High impact information on Ptpro

• Biochemical analyses revealed that Ptpro dephosphorylates a phosphotyrosine residue conserved in the juxtamembrane region, which is required for the activation and signal transmission of Eph receptors [1].
• Here, we identified protein tyrosine phosphatase receptor type O (Ptpro) as a specific PTP that efficiently dephosphorylates both EphA and EphB receptors as substrates [1].
• Altered podocyte structure in GLEPP1 (Ptpro)-deficient mice associated with hypertension and low glomerular filtration rate [2].
• The restricted expression of the shorter isoforms of PTP phi and their regulation by colony stimulating factor-1 in macrophages suggest that PTP phi may play a role in mononuclear phagocyte survival, proliferation, and/or differentiation [3].
• A heteromorphic protein-tyrosine phosphatase, PTP phi, is regulated by CSF-1 in macrophages [3].

Biological context of Ptpro

• The deduced amino acid sequences showed 89, 95, and 92% identities with human, rabbit, and chicken homologues of PTP-BK [4].
• Western blot analysis indicated that anti-PTP-BK antibody specifically immunoreacted to 2 distinct molecules of 200 kDa and 220 kDa in COS cells, possibly due to differential glycosylation [4].
• Radiation hybrid panel assigned mouse PTP-BK gene to 5.02cR distal to from the marker D6Mit339 on chromosome 6 [4].
• A novel protein-tyrosine phosphatase, PTP phi, was cloned from a murine macrophage cDNA library [3].
• As a result of alternative splicing, macrophage PTP phi mRNAs are predicted to encode two membrane-spanning molecules and a cytosolic enzyme with identical catalytic domains [3].

Anatomical context of Ptpro

• Mouse PTPRO mRNA is expressed exclusively in two cell types: neurons and kidney podocytes [5].
• Expression of PTP phi mRNA is low and restricted to macrophage cell lines, macrophage-rich tissues, and brain, kidney, and heart [3].
• In adult human and rabbit kidneys, GLEPP1 is found exclusively on apical membranes of podocytes and especially on surfaces of foot processes [6].
• Expression of PTPRO was also observed in human CD34+ bone marrow cells and 5-FU-treated murine primitive stem cells [7].

Associations of Ptpro with chemical compounds

• The recombinant PTP-BK showed the phosphatase activity specific for the phosphotyrosine, but not for the phosphoserine residue of phosphopeptides in vitro [4].
• Through additional two-hybrid experiments, cotransfection and reciprocal coprecipitation, glutathione S-transferase pulldown, and immunoprecipitation in vivo, we confirm that NPCD isoforms interact with the catalytic phosphatase domain of PTPRO [8].

Other interactions of Ptpro

• Expression of PTPRO during mouse development suggests involvement in axonogenesis and differentiation of NT-3 and NGF-dependent neurons [5].
• The biochemical complexity and neuronal expression pattern of NPCD, together with its interaction with PTPRO, suggests involvement in multiple neuronal processes [9].

References