Stimulation of human DNA topoisomerase II activity by its direct association with the beta subunit of protein kinase CKII.
DNA topoisomerase II copurifies with and is phosphorylated by protein kinase CKII. In this study, a yeast two-hybrid system was used to investigate the interaction between human topoisomerase II isozymes and CKII subunits. The two-hybrid test clearly showed that both topoisomerase IIalpha and IIbeta interact with the CKIIbeta, but not the CKIIalpha subunit. The two-hybrid test also demonstrated that topoisomerase IIbeta residues 1099-1263 and topoisomerase IIalpha residues 1078-1182 mediate the interaction with the CKIIbeta subunit, providing evidence that the leucine zipper motif and the major CKII-dependent phosphorylation sites of topoisomerase II are unnecessary for its physical binding to CKIIbeta. Furthermore, a DNA relaxation assay demonstrated that the CKII subunit enhances topoisomerase II activity by physical interaction with topoisomerase II.
Department of Biochemistry, College of Natural Sciences, Kyungpook National University, Taegu, Korea.
G H
GH
Park
Y T
YT
Lee
Y S
YS
Bae
D001665:Binding Sites / Q000502:physiology; D047390:Casein Kinase II; D004247:DNA / Q000378:metabolism; D004250:DNA Topoisomerases, Type II / Q000235:genetics* / Q000378:metabolism*; D004789:Enzyme Activation / Q000502:physiology; D017353:Gene Deletion; D006801:Humans; D016350:Leucine Zippers / Q000502:physiology; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D020798:Two-Hybrid System Techniques; D015003:Yeasts
D004247:DNA; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D004250:DNA Topoisomerases, Type II