Structure and function of lipid rafts; investigating the role of membrane microdomains in cellular signalling

Biological membranes are no longer considered as homogenous fluid structures with embedded proteins; rather, the have been shown to contain microdimains or lipid rafts that function as platforms for co-ordination, organisation adn assembly of proteins inv olved in cellular processes such as signal transduction pathways. An investigation of the properties of these lipid rafts will be carried out, using molecular biology in combination with microscopy techniques. Thes study will focus on rvealing mechanism s that regulate phase separation, raft size and stability, using both artificial double layers as well as isolated cell membrane fractions. Of particular interest to this study is the raft concentration of signalling molecules belonging to the cAMP pathwa y. A protein of this pathway, Csk , serves as a gaekeeper for T cell activation. Csk is activated by protein kinase A and is targeted to lipid rafts via binding to the 80-kDa tyrosine phoshporylated molecule Cbp. It is hoped to fio