研究内容

スライドショー(研究紹介)

Slide Show 1 The Membrane Skeleton "Fence (Corral)" Model. Single molecule observations of the dynamics of transmembrane proteins have revealed that the plasma membrane is compartmentalized with regard to translational diffusion of transmembrane proteins. Optical trap experiments and high-resolution single particle tracking observations in the presence and absence of reagents that modulate the membrane skeleton, with and without modulations of the cytoplasmic domains of the transmembrane proteins, indicated that the compartment boundaries are made of the membrane skeleton. In this "fence" model, the cytoplasmic domains of the transmembrane proteins collide with the actin-based membrane skeleton, inducing temporary confinement of the transmembrane proteins in the membrane skeleton mesh. The biological significance of the membrane skeleton is also discussed.
Slide Show 2 The Anchored-Protein "Picket" Model. We found that even phospholipids are corralled by the membrane skeleton by way of transmembrane proteins anchored to the membrane skeleton. This was found by carrying out single particle tracking at a time resolution as high as 25 μs (the effect of gold particles on lipid diffusion turned out to be very small as we compared single molecule dynamics of Cy3-tagged lipid with that of gold-tagged lipids). 　The compartment boundaries do not have to be totally closed off by the transmembrane proteins anchored to the membrane skeleton for temporary confinement of lipids within a compartment. Our Monte Carlo simulations showed that when only 20-30% of the boundary is occupied by these anchored transmembrane proteins, they induced temporary confinement like that observed in our single molecule experiments. This is due to the hydrodynamic-like friction effect (or ordering effect) of immobile proteins that would extend from the protein surface over the distance of about the diameter of the transmembrane protein.
Slide Show 3 The Diffusion Barrier in the Neuronal Cell Membrane. This slide show is based on the talks given by Dr. Chieko Nakada, a post doc in our lab, in several occasions.
Slide Show 3 一分子観察・操作法による 神経細胞膜における拡散障壁の形成機構の研究 本研究室に所属する、日本学術振興会特別研究員の中田千枝子さんが、いくつかのシンポジウムで話した内容をまとめたものです。
Slide Show 4 Three-dimensional reconstruction of the membrane skeleton at the plasma membrane … This slide show is based on the presentation given by Dr. Nobuhiro Morone, who is now Group Leader at the National Center for Neurology and Psychiatry in various occasions.The Membrane-skeleton fence and anchored transmembrane-protein picket models shown in the Slide Shows 1 and 2 have now a strong support from the results of electron tomography of the membrane skeleton, shown in this Slide Show 4.
ページの上へ