Chromokinesin Kid and kinetochore kinesin CENP-E differentially support chromosome congression without end-on attachment to microtubules.
Chromosome congression is the alignment of chromosomes at the spindle equator, and is a prerequisite for faithful chromosome segregation. Recent data suggest that before kinetochores attach to the end of microtubules (end-on attachment), chromosomes can move along microtubules towards the spindle equator through attachment of kinetochores to the lateral surface of microtubules (lateral attachment). Here we address this mechanism, focusing on the contribution of two mitotic motors, Kid and CENP-E. In cells depleted of Hec1, which is essential for end-on attachment, chromosomes show partial and transient congression. This transient congression is further perturbed by co-depletion of Kid, suggesting its role in chromosome congression. In comparison, CENP-E suppresses chromosome congression, probably by tethering kinetochores to short, unstable microtubules, and works in congression only when microtubules are stabilized. Our results may reflect the differential contributions of Kid and CENP-E in chromosome congression in physiological conditions where stabilized microtubules are becoming increased.
Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
Kenji
K
Iemura
Department of Molecular Oncology, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8575, Japan.
Kozo
0000000160862858
K
Tanaka
D000818:Animals; D015153:Blotting, Western; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D023902:Chromosome Pairing / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins / Q000378:metabolism*; D018386:Kinetochores / Q000502:physiology; D051379:Mice; D008870:Microtubules / Q000378:metabolism*; D020409:Molecular Motor Proteins / Q000378:metabolism*; D009841:Oligonucleotides / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D034622:RNA Interference; D018709:Statistics, Nonparametric
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; C098764:KIF22 protein, human; D020409:Molecular Motor Proteins; D009841:Oligonucleotides; C068688:centromere protein E; D016547:Kinesins