MCAK, a Kin I kinesin, increases the catastrophe frequency of steady-state HeLa cell microtubules in an ATP-dependent manner in vitro.
Mitotic-centromere-associated kinesin (MCAK) is a member of the KIN I (internal motor domain) subfamily of kinesin related proteins. MCAK and its homologues destabilize microtubules both in cells and in vitro. Here, we analyzed the effects of MCAK in the presence and absence of ATP on the dynamic instability behavior of steady state microtubules assembled from purified HeLa cell tubulin. In the presence of ATP, substoichiometric levels of full length MCAK and a segment (A182) consisting of the motor and neck domains strongly increased the catastrophe frequency of the microtubules. These data demonstrate that MCAK is a microtubule-catastrophe promoting factor in vitro, and support the hypothesis that MCAK may serve as a catastrophe-promoting factor in cells.
Department of Molecular, Cellular, and Developmental Biology, and The Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA.
Cori N
CN
Newton
Michael
M
Wagenbach
Yulia
Y
Ovechkina
Linda
L
Wordeman
Leslie
L
Wilson
D000255:Adenosine Triphosphate / Q000378:metabolism*; D003001:Cloning, Molecular; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D007700:Kinetics; D008870:Microtubules / Q000201:enzymology* / Q000473:pathology; D011994:Recombinant Proteins / Q000378:metabolism
C091489:KIF2C protein, human; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D016547:Kinesins