Biological Activity
E1A binding protein p300 (p300) and CBP (CREB binding protein) are highly related transcriptional coactivators. Both proteins have been identified through protein interaction assays. In addition to interacting with a variety of cellular factors and oncoproteins, loss of the wild type CBP alleles in isolated tumors suggests th at CBP/p300 might serve as tumor suppressors. The ability of p300 to acetylate many transcription factors, including tumor suppressor p53, E2 factor (E2F), transcription factors II E and -F (TFIIE and -F) etc. demonstrates a novel mechanism of targeted p300 regulation of gene expression. Mutations in the gene encoding the protein have been linked to Rubinstein-Taybi syndrome (RSTS).