José M. Musacchio

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The protein tyrosine kinase PYK2, which is highly expressed in the central nervous system, is rapidly phosphorylated on tyrosine residues in response to various stimuli that elevate the intracellular calcium concentration, as well as by protein kinase C activation. Activation of PYK2 leads to modulation of ion channel function and activation of the MAP(More)
We show that GGF/neuregulin is a mitogen for prooligodendrocytes (O4+/O1- cells), oligodendrocytes (O4+/O1+ cells), and type-2 astrocytes. Heregulin beta 1, another neuregulin isoform, is also mitogenic. The proliferative effect of glial growth factor (GGF) does not require, but is greatly potentiated by, serum factors. GGF also promotes the survival of(More)
In situ hybridization and Northern analysis demonstrate that the three splicing variants of RPTP-beta have different spatial and temporal patterns of expression in the developing brain. The 9.5-kb and 6.4-kb transcripts, which encode transmembrane protein tyrosine phosphatases with different extracellular domains, are predominantly expressed in glial(More)
We describe a new member of the receptor protein tyrosine phosphatase family, R-PTP-kappa, cDNA cloning predicts that R-PTP-kappa is synthesized from a precursor protein of 1,457 amino acids. Its intracellular domain displays the classical tandemly repeated protein tyrosine phosphatase homology, separated from the transmembrane segment by an(More)
Dextromethorphan (DM), a non-narcotic antitussive with anticonvulsant activity, binds to high (Kd, 57 nM)- and low-affinity sites (Kd, 24 microM) in the guinea pig brain. This work, done at physiological pH, expands previous results obtained at pH 8.3. Phenytoin (PHT) produces an allosteric increase in the binding of [3H]DM, which is more marked than that(More)
A novel transmembrane receptor protein tyrosine phosphatase-sigma (RPTP-sigma) was cloned from a rat brain stem cDNA library. The extracellular segment of one form of RPTP-sigma contains 824 amino acids and is composed of three immunoglobulin-like and five fibronectin type III (FNIII)-like repeats. The 627-amino acid cytoplasmic region of RPTP-sigma(More)
Dextromethorphan (DM), a non-narcotic antitussive, binds in the guinea pig brain to specific high- and low-affinity sites with Kd values of 57 nM and 24 microM, respectively (Musacchio et al., 1988). The antitussives carbetapentane, caramiphen, butamirate and dimethoxanate competed with the high-affinity binding of [3H]DM at pH 7.4 with nanomolar Ki values.(More)
Analysis of the localization of receptor-type protein tyrosine phosphatase-beta (RPTP-beta) by in situ hybridization and immunocytochemistry indicates that it is predominantly expressed in the developing central nervous system (CNS). RPTP-beta is highly expressed in radial glia and other forms of glial cells that play an important role during development.(More)