Kinetochore alignment within the metaphase plate is regulated by centromere stiffness and microtubule depolymerases.
During mitosis in most eukaryotic cells, chromosomes align and form a metaphase plate halfway between the spindle poles, about which they exhibit oscillatory movement. These movements are accompanied by changes in the distance between sister kinetochores, commonly referred to as breathing. We developed a live cell imaging assay combined with computational image analysis to quantify the properties and dynamics of sister kinetochores in three dimensions. We show that baseline oscillation and breathing speeds in late prometaphase and metaphase are set by microtubule depolymerases, whereas oscillation and breathing periods depend on the stiffness of the mechanical linkage between sisters. Metaphase plates become thinner as cells progress toward anaphase as a result of reduced oscillation speed at a relatively constant oscillation period. The progressive slowdown of oscillation speed and its coupling to plate thickness depend nonlinearly on the stiffness of the mechanical linkage between sisters. We propose that metaphase plate formation and thinning require tight control of the state of the mechanical linkage between sisters mediated by centromeric chromatin and cohesion.
Jaqaman
Khuloud
K
Marine Biological Laboratory, Woods Hole, MA 02543, USA.
King
Emma M
EM
Amaro
Ana C
AC
Winter
Jennifer R
JR
Dorn
Jonas F
JF
Elliott
Hunter L
HL
McHedlishvili
Nunu
N
McClelland
Sarah E
SE
Porter
Iain M
IM
Posch
Markus
M
Toso
Alberto
A
Danuser
Gaudenz
G
McAinsh
Andrew D
AD
Meraldi
Patrick
P
Swedlow
Jason R
JR
D001324:Autoantigens / Q000235:genetics / Q000378:metabolism; D001681:Biological Assay / Q000379:methods; D002503:Centromere / Q000737:chemistry / Q000378:metabolism*; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004548:Elasticity; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins / Q000235:genetics / Q000378:metabolism; D018386:Kinetochores / Q000378:metabolism*; D008677:Metaphase / Q000502:physiology*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D010507:Periodicity; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism
D001324:Autoantigens; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone; C091489:KIF2C protein, human; D008869:Microtubule-Associated Proteins; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; C502735:KIF18A protein, human; D016547:Kinesins