Identification and characterization of the BmCyclin L1-BmCDK11A/B complex in relation to cell cycle regulation.

Cyclin proteins are the key regulatory and activity partner of cyclin-dependent kinases (CDKs)， which play pivotal regulatory roles in cell cycle progression. In the present study， we identified a Cyclin L1 and 2 CDK11 2 CDK11 splice variants， CDK11A and CDK11B， from silkworm， Bombyx mori. We determined that both Cyclin L1 and CDK11A/B are nuclear proteins， and further investigations were conducted to elucidate their spatiofunctional features. Cyclin L1 forms a complex with CDK11A/B and were co-localized to the nucleus. Moreover， the dimerization of CDK11A and CDK11B and the effects of Cyclin L1 and CDK11A/B on cell cycle regulation were also investigated. Using overexpression or RNA interference experiments， we demonstrated that the abnormal expression of Cyclin L1 and CDK11A/B leads to cell cycle arrest and cell proliferation suppression. Together， these findings indicate that CDK11A/B interacts with Cyclin L1 to regulate the cell cycle.