Drosophila histone locus bodies form by hierarchical recruitment of components
Drosophila histone locus bodies form by hierarchical recruitment of components
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DOI：
10.1083/jcb.201012077
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发表时间：
2011-05-16
影响因子：
7.8
通讯作者：
Duronio, Robert J.
中科院分区：
文献类型：
--
作者：
White, Anne E.;Burch, Brandon D.;Duronio, Robert J.
核体是包含蛋白质和RNA的结构，其参与对基因组功能至关重要的广泛过程。分子自组织被认为是驱动核体形成的原因，但这是随机发生的，还是通过有序的、层次化的过程发生的，还没有完全弄清楚。我们解决了这个问题，使用RNAi和蛋白质组学方法在果蝇中识别和表征组蛋白基因座体（HLB），参与复制依赖性组蛋白基因表达的核体的新组件。我们确定了转录延伸因子抑制Ty 6（Spt 6）和同源的哺乳动物细胞核蛋白的共济失调毛细血管扩张症突变的基因座编码的同源异型基因多性梳（mxc）作为新的HLB组件。通过将细胞培养和胚胎中的遗传操作与Mxc、Spt 6和已知HLB组分、FLICE相关巨大蛋白、Mute、U 7小核核糖核蛋白和MPM-2磷酸化表位的细胞学观察相结合，我们证明了在发育过程中因子定位于HLB的顺序招募和分级依赖性，这表明有序组装可以在核体形成中发挥作用。
Nuclear bodies are protein-and RNA-containing structures that participate in a wide range of processes critical to genome function. Molecular self-organization is thought to drive nuclear body formation, but whether this occurs stochastically or via an ordered, hierarchical process is not fully understood. We addressed this question using RNAi and proteomic approaches in Drosophila melanogaster to identify and characterize novel components of the histone locus body (HLB), a nuclear body involved in the expression of replication-dependent histone genes. We identified the transcription elongation factor suppressor of Ty 6 (Spt6) and a homologue of mammalian nuclear protein of the ataxia telangiectasia-mutated locus that is encoded by the homeotic gene multisex combs (mxc) as novel HLB components. By combining genetic manipulation in both cell culture and embryos with cytological observations of Mxc, Spt6, and the known HLB components, FLICE-associated huge protein, Mute, U7 small nuclear ribonucleoprotein, and MPM-2 phosphoepitope, we demonstrated sequential recruitment and hierarchical dependency for localization of factors to HLBs during development, suggesting that ordered assembly can play a role in nuclear body formation.