Molecular cloning and expression of a cDNA encoding a protein tyrosine phosphatase from mouse brain

A mouse brain cDNA library was screened with a radioisotope-labeled probe of human placental protein tyrosine phosphatase. The isolated clone (MBPTP1B) was found to contain an open reading frame of 1,296 nucleotides as well as 5' (709 nucleotides) and 3' (341 nucleotides) non-coding regions. This cDNA encodes a PTP of 432 amino acids having a mass of 49,563 daltons and exhibiting 83% and 93.5% sequence identity to that of human PTP1B and rat PTP1, respectively. The expression of the cDNA in yeast was identified by western blot analysis and PTP activity assay.