Condensin regulates the stiffness of vertebrate centromeres.
When chromosomes are aligned and bioriented at metaphase, the elastic stretch of centromeric chromatin opposes pulling forces exerted on sister kinetochores by the mitotic spindle. Here we show that condensin ATPase activity is an important regulator of centromere stiffness and function. Condensin depletion decreases the stiffness of centromeric chromatin by 50% when pulling forces are applied to kinetochores. However, condensin is dispensable for the normal level of compaction (rest length) of centromeres, which probably depends on other factors that control higher-order chromatin folding. Kinetochores also do not require condensin for their structure or motility. Loss of stiffness caused by condensin-depletion produces abnormal uncoordinated sister kinetochore movements, leads to an increase in Mad2(+) kinetochores near the metaphase plate and delays anaphase onset.
Ribeiro
Susana A
SA
Wellcome Trust Centre for Cell Biology, Institute of Cell and Molecular Biology, University of Edinburgh, Edinburgh EH9 3JR, United Kingdom.
Gatlin
Jesse C
JC
Dong
Yimin
Y
Joglekar
Ajit
A
Cameron
Lisa
L
Hudson
Damien F
DF
Farr
Christine J
CJ
McEwen
Bruce F
BF
Salmon
Edward D
ED
Earnshaw
William C
WC
Vagnarelli
Paola
P
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D001324:Autoantigens / Q000378:metabolism; D002460:Cell Line; D002503:Centromere / Q000378:metabolism* / Q000648:ultrastructure; D000076247:Centromere Protein A; D002843:Chromatin / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D020868:Gene Silencing; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D018386:Kinetochores / Q000378:metabolism / Q000648:ultrastructure; D008870:Microtubules / Q000648:ultrastructure; D008938:Mitosis; D046912:Multiprotein Complexes / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D008941:Spindle Apparatus / Q000378:metabolism / Q000648:ultrastructure; D014714:Vertebrates / Q000378:metabolism*
D001324:Autoantigens; D000076247:Centromere Protein A; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; D011993:Recombinant Fusion Proteins; C108312:condensin complexes; D049452:Green Fluorescent Proteins; D000251:Adenosine Triphosphatases