The SAGA complex is an evolutionarily conserved transcriptional coactivator that regulates gene expression through its histone acetyltransferase and deubiquitylase activities, recognition of specific histone modifications, and interactions with transcription factors. Multiple lines of evidence indicate the existence of distinct variants of SAGA among organisms as well as within a species, permitting diverse functions to dynamically regulate cellular pathways. Our co-expression analysis of genes encoding human SAGA components showed enrichment in reproductive organs, brain tissues and the skeletal muscle, which corresponds to their established roles in developmental programs, emerging roles in neurodegenerative diseases, and understudied functions in specific cell types. SAGA subunits modulate growth, development and response to various stresses from yeast to plants and metazoans. In metazoans, SAGA further participates in the regulation of differentiation and maturation of both innate and adaptive immune cells, and is associated with initiation and progression of diseases including a broad range of cancers. The evolutionary conservation of SAGA highlights its indispensable role in eukaryotic life, thus deciphering the mechanisms of action of SAGA is key to understanding fundamental biological processes throughout evolution. To illuminate the diversity and conservation of this essential complex, here we discuss variations in composition, essentiality and co-expression of component genes, and its prominent functions across Fungi, Plantae and Animalia kingdoms.

中文翻译：

---

跨界真核 SAGA 共激活子复合物的保护和多样性


SAGA 复合体是一种进化上保守的转录共激活因子，通过其组蛋白乙酰转移酶和去泛素化酶活性、特定组蛋白修饰的识别以及与转录因子的相互作用来调节基因表达。多种证据表明，生物体之间以及物种内部存在 SAGA 的不同变体，从而允许动态调节细胞途径的多种功能。我们对编码人类 SAGA 成分的基因的共表达分析显示，它们在生殖器官、脑组织和骨骼肌中富集，这与它们在发育程序中的既定作用、在神经退行性疾病中的新作用以及特定细胞类型中尚未研究的功能相对应。 SAGA 亚基调节从酵母到植物和后生动物的生长、发育和对各种应激的反应。在后生动物中，SAGA 进一步参与先天性和适应性免疫细胞的分化和成熟的调节，并与包括多种癌症在内的疾病的发生和进展相关。 SAGA的进化保守性凸显了其在真核生命中不可或缺的作用，因此破译SAGA的作用机制是理解整个进化过程中基本生物过程的关键。为了阐明这一重要复合体的多样性和保护性，我们在这里讨论组成基因的组成、重要性和共表达的变化，及其在真菌、植物和动物界中的突出功能。