Human septins organize as octamer-based filaments and mediate actin-membrane anchoring in cells.
Human septins organize as octamer-based filaments and mediate actin-membrane anchoring in cells.
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DOI：
10.1083/jcb.202203016
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发表时间：
2023-03-06
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影响因子：
--
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中科院分区：
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--
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马丁斯等人。研究表明，与肌动蛋白应力纤维相关的所有脓蛋白都组织为介导肌动蛋白膜锚定的八聚体细丝。耗尽八聚体或阻止脓毒症聚合会导致应力纤维部分损失并损害细胞力学。脓蛋白是从藻类、原生生物到哺乳动物中保守的细胞骨架蛋白。脓毒症的一个独特特征是它们以异聚复合物的形式存在，在溶液中和脂膜上聚合成丝。尽管动物脓蛋白与细胞中基于肌动蛋白的结构广泛相关，但脓蛋白是否在细胞中组织成细丝以及脓蛋白组织是否影响脓蛋白功能尚不清楚。定制三方分裂-GFP互补测定，我们表明装饰肌动蛋白应力纤维的所有隔膜都是含有八聚体的丝。耗尽八聚体或阻止脓毒症聚合会导致应力纤维损失并降低细胞硬度。超分辨率显微镜显示出其宽度与其组织相匹配的脓蛋白纤维，为成对的脓蛋白丝。纳米分辨率的距离测量和单蛋白追踪进一步表明，隔膜丝是膜结合的并且大部分是固定的。最后，重构分析表明脓毒丝介导肌动蛋白-膜锚定。我们认为，隔膜组织作为基于八聚体的丝对于隔膜在质膜上锚定和稳定肌动蛋白丝的功能至关重要。
Martins et al. show that all septins associated with actin stress fibers organize as octamer-based filaments that mediate actin-membrane anchoring. Depleting octamers or preventing septins from polymerizing leads to a partial loss of stress fibers and compromised cell mechanics. Septins are cytoskeletal proteins conserved from algae and protists to mammals. A unique feature of septins is their presence as heteromeric complexes that polymerize into filaments in solution and on lipid membranes. Although animal septins associate extensively with actin-based structures in cells, whether septins organize as filaments in cells and if septin organization impacts septin function is not known. Customizing a tripartite split-GFP complementation assay, we show that all septins decorating actin stress fibers are octamer-containing filaments. Depleting octamers or preventing septins from polymerizing leads to a loss of stress fibers and reduced cell stiffness. Super-resolution microscopy revealed septin fibers with widths compatible with their organization as paired septin filaments. Nanometer-resolved distance measurements and single-protein tracking further showed that septin filaments are membrane bound and largely immobilized. Finally, reconstitution assays showed that septin filaments mediate actin–membrane anchoring. We propose that septin organization as octamer-based filaments is essential for septin function in anchoring and stabilizing actin filaments at the plasma membrane.
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DOI：
10.1083/jcb.69.3.717
发表时间：
1976-06
期刊：
The Journal of cell biology
影响因子：
--
作者：
Byers B;Goetsch L
通讯作者：
Goetsch L
影响因子：
35
作者：
Chizhik, Alexey I.;Rother, Jan;Enderlein, Joerg
通讯作者：
Enderlein, Joerg
影响因子：
5.5
作者：
Cavini IA;Leonardo DA;Rosa HVD;Castro DKSV;D'Muniz Pereira H;Valadares NF;Araujo APU;Garratt RC
通讯作者：
Garratt RC
影响因子：
7.8
作者：
Farrugia, Aaron J.;Rodriguez, Javier;Calvo, Fernando
通讯作者：
Calvo, Fernando
影响因子：
5.6
作者：
Bertin A;McMurray MA;Thai L;Garcia G 3rd;Votin V;Grob P;Allyn T;Thorner J;Nogales E
通讯作者：
Nogales E