Characterization of rat receptor-like protein tyrosine phosphatase gamma isoforms.
We identified four isoforms of receptor-like protein tyrosine phosphatase gamma (RPTPgamma) from rat brain by cDNA cloning. We designated these molecules RPTPgamma-A, -B, -C, and -S. RPTPgamma-A was the longest form and had the same structure as human and mouse RPTPgamma. RPTPgamma-B lacked the intracellular juxtamembrane 29 amino acids of RPTPgamma-A. RPTPgamma-C had a single phosphatase domain. RPTPgamma-S is an extracellular variant of RPTPgamma. mRNAs of the four isoforms were expressed in the brain, kidney, lung, and heart. Transfection of RPTPgamma-A and -S expression plasmids into COS7 cells resulted in the expression of membrane-bound 190-kDa proteins and secreted 120-kDa proteins, respectively. These molecules were similar to PTPzeta/RPTPbeta with regard not only to structure but also to the presence of both secretory and transmembrane forms. However, RPTPgamma isoforms were not expressed as proteoglycans.
Shintani
T
T
Division of Molecular Neurobiology, National Institute for Basic Biology, and Department of Molecular Biomechanics, The Graduate University for Advanced Studies, Okazaki, Japan.
Maeda
N
N
Nishiwaki
T
T
Noda
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000201:enzymology*; D019556:COS Cells; D002462:Cell Membrane / Q000201:enzymology; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D014644:Genetic Variation; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis* / Q000737:chemistry; D007668:Kidney / Q000201:enzymology; D008168:Lung / Q000201:enzymology; D051379:Mice; D008969:Molecular Sequence Data; D009206:Myocardium / Q000201:enzymology; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000737:chemistry; D016133:Polymerase Chain Reaction; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis* / Q000737:chemistry; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000737:chemistry; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014162:Transfection
D017931:DNA Primers; D018076:DNA, Complementary; D007527:Isoenzymes; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C516850:PTPRG protein, human; D017027:Protein Tyrosine Phosphatases; C516851:Ptprg protein, mouse; C516852:Ptprg protein, rat; D054633:Receptor-Like Protein Tyrosine Phosphatases, Class 5