2017/01/23
Keio University
Project Assistant Professor Eiji Yamamoto and Project Associate Professor Takuma Akimoto of the Graduate School of Science and Technology, Keio University, and Professor Kenji Yasuoka of the Faculty of Science and Technology, in collaboration with Academic Fellow Antreas C. Kalli of the University of Leeds and Professor Mark S. P. Sansom of the University of Oxford, have discovered that peripheral membrane proteins diffusing on the surface of biological membranes not only remain on the membrane by binding to specific lipid molecules called phosphatidylinositol phosphates (PIPs), but also that the diffusivity of the proteins changes over time depending on the strength of their binding to PIPs.
In cells, various types of proteins and lipid molecules interact with each other on biological membranes to transmit information into and out of the cell to maintain cellular functions. When this signal transduction mechanism fails to function properly, it can lead to various diseases such as cancer, diabetes, neurological disorders, and immunodeficiency. The diffusion of proteins on biological membranes is crucial for finding their interacting protein partners and is strongly influenced by the spatiotemporally complex and changing biological membrane. Through large-scale molecular simulations, the team investigated the temporal changes in the diffusivity of peripheral membrane proteins on the surface of biological membranes. They discovered that the diffusivity of the proteins fluctuates depending on the number of PIPs bound to them, resulting in heterogeneous diffusion. Furthermore, these findings suggest that PIPs not only act as anchors for proteins to stay on the membrane surface but may also regulate interactions between proteins on the biological membrane by controlling the diffusivity of their binding partners, thereby contributing to the efficiency of biological reactions. This has revealed a new biological function.
The results of this research were published in the American scientific journal Science Advances on January 20, 2017 (local time).
Please see below for the full press release.