A novel receptor-type protein tyrosine phosphatase with a single catalytic domain is specifically expressed in mouse brain.
Protein tyrosine phosphatases (PTPases) are important regulatory proteins that, together with protein tyrosine kinases, determine the phosphotyrosine levels in cell signalling proteins. By PCR amplification of mouse brain cDNA fragments encoding the catalytic domains of these enzymes, we identified three novel members of the PTPase gene family. Northern-blot analysis showed that two of these novel clones represent brain-specific PTPases, whereas the third originates from a large-sized mRNA that is more ubiquitously expressed. A full-length cDNA encoding one of the brain-specific PTPases, PTP-SL, was isolated. Sequence analysis revealed a transmembrane PTPase containing a single catalytic phosphatase domain that has 45% homology to a rat cytoplasmic brain-specific PTPase named STEP. This suggests a role for PTP-SL in cell-cell signalling processes in the brain.
Department of Cell Biology and Histology, University of Nijmegen, The Netherlands.
W
W
Hendriks
J
J
Schepens
C
C
Brugman
P
P
Zeeuwen
B
B
Wieringa
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D015152:Blotting, Northern; D001921:Brain / Q000201:enzymology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005982:Glutathione Transferase / Q000096:biosynthesis / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D054634:Receptor-Like Protein Tyrosine Phosphatases, Class 7; D011956:Receptors, Cell Surface / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D017027:Protein Tyrosine Phosphatases; C513472:Ptprr protein, mouse; C513471:Ptprr protein, rat; D054634:Receptor-Like Protein Tyrosine Phosphatases, Class 7