CHARACTERIZATION AND GENOMIC MAPPING OF GENES AND PSEUDOGENES OF A NEW HUMAN PROTEIN-TYROSINE-PHOSPHATASE

Previously described protein tyrosine phosphatases (PTPs) are classifi ed into three types according to their sequence homology and structura l features, Here we describe the characterization of genes and pseudog enes of a member of a fourth type of PTP, designated protein tyrosine phosphatase 4A (PTP4A). The 167-amino-acid human PTP4A bears the signa ture active site of all PTPs, but does not show any other sequence hom ology to any of the previously described PTPs, Two cDNAs encoding PTP4 A that differed in their noncoding regions were isolated, Another cDNA that has a high level of sequence identity with these two cDNAs and a deletion in the coding region was also isolated, Northern analysis us ing a probe from a common 3'-untranslated region of the cDNAs recogniz ed mRNAs of about 2 and 4 hb, Both species of mRNA were seen in all hu man adult and fetal tissues tested. Fluorescence in situ hybridization mapping of the corresponding yeast artificial chromosome clones and s equence-tagged site analysis suggested that one of the PTP4A coding ge nes is located at 1p35 and the other is on chromosome 11, A processed pseudogene for PTP4A was found in the BRCA1 region of 17q21 and shares 96% sequence identity to one of the PTP4A coding cDNAs. Our studies a lso suggest the existence of another processed pseudogene on chromosom e 11. (C) 1996 Academic Press, Inc.