Absence of cyclin D/cdk complexes in cells lacking functional retinoblastoma protein.

摘要: Cyclins D1, D2 and D3 are thought to function in the G1 phase of cell division cycle by regulating activity cyclin-dependent protein kinases. All three D-type cyclins can be shown associate with two specific kinases, cdk4 cdk6, providing at least six possible combinations. To establish whether different types require subsets these complexes they altered tumours where D-cyclin expression is perturbed, we surveyed a series tumour lines compared them non-tumorigenic counterparts. Although involving or cdk6 were readily observed many lines, no detectable human cells harbouring DNA virus oncoproteins which retinblastoma gene product (pRb) mutated missing. These data suggest that as well being potential substrate for D-cyclin-kinases, functional pRb contributes formation stability complexes, cells.