| First Author | Ohnishi H | Year | 1996 |
| Journal | J Biol Chem | Volume | 271 |
| Issue | 41 | Pages | 25569-74 |
| PubMed ID | 8810330 | Mgi Jnum | J:36295 |
| Mgi Id | MGI:83760 | Doi | 10.1074/jbc.271.41.25569 |
| Citation | Ohnishi H, et al. (1996) Activation of protein-tyrosine phosphatase SH-PTP2 by a tyrosine-based activation motif of a novel brain molecule. J Biol Chem 271(41):25569-74 |
| abstractText | BIT (a brain immunoglobulin-like molecule with tyrosine-based activation motifs) is a brain-specific membrane protein which has two cytoplasmic TAMs (tyrosine-based activation motifs). Using the Far Western blotting technique, we detected association of a 70-kDa protein with the tyrosine-phosphorylated TAMs of BIT. A mouse brain cDNA library in lambdagt11 was screened for this association, and two positive clones encoding tyrosine phosphatase SH-PTP2 were isolated. SH-PTP2 has two SH2 domains and is believed to function as a positive mediator in receptor tyrosine kinase signaling. SH-PTP2 and BIT were coimmunoprecipitated from phosphorylated rat brain lysate, and BIT was a major tyrosine-phosphorylated protein associated with SH-PTP2 in this lysate. This interaction was also observed in Jurkat T cells transfected with BIT cDNA depending on tyrosine phosphorylation of BIT. Bisphosphotyrosyl peptides corresponding to BIT-TAMs stimulated SH-PTP2 activity 33-35-fold in vitro, indicating that two SH2 domains of SH-PTP2 simultaneously interact with two phosphotyrosines of BIT-TAM. Our findings suggest that the tyrosine phosphorylation of BIT results in stimulation of the signal transduction pathway promoted by SH-PTP2 and that BIT is probably a major receptor molecule in the brain located just upstream of SH-PTP2. |
