes simplex virus type 1 （HSV-1）, ICP22 is a multifunctional viral regulator that localizes in the nucleus of infected cells. It is required in experimental animal systems and some nonhuman cell lines, but not in Vero or HEp-2 cells. ICP22 is extensively phosphorylated by viral and cellular kinases and nucleotidylylated by casein kinase Ⅱ. It has been shown to be required for efficient expression of early （E） genes and a subset of late （L） genes. ICP22, in conjunction with the UL13 kinase, mediates the phosphorylation of RNA polymerase Ⅱ. Both ICP22 and UL13 are required for the activation of cdc2, the degradation of cyclins A and B and the acquisition of a new cdc2 partner, the UL42 DNA polymerase processivity factor. The cdc2-UL42 complex mediates postranscriptional modification of topoisomerase Ⅱα in an ICP22-dependent manner to promote L gene expression. In addition, ICP22 interacts with cdk9 in a Us3 kinase dependent fashion to phosphorylate RNA polymerase Ⅱ
基金
The Startup Fund of the Hundred Talents Program of the Chinese Academy of Science(20071010141)
National Natural Science Foundation of China (30870120)
Open Research Fund Program of the State Key Laboratory of Virology of China(2007003,2009 007)
Hubei Province Natural Science Foundation of Innovation Groups Project(2008CDA013)
