MOLECULAR-CLONING OF A NOVEL RECEPTOR-TYPE PROTEIN-TYROSINE-PHOSPHATASE FROM MURINE FETAL LIVER

A cDNA fragment encoding a novel tyrosine phosphatase (PTPase), termed ptpf, was isolated from day 11.5 mouse fetal liver using reverse tran scription-polymerase chain reaction (RT-PCR) with degenerate primers. The 5.5-kb cDNA encoding the complete coding region was isolated from an adult mouse kidney cDNA library. This cDNA contained a single open reading frame (ORF) encoding a predicted 1436-amino-acid protein with a molecular mass of 161 150 Da. Sequence analysis revealed that PTPf w as homologous to PTP mu and PTP kappa, and a putative receptor-type PT Pase. Northern blotting analysis of adult mouse mRNA indicated the exi stence of four major ptpf transcripts of approximately 10, 6, 3 and 2. 7 kb, and these transcripts were expressed in a tissue-specific manner . During embryogenesis, only the 6-kb transcript was detected. (C) 199 7 Elsevier Science B.V.