Protein phosphatase 1 regulatory subunit 9B (PPP1R9B)

Protein phosphatase 1 regulatory subunit 9B (PPP1R9B), also known as Spinophilin or Neurabin-2, is a scaffold protein highly expressed in dendritic spines of the central nervous system. It acts as a regulatory subunit for protein phosphatase 1 (PP1), modulating excitatory synaptic transmission and dendritic spine morphology. PPP1R9B binds actin filaments and serves as a linker between the cytoskeleton and the plasma membrane at synaptic junctions. Through targeting PP1 to specific subcellular locations, PPP1R9B confers substrate specificity for processes including ion channel regulation, glutamate receptor function (AMPA and NMDA types), and G-protein coupled receptor signaling (dopamine D2, alpha-adrenergic receptors). It also plays a role in cell migration and is implicated in tumor suppression, schizophrenia, and limbic encephalitis.

Other names

Neurabin-2SpinophilinNeurabin-IIPPP1R6PPP1R9SPINOSpn

Agents modulating PPP1R9B (not clinically available) would function by altering PP1 localization/activity, synaptic transmission, or receptor signaling. Drugs affecting dopamine receptor activity might indirectly interact with PPP1R9B functions, but none specifically target PPP1R9B at present.