Protein Phosphatase 1, Regulatory Subunit 15A (PPP1R15A)

Protein phosphatase 1 regulatory subunit 15A is a member of a group of genes whose transcript levels are increased following stressful growth arrest conditions and treatment with DNA-damaging agents. The induction of this gene by ionizing radiation occurs in certain cell lines regardless of p53 status, and its protein response is correlated with apoptosis following ionizing radiation.

The predicted 674-amino acid protein is highly negatively charged and contains 4 central 34-residue repeats. It shares 52 to 55% amino acid identity with its rodent homologs. In addition, the C terminus of GADD34 shares significant homology with the C terminus of ICP34.5, an apoptosis inhibition protein of herpes simplex virus (HSV)-1.