Cloning and expression of two structurally distinct receptor-linked protein-tyrosine phosphatases generated by RNA processing from a single gene.
We describe here the first example of RNA processing generating two functional receptor-linked protein-tyrosine phosphatases (PTP) (protein-tyrosine-phosphate phosphohydrolase, EC 3.1.3.48) that are structurally distinct within their catalytic domains. Two cDNAs, PTP-P1 and PTP-PS, were isolated from rat pheochromocytoma cells, which encode two receptor-linked protein-tyrosine-phosphatases and are produced by alternative splicing and differential use of polyadenylation sites. Both cDNAs share an identical extracellular domain and a single transmembrane domain, but differ within their cytoplasmic regions: PTP-P1 contains two tandem repeated PTPase catalytic domains, whereas PTP-PS contains only the amino-terminal domain. Bacterial expression of PTPase domains of both cDNAs demonstrates that PTP-P1 and PTP-PS contain tyrosine-phosphatase activity. PTP-P1 is encoded by three transcripts of approximately 8, 6, and 4 kilobases, whereas PTP-PS is encoded by a single 4.8-kilobase transcript. PTP-P1 (6 kilobases) and PTP-PS are mainly expressed within the brain and in neuronal and endocrine cells. These data suggest that PTP-P1 and PTP-PS may be involved in neuronal function.
Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201-3098.
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D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D015723:Gene Library; D007700:Kinetics; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016716:PC12 Cells; D016133:Polymerase Chain Reaction / Q000379:methods; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000096:biosynthesis*; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid
D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D017027:Protein Tyrosine Phosphatases