Cytoplasmic dynein is a minus end-directed motor for membranous organelles.
The role of cytoplasmic dynein in microtubule-based organelle transport was examined using a reconstituted assay developed from chick embryo fibroblasts. Factors present in a high-speed cytosol caused the movement of purified organelles on microtubules predominantly in the minus end direction. Inactivation of cytoplasmic dynein in the high-speed cytosol by vanadate-mediated UV photocleavage inhibited minus end-directed organelle motility by over 90%. Addition of purified cytoplasmic dynein to the inactive cytosol restored minus end-directed organelle motility, although purified cytoplasmic dynein by itself did not support organelle movement. We propose that cytoplasmic dynein is the motor for minus end-directed organelle movement, but that additional cytosolic factors are also required to produce organelle motility.
Schroer
T A
TA
Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110.
Steuer
E R
ER
Sheetz
M P
MP
D000251:Adenosine Triphosphatases / Q000502:physiology*; D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000166:cytology; D002642:Chick Embryo; D003593:Cytoplasm / Q000032:analysis / Q000648:ultrastructure; D004398:Dyneins / Q000032:analysis / Q000302:isolation & purification / Q000502:physiology*; D005347:Fibroblasts / Q000166:cytology / Q000648:ultrastructure; D007425:Intracellular Membranes / Q000032:analysis / Q000502:physiology; D008970:Molecular Weight; D015388:Organelles / Q000032:analysis / Q000378:metabolism / Q000502:physiology; D014466:Ultraviolet Rays
D000251:Adenosine Triphosphatases; D004398:Dyneins