The multifunctional herpes simplex virus IE63 protein interacts with heterogeneous ribonucleoprotein K and with casein kinase 2.
Herpes simplex virus type 1 (HSV-1), the prototype alpha-herpesvirus, causes several prominent diseases. The HSV-1 immediate early (IE) protein IE63 (ICP27) is the only regulatory gene with a homologue in every mammalian and avian herpesvirus sequenced so far. IE63 is a multifunctional protein affecting transcriptional and post-transcriptional processes, and it can shuttle from the nucleus to the cytoplasm. To identify interacting cellular proteins, a HeLa cDNA library was screened in the yeast two-hybrid system using IE63 as bait. Several interacting proteins were identified including heterogeneous nuclear ribonucleoprotein K (hnRNP K), a multifunctional protein like IE63, and the beta subunit of casein kinase 2 (CK2), a protein kinase, and interacting regions were mapped. Confirmation of interactions was provided by fusion protein binding assays, co-immunoprecipitation from infected cells, and CK2 activity assays. hnRNP K co-immunoprecipitated from infected cells with anti-IE63 serum was a more rapidly migrating subfraction than hnRNP K immunoprecipitated by anti-hnRNP K serum. Using anti-IE63 serum, both IE63 and hnRNP K were phosphorylated in vitro by CK2, while in immunoprecipitates using anti-hnRNP K serum, IE63 but not hnRNP K was phosphorylated by CK2. These data provide important new insights into how this key viral regulatory protein exerts its functions.
Wadd
S
S
Institute of Virology, University of Glasgow, Church St., Glasgow G11 5JR, Scotland, United Kingdom.
Bryant
H
H
Filhol
O
O
Scott
J E
JE
Hsieh
T Y
TY
Everett
R D
RD
Clements
J B
JB
D000818:Animals; D047390:Casein Kinase II; D002460:Cell Line; D006224:Cricetinae; D015967:Gene Expression Regulation, Viral; D006367:HeLa Cells; D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism*; D015003:Yeasts / Q000235:genetics
D034641:Heterogeneous-Nuclear Ribonucleoprotein K; C057120:ICP27 protein, human herpesvirus 1; D017874:Immediate-Early Proteins; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; C072074:HNRNPK protein, human; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases