Molecular control of kinetochore-microtubule dynamics and chromosome oscillations.
Chromosome segregation in metazoans requires the alignment of sister kinetochores on the metaphase plate. During chromosome alignment, bioriented kinetochores move chromosomes by regulating the plus-end dynamics of the attached microtubules. The bundles of kinetochore-bound microtubules alternate between growth and shrinkage, leading to regular oscillations along the spindle axis. However, the molecular mechanisms that coordinate microtubule plus-end dynamics remain unknown. Here we show that centromere protein (CENP)-H, a subunit of the CENP-A nucleosome-associated and CENP-A distal complexes (CENP-A NAC/CAD), is essential for this coordination, because kinetochores lacking CENP-H establish bioriented attachments but fail to generate regular oscillations, as a result of an uncontrolled rate of microtubule plus-end turnover. These alterations lead to rapid erratic movements that disrupt metaphase plate organization. We also show that the abundance of the CENP-A NAC/CAD subunits CENP-H and CENP-I dynamically change on individual sister kinetochores in vivo, because they preferentially bind the sister kinetochore attached to growing microtubules, and that one other subunit, CENP-Q, binds microtubules in vitro. We therefore propose that CENP-A NAC/CAD is a direct regulator of kinetochore-microtubule dynamics, which physically links centromeric DNA to microtubule plus ends.
Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH) Zurich, CH-8093 Zurich, Switzerland.
Ana C
AC
Amaro
Catarina P
CP
Samora
René
R
Holtackers
Enxiu
E
Wang
Isabel J
IJ
Kingston
Maria
M
Alonso
Michael
M
Lampson
Andrew D
AD
McAinsh
Patrick
P
Meraldi
D001324:Autoantigens / Q000378:metabolism; D015374:Biosensing Techniques; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D020090:Chromosome Segregation; D002877:Chromosomes, Human / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000378:metabolism*; D008677:Metaphase / Q000235:genetics; D018613:Microscopy, Confocal; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D034622:RNA Interference; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D013997:Time Factors; D014162:Transfection; D014404:Tubulin / Q000378:metabolism
D001324:Autoantigens; C000619700:CENPA protein, human; C121933:CENPH protein, human; C484297:CENPI protein, human; D018797:Cell Cycle Proteins; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D014404:Tubulin