Spinophilin, also known as Neuronal Phosphoprotein 1 (NPP1) or PPP1R9B, is a dendritic spine-enriched scaffolding protein that plays critical roles in synaptic structure, function, and plasticity. As a regulatory subunit of protein phosphatase 1 (PP1), spinophilin targets phosphatase activity to postsynaptic densities, where it modulates synaptic transmission, spine morphology, and learning. Spinophilin dysfunction has been implicated in neurodegenerative diseases including Alzheimer's Disease and Parkinson's Disease.
| Spinophilin | |
|---|---|
| Protein Name | Spinophilin |
| Gene | PPP1R9B |
| UniProt ID | Q9Y2T7 |
| PDB Structures | 1T0O |
| Molecular Weight | 131 kDa |
| Subcellular Localization | Dendritic spines, Postsynaptic density |
| Protein Family | Spinophilin family |
Spinophilin is named for its enrichment in dendritic spines, the tiny protrusions from neurons that receive excitatory synaptic input. The protein serves multiple functions including as a scaffold for synaptic proteins, a regulatory subunit of protein phosphatase 1, and an actin-binding protein that influences spine morphology. Spinophilin's ability to cluster receptors and signaling molecules at postsynaptic sites makes it essential for proper synaptic function.
The PPP1R9B gene encodes spinophilin, which is highly expressed in the brain particularly in the cortex and hippocampus. Research has demonstrated that spinophilin is critical for synaptic plasticity and memory formation. Spinophilin knockout mice exhibit altered spine morphology and impaired learning. In neurodegenerative diseases, spinophilin levels are often reduced, correlating with synaptic loss. The protein's role in targeting PP1 to synaptic substrates makes it important for regulating phosphorylation of receptors and signaling molecules involved in synaptic function.
Spinophilin is a 131 kDa protein belonging to the Spinophilin family.
Spinophilin is a dendritic spine-enriched scaffold protein that modulates synaptic transmission and plasticity. It regulates AMPA receptor trafficking, NMDA receptor signaling, and acts as a regulatory subunit for protein phosphatase 1.
Spinophilin in neurodegeneration:
Reduced in AD brains correlating with synaptic loss
Modulates tau phosphorylation
Affects alpha-synuclein aggregation
Alzheimer's Disease, Parkinson's Disease
Further research is needed to identify key publications for this protein.