RESUMEN
The leucocyte surface glycosylphosphatidylinositol (GPI)-anchored membrane proteins are localized within specific membrane microdomains which also contain specific (glyco)lipids and intracellular proteins including protein kinases. These "GPI-domains" are devoid of most abundant transmembrane proteins, but in T-cells they appear to contain small amounts of CD4 and CD8 and in B-cell lines, small amounts of CD10. The existence of these relatively detergent-resistant membrane microdomains explains the signal-transducing ability of GPI-anchored receptors. In addition to the "GPI-microdomains", several other types of analogous very large detergent-resistant complexes/domains appear to exist, such as those containing T-cell receptor, others containing CD45R molecules associated with a protein kinase, and still others composed mainly of several proteins of the tetraspan family. Therefore, we suggest that the leucocyte surface is a mosaic of microdomains of unique composition associated with specific signal-transducing molecules.
Asunto(s)
Antígenos CD/análisis , Antígenos de Superficie/análisis , Glicosilfosfatidilinositoles/química , Leucocitos/química , Glicoproteínas de Membrana/análisis , Antígenos CD/química , Antígenos de Superficie/química , Linfocitos B/química , Linfocitos B/inmunología , Glicosilfosfatidilinositoles/biosíntesis , Humanos , Leucocitos/inmunología , Glicoproteínas de Membrana/química , Linfocitos T/química , Linfocitos T/inmunologíaRESUMEN
The leucocyte surface glycosylphosphatidylinositol (GPI)-anchored membrane proteins are localized within specific membrane microdomains which also contain specific (glyco)lipids and intracellular proteins including protein kinases. These "GPI-domains" are devoid of most abundant transmembrane proteins, but in T-cells they appear to contain small amounts of CD4 and CD8 and in B-cell lines, small amounts of CD10. The existence of these relatively detergent-resistant membrane microdomains explains the signal-transducing ability of GPI-anchored receptors. In addition to the "GPI-microdomains", several other types of analogous very large detergent-resistant complexes/domains appear to exist, such as those containing T-cell receptor, others containing CD45R molecules associated with a protein kinase, and still others composed mainly of several proteins of the tetraspan family. Therefore, we suggest that the leucocyte surface is a mosaic of microdomains of unique composition associated with specific signal-transducing molecules