【资源】Nature：凝缩蛋白的“招募” 【生物探索】
丁香园论坛
1929
转自：生物探索 http://www.biodiscover.com/news/proteomics.html
背景：在有丝分裂过程中，染色体在凝缩蛋白作用下变得紧凑和僵硬。已知这种蛋白在染色体臂和着丝点上的作用机制不同，但还不清楚它是怎样定位到这些区域的。
研究结论：Tada等人发现，着丝点蛋白 Monopolin 是着丝点凝缩蛋白的一个招募者(recruiter),此外，Aurora B激酶的磷酸化作用促进凝缩蛋白与某些组蛋白的结合。
推测：Aurora B的定位作用(localization)在细胞周期中各不相同，这也许可以解释凝缩蛋白“招募”到“着丝点”的过程表现出周期性。
<center> <br /> </center>
<center> <br /> 致密染色体结构是怎样形成的？</center>
生物探索推荐英文摘要
<center> <br /> <strong>Condensin association with histone H2A shapes mitotic chromosomes</strong></center>
Abstract： Chromosome structure is dynamically
regulated during cell division, and this regulation is dependent, in
part, on condensin. The localization of condensin at chromosome arms is
crucial for chromosome partitioning during anaphase. Condensin is also
enriched at kinetochores but its precise role and loading machinery
remain unclear. Here we show that fission yeast (Schizosaccharomyces
pombe) kinetochore proteins Pcs1 and Mde4—homologues of budding yeast
(Saccharomyces cerevisiae) monopolin subunits and known to prevent
merotelic kinetochore orientation—act as a condensin ‘recruiter’ at
kinetochores, and that condensin itself may act to clamp microtubule
binding sites during metaphase. In addition to the regional recruitment
factors, overall condensin association with chromatin is governed by the
chromosomal passenger kinase Aurora B. Aurora-B-dependent
phosphorylation of condensin promotes its association with histone H2A
and H2A.Z, which we identify as conserved chromatin ‘receptors’ of
condensin. Condensin phosphorylation and its deposition onto chromosome
arms reach a peak during anaphase, when Aurora B kinase relocates from
centromeres to the spindle midzone, where the separating chromosome arms
are positioned. Our results elucidate the molecular basis for the
spatiotemporal regulation of mitotic chromosome architecture, which is
crucial for chromosome partitioning.
背景：在有丝分裂过程中，染色体在凝缩蛋白作用下变得紧凑和僵硬。已知这种蛋白在染色体臂和着丝点上的作用机制不同，但还不清楚它是怎样定位到这些区域的。
研究结论：Tada等人发现，着丝点蛋白 Monopolin 是着丝点凝缩蛋白的一个招募者(recruiter),此外，Aurora B激酶的磷酸化作用促进凝缩蛋白与某些组蛋白的结合。
推测：Aurora B的定位作用(localization)在细胞周期中各不相同，这也许可以解释凝缩蛋白“招募”到“着丝点”的过程表现出周期性。
<center> <br /> </center>
<center> <br /> 致密染色体结构是怎样形成的？</center>
生物探索推荐英文摘要
<center> <br /> <strong>Condensin association with histone H2A shapes mitotic chromosomes</strong></center>
Abstract： Chromosome structure is dynamically
regulated during cell division, and this regulation is dependent, in
part, on condensin. The localization of condensin at chromosome arms is
crucial for chromosome partitioning during anaphase. Condensin is also
enriched at kinetochores but its precise role and loading machinery
remain unclear. Here we show that fission yeast (Schizosaccharomyces
pombe) kinetochore proteins Pcs1 and Mde4—homologues of budding yeast
(Saccharomyces cerevisiae) monopolin subunits and known to prevent
merotelic kinetochore orientation—act as a condensin ‘recruiter’ at
kinetochores, and that condensin itself may act to clamp microtubule
binding sites during metaphase. In addition to the regional recruitment
factors, overall condensin association with chromatin is governed by the
chromosomal passenger kinase Aurora B. Aurora-B-dependent
phosphorylation of condensin promotes its association with histone H2A
and H2A.Z, which we identify as conserved chromatin ‘receptors’ of
condensin. Condensin phosphorylation and its deposition onto chromosome
arms reach a peak during anaphase, when Aurora B kinase relocates from
centromeres to the spindle midzone, where the separating chromosome arms
are positioned. Our results elucidate the molecular basis for the
spatiotemporal regulation of mitotic chromosome architecture, which is
crucial for chromosome partitioning.
