STRUCTURE OF THE HUMAN LC-PTP (HEPTP) GENE - SIMILARITY IN GENOMIC ORGANIZATION WITHIN PROTEIN-TYROSINE-PHOSPHATASE GENES

Recently, various cDNA sequences coding protein-tyrosine phosphatases (PTPs) have been reported and their extensive similarities in the cata lytic domains clarified, but knowledge of the structures and organizat ions of their genes is still limited. In this study, a detailed struct ure and organization of the human intracellular LC-PTP (also called He PTP) gene is reported. The 13 to 18.5 kb genomic clones encoding human LC-PTP have been isolated. The LC-PTP gene is organized into 11 exons , including the 5'-noncoding first exon and the 3'-noncoding exon. Spl icing sites for exons 4 to 10, which encode the conserved catalytic PT P domain, arise almost at the same position as for the CD45 gene. This elucidation of the LC-PTP gene structure provides insight into the do main evolution of intracellular LC-PTP and transmembrane CD45, which m ay be generated by gene duplications of an ancestral gene.