Title:
Membrane dynamics and Signal Transduction

Speaker:
Masahiro TAKAGI
School of Materials Science, Japan Advanced Institute of Science and Technology

Abstract:
Rafts are dynamic clusters composed largely of cholesterol and sphingolipids, which are rich in highly ordered saturated acyl chains. At heterogeneous biological membranes, microdomains are expected to function as platforms of endocytic carriers. Not only embedded and associated proteins but also the mechanical properties of the bilayer itself play an important role in controlling the shape of lipid-raft-derived vacuoles. Along these lines, giant multicomponent liposomes, raft-exhibiting model membranes, are efficient tools for studying the physicochemical properties of microdomains.

We have shown that some simple stimuli (osmosis, an enzyme, or detergents) may induce bud formation of raft domains in model membranes.  We showed interaction between Amyloid beta (Aβ) and model membrane.  Moreover, morphological changes might be related to the neurotoxicity in the pathology of Alzheimer's disease (AD). We used both liposomes and actual living cells for studies of dynamic movement of membrane structure.