PTPN9: Protein Tyrosine Phosphatase Non-Receptor Type 9
A key regulator of receptor tyrosine kinase signaling and vesicle trafficking
Gene Information Card
| Symbol | PTPN9 |
|---|---|
| Full Name | Protein Tyrosine Phosphatase Non-Receptor Type 9 |
| Gene Type | Protein coding |
| Chromosomal Location | 15q24.2 |
| NCBI Gene ID | 5780 ncbi.nlm.nih.gov/gene/5780 |
| Ensembl ID | ENSG00000169418 |
| UniProt ID | P43378 |
| OMIM ID | 603171 |
| HGNC ID | 9659 |
| Aliases | PTP-MEG2, MEG2 |
Description
PTPN9 encodes a member of the protein tyrosine phosphatase (PTP) family. The encoded protein is a non-receptor type tyrosine phosphatase that dephosphorylates receptor tyrosine kinases (e.g., EGFR, VEGFR2) and regulates intracellular vesicle trafficking. It is involved in hematopoiesis, insulin signaling, and immune cell function.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Dephosphorylation of EGFR; reduced PTPN9 expression correlates with poor prognosis | PMID: 23382219 |
| Type 2 diabetes | Regulation of insulin receptor signaling; PTPN9 knockdown improves insulin sensitivity | PMID: 25615953 |
| Leukemia | Dysregulation of JAK-STAT signaling; PTPN9 acts as a tumor suppressor in myeloid malignancies | PMID: 28446463 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Bone marrow | 12.5 | Medium |
| Spleen | 10.8 | Medium |
| Lung | 8.2 | Low |
| Liver | 6.1 | Low |
| Brain | 4.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| K-562 (leukemia) | 15.2 | High expression |
| HepG2 (liver) | 7.8 | Moderate expression |
| MCF7 (breast) | 5.1 | Low expression |
| A549 (lung) | 4.6 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1012C>T (p.Arg338Trp) | Missense | <0.01% (gnomAD) | Loss of phosphatase activity; associated with altered EGFR signaling |
| c.1456G>A (p.Glu486Lys) | Missense | <0.01% (gnomAD) | Unknown functional effect |
| c.1789_1790insA (p.Thr597Asnfs*12) | Frameshift | Rare | Predicted loss of function |
Mutation functional classification
Loss of Function (LOF)
Missense mutations in the catalytic domain (e.g., p.Arg338Trp) reduce phosphatase activity, impairing dephosphorylation of substrates such as EGFR and VEGFR2.
Gain of Function (GOF)
No gain-of-function mutations have been reported in PTPN9.
Dominant Negative (DN)
No dominant-negative mutations have been characterized for PTPN9.
View complete mutation data：
Gene Ontology (GO)
Pathways
• EGFR tyrosine kinase inhibitor resistance (KEGG: hsa01521)
• VEGF signaling pathway (KEGG: hsa04370)
• Insulin signaling pathway (KEGG: hsa04910)
• JAK-STAT signaling pathway (KEGG: hsa04630)
Protein Summary
PTPN9 (also known as PTP-MEG2) is a 68 kDa non-receptor protein tyrosine phosphatase localized to the cytoplasm and vesicular membranes. It contains a single catalytic PTP domain and an N-terminal Sec14p-like lipid-binding domain. PTPN9 dephosphorylates key tyrosine residues on receptor tyrosine kinases (e.g., EGFR, VEGFR2) and adaptor proteins, thereby modulating cell proliferation, migration, and vesicle fusion. It is highly expressed in hematopoietic tissues and plays a role in platelet dense granule secretion and insulin signaling.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PTPN9 Knockout HEK293 Cell Line | EDJ-KQ5595 | Human | 5780 | Details Get a Quote |
| PTPN9 Knockout A-549 Cell Line | EDJ-KQ28869 | Human | 5780 | Details Get a Quote |
| PTPN9 Knockout HCT 116 Cell Line | EDJ-KQ28870 | Human | 5780 | Details Get a Quote |
| PTPN9 Knockout HeLa Cell Line | EDJ-KQ28871 | Human | 5780 | Details Get a Quote |
