Identification and characterization of RPTP ρ, a novel RPTP μ/ κ-like receptor protein tyrosine phosphatase whose expression is restricted to the central nervous system

• Published in: Brain research. Molecular brain research. 1998-05, Vol.56 (1), p.9-21
• Main Authors: McAndrew, P.E, Frostholm, A, White, R.A, Rotter, A, Burghes, A.H.M
• Format: Article
• Language: English
• Subjects: Adult; Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Biochemistry and metabolism; Biological and medical sciences; Blotting, Northern; Brain - metabolism; Cell adhesion; Central nervous system; Chromosome Mapping; Cloning, Molecular; Dephosphorylation; Development; Fundamental and applied biological sciences. Psychology; Humans; In Situ Hybridization; Mice; Mice, Inbred C57BL; Molecular Sequence Data; Mouse; Nerve Tissue Proteins - chemistry; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - isolation & purification; Phosphorylation; Protein Tyrosine Phosphatases - metabolism; Protein-Tyrosine Kinases - chemistry; Protein-Tyrosine Kinases - genetics; Receptor-Like Protein Tyrosine Phosphatases, Class 2; Receptors, Cell Surface - metabolism; Spinal Cord - metabolism; Vertebrates: nervous system and sense organs
• ISSN: 0169-328X; 1872-6941
• DOI: 10.1016/S0169-328X(98)00014-X

We describe the cloning, chromosomal localization and characterization of RPTP ρ, a new member of the RPTP μ/ κ phosphatase subfamily. Receptor tyrosine phosphatases in this subfamily are comprised of a MAM domain near the N-terminal, an immunoglobulin-like domain, four fibronectin type III repeats, a single transmembrane domain, and a large juxtamembrane segment followed by two intracellular phosphatase domains. An alternatively spliced mini-exon was identified in the extracellular segment of RPTP ρ, between the fourth fibronectin type III repeat and the transmembrane domain. The RPTR ρ gene was mapped to human chromosome 20 and mouse chromosome 2. Northern blot analysis demonstrated that RPTP ρ expression was restricted to the central nervous system, and in situ hybridization studies showed that the RPTP ρ transcript was distributed throughout the murine brain and spinal cord. Exceptionally high levels of the transcript were present in the cortex and olfactory bulbs during perinatal development, but were down-regulated during postnatal week two. The motifs found in the extracellular segment of type II receptor protein tyrosine phosphatases are commonly found in neural cell adhesion molecules, suggesting that RPTP ρ may be involved in both signal transduction and cellular adhesion in the central nervous system.