The histone acetyltransferase Gcn5 is conserved throughout eukaryotes where it functions as part of large multi-subunit transcriptional coactivator complexes that stimulate gene expression. Here, we describe how studies in the model insect Drosophila melanogaster have provided insight into the essential roles played by Gcn5 in the development of multicellular organisms. We outline the composition and activity of the four different Gcn5 complexes in Drosophila: the Spt-Ada-Gcn5 Acetyltransferase (SAGA), Ada2a-containing (ATAC), Ada2/Gcn5/Ada3 transcription activator (ADA), and Chiffon Histone Acetyltransferase (CHAT) complexes. Whereas the SAGA and ADA complexes are also present in the yeast Saccharomyces cerevisiae, ATAC has only been identified in other metazoa such as humans, and the CHAT complex appears to be unique to insects. Each of these Gcn5 complexes is nucleated by unique Ada2 homologs or splice isoforms that share conserved N-terminal domains, and differ only in their C-terminal domains. We describe the common and specialized developmental functions of each Gcn5 complex based on phenotypic analysis of mutant flies. In addition, we outline how gene expression studies in mutant flies have shed light on the different biological roles of each complex. Together, these studies highlight the key role that Drosophila has played in understanding the expanded biological function of Gcn5 in multicellular eukaryotes. This article is part of a Special Issue entitled: Gcn5: the quintessential histone acetyltransferase.

组蛋白乙酰基转移酶Gcn5在整个真核生物中都是保守的，在其中它充当刺激基因表达的大型多亚基转录共激活因子复合物的一部分。在这里，我们描述了如何在模型昆虫果蝇（Drosophila melanogaster）中进行的研究如何洞察Gcn5在多细胞生物发展中所起的重要作用。我们概述了果蝇中四种不同Gcn5复合物的组成和活性：Spt-Ada-Gcn5乙酰基转移酶（SAGA），含Ada2a的（ATAC），Ada2 / Gcn5 / Ada3转录激活剂（ADA）和雪纺组蛋白乙酰基转移酶（CHAT ）复合体。SAGA和ADA复合物也存在于酿酒酵母中，仅在人类等其他后生动物中发现了ATAC，CHAT复合体似乎是昆虫特有的。这些Gcn5复合体中的每一个都由独特的Ada2同系物或剪接同工型成核，它们共享保守的N端结构域，但仅在其C端结构域不同。我们描述了基于突变果蝇的表型分析的每个Gcn5复合体的共同和专门的发育功能。此外，我们概述了突变果蝇中的基因表达研究如何阐明每种复合物的不同生物学作用。总之，这些研究突出了果蝇在理解Gcn5在多细胞真核生物中扩展的生物学功能中所发挥的关键作用。本文是标题为：Gcn5：典型的组蛋白乙酰转移酶。