title: High phosphorylation of HBV core protein by two alpha-type CK2-activated cAMP-dependent protein kinases in vitro.
abstract: Two alpha-type CK2-activated PKAs (CK2-aPKAIalpha and CK2-aPKAIIalpha) were biochemically characterized in vitro using GST-HBV core fusion protein (GST-Hcore) and GST-Hcore157B as phosphate acceptors. It was found that (i), in the absence of cAMP, these two CK2-aPKAs phosphorylated both Ser-170 and Ser-178 on GST-Hcore and Hcore157B; (ii) this phosphorylation was approx. 4-fold higher than their phosphorylation by cAMP-activated PKAs; and (iii) suramin effectively inhibited the phosphorylation of Hcore157B by CK2-aPKAIIalpha through its direct binding to Hcore157B in vitro. These results suggest that high phosphorylation of HBV-CP by two CK2-aPKAs, in the absence of cAMP, may be involved in the pregenomic RNA (pgRNA) encapsidation and DNA-replication in HBV-infected cells.
authors.affiliation: Laboratory of Genetical Biochemistry and Signal Biology, Graduate School of Medical Sciences, Kitasato University, Sagamihara 228-8555, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Enomoto
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Sawano
authors.forename: Seiji
authors.initials: S
authors.lastname: Kosuge
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yamano
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kuroki
authors.forename: Kenzo
authors.initials: K
authors.lastname: Ohtsuki
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D047390:Casein Kinase II / Q000378:metabolism*; D002417:Cattle; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases; D004789:Enzyme Activation; D016679:Genome, Viral / Q000502:physiology; D006509:Hepatitis B / Q000201:enzymology; D006515:Hepatitis B virus / Q000378:metabolism*; D006801:Humans; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013498:Suramin / Q000494:pharmacology; D014758:Viral Core Proteins / Q000378:metabolism*; D014779:Virus Replication / Q000187:drug effects / Q000502:physiology
chemical_list: D000970:Antineoplastic Agents; D012367:RNA, Viral; D014758:Viral Core Proteins; D012694:Serine; D013498:Suramin; D000242:Cyclic AMP; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases