Transcription factor FOXM1c is repressed by RB and activated by cyclin D1/Cdk4.

摘要: The proliferation-stimulating transactivator FOXM1c (MPP2) is repressed by RB and activated cyclin D1/Cdk4 therefore behaves like E2F. Despite its strong transactivation domain, kept almost inactive two different inhibitory domains, the N-terminus central domain. tumor suppressor binds directly to domain of thereby indirectly represses so that functions as an RB-recruiting negative-regulatory Cyclin releases from this repression own N-terminus, strongly activating FOXM1c. However, does not affect or DNA-binding By phosphorylation RB, but FOXM1c, interrupts their direct interaction thus abrogates RB. also eliminates inhibition probably interruption interaction. Consequently, G1-phase proliferation signal converts form into a in G1-phase, i.e., just at time point which transcriptional activity FOXM1 required for stimulation G1/S-transition.