Less kinesin, more condensation

杨柳

Kinesin motors drag cargos, including chromosomes, but do not normally reshape those cargos. But on page 613, Mazumdar et al. demonstrate that a human chromokinesin HKIF4A is needed to establish the correct condensation state of chromosomes.
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Chromokinesins are localized along chromosome arms and are thought, at least in some cases, to act as part of the polar wind: they walk along microtubules away from centrosomes, thus dragging their chromosome cargos toward the middle of the mitotic spindle. The authors depleted HKIF4A from human fibroblast cells using antibodies and RNAi. They observed numerous mitotic defects including misaligned chromosomes, incomplete chromosome separation during anaphase, and disorganized spindles. The resulting daughter cells had a high rate of aneuploidy.
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When the authors visually examined the chromosomes in RNAi-treated cells, they saw that chromosomes were hypercondensed relative to those in control cells. This was not due to an extended mitosis, as chromosomes of cells just entering mitosis were also hypercondensed. Furthermore, they found that HKIF4A interacts with the condensin complexes responsible for chromosome condensation." {/ w. w) \# O7 _6 e

- l% @0 K5 `: R( Q6 ^0 L/ i- y' TCells lacking HKIF4A had a diffuse rather than the normal axial localization of some condensin complex proteins. Thus, HKIF4A, having localized to chromosomes so that it can perhaps act as part of a polar wind, may use that localization to recruit or otherwise organize the condensins so that they can do their job. The more provocative possibility is that the kinesin motor itself is used to power a condensation event—a possibility that can be tested by injecting a kinase-dead mutant. The group also hopes to understand whether the segregation errors are triggered by the condensation problems, lack of motor function, or both.(Without HKIF4a, chromosomes are shorter )

dada

长时间没来看了 ～～  

加菲猫

回贴赚学识，不错了  

ines

支持一下吧  

immail

说的真有道理啊！

张佳

活着，以死的姿态……  

杏花

佩服佩服啊.  

快乐小郎

不错不错.,..我喜欢  

Whole

回贴赚学识，不错了  

whyboy

文笔流畅，修辞得体，深得魏晋诸朝遗风，更将唐风宋骨发扬得入木三分，能在有生之年看见楼主的这个帖子。实在是我三生之幸啊。