Isolation and characterization of murine orthologue of PTP-BK.
We isolated and characterized a murine orthologue of PTP-BK, a receptor-type protein tyrosine phosphatase expressed in brain and kidney. The deduced amino acid sequences showed 89, 95, and 92% identities with human, rabbit, and chicken homologues of PTP-BK. Mouse PTP-BK encodes a polypeptide of 1,226 amino acids with calculated molecular weight of 138,598 Da. The mature form of PTP-BK constitutes of 3 domain structures including extracellular, transmembrane, and a single intracellular PTPase domain. Western blot analysis indicated that anti-PTP-BK antibody specifically immunoreacted to 2 distinct molecules of 200 kDa and 220 kDa in COS cells, possibly due to differential glycosylation. The recombinant PTP-BK showed the phosphatase activity specific for the phosphotyrosine, but not for the phosphoserine residue of phosphopeptides in vitro. Radiation hybrid panel assigned mouse PTP-BK gene to 5.02cR distal to from the marker D6Mit339 on chromosome 6. Mouse PTP-BK was classified in PTPRO family in novel nomenclature. We discuss here the diversity and physiological functions of PTPRO family of PTP.
Tomemori
T
T
Department of Molecular Genetics, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.
Seki
N
N
Suzuki
Y
Y
Shimizu
T
T
Nagata
H
H
Konno
A
A
Shirasawa
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D019556:COS Cells; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics; D003001:Cloning, Molecular; D019143:Evolution, Molecular; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D019000:Phosphotyrosine / Q000378:metabolism; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D017027:Protein Tyrosine Phosphatases / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D021101:Radiation Hybrid Mapping; D016415:Sequence Alignment; D017385:Sequence Homology; D009626:Terminology as Topic; D014162:Transfection
D019000:Phosphotyrosine; D017027:Protein Tyrosine Phosphatases