Kinetochores
نویسنده
چکیده
Not to be confused with1⁄4 centrosomes. But it’s OK to confuse them with centromeres. The centromere is the chromosomal domain where the kinetochore is assembled. Genetically speaking, the centromere is the locus necessary to segregate chromosomes. In many species, the centromere is also defined cytologically as the primary constriction visible on condensed chromosomes (the intersection point of the classical X-shaped chromosome) — this is also the point where one observes connection to spindle microtubules. Probably the most commonsensical definition describes the kinetochore as the protein machine that assembles on centromeric DNA during mitosis/meiosis.
منابع مشابه
Localization of Mad2 to Kinetochores Depends on Microtubule Attachment, Not Tension
A single unattached kinetochore can delay anaphase onset in mitotic tissue culture cells (Rieder, C.L., A. Schultz, R. Cole, G. Sluder. 1994. J. Cell Biol. 127:1301-1310). Kinetochores in vertebrate cells contain multiple binding sites, and tension is generated at kinetochores after attachment to the plus ends of spindle microtubules. Checkpoint component Mad2 localizes selectively to unattache...
متن کاملRecruitment of Mad1 to metaphase kinetochores is sufficient to reactivate the mitotic checkpoint
The mitotic checkpoint monitors kinetochore-microtubule attachment and prevents anaphase until all kinetochores are stably attached. Checkpoint regulation hinges on the dynamic localization of checkpoint proteins to kinetochores. Unattached, checkpoint-active kinetochores accumulate multiple checkpoint proteins, which are depleted from kinetochores upon stable attachment, allowing checkpoint si...
متن کاملFunctional Redundancy in the Maize Meiotic Kinetochore
Kinetochores can be thought of as having three major functions in chromosome segregation: (a) moving plateward at prometaphase; (b) participating in spindle checkpoint control; and (c) moving poleward at anaphase. Normally, kinetochores cooperate with opposed sister kinetochores (mitosis, meiosis II) or paired homologous kinetochores (meiosis I) to carry out these functions. Here we exploit thr...
متن کاملDirect observation of microtubule dynamics at kinetochores in Xenopus extract spindles
Microtubule plus ends dynamically attach to kinetochores on mitotic chromosomes. We directly imaged this dynamic interface using high resolution fluorescent speckle microscopy and direct labeling of kinetochores in Xenopus extract spindles. During metaphase, kinetochores were stationary and under tension while plus end polymerization and poleward microtubule flux (flux) occurred at velocities v...
متن کاملProbing microtubule polymerisation state at single kinetochores during metaphase chromosome motion
Kinetochores regulate the dynamics of attached microtubule bundles (kinetochore-fibres, K-fibres) to generate the forces necessary for chromosome movements in mitosis. Current models suggest that poleward-moving kinetochores are attached to depolymerising K-fibres and anti-poleward-moving kinetochores to polymerising K-fibres. How the dynamics of individual microtubules within the K-fibre relat...
متن کاملDirect observation of microtubule dynamics at kinetochores in Xenopus extract spindles: implications for spindle mechanics
icrotubule plus ends dynamically attach to kinetochores on mitotic chromosomes. We directly imaged this dynamic interface using high resolution fluorescent speckle microscopy and direct labeling of kinetochores in Xenopus extract spindles. During metaphase, kinetochores were stationary and under tension while plus end polymerization and poleward microtubule flux (flux) occurred at velocities va...
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عنوان ژورنال:
- Current Biology
دوره 10 شماره
صفحات -
تاریخ انتشار 2000