EP300 Gene

The EP300 gene provides instructions for making a protein called p300, which regulates the activity of many genes in tissues throughout the body. This protein plays an essential role in controlling cell growth and division and prompting cells to mature and take on specialized functions (differentiate). The p300 protein appears to be critical for normal development before and after birth.

The p300 protein carries out its functions by turning on (activating) transcription, which is the first step in the production of protein from the instructions stored in DNA. The p300 protein ensures the DNA is ready for transcription by attaching a small molecule called an acetyl group (a process called acetylation) to proteins called histones. Histones are structural proteins that bind DNA and give chromosomes their shape. Acetylation of the histone changes the shape of the chromosome, making genes available for transcription. On the basis of this function, the p300 protein is called a histone acetyltransferase.

In addition, the p300 protein connects other proteins that start the transcription process (known as transcription factors) with the group of proteins that carries out transcription. On the basis of this function, the p300 protein is called a transcriptional coactivator.