小柯机器人

英国帝国理工学院Harry H. Low、伦敦大学学院Buzz Baum等研究人员合作发现，细菌Vipp1和PspA是古老的ESCRT-III膜重塑超家族成员。这一研究成果于2021年6月23日在线发表在国际学术期刊《细胞》上。

据研究人员介绍，膜重塑和修复对所有细胞都是必不可少的。执行这些功能的蛋白质包括光合质体中的Vipp1/IM30、细菌中的PspA和真核生物中的ESCRT-III。

结合进化和结构分析，研究人员表明这些蛋白质家族是同源的，并且共享一个共同的古老进化起源，可能早于最后一个普遍共同祖先。这种同源性在来自蓝细菌Nostoc punctiforme的Vipp1环冷冻电镜结构中很明显，该结构呈现出一系列对称性。每个环由堆叠并逐渐倾斜以形成圆顶形曲率的梯级组装而成。Vipp1单体中的铰链促进了组装，类似于ESCRT-III蛋白中的铰链，它能够形成柔性聚合物。环有一个内腔，能够结合并改变膜。

总的来说，这些数据表明了不同生物中Vipp1、PspA和ESCRT-III依赖性膜重塑的保守机制原理。

附：英文原文

Title: Bacterial Vipp1 and PspA are members of the ancient ESCRT-III membrane-remodeling superfamily

Author: Jiwei Liu, Matteo Tassinari, Diorge P. Souza, Souvik Naskar, Jeffrey K. Noel, Olga Bohuszewicz, Martin Buck, Tom A. Williams, Buzz Baum, Harry H. Low

Issue&Volume: 2021-06-23

Abstract: Membrane remodeling and repair are essential for all cells. Proteins that perform these functions include Vipp1/IM30 in photosynthetic plastids, PspA in bacteria, and ESCRT-III in eukaryotes. Here, using a combination of evolutionary and structural analyses, we show that these protein families are homologous and share a common ancient evolutionary origin that likely predates the last universal common ancestor. This homology is evident in cryo-electron microscopy structures of Vipp1 rings from the cyanobacterium Nostoc punctiforme presented over a range of symmetries. Each ring is assembled from rungs that stack and progressively tilt to form dome-shaped curvature. Assembly is facilitated by hinges in the Vipp1 monomer, similar to those in ESCRT-III proteins, which allow the formation of flexible polymers. Rings have an inner lumen that is able to bind and deform membranes. Collectively, these data suggest conserved mechanistic principles that underlie Vipp1, PspA, and ESCRT-III-dependent membrane remodeling across all domains of life.

DOI: 10.1016/j.cell.2021.05.041

Source: https://www.cell.com/cell/fulltext/S0092-8674(21)00696-6