In this Special Issue, we bring together many of the original researchers involved in the initial studies to identify and characterize Gcn5, together with leaders from the field who have contributed to our understanding of this quintessential histone acetyltransferase. First, Jim Brownell and David Allis describe the discovery of Gcn5 , followed by Brittany Albaugh and John Denu who highlight key structural and catalytic attributes of Gcn5 as the defining member of the Gcn5-related N-acetyltransferase (GNAT) protein superfamily . Next, Michael Sack and colleagues describe a protein that is closely related to Gcn5, Gcn5L1, which lacks intrinsic histone acetylation activity but is still involved in protein acetylation as part of multi-subunit complexes that regulate aspects of vacuolar organelle function . Gcn5, like Gcn5L1, is also found as part of large multi-subunit complexes, and in , Shelley Berger, Patrick Grant, and Fred Winston describe the genetic and biochemical studies that led to the identification of the most famous of these Gcn5 complexes, the Spt-Ada-Gcn5 acetyltransferase (SAGA) complex in
the yeast S. cerevisiae. Next, Jose M. Espinola Lopez and Song Tan describe the close interactions between Gcn5 and its immediate binding partners, the Ada2, Ada3 and Sgf29 proteins, that influence Gcn5 activity and control its incorporation into different complexes  . A recent series of cryo-EM studies have provided a window into SAGA structure and function, and our current understanding of the structure of the Gcn5 complexes and their function is outlined in the Special Issue by Dominique Helmlinger, Gabor Papai, Didier Devys, and László Tora . The discussion of SAGA’s role in transcription is elaborated on by Brian Strahl and Scott Briggs in , who also discuss the interplay between histone modifications catalyzed by SAGA and other chromatin marks including histone phosphorylation, ubiquitination, and methylation.
Date of this Version
Weake VM. Gcn5: The quintessential histone acetyltransferase. Biochim Biophys Acta Gene Regul Mech. 2021 Feb;1864(2):194658. doi: 10.1016/j.bbagrm.2020.194658.