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 transcription-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 was homologous to PTPmu and PTPkappa, and a putative receptor-type PTPase. Northern blotting analysis of adult mouse mRNA indicated the existence 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.