Glycosphingolipid-enriched membrane

Receptor desensitisation, initiated by phosphorylation of the receptor, can be subsequently followed by receptor internalisation via multiple methods including clathrin-coated pits and/or lipid rafts/caveolae. Clathrin-coated pits are specialized regions of the cell surface that mediates the internalisation of the most of GPCRs to endosomes. Lipid rafts are planar domains in cell membranes that are enriched in specific lipid and proteins with an high content of cholesterol and glycosphingolipid (Chini and Parenti 2004). Caveolae are flask-shaped invaginations located at or near the plasma membrane and are considered a non-planar subfamily of lipid rafts (Ferguson 2001 Chini and Parenti 2004). 

Integrins associate with the membrane protein caveolin.34 Although little is yet known about this particular interaction, it could assist in forming integrin clusters at the plasma membrane which might serve as a scaffold for the assembly of multi-component signalling complexes. This possibility is attractive, because caveolin binds cholesterol and glycosphingolipids and forms membrane rafts , enriched in myristoylated and palmitoy-lated Src-family kinases (Chapter 8).35... 

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