Developmentally regulated expression of a murine receptor-type protein tyrosine phosphatase in the thymus.
Reversible phosphorylation of tyrosine residues plays a crucial regulatory role in various cellular events, including differentiation and proliferation of lymphocytes. Here, we report the isolation of a murine receptor-type protein tyrosine phosphatase (PTP), mRPTP-sigma, which is expressed in both immature thymocytes and stroma cells. At least two alternatively spliced transcripts of mRPTP-sigma (T and B) were observed. mRPTP-sigma T was the dominant form in the thymus and had three Ig-like and eight fibronectin type III-like domains in the extracellular portion. mRPTP-sigma T was almost identical with RPTP-sigma/PTP NE-3/PTP-P1/CPTP1, a PTP recently cloned from rat brain, except that RPTP-sigma/PTP NE-3/PTP-P1 was about 400 amino acids shorter than mRPTP-sigma T. mRPTP-sigma B, the second form of mRPTP-sigma, was dominant in the brain and was most likely the murine counterpart of RPTP-sigma/PTP NE-3/PTP-P1. In the developing thymocytes, the expression of mRPTP-sigma was high in double negative (CD4-CD8-), low in double positive (CD4+CD8+), and marginal in single positive (SP; CD4+CD8- or CD4-CD8+) subpopulations. No upregulation of mRPTP-sigma was observed in the spleen cells stimulated with Con A. Developmental regulation of mRPTP-sigma expression suggests its involvement in the control of T lymphocyte differentiation.
Biomedical Research Center, Osaka University Medical School, Japan.
M
M
Ogata
M
M
Sawada
A
A
Kosugi
T
T
Hamaoka
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D016513:Mice, SCID; D008969:Molecular Sequence Data; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis* / Q000235:genetics; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000201:enzymology*; D013950:Thymus Gland / Q000166:cytology / Q000196:embryology / Q000254:growth & development
D017027:Protein Tyrosine Phosphatases; C516885:Ptprs protein, mouse; D054623:Receptor-Like Protein Tyrosine Phosphatases, Class 2