The N-terminal and C-terminal domains of a receptor tyrosine phosphatase are associated by non-covalent linkage.
We have cloned the rat homolog of the human leukocyte common antigen-related gene (LAR), which encodes a transmembrane receptor phosphotyrosine phosphatase, and raised antibodies against its protein product. We present evidence here for a processing event resulting in a two-chain structure of the mature receptor on the cell surface. The LAR protein is synthesized as a 190-kDa precursor which is subsequently cleaved into 145-kDa and 85-kDa fragments. The 145-kDa fragment, representing the amino terminus of the protein, is exclusively extracellular and is modified by N-linked glycosylation. The 85-kDa component, derived from the C-terminus of the protein, contains the transmembrane region and intracellular phosphotyrosine phosphatase domains. The two products, associated in a non-covalent manner, comprise the functional LAR cell-surface receptor.
Yu
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Whitehead Institute for Biomedical Research, Department of Biology, MIT, Cambridge 02142.
Lenardo
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Weinberg
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D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D015723:Gene Library; D006031:Glycosylation; D007106:Immune Sera; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D011247:Pregnancy; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D051381:Rats; D054630:Receptor-Like Protein Tyrosine Phosphatases, Class 4; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
D015342:DNA Probes; D007106:Immune Sera; D010455:Peptides; D011956:Receptors, Cell Surface; D004247:DNA; C516841:PTPRA protein, human; D017027:Protein Tyrosine Phosphatases; C516845:Ptpra protein, rat; D054630:Receptor-Like Protein Tyrosine Phosphatases, Class 4