Phosphatase and actin regulator (PHACTR) family members bind to actin and regulate protein phosphatase 1 (PP1) []. PHACTRs are comprised of four family members (Phactr1-4) with distinct expression patterns in the adult brain. They appear to be involved in the regulation of synaptic plasticity via modulating PP1 activity []. Phactr3 (also known as Scapinin) enhances cell spreading and motility by interacting with the actin cytoskeleton []. In mice it is mainly expressed in the brain where it serves as a regulator of neurite outgrowth and neuroplasticity [].