The COP9 signalosome (CSN) is a conserved protein complex, typically composed of eight subunits (designated as CSN1 to CSN8) in higher eukaryotes such as plants and animals, but of fewer subunits in some lower eukaryotes such as yeasts. The CSN complex is originally identified in plants from a genetic screen for mutants that mimic light‐induced photomorphogenic development when grown in the dark. The CSN complex regulates the activity of cullin‐RING ligase (CRL) families of E3 ubiquitin ligase complexes, and play critical roles in regulating gene expression, cell proliferation, and cell cycle. This review aims to summarize the discovery, composition, structure, and function of CSN in the regulation of plant development in response to external (light and temperature) and internal cues (phytohormones).

中文翻译：

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COP9信号小体：发现，保守，活性和功能。

COP9信号体（CSN）是一种保守的蛋白质复合物，通常由植物和动物等高等真核生物中的8个亚基（称为CSN1至CSN8）组成，而在某些低等真核生物（如酵母）中则较少。CSN复合物最初是在植物的遗传筛选中鉴定出来的，这些突变体模仿了在黑暗中生长时模拟光诱导的光形态发生发育的突变体。CSN复合物调节E3泛素连接酶复合物的cullin-ring连接酶（CRL）家族的活性，并在调节基因表达，细胞增殖和细胞周期中起关键作用。这篇综述旨在总结CSN在响应外部（光照和温度）和内部提示（植物激素）而调节植物发育中的发现，组成，结构和功能。