Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protein kinase CKII is composed of two catalytic (alpha or alpha') subunits and two regulatory (beta) subunits. The CKIIbeta subunit is thought to mediate the tetramer formation and interact with other target proteins. Previously we have shown that CKIIbeta interacts with ribosomal proteins L5 and L41, DNA topoisomerase IIbeta, and SAG/CKBBP1. In this study, the two-hybrid system was used to define the subregions of CKIIbeta that are involved in the interaction with L5, L41, topoisomerase IIbeta, SAG/CKBBP1, and unknown proteins, CKBBP2 and CKBBP3. The results indicated that the region between residues 1 and 167 of CKIIbeta is common binding site for L5, topoisomerase IIbeta, SAG/CKBBP1, and L41. The region between amino acids 19 and 167 of CKIIbeta is sufficient for the interaction with CKBBP3. The region between residues 67 and 130 of CKIIbeta is a minimal fragment that is required for interaction with CKBBP2. Overlay experiments showed that the region between residues 1 and 167 of CKIIbeta interacts with L5, L41, and SAG/CKBBP1 in vitro. These results suggest that the binding sites of CKIIbeta for these target proteins are not located within a small linear sequence stretch, but rather are created by a three-dimensional structure.
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PMID:Mapping of the interaction domain of the protein kinase CKII beta subunit with target proteins. 1171 May 15

CKII plays a significant role in cell proliferation and cell cycle control. In this report, yeast two-hybrid assay and pull-down assay demonstrate that CKBBP2/CRIF1 associates with the beta subunit of CKII in vitro and in vivo. Recombinant CKBBP2/CRIF1 is phosphorylated in vitro by purified CKII and by CKII inhibitor apigenin-sensitive protein kinase in HEK293 cell extract. Phosphoamino acid analysis and mutational analysis indicate that CKII phosphorylates serine at residue 221 within CKBBP2/CRIF1. Furthermore, serine to alanine mutation at residue 221 abrogates the phosphorylation of CKBBP2/CRIF1 observed in HEK293 cell extract, indicating that CKII is a major kinase that is responsible for phosphorylation of CKBBP2/CRIF1. As compared with the wild-type CKBBP2/CRIF1 or nonphosphorylatable mutant CKBBP2(S221A) (in which the serine-221 is replaced by alanine), overexpression of CKBBP2(S221E) in COS7 cells promotes cell proliferation. Taken together, the present results suggest that CKII may be involved in cell proliferation, at least in part, through the phosphorylation of serine-221 within CKBBP2/CRIF1.
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PMID:Phosphorylation of CKBBP2/CRIF1 by protein kinase CKII promotes cell proliferation. 1706 92