Disease relevance of Ptprj

• Our recent experiments suggested that specific PTPases, PTP beta 2 and PTP epsilon, are involved in the early molecular events for in vitro differentiation of mouse erythroleukemia (MEL) as well as embryonic carcinoma (F9) cells [1].
• Previously, we described in mouse strain CcS-19/Dem five susceptibility to colon cancer (Scc) loci, Scc1-Scc5 controlling tumor numbers [2].

High impact information on Ptprj

• Previously, applying a protocol of 26 injections of 1,2-dimethylhydrazine (DMH), we detected two susceptibility loci, Scc1 and Scc2, on chromosome 2 (refs 4, 5) [3].
• A mutant receptor tyrosine phosphatase, CD148, causes defects in vascular development [4].
• In contrast, CD148 expression on thymocytes and mature T cells is substantially lower [5].
• Through the use flow cytometry and immunofluorescence microscopy on tissue sections, we examined the expression of CD148 on multiple murine hemopoietic cell lineages [5].
• We found that CD148 is moderately expressed during all stages of B cell development in the bone marrow, as well as peripheral mature B cells [5].

Biological context of Ptprj

• The protein-tyrosine phosphatase DEP-1 modulates growth factor-stimulated cell migration and cell-matrix adhesion [6].
• Using CcS-19, one of the highly susceptible RC strains, we mapped a novel colon tumor susceptibility gene, Scc-1, different from the oncogenes and tumor-suppressor genes known to be involved in colon tumorigenesis, in the vicinity of CD44 (Ly-24, Pgp-1) on chromosome 2 [7].
• The putative Byp protein consists of 1238 amino acids, which possesses a single catalytic domain in the cytoplasmic region [8].
• We have investigated the pattern of transcripts of PTPases during MEL cell differentiation and found that while the transcripts of most PTPases were unchanged or undetected in the cells, transcripts for two PTPases (PTP beta 2 and RIP) exhibited distinct patterns of induction at a very early stage of differentiation [9].
• It has also been suggested that CD148 could be involved in mechanisms of differentiation and inhibition of cell growth [10].

Anatomical context of Ptprj

• We analysed cell lines with inducible DEP-1 expression for cellular functions of DEP-1 [6].
• Murine DEP-1, a receptor protein tyrosine phosphatase, is expressed in macrophages and is regulated by CSF-1 and LPS [11].
• Four molecules not previously reported on dendritic cells were documented: CD87, CD98, CD147 and CD148 [12].
• CD148, a new membrane tyrosine phosphatase involved in leukocyte function [10].
• In addition, CD148 seems to be associated with a serine/threonine kinase in certain epithelial cell lines and leucocytes [10].

Associations of Ptprj with chemical compounds

• Chromosomal location of murine protein tyrosine phosphatase (Ptprj and Ptpre) genes [1].

Other interactions of Ptprj

• Moreover, CD148 is able to modulate the signal transduction through the TCR/CD3 complex, in a manner similar to CD45 [10].

Analytical, diagnostic and therapeutic context of Ptprj

• Molecular cloning and characterization of Byp, a murine receptor-type tyrosine phosphatase similar to human DEP-1 [8].

References