德国马克斯普朗克研究所Andrea Musacchio、Valentina Piano等研究人员合作发现，CDC20在有丝分裂检查点复合体中协助其催化整合。这一研究成果于2021年1月1日在线发表在国际学术期刊《科学》上。

研究人员表示，HORMA结构域蛋白的开放（O）和封闭（C）拓扑结构分别与基本细胞途径的失活状态和活跃状态相关。结合CDC20后，HORMA蛋白O-MAD2转换为C-MAD2。这是有丝分裂检查点复合物（MCC）组装的速率限制环节，而有丝分裂检查点复合物是准确有丝分裂所需的检查点执行者。在动植物中组装的催化剂通过目前尚不清楚的机制来加速MAD2：CDC20结合。

使用重构的SAC系统，研究人员发现CDC20是不可渗透的底物，要接近MAD2需要同时对接在催化配合物的多个位点上。分析表明，检查点催化剂是底物辅助型的，并且通过MAD2和CDC20的时空协调构象变化促进了MCC组装。这可以为其他HORMA控制的系统定义一种范例。

附：英文原文

Title: CDC20 assists its catalytic incorporation in the mitotic checkpoint complex

Author: Valentina Piano, Amal Alex, Patricia Stege, Stefano Maffini, Gerardo A. Stoppiello, Pim J. Huis in ’t Veld, Ingrid R. Vetter, Andrea Musacchio

Issue&Volume: 2021/01/01

Abstract: Open (O) and closed (C) topologies of HORMA-domain proteins are respectively associated with inactive and active states of fundamental cellular pathways. The HORMA protein O-MAD2 converts to C-MAD2 upon binding CDC20. This is rate limiting for assembly of the mitotic checkpoint complex (MCC), the effector of a checkpoint required for mitotic fidelity. A catalyst assembled at kinetochores accelerates MAD2:CDC20 association through a poorly understood mechanism. Using a reconstituted SAC system, we discovered that CDC20 is an impervious substrate for which access to MAD2 requires simultaneous docking on several sites of the catalytic complex. Our analysis indicates that the checkpoint catalyst is substrate assisted and promotes MCC assembly through spatially and temporally coordinated conformational changes in both MAD2 and CDC20. This may define a paradigm for other HORMA-controlled systems.

DOI: 10.1126/science.abc1152

Source: https://science.sciencemag.org/content/371/6524/67