An E2F site in the 5′‐promoter region contributes to serum‐dependent up‐regulation of the human proliferating cell nuclear antigen gene

摘要

>The synthesis of proliferating cell nuclear antigen (PCNA) is strictly regulated during the cell cycle. To investigate the contribution of the promoter region to the up-regulation of human PCNA expression at the onset of S phase, we have examined 17 putative elements with reporter assays in quiescent L-O2 cells and following serum stimulation. The E2F-like sequence 5′-TTCCCCGCAA-3′ located at −84 to −75 is required for the serum-induced transactivation. In electrophoretic mobility shift assays, nuclear extracts from asynchronous L-O2 cells exhibit two binding activities toward the −75 E2F oligonucleotide, and the minor band, whose formation could be interfered with by E2F-1 antibody, represents an S phase-specific complex. This is the first demonstration of the E2F site in the human PCNA 5′ promoter as a serum-responsive element.