protein phosphatase 1 regulatory inhibitor subunit 1B(PPP1R1B) Homo sapiens This gene encodes a bifunctional signal transduction molecule. Dopaminergic and glutamatergic receptor stimulation regulates its phosphorylation and function as a kinase or phosphatase inhibitor. As a target for dopamine, this gene may serve as a therapeutic target for neurologic and psychiatric disorders. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2011],