DNA loops generate intracentromere tension in mitosis
نویسندگان
چکیده
The centromere is the DNA locus that dictates kinetochore formation and is visibly apparent as heterochromatin that bridges sister kinetochores in metaphase. Sister centromeres are compacted and held together by cohesin, condensin, and topoisomerase-mediated entanglements until all sister chromosomes bi-orient along the spindle apparatus. The establishment of tension between sister chromatids is essential for quenching a checkpoint kinase signal generated from kinetochores lacking microtubule attachment or tension. How the centromere chromatin spring is organized and functions as a tensiometer is largely unexplored. We have discovered that centromere chromatin loops generate an extensional/poleward force sufficient to release nucleosomes proximal to the spindle axis. This study describes how the physical consequences of DNA looping directly underlie the biological mechanism for sister centromere separation and the spring-like properties of the centromere in mitosis.
منابع مشابه
The tension mounts at centromeric loops
Centromeres are more than just simple stretches of DNA that recruit the kineto-chore proteins required to bind spindle microtubules and segregate chromosomes during mitosis. In fact, the chromatin surrounding centromeres is organized into a spring-like structure that bridges the cen-tromeres of sister chromatids and resists the pull of spindle microtubules. The tension generated when sister kin...
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عنوان ژورنال:
دوره 210 شماره
صفحات -
تاریخ انتشار 2015