The Gcn5 complexes in Drosophila as a model for metazoa

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 essential roles played by development multicellular organisms. We outline composition and activity four different Drosophila: Spt-Ada-Gcn5 Acetyltransferase (SAGA), Ada2a-containing (ATAC), Ada2/Gcn5/Ada3 transcription activator (ADA), Chiffon Histone (CHAT) complexes. Whereas SAGA ADA are also present yeast Saccharomyces cerevisiae, ATAC has only been identified other metazoa such humans, CHAT complex appears to be unique insects. Each these nucleated Ada2 homologs or splice isoforms share N-terminal domains, differ their C-terminal domains. common specialized developmental each based on phenotypic analysis mutant flies. In addition, expression flies shed light biological complex. Together, highlight key role understanding expanded function eukaryotes.