ACTIN-BASED ORGANELLE MOVEMENT

Evidence for actin-dependent organelle movement was first obtained fro m studies of cytoplasmic streaming in plants. These studies, together with cell-free organelle motility studies and biophysical analyses of muscle myosin, support a model whereby organelle-associated motor mole cules utilize the energy of adenosine triphosphate binding and hydroly sis to drive movement along F-actin tracks. Recent studies indicate th at this mechanism for organelle movement may be responsible for organe lle and vesicle movement during secretion, endocytosis and mitochondri al inheritance in a variety of eukaryotes.