Molecular cloning and chromosome mapping of the human gene encoding protein phosphotyrosyl phosphatase 1B.

The inactivation of growth suppressor genes appears to play a major role in the malignant process. To assess whether protein phosphotyrosyl phosphatases (protein-tyrosine-phosphate phosphohydrolase, EC 3.1.3.48) function as growth suppressors, we have isolated a cDNA clone encoding human protein phosphotyrosyl phosphatase 1B for structural and functional characterization. The translation product deduced from the 1305-nucleotide open reading frame predicts a protein containing 435 amino acids and having a molecular mass of 49,966 Da. The amino-terminal 321 amino acids deduced from the cDNA sequence are identical to the empirically determined sequence of protein phosphotyrosyl phosphatase 1B. Charbonneau, H., Tonks, N. K., Kumar, S., Diltz, C. D., Harrylock, M., Cool, D. E., Krebs, E. G., Fischer, E. H. & Walsh, K. A. (1989) Proc. Natl. Acad. Sci. USA 86, 5252-5256. A genomic clone has been isolated and used in an in situ hybridization to banded metaphase chromosomes to determine that the gene encoding protein phosphotyrosyl phosphatase 1B maps as a single-copy gene to the long arm of chromosome 20 in the region q13.1-q13.2.