CD45

Developmental stage

Isoform 1: During T-cell development, expressed at the CD3-CD4-CD8- and CD3+CD4+CD8- stages but barely detectable at the CD3-CD4+CD8+ stage. Isoform 2: During T-cell development, expressed at low levels at the CD3-CD4-CD8- and CD3-CD4+CD8- stages but up-regulated at the CD3+CD4+CD8+ and CD3+CD4+CD8- stages. Isoform 3: During T-cell development, expressed at the CD3-CD4-CD8- and CD3+CD4+CD8- stages but barely detectable at the CD3-CD4+CD8+ stage. Isoform 5: During T-cell development, expressed at the CD3-CD4-CD8- and CD3+CD4+CD8- stages but barely detectable at the CD3-CD4+CD8+ stage. Isoform 7: Consistently expressed at high levels at all stages of T-cell development.

Domain

The first PTPase domain interacts with SKAP1.

Function

Protein tyrosine-protein phosphatase required for T-cell activation through the antigen receptor. Acts as a positive regulator of T-cell coactivation upon binding to DPP4. The first PTPase domain has enzymatic activity, while the second one seems to affect the substrate specificity of the first one. Upon T-cell activation, recruits and dephosphorylates SKAP1 and FYN. Dephosphorylates LYN, and thereby modulates LYN activity (By similarity).

(Microbial infection) Acts as a receptor for human cytomegalovirus protein UL11 and mediates binding of UL11 to T-cells, leading to reduced induction of tyrosine phosphorylation of multiple signaling proteins upon T-cell receptor stimulation and impaired T-cell proliferation.

Involvement in disease

Severe combined immunodeficiency autosomal recessive T-cell-negative/B-cell-positive/NK-cell-positive

T(-)B(+)NK(+) SCID

A form of severe combined immunodeficiency (SCID), a genetically and clinically heterogeneous group of rare congenital disorders characterized by impairment of both humoral and cell-mediated immunity, leukopenia, and low or absent antibody levels. Patients present in infancy recurrent, persistent infections by opportunistic organisms. The common characteristic of all types of SCID is absence of T-cell-mediated cellular immunity due to a defect in T-cell development.

None

The disease is caused by variants affecting the gene represented in this entry.

Multiple sclerosis

MS

A multifactorial, inflammatory, demyelinating disease of the central nervous system. Sclerotic lesions are characterized by perivascular infiltration of monocytes and lymphocytes and appear as indurated areas in pathologic specimens (sclerosis in plaques). The pathological mechanism is regarded as an autoimmune attack of the myelin sheath, mediated by both cellular and humoral immunity. Clinical manifestations include visual loss, extra-ocular movement disorders, paresthesias, loss of sensation, weakness, dysarthria, spasticity, ataxia and bladder dysfunction. Genetic and environmental factors influence susceptibility to the disease.

None

Disease susceptibility may be associated with variants affecting the gene represented in this entry.

Post-translational modifications

Heavily N- and O-glycosylated.

Sequence similarities

Belongs to the protein-tyrosine phosphatase family. Receptor class 1/6 subfamily.

Tissue specificity

Isoform 1: Detected in thymocytes. Isoform 2: Detected in thymocytes. Isoform 3: Detected in thymocytes. Isoform 4: Not detected in thymocytes. Isoform 5: Detected in thymocytes. Isoform 6: Not detected in thymocytes. Isoform 7: Detected in thymocytes. Isoform 8: Not detected in thymocytes.

Cellular localization

• Cell membrane
• Single-pass type I membrane protein
• Membrane raft
• Colocalized with DPP4 in membrane rafts.

Alternative names

• Receptor-type tyrosine-protein phosphatase C
• Leukocyte common antigen
• T200
• L-CA
• PTPRC
• CD45

Database links

• entrezGene:5788
• omim:151460
• swissprot:P08575

Target type

Proteins

Molecular weight

138034Da