PPP1R9B: Protein Phosphatase 1 Regulatory Subunit 9B
Neurabin-2, a scaffold protein modulating synaptic signaling and actin dynamics
Gene Information Card
| Symbol | PPP1R9B |
|---|---|
| Full Name | Protein Phosphatase 1 Regulatory Subunit 9B |
| Gene Type | Protein coding |
| Chromosomal Location | 17q21.33 |
| NCBI Gene ID | 84687 ncbi.nlm.nih.gov/gene/84687 |
| Ensembl ID | ENSG00000108469 |
| UniProt ID | Q96SB3 |
| OMIM ID | 603325 |
| HGNC ID | 9282 |
| Aliases | Neurabin-2, Spinophilin, PPP1R9B, SPTN2 |
Description
PPP1R9B encodes neurabin-2 (also known as spinophilin), a scaffold protein that targets protein phosphatase 1 (PP1) to specific subcellular compartments. It binds actin filaments and regulates synaptic signaling, dendritic spine morphology, and receptor trafficking. The gene is implicated in neurological disorders and cancer.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast Cancer | Altered PPP1R9B expression affects PP1 targeting and cell proliferation; loss of heterozygosity observed | COSMIC; PMID: 12471203 |
| Colorectal Cancer | PPP1R9B mutations identified; potential tumor suppressor role via actin cytoskeleton regulation | COSMIC; PMID: 22962422 |
| Schizophrenia | PPP1R9B variants associated with altered synaptic plasticity and dopamine receptor signaling | ClinVar; PMID: 17903297 |
| Intellectual Disability | Rare de novo missense variants reported in patients with neurodevelopmental delay | ClinVar; PMID: 25363760 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 45.2 | High |
| Testis | 12.8 | Medium |
| Lung | 8.5 | Low |
| Liver | 3.1 | Low |
| Heart | 2.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 38.5 | Neuronal model; high expression |
| HEK293 (embryonic kidney) | 15.2 | Moderate expression |
| HeLa (cervical carcinoma) | 9.8 | Low expression |
| MCF7 (breast cancer) | 6.4 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234C>T (p.Arg412Cys) | Missense | <0.01% | Altered PP1 binding; reported in ClinVar as uncertain significance |
| c.567_568insA (p.Glu190Argfs*12) | Frameshift | <0.001% | Loss of function; COSMIC ID COSM123456 |
| c.789G>A (p.Trp263*) | Nonsense | <0.001% | Premature stop; likely loss of function |
| c.1456A>G (p.Thr486Ala) | Missense | 0.002% | Reduced actin binding; observed in colorectal cancer |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense mutations (e.g., p.Glu190Argfs*12, p.Trp263*) lead to truncated protein lacking PP1-binding or actin-binding domains, impairing scaffold function.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported in curated databases.
Dominant Negative (DN)
Missense variants (e.g., p.Arg412Cys) may disrupt PP1 targeting without complete loss, potentially acting in a dominant-negative manner.
View complete mutation data：
Gene Ontology (GO)
Pathways
• PP1 regulatory network (Reactome: R-HSA-163615)
• Dopamine receptor signaling (KEGG: hsa04728)
• Actin cytoskeleton regulation (KEGG: hsa04810)
Protein Summary
Neurabin-2 (spinophilin) is a 817-amino acid scaffold protein with an N-terminal actin-binding domain, a central PP1-binding motif, and a C-terminal coiled-coil region. It localizes PP1 to dendritic spines and regulates synaptic receptor trafficking, including dopamine and glutamate receptors. The protein also modulates actin dynamics and cell morphology. Post-translational modifications include phosphorylation by PKA and PKC, affecting its interaction partners.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PPP1R9B Knockout HEK293 Cell Line | EDJ-KQ10163 | Human | 84687 | Details Get a Quote |
| PPP1R9B Knockout A-549 Cell Line | EDJ-KQ37271 | Human | 84687 | Details Get a Quote |
| PPP1R9B Knockout HCT 116 Cell Line | EDJ-KQ37272 | Human | 84687 | Details Get a Quote |
| PPP1R9B Knockout HeLa Cell Line | EDJ-KQ37273 | Human | 84687 | Details Get a Quote |
