Figure 9.
Model of fatty acylation-dependent membrane localization. The model depicts the localization of acylated GFPs with cholesterol and sphingolipid-enriched membrane microdomains (CSMs, dotted area). All three types of membrane association signal combinations (myristoylation plus palmitoylation: YesGFP; myristoylation plus polybasic region: Src16GFP; and dual palmitoylation plus polybasic region: GAP-43GFP) showed similar localization at the plasma membrane. Acylated full-length Yes PTK is shown in the cholesterol- and sphingolipid-enriched detergent-resistant membrane fraction (DRM, hatched area). Yes PTK is depicted in a DRM separate from DRMs containing caveolin, right (because Yes PTK and caveolin do not colocalize). Protein-protein interactions (represented by association with the unidentified orange protein) are believed to mediate Yes PTK association with the DRM core. For simplicity, lipid rafts present in endosomal or Golgi structures are not illustrated. Models of various lipid raft membrane constituents are shown in the legend at right.