PTPRJ: Human tyrosine receptor phosphatase J
PDB Code: 2CFV, 2NZ6
PTPRJ is a member of the R3 family of protein tyrosine phosphatases. It possesses an extracellular region containing fibronectin type III repeats, a single transmembrane region, and a single intracytoplasmic catalytic domain. PTPRJ is expressed in all hematopoietic lineages in particular in granulocytes and monocytes/macrophages. Weaker expression levels have been described for peripheral blood lymphocytes, including CD4 and CD8-positive T-cell subsets, B cells- in particular memory B cells- platelets, natural killer (NK) cells, dendritic cell types and transformed lymphoid T- and B cell lines. Among non-lymphoid tissues PTPRJ is found on the epithelium of the small and large bowel mucosa, appendix, endometrium, fallopian tubes, mammary glands, prostate glands, pancreatic acini and ducts, glandula parotis, cutaneous sweat glands and proximal and distal tubules of the kidney, fibrocytes, melanocytes and Schwann cells. It is also expressed at high levels in endothelia, including developing renal vascular endothelia. PTPRJ expression is up-regulated in leukocytes present in inflamed tissues as well as after in vitro activation with stimuli such as Con A, PMA or LPS. CSF-1 (macrophage colony-stimulating factor) leads to down-regulation of expression levels.
It is a negative regulator of cellular proliferation and is involved in cell differentiation by inducing cytoskeletal rearrangements, aberrant cell-substratum interactions , reduction of motility and chemotaxis in fibroblasts. It also plays a role in developmental vascular organization, endothelial proliferation and endothelium-pericyte interactions. PTPRJ negatively regulates T cell receptor signaling possibly through interfering with the phosphorylation of phospholipase C gamma 1 (PLCG1) and linker for activation of T cells (LAT).
In eosinophiles activation of PTPRJ leads to degranulation and induction of generation of superoxide anions frequent deletions, loss of heterozygosity (LOH), and missense mutations in the PTPRJ gene is associated with cancer (colon, breast, thyroid, lung). It has been suggested that PTPRJ may be important in the early events leading to colorectal cancer.
PTPRJ knockin mice from which cytoplasmic phosphatase sequences have been removed die at 10.5 days of gestation due to failure of developmental vascularization and associated growth retardation.
PTPRJ has several characteristics of a tumour-suppressor gene: Expression of PTPRJ suppresses the malignant phenotype in transformed rat thyroid cells, human colon, lung and breast cancers frequently present somatic missense mutations, loss of heterozygosity or deletions of the PTPRJ gene dedifferentiation of tumor cells might be associated with a reduced expression of PTPRJ. PTPRJ also plays a potential role in inflammatory diseases, such as allergic and parasitic diseases, associated with eosinophilia. The wild type protein did unfortunately not crystallize and the SGC determined two crystal structures of PTPRJ inactive mutants so far. One mutant in which the WPD loop tryptophane was changed to an alanine and a classical active site Cys/Ser mutant. Both mutants were crystallized in the presence of a substrate peptide. Due to the weak affinity of the peptide no substrate density was observed in the structures. However, the Cys/Ser mutant a peptide containing tryptophan located a C-terminal flanking region bound to its active site suggesting a mechanism of regulation involving residues C-terminal to the PTPRJ catalytic domain.
Welcome to buy
This form is unable to receive your inquiry from aol, hotmail, gmail or others but company email address.After send online enquiry, we will reply you as soon as possible, if not get any response on time please contact us by Tel or Email.
1. Email: firstname.lastname@example.org
2. Tel: +86 592 5365887
3.WhatsApp: +86 189 6515 7632
4. Send enquiry online
You may also be interested in :
For more information of product, please send the email to email@example.com