Protein phosphatase 1, catalytic subunit, alpha isoform, also known as PPP1CA, is one of the three catalytic subunits of protein phosphatase 1. The protein is highly conserved in eukaryotic cells and play a role in dephosphorylating substrates such as the postsynaptic density-associated Ca2+/calmodulin dependent protein kinase II. It is participate in the regulation of a variety of cellular processes, such as cell division, glycogen metabolism, muscle contractility, protein synthesis and apoptosis