The mitotic kinesin CENP-E is a processive transport motor.
In vivo studies suggest that centromeric protein E (CENP-E), a kinesin-7 family member, plays a key role in the movement of chromosomes toward the metaphase plate during mitosis. How CENP-E accomplishes this crucial task, however, is not clear. Here we present single-molecule measurements of CENP-E that demonstrate that this motor moves processively toward the plus end of microtubules, with an average run length of 2.6 +/- 0.2 mum, in a hand-over-hand fashion, taking 8-nm steps with a stall force of 6 +/- 0.1 pN. The ATP dependence of motor velocity obeys Michaelis-Menten kinetics with K(M,ATP) = 35 +/- 5 muM. All of these features are remarkably similar to those for kinesin-1-a highly processive transport motor. We, therefore, propose that CENP-E transports chromosomes in a manner analogous to how kinesin-1 transports cytoplasmic vesicles.
Yardimci
Hasan
H
Department of Physics and Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
van Duffelen
Marilyn
M
Mao
Yinghui
Y
Rosenfeld
Steven S
SS
Selvin
Paul R
PR
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000378:metabolism*; D016547:Kinesins / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism*; D008938:Mitosis; D014981:Xenopus
D002868:Chromosomal Proteins, Non-Histone; C068688:centromere protein E; D000255:Adenosine Triphosphate; D016547:Kinesins