The induction of premature chromosome condensation (PCC) in tsBN2 cells, a temperature-sensitive (ts) mutant of BHK21/13 which shows PCC at the non-permissive temperature, was almost completely inhibited by 40 μM W-7, an antagonist of calmodulin. The mitotic phosphorylation of histone H1 and H3 was also inhibited by W-7, W-5, a chlorine-deficient analogue of W-7 and which interacts weakly with calmodulin, did not inhibit the induction of PCC, even at a dose of 80 μM. The content of calmodulin in tsBN2 cells was increased by a temperature shift to 40.5°C. All these results suggested that calmodulin is required for the chromosome condensation.
All Science Journal Classification (ASJC) codes
- Cell Biology