The coiled coils of cohesin are conserved in animals, but not in yeast.
The coiled coils of cohesin are conserved in animals, but not in yeast.
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DOI：
10.1371/journal.pone.0004674
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Erickson HP
中科院分区：
文献类型：
--
作者：
White GE;Erickson HP
SMC蛋白参与整个真核生物的DNA修复、染色体凝聚和姐妹染色单体内聚。长，反平行的卷曲线圈是SMC蛋白的一个突出特征，被认为是作为间隔棒，提供一个细长的结构和分离的区域。我们最近报道了哺乳动物凝血蛋白（SMC2/4）的卷曲线圈显示出适度的序列分化（≈10-15%），与它们作为间隔棒的功能一致。然而，哺乳动物内聚蛋白（SMC1/3）的盘绕线圈受到高度限制，氨基酸序列差异通常<0.5%。这些盘绕的线圈是最高度保守的哺乳动物蛋白质之一，这表明它们在整个表面上都有广泛的接触。在这里，我们扩大了我们对凝聚蛋白和黏结蛋白的初步分析，以包括额外的脊椎动物和无脊椎动物生物以及多种酵母。我们发现smc /3的盘绕盘绕在果蝇和其他昆虫中受到高度限制，在所有动物物种中更为普遍。然而，在酵母中，它们并不比SMC2/4和Ndc80/Nuf2p线圈更受限制，这表明它们主要是作为间隔棒。SMC1/3在所有物种中都起姐妹染色单体内聚的作用。由于其卷曲的线圈在酵母中显然只充当间隔棒，这可能足以在所有物种中实现姐妹染色单体的内聚。这表明动物体内还有一种额外的功能，限制了盘绕线圈的序列。最近的几项研究表明，黏结蛋白在果蝇和其他动物细胞有丝分裂后神经元的基因表达中起作用。人类Cornelia de Lange综合征的一些变体涉及人类SMC1/3的突变。我们认为，内聚蛋白在基因表达中的作用可能与SMC1/3的卷曲线圈密切接触，并对序列分化施加约束。
The SMC proteins are involved in DNA repair, chromosome condensation, and sister chromatid cohesion throughout Eukaryota. Long, anti-parallel coiled coils are a prominent feature of SMC proteins, and are thought to serve as spacer rods to provide an elongated structure and to separate domains. We reported recently that the coiled coils of mammalian condensin (SMC2/4) showed moderate sequence divergence (≈10–15%) consistent with their functioning as spacer rods. The coiled coils of mammalian cohesins (SMC1/3), however, were very highly constrained, with amino acid sequence divergence typically <0.5%. These coiled coils are among the most highly conserved mammalian proteins, suggesting that they make extensive contacts over their entire surface. Here, we broaden our initial analysis of condensin and cohesin to include additional vertebrate and invertebrate organisms and multiple species of yeast. We found that the coiled coils of SMC1/3 are highly constrained in Drosophila and other insects, and more generally across all animal species. However, in yeast they are no more constrained than the coils of SMC2/4 and Ndc80/Nuf2p, suggesting that they are serving primarily as spacer rods. SMC1/3 functions for sister chromatid cohesion in all species. Since its coiled coils apparently serve only as spacer rods in yeast, it is likely that this is sufficient for sister chromatid cohesion in all species. This suggests an additional function in animals that constrains the sequence of the coiled coils. Several recent studies have demonstrated that cohesin has a role in gene expression in post-mitotic neurons of Drosophila, and other animal cells. Some variants of human Cornelia de Lange Syndrome involve mutations in human SMC1/3. We suggest that the role of cohesin in gene expression may involve intimate contact of the coiled coils of SMC1/3, and impose the constraint on sequence divergence.
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影响因子：
64.8
作者：
Clark, Andrew G.;Eisen, Michael B.;MacCallum, Iain
通讯作者：
MacCallum, Iain
影响因子：
16
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4
作者：
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影响因子：
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作者：
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通讯作者：
Iozzo, RV
影响因子：
4.6
作者：
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