The role of the kinesin-13 neck in microtubule depolymerization.
To ensure genetic integrity, replicated chromosomes must be accurately distributed to daughter cells-a process that is accomplished on the microtubule spindle. Kinesin-13 motors play an essential role in this process by performing regulated microtubule depolymerization. We set out to dissect the depolymerization mechanism of these kinesins, and in particular, the role of their conserved neck sequence. We used a monomeric kinesin-13 MCAK, consisting of the neck and motor core, which has strong depolymerizing activity. In the presence of a non-hydrolysable ATP analogue, this construct induced formation of rings around microtubules. The rings are built from tubulin protofilaments that are bent by the kinesin-13 motor engaged at the ATP-binding step of its ATPase cycle. Our data suggest that the ring-microtubule interaction is mediated by the neck and support the idea of a role for the kinesin-13 neck in depolymerization efficiency, acting by optimizing release of tubulin from microtubule ends.
Moores
Carolyn A
CA
School of Crystallography, Birkbeck College, London, UK.
Cooper
Jeremy
J
Wagenbach
Mike
M
Ovechkina
Yulia
Y
Wordeman
Linda
L
Milligan
Ronald A
RA
D000255:Adenosine Triphosphate / Q000737:chemistry; D000266:Adenylyl Imidodiphosphate / Q000737:chemistry; D002455:Cell Division / Q000502:physiology; D016547:Kinesins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008870:Microtubules / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism
D020409:Molecular Motor Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D014404:Tubulin; C490417:mitotic centromere-associated kinesin, hamster; D000266:Adenylyl Imidodiphosphate; D000255:Adenosine Triphosphate; D016547:Kinesins