PTPRCAP
Protein Tyrosine Phosphatase Receptor Type C Associated Protein
Gene Information Card
| Symbol | PTPRCAP |
|---|---|
| Full Name | Protein Tyrosine Phosphatase Receptor Type C Associated Protein |
| Gene Type | Protein coding |
| Chromosomal Location | 11q13.1 |
| NCBI Gene ID | 5790 ncbi.nlm.nih.gov/gene/5790 |
| Ensembl ID | ENSG00000110367 |
| UniProt ID | Q14761 |
| OMIM ID | 601577 |
| HGNC ID | 9660 |
| Aliases | CD45-AP, LPAP, LSM2 |
Description
PTPRCAP (Protein Tyrosine Phosphatase Receptor Type C Associated Protein) encodes a transmembrane protein known as CD45-associated protein (CD45-AP) or LPAP. This protein binds to the cytoplasmic domain of protein tyrosine phosphatase receptor type C (PTPRC/CD45) and is essential for proper CD45 expression and function in T cells. It plays a critical role in T cell receptor (TCR) signaling by regulating CD45 activity, which dephosphorylates Lck and Fyn kinases. PTPRCAP is predominantly expressed in lymphoid tissues and is involved in immune system regulation.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Severe combined immunodeficiency (SCID) | Loss-of-function mutations in PTPRCAP impair CD45 expression and TCR signaling, leading to T cell deficiency. | Case reports and functional studies (PMID: 23453689) |
| Autoimmune lymphoproliferative syndrome (ALPS) | Dysregulation of CD45 signaling due to PTPRCAP variants may contribute to defective apoptosis. | Limited evidence; inferred from CD45 pathway studies |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lymph node | 45.2 | High |
| Spleen | 38.7 | High |
| Thymus | 32.1 | High |
| Bone marrow | 18.5 | Medium |
| Blood | 22.3 | Medium |
| Lung | 2.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Jurkat (T cell leukemia) | 50.4 | High expression; used in functional studies |
| Raji (B cell lymphoma) | 35.8 | Moderate expression |
| HEK293 (embryonic kidney) | 0.5 | Very low; not endogenous |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Nonsense | Rare | Loss of start codon; predicted loss of protein |
| c.124C>T (p.Arg42*) | Nonsense | Rare | Premature stop; loss of function |
| c.200_201del (p.Glu67fs) | Frameshift | Rare | Frameshift; loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations in PTPRCAP lead to truncated or absent protein, impairing CD45 expression and T cell activation.
Gain of Function (GOF)
No gain-of-function mutations reported in PTPRCAP.
Dominant Negative (DN)
No dominant-negative mutations described; recessive loss-of-function is typical.
View complete mutation data：
Gene Ontology (GO)
| • protein binding (GO:0005515) | • plasma membrane (GO:0005886) |
| • signal transduction (GO:0007165) | • cytoplasm (GO:0005737) |
| • integral component of membrane (GO:0016021) | • T cell receptor signaling pathway (GO:0050852) |
Pathways
• T cell receptor signaling pathway (Reactome: R-HSA-202403)
• CD45-mediated dephosphorylation (Reactome: R-HSA-388844)
Protein Summary
The PTPRCAP protein (CD45-AP) is a 27 kDa transmembrane adaptor that binds to the cytoplasmic tail of CD45. It stabilizes CD45 at the plasma membrane and facilitates its phosphatase activity, which is crucial for TCR signaling. The protein contains a single transmembrane domain and a short intracellular region that interacts with CD45. Loss of PTPRCAP leads to reduced CD45 surface expression and impaired T cell development and function.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PTPRCAP Knockout HEK293 Cell Line | EDJ-KQ50551 | Human | 5790 | Details Get a Quote |
| PTPRCAP Knockout HeLa Cell Line | EDJ-KQ54272 | Human | 5790 | Details Get a Quote |
| PTPRCAP Knockout A-549 Cell Line | EDJ-KQ62765 | Human | 5790 | Details Get a Quote |
| PTPRCAP Knockout HCT 116 Cell Line | EDJ-KQ71234 | Human | 5790 | Details Get a Quote |
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