Disease relevance of LTP1

• The yeast Ltp1 protein was expressed in Escherichia coli, purified to homogeneity, and shown to possess PTPase activity [1].
• For instance, the virulence determinant gene, yopH, of Yersinia pseudotuberculosis encodes a PTPase [2].

High impact information on LTP1

• This gene, LTP1, together with a neighboring gene, TKL1, is shown to be located on the right arm of chromosome XVI [1].
• In the case of adenine, the activity of Ltp1 was increased by approximately 30-fold [1].
• The low molecular weight protein-tyrosine phosphatase (low M(r) PTPase) is an 18-kDa cytoplasmic enzyme of unknown function that has been previously found in several vertebrates [1].
• The recombinant Ltp1 efficiently hydrolyzes phosphotyrosine and a phosphotyrosine-containing peptide, Tyr531-fyn, but it shows low activity toward phosphoserine and phosphothreonine [1].
• Small tyrosine phoshatase 1 (Stp1) is a Schizosaccharomyces pombe low-molecular-mass phosphotyrosine-phosphatase 50% identical to Saccharomyces cerevisiae Ltp1 [3].

Biological context of LTP1

• In the crystal of the inactive mutant of LTP1, one molecule has a pNPP in the active site, while the other has a phosphate ion [4].
• The in vivo tyrosine phosphorylation level of yeast immunophilin Fpr3 is influenced by the LMW-PTP Ltp1 [5].

Other interactions of LTP1

• Here we show the phosphatase activity of Ltp1 on Fpr3 and we demonstrated that Tyr 184 is the residue phosphorylated on in vivo Fpr3 [5].

Analytical, diagnostic and therapeutic context of LTP1

• Site-directed mutagenesis of two aromatic residues lining the active site pocket of the yeast Ltp1 [6].

References