Goodchild James A, Curtis Brandy N, Pan Yangang, Jiang Yining, Jiao Fang, Gladfelter Amy S, Scheuring Simon
Weill Cornell Medicine, Department of Anesthesiology, New York, NY, USA.
University of North Carolina-Chapel Hill, Department of Biochemistry and Biophysics, Chapel Hill, NC, USA.
Nat Commun. 2025 May 30;16(1):5055. doi: 10.1038/s41467-025-60344-w.
Septins are cytoskeletal proteins that form filaments and higher-order structures, and remodel membranes in a variety of processes. Structural and cell biological studies provided atomic- and micro-scale details, but the understanding of septin assembly at the mesoscale is limited. Here, we used high-speed atomic force microscopy (HS-AFM) to analyze yeast septin assembly on yeast supported lipid bilayers (SLBs). We found the coexistence of three lipid phases in yeast membranes, where septin polymerized selectively on the liquid-disordered phase. Septin filaments adhered to membranes with a conserved face; and paired filaments, previously reported in less native environments, were not observed. Additionally, septin filaments exhibited lateral and longitudinal alignment. We used HS-AFM force-sweep experiments to disrupt septin structures and observe organizational recovery through self-templating. Finally, septin filaments stacked, where higher layer filament alignment was templated by the layer below. Thus, septins encode their 3D-structural organization, likely tunable by the membrane and bulk environment.
Septins是一种细胞骨架蛋白，可形成细丝和高阶结构，并在各种过程中重塑膜结构。结构和细胞生物学研究提供了原子尺度和微观尺度的细节，但对中尺度下septin组装的理解仍然有限。在这里，我们使用高速原子力显微镜（HS-AFM）分析酵母支持脂质双层（SLB）上的酵母septin组装。我们发现酵母膜中存在三种脂质相，septin在液态无序相上选择性聚合。Septin细丝以保守面附着于膜上；并且未观察到先前在不太自然的环境中报道的成对细丝。此外，septin细丝表现出横向和纵向排列。我们使用HS-AFM力扫描实验破坏septin结构，并通过自模板观察组织恢复。最后，septin细丝堆叠，上层细丝的排列由下层模板化。因此，septin编码其三维结构组织，可能受膜和整体环境的调节。
