Key motifs in EBV (Epstein-Barr virus)-encoded protein kinase for phosphorylation activity and nuclear localization.
Key motifs in EBV (Epstein-Barr virus)-encoded protein kinase for phosphorylation activity and nuclear localization.
复制标题
EBV（EBV（Epstein-Barr病毒）编码蛋白激酶的关键基序用于磷酸化活性和核定位。
DOI：
10.1042/bj20100558
复制
发表时间：
2010-10-15
期刊：
影响因子：
--
通讯作者：
Gershburg E
中科院分区：
文献类型：
--
作者：
Gershburg S;Murphy L;Marschall M;Gershburg E
EBV（Epstein-Barr virus）编码的蛋白激酶（EBV-PK）（BGLF 4基因产物）在病毒感染中起重要作用。虽然这种蛋白质的一些目标已被确定，激酶本身仍然在很大程度上未研究其酶学和结构。在本研究中，定点诱变已被用于产生突变靶向参与EBV-PK的核定位的残基，在大多数蛋白激酶中保守的蛋白激酶结构域的亚结构域III中的核心残基或仅在HPK（疱疹病毒编码的蛋白激酶）组内保守的亚结构域VIa中的残基。氨基酸389-391的缺失导致蛋白质的排他性细胞质定位，表明该区域参与EBV-PK的核转位。氨基酸Glu 113（核心组分）、Phe 175、Leu 178、Phe 184、Leu 185和Asn 186（在HPK中保守）的突变导致EBV-PK自磷酸化、蛋白质底物[EBV EA-D（早期抗原扩散）]磷酸化和促进更昔洛韦磷酸化的能力丧失。这些结果重申了该组激酶的独特功能，并为设计更特异的抗病毒化合物提供了机会。
A sole EBV (Epstein–Barr virus)-encoded protein kinase (EBV-PK) (the BGLF4 gene product) plays important roles in viral infection. Although a number of targets of this protein have been identified, the kinase itself remains largely unstudied with regard to its enzymology and structure. In the present study, site-directed mutagenesis has been employed to generate mutations targeting residues involved in nuclear localization of the EBV-PK, core residues in subdomain III of the protein kinase domain conserved in most protein kinases or residues in subdomain VIa conserved only within the HPK (herpesvirus-encoded protein kinase) group. Deletion of amino acids 389–391 resulted in exclusive cytoplasmic localization of the protein, indicating the involvement of this region in nuclear translocation of the EBV-PK. Mutations at the amino acids Glu113 (core component), Phe175, Leu178, Phe184, Leu185 and Asn186 (conserved in HPKs) resulted in loss of EBV-PK autophosphorylation, protein substrate [EBV EA-D (early antigen diffused)] phosphorylation, and ability to facilitate ganciclovir phosphorylation. These results reiterate the unique features of this group of kinases and present an opportunity for designing more specific antiviral compounds.