A p65/p95 Neural Surface Receptor is Expressed at the S-G2 Phase of the Cell Cycle and Defines Distinct Populations |
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Authors: | Najet Rebai Guillermina Almazan Ling Wei Mark I. Greene H. Uri Saragovi |
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Affiliation: | Department of Pharmacology and Therapeutics, McGill University;McGill Cancer Center, Montreal, QC, Canada H3G 1Y6;Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104–6082, USA |
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Abstract: | A surface receptor complex of M r˜65 000 (p65) and ˜95 000 (p95) is expressed in cells of the central nervous system of mice. This receptor is recognized by monoclonal antibody 87.92.6 or by reovirus type 3 haemagglutinin as unnatural ligands. The p65/p95 receptor is expressed mostly in neural embryonic precursors undergoing proliferation, especially those in the S-G2 phase of the cell cycle. Receptor expression decreases progressively throughout embryogenesis to low but detectable levels in the adult brain. Biochemical characterization revealed that the neural p65/p95 receptor complex is indistinguishable from the p65/p95 receptor expressed in T cells, where receptor ligation leads to a mitogenic block. In neural and lymphoid tissues the p65/p95 receptor (or an associated protein) possesses a tyrosine kinase enzymatic activity. Receptor ligation in neural cells resulted in the rapid tyrosine phosphorylation of cellular proteins which are different from substrates phosphorylated in T cells. Differential substrate coupling to the receptor may account for differences in signal transduction and biology between neural cells and T cells. Further study of this receptor complex may help define important features of neural proliferation, differentiation and survival. |
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Keywords: | neural receptor brain development signal transduction mouse |
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