Regulation of PP1 by the Phactr family

PP1, Protein phosphatase 1, controls many physiological processes including cell cycle, metabolism, cell motility, and signaling since it is a critical serine threonine phosphatase in eukaryotic cells. PP1’s activity is controlled by specific interactions with a large number of different regulatory subunits, including MYPT1, myosin phosphatase target subunit1, as well as, GADD34, growth arrest and DNA damage inducible protein. Phosphatase and actin regulator, Phactr family, is a recently discovered and not fully characterized set of these regulatory subunits. Phactr proteins are important in controlling cancer motility, cell motility, and apoptosis and are known to interact with actin in the cytoskeleton and PP1, even though the roles of individual Phactr proteins are not well understood. The mechanisms by which they bind to the unconventional PP1 binding domain is unusual. We have performed site-directed mutagenesis on PP1α and PP1β in the canonical way to which they bind to their targets. We also ligated Phactr into vectors and are using Coimunoprecipitation, Co-IP, from mammalian cell culture to observe whether its interaction with PP1 is in a classical or novel way