Disease relevance of PTP1

• A translocated protein tyrosine phosphatase of Pseudomonas syringae pv. tomato DC3000 modulates plant defence response to infection [1].

High impact information on PTP1

• In summary, we have identified AtPTP1 as a tyrosine-specific protein phosphatase that may function in stress responses of higher plants [2].
• The recombinant AtPTP1 protein specifically hydrolyzed phosphotyrosine, but not phosphoserine/threonine, in protein substrates [2].
• This chimeric homologue, identified as HopPtoD2 in the annotated DC3000 genome, consisted of an amino terminal secretion domain similar to that of AvrPphD fused to a potential protein tyrosine phosphatase domain [1].
• Taken together, these results show that PHS1, which encodes a dual-specificity PTP, is a negative regulator of ABA signalling [3].
• The phs1-3 mutation in a putative dual-specificity protein tyrosine phosphatase gene provokes hypersensitive responses to abscisic acid in Arabidopsis thaliana [3].

Anatomical context of PTP1

• Immunoprecipitates of Arabidopsis extracts with anti-ATMPK4 antibodies displayed myelin basic protein kinase activity that was sensitive to treatment with AtPTP1 [4].

Other interactions of PTP1

• Tyr dephosphorylation by the Arabidopsis Tyr-specific phosphatase AtPTP1 resulted in an almost complete loss of ATMPK4 activity [4].

Analytical, diagnostic and therapeutic context of PTP1

• Site-directed mutagenesis defined two highly conserved amino acids, cysteine-265 and aspartate-234, as being essential for the phosphatase activity of the AtPTP1 protein, suggesting a common catalytic mechanism for PTPases from all eukaryotic systems [2].

References