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Updated: Aug 13, 2026

Identifying Inhibitors of the HBx-DDB1 Interaction Using a Split Luciferase Assay System
Published on: December 21, 2019
High phosphorylation of HBV core protein by two alpha-type CK2-activated cAMP-dependent protein kinases in vitro
Masato Enomoto1, Yoshitaka Sawano, Seiji Kosuge
1Laboratory of Genetical Biochemistry and Signal Biology, Graduate School of Medical Sciences, Kitasato University, Sagamihara 228-8555, Japan.
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.
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