Format

Send to

Choose Destination
EMBO J. 1992 May;11(5):1785-96.

Casein kinase II phosphorylates the eukaryote-specific C-terminal domain of topoisomerase II in vivo.

Author information

1
Swiss Institute for Experimental Cancer Research, Epalinges s/Lausanne.

Abstract

The decatenation activity of DNA topoisomerase II is essential for viability as eukaryotic cells traverse mitosis. Phosphorylation has been shown to stimulate topoisomerase II activity in vitro. Here we show that topoisomerase II is a phosphoprotein in yeast and that the level of incorporated phosphate is significantly higher at mitosis than in G1. Comparison of tryptic phosphopeptide maps reveals that the major phosphorylation sites in vivo are targets for casein kinase II. Incorporation of phosphate into topoisomerase II is nearly undetectable at the non-permissive temperature in a conditional casein kinase II mutant. The sites modified by casein kinase II are located in the extreme C-terminal domain of topoisomerase II. This domain is absent in prokaryotic and highly divergent among eukaryotic type II topoisomerases, and may serve to regulate functions of topoisomerase II that are unique to eukaryotic cells.

PMID:
1316274
PMCID:
PMC556636
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center