Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo 153, Japan. akusumi@kusumib.c.u-tokyo.ac.jp
Single-particle tracking and laser tweezers have facilitated the observation of the mechanics of molecular interactions in the plasma membrane of living cells at the level of single (or a few) molecules at nanometer/piconewton precision. These techniques have recently revealed that the membrane skeleton provides both confining and binding effects on the movement of membrane proteins, and that it can play a pivotal role in the molecular organization of the plasma membrane, especially in the formation of special membrane domains.