What we talk about when we talk about nuclear actin
What we talk about when we talk about nuclear actin
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DOI：
10.4161/nucl.25960
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发表时间：
2013-07-01
期刊：
影响因子：
3.7
通讯作者：
Mullins, R. Dyche
中科院分区：
文献类型：
--
作者：
Belin, Brittany J.;Mullins, R. Dyche
在细胞质中，肌动蛋白丝形成交联网络，使真核细胞能够运输货物，改变形状和移动。肌动蛋白也存在于细胞核中，但在这个区室中，其功能更加神秘和有争议。如果我们将大量关于核肌动蛋白的文献提炼到其本质，我们会发现四个反复出现的、或多或少独立的主张：（1）常规肌动蛋白丝的交联网络跨越细胞核，并帮助维持其结构和组织其内容物;（2）组装或收缩丝调节特定的核事件;（3）肌动蛋白单体作为染色质重构复合物的亚单位，独立于它们形成细丝的能力;和（4）修饰的肌动蛋白单体或寡聚体，在结构上不同于典型的细胞骨架丝，通过未知的机制介导核事件。我们将讨论这些主张背后的证据，以及它们的优点和缺点。接下来，我们描述了我们最近的工作，其中我们建立了核肌动蛋白特异性探针，并用它们来描述体细胞核中肌动蛋白的形式和分布。最后，我们讨论了不同形式的核肌动蛋白在不同的细胞类型和生理环境中可能发挥不同的作用。
In the cytoplasm, actin filaments form crosslinked networks hat enable eukaryotic cells to transport cargo, change shape, and move. Actin is also present in the nucleus but, in this compartment, its functions are more cryptic and controversial. If we distill the substantial literature on nuclear actin down to its essentials, we find four, recurring, and more-or-less independent, claims: (1) crosslinked networks of conventional actin filaments span the nucleus and help maintain its structure and organize its contents; (2) assembly or contraction filaments regulates specific nuclear events; (3) actin monomers moonlight as subunits of chromatin remodeling complexes, independent of their ability to form filaments; and (4) modified actin monomers or oligomers, structurally distinct from canonical, cytoskeletal filaments, mediate nuclear events by unknown mechanisms. We discuss the evidence underlying these claims and as well as their strengths and weaknesses. Next, we describe our recent work, in which we built probes specific for nuclear actin and used them to describe the form and distribution of actin in somatic cell nuclei. Finally, we discuss how different forms of nuclear actin may play different roles in different cell types and physiological contexts.