Movement of axoplasmic organelles on actin filaments from skeletal muscle

摘要: It was recently shown that, in addition to the well-established microtubule-dependent mechanism, fast transport of organelles squid giant axons also occurs presence actin filaments [Kuznetsov et al., 1992, Nature 356:722-725]. The objectives this study were obtain direct evidence axoplasmic organelle movement on and demonstrate that these are able move skeletal muscle filaments. Organelles visualized by video-enhanced contrast differential interference (AVEC-DIC) microscopy video intensified fluorescence microscopy. Actin filaments, prepared polymerization monomeric purified from rabbit muscle, stabilized with rhodamine-phalloidin adsorbed cover slips. When axoplasm extruded slips buffer containing cytochalasin B prevents formation endogenous axonal observed at rate. Also, bundles sufficient thickness be detected directly AVEC-DIC range average velocities not statistically different level motile activity (number moving/min/field) exogenous less than probably due entanglement slip surface. We found calmodulin (CaM) increased In addition, CaM stimulated elongated membranous appeared tubular elements smooth endoplasmic reticulum or extensions prelysosomes. These studies provide first higher animal cells such as neurons biochemically defined © 1994 Wiley-Liss, Inc.