ATAC and SAGA co-activator complexes utilize co-translational assembly, but their cellular localization properties and functions are distinct

Gizem Yayli (1) , Andrea Bernardini (1) , Paulina Karen Mendoza Sanchez (2, 3) , Elisabeth Scheer (1) , Mylène Damilot (1) , Karim Essabri (1) , Bastien Morlet (1) , Luc Negroni (1) , Stéphane D Vincent (1) , H T Marc Timmers (3) , László Tora (1)

1 IGBMC - Institut de Génétique et de Biologie Moléculaire et Cellulaire
2 University of Freiburg [Freiburg]
3 German Cancer Consortium (DKTK) partner site Freiburg, German Cancer Research Center (DKFZ) and Department of Urology, Medical Center-University of Freiburg

To understand the function of multisubunit complexes, it is of key importance to uncover the precise mechanisms that guide their assembly. Nascent proteins can find and bind their interaction partners during their translation, leading to co-translational assembly. Here, we demonstrate that the core modules of ATAC (ADA-two-A-containing) and SAGA (Spt-Ada-Gcn5-acetyltransferase), two lysine acetyl transferase-containing transcription co-activator complexes, assemble co-translationally in the cytoplasm of mammalian cells. In addition, a SAGA complex containing all of its modules forms in the cytoplasm and acetylates non-histone proteins. In contrast, ATAC complex subunits cannot be detected in the cytoplasm of mammalian cells. However, an endogenous ATAC complex containing two functional modules forms and functions in the nucleus. Thus, the two related co-activators, ATAC and SAGA, assemble using co-translational pathways, but their subcellular localization, cytoplasmic abundance, and functions are distinct.

Domaines: Sciences du Vivant [q-bio]

Gizem Yayli, Andrea Bernardini, Paulina Karen Mendoza Sanchez, Elisabeth Scheer, Mylène Damilot, et al.. ATAC and SAGA co-activator complexes utilize co-translational assembly, but their cellular localization properties and functions are distinct. Cell Reports, 2023, 42 (113099), ⟨10.1016/j.celrep.2023.113099⟩. ⟨hal-04206088⟩