PPP1R12B (MBS) - Protein Phosphatase 1 Regulatory Subunit 12B
A key regulator of myosin phosphatase activity, implicated in smooth muscle contraction, cell motility, and cancer.
Gene Information Card
| Symbol | PPP1R12B |
|---|---|
| Full Name | protein phosphatase 1 regulatory subunit 12B |
| Gene Type | protein coding |
| Chromosomal Location | 1q32.1 |
| NCBI Gene ID | 4665 ncbi.nlm.nih.gov/gene/4665 |
| Ensembl ID | ENSG00000134202 |
| UniProt ID | O60237 |
| OMIM ID | 602547 |
| HGNC ID | 9287 |
| Aliases | MBS, MYPT2, PP1BP55 |
Description
PPP1R12B encodes the myosin phosphatase targeting subunit 2 (MYPT2), a regulatory component of myosin light chain phosphatase (MLCP). MLCP dephosphorylates myosin light chain, thereby inhibiting smooth muscle contraction. PPP1R12B is involved in regulating actin cytoskeleton dynamics, cell migration, and proliferation. It is expressed in various tissues, with high levels in heart and skeletal muscle. Alterations in PPP1R12B expression or function have been linked to cancer progression and cardiovascular conditions.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (various types) | Altered expression or mutations may affect cell motility and invasion via MLCP regulation. | COSMIC: somatic mutations found in multiple cancer types; ClinVar: variants of uncertain significance. |
| Smooth muscle dysfunction | Impaired MLCP activity can lead to abnormal contraction, potentially contributing to vascular or gastrointestinal disorders. | Inferred from functional studies; no direct OMIM disease association. |
| Cardiovascular disease | PPP1R12B is highly expressed in heart; dysregulation may affect cardiac contractility. | Expression data from GTEx; no direct clinical evidence. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 25.3 | High |
| Skeletal Muscle | 20.1 | High |
| Brain | 8.5 | Medium |
| Lung | 6.2 | Medium |
| Liver | 2.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 12.4 | Moderate expression |
| A549 | 8.7 | Moderate expression |
| MCF7 | 5.3 | Low expression |
| K562 | 3.2 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234A>G (p.Ile412Val) | Missense | 0.01% (gnomAD) | Unknown; predicted benign |
| c.456delC (p.Pro153LeufsTer23) | Frameshift | Rare | Loss of function; may impair MLCP regulation |
| c.789C>T (p.Arg263Trp) | Missense | 0.005% (gnomAD) | Unknown; possibly damaging |
Mutation functional classification
Loss of Function (LOF)
Frameshift or nonsense mutations leading to truncated protein, reducing MLCP activity and enhancing myosin phosphorylation.
Gain of Function (GOF)
Not well documented; some missense variants may alter protein stability or interaction, but no clear gain-of-function reported.
Dominant Negative (DN)
Potential if mutant subunit competes with wild-type for binding to PP1c, but not confirmed.
View complete mutation data：
Gene Ontology (GO)
| • protein phosphatase regulator activity | • myosin phosphatase activity |
| • signal transduction | • regulation of smooth muscle contraction |
| • actin cytoskeleton organization | • cell migration |
Pathways
• Smooth muscle contraction pathway
• Regulation of actin cytoskeleton
• Focal adhesion pathway
Protein Summary
PPP1R12B (MYPT2) is a 100 kDa protein that binds to the catalytic subunit of protein phosphatase 1 (PP1c) to form the myosin light chain phosphatase holoenzyme. It targets PP1c to myosin, facilitating dephosphorylation of myosin light chain and promoting muscle relaxation. MYPT2 also interacts with other proteins to regulate cytoskeletal dynamics. Its expression is tissue-specific, with highest levels in cardiac and skeletal muscle. Post-translational modifications, such as phosphorylation by Rho kinase, can inhibit its activity, linking it to signaling pathways that control cell contractility and motility.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PPP1R12B Knockout HEK293 Cell Line | EDJ-KQ2300 | Human | 4660 | Details Get a Quote |
| PPP1R12B Knockout A-549 Cell Line | EDJ-KQ22667 | Human | 4660 | Details Get a Quote |
| PPP1R12B Knockout HCT 116 Cell Line | EDJ-KQ22668 | Human | 4660 | Details Get a Quote |
| PPP1R12B Knockout HeLa Cell Line | EDJ-KQ22669 | Human | 4660 | Details Get a Quote |
| PPP1R12B Knockout Hep-G2 Cell Line | EDJ-KZ41 | Human | 4660 | Details Get a Quote |
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