Signaling triggered by Thy-1 interaction with ß3 integrin on astrocytes is an essential step towards unraveling neuronal Thy-1 function

• ANA MARIA AVALOS ^[1] ; CECILIA V. LABRA ^[1] ; ANDREW F.G. QUEST ^[1] ; LISSETTE LEYTON ^[1]
  1. [1] Universidad de Chile

     Universidad de Chile

     Santiago, Chile

     
• Localización: Biological Research, ISSN-e 0717-6287, ISSN 0716-9760, Vol. 35, Nº. 2, 2002, págs. 231-238
• Idioma: inglés
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• Resumen

  • Thy-1 is an abundant neuronal glycoprotein in mammals. Despite such prevalence, Thy-1 function remains largely obscure in the absence of a defined ligand. Recently described evidence that Thy-1 interacts with ß3 integrin on astrocytes will be discussed. Thy-1 binding to ß3 integrin triggers tyrosine phosphorylation of focal adhesion proteins in astrocytes, thereby promoting focal adhesion formation, cell attachment and spreading. Thy-1 has been reported to modulate neurite outgrowth by triggering a cellular response in neurons. However, our data indicate that Thy-1 can also initiate signaling events that promote adhesion of adjacent astrocytes to the underlying surface. Preliminary results suggest that morphological changes observed in the actin cytoskeleton of astrocytes as a consequence of Thy-1 binding is mediated by small GTPases from the Rho family. Our findings argue that Thy-1 functions in a bimodal fashion, as a receptor on neuronal cells and as a ligand for ß3 integrin receptor on astrocytes. Since Thy-1 is implicated in the inhibition of neurite outgrowth, signaling events in astrocytes are likely to play an important role in this process