Interactions of the p107 and Rb proteins with E2F during the cell proliferation response.

摘要: The E2F transcription factor is found in complexes with a variety of cellular proteins including the retinoblastoma tumor suppressor protein. Various assays have demonstrated tight correlation between functional capacity Rb as growth and its ability to bind E2F. Moreover, only underphosphorylated form Rb, which appears be active species, interacts Despite fact that majority becomes hyperphosphorylated at end G1, we now show E2F-Rb interaction persists through G1/S transition into S phase. A distinct complex does appear regulated relation from G1 We demonstrate this contains Rb-related p107 like protein, inhibits E2F-dependent co-transfection assay. This result, together observation free, uncomplexed accumulates cells leave enter phase, suggests protein may regulate during G1. In contrast, although transcriptional activity E2F, association not coincide phase transition.