Characterization of the sea-urchin egg microtubule-activated ATPase.
We have found that cytoplasmic extracts from unfertilized sea-urchin eggs contain a prominent microtubule-activated ATPase activity. This activity is induced by polymeric tubulin, but not by tubulin subunits. The activity cosediments with taxol-stabilized microtubules in an ATP-independent manner. We have separated the ATPase from cytoplasmic dynein and other ATPases on sucrose gradients. The sedimentation, enzymic and microtubule-binding properties of the microtubule-activated species show it to be distinct from cytoplasmic dynein, myosin and kinesin. Since the major function of microtubules in the early sea-urchin embryo is in mitosis, this enzyme represents a new candidate for a role in spindle motility.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D003593:Cytoplasm / Q000201:enzymology; D004789:Enzyme Activation; D008870:Microtubules / Q000502:physiology*; D008954:Models, Biological; D010063:Ovum / Q000201:enzymology*; D012617:Sea Urchins; D014404:Tubulin / Q000502:physiology
D014404:Tubulin; D000251:Adenosine Triphosphatases