The metazoan ATAC and SAGA coactivator HAT complexes regulate different sets of inducible target genes

Abstract

Histone acetyl transferases (HATs) play a crucial role in eukaryotes by regulating chromatin architecture and locus-specific transcription. The GCN5 HAT was identified as a subunit of the SAGA (Spt-Ada-Gcn5-Acetyltransferase) multiprotein complex. Vertebrate cells express a second HAT, PCAF, that is 73% identical to GCN5. Here, we report the characterization of the mammalian ATAC (Ada-Two-A-Containing) complexes containing either GCN5 or PCAF in a mutually exclusive manner. In vitro ATAC complexes acetylate lysine 14 of histone H3. Moreover, ATAC- or SAGA-specific knock-down experiments suggest that both ATAC and SAGA are involved in the acetylation of histone H3K9 and K14 residues. Despite their catalytic similarities, SAGA and ATAC execute their coactivator functions on distinct sets of inducible target genes. Interestingly, ATAC strongly influences the global phosphorylation level of histone H3S10, suggesting that in mammalian cells a cross-talk exists linking ATAC function to H3S10 phosphorylation.

Coactivators and general transcription factors have two distinct dynamic populations dependent on transcription

“…Rabbit polyclonal anti‐GFP (Abcam, ab290; dilution 1:2,000); mouse monoclonal anti‐alpha‐Tubulin (Sigma‐Aldrich, T9026; dilution 1:1,000); rabbit polyclonal anti‐ASH2L (gift from Winship Herr; dilution 1:2,000); rabbit polyclonal anti‐Lamin A (Sigma‐Aldrich, L1293; dilution 1:2,000); mouse monoclonal anti‐RPB1 CTD (1PB 7C2, (Nguyen et al , 1996; dilution 1:20,000); rat monoclonal anti‐RPB1 CTD phospho Ser2 (Active Motif, 61083; dilution 1:2,000); rabbit polyclonal anti‐H3K4me3 (Abcam, ab8580; dilution 1:1,000); rabbit polyclonal anti‐H3K36me3 (Abcam, ab9050; dilution 1:1,000); rabbit polyclonal anti‐H3K9ac (Abcam, ab4441; dilution 1:1,000); rabbit monoclonal anti‐H2Bub (Cell Signaling Technology, 5546; dilution 1:5,000); rabbit polyclonal anti‐H3 (Abcam, ab1791; dilution 1:2,000), mouse monoclonal anti‐GCN5 2GC 2C11 (dilution 1:1,000; Brand et al , 2001) or 5GC 2AG (dilution 1:1,000; Krebs et al , 2010); rabbit polyclonal anti‐ZZZ3 2616 and anti‐mADA3 2678 (dilution 1:1,000; Nagy et al , 2010); rabbit polyclonal anti‐SPT20 3006 (dilution 1:1,000; Krebs et al , 2011); mouse monoclonal anti‐TRRAP 2TRR 2D5 dilution (1:1,000; Robert et al , 2006), rabbit polyclonal anti‐SGF29 2461 dilution (1:1,000) and rabbit polyclonal anti‐YEATS2 2783 (dilution 1:1,000; Nagy et al , 2010). …”

“…SAGA contains about 18‐20 subunits, which are organized in histone acetyltransferase (HAT), histone H2Bub1 deubiquitinase (DUB) and TATA binding protein (TBP) regulatory and structural modules (Lee et al , 2011; Spedale et al , 2012). Metazoan GCN5 was also identified as a subunit of a second coactivator HAT complex in Drosophila and mammals, named ATAC (Ada Two A Containing; Guelman et al , 2006; Wang et al , 2008; Nagy et al , 2010). ATAC contains 10 well‐characterized subunits.…”

A dual role of linker histone H1.4 Lys 34 acetylation in transcriptional activation

“…The expression and purification of hGCN5 using the baculovirus system was performed as published before (Demé ny et al 2007). The purification of endogenous GCN5-containing SAGA and ATAC complexes from HeLa cells was as described previously (Nagy et al 2009(Nagy et al , 2010. Histone H1 extraction with perchloric acid (PCA) was performed as described previously (Wisniewski et al 2007).…”

“…To complement this static snapshot of H1.4K34ac distribution, we followed the kinetics of H1.4K34ac upon transcriptional activation using TPA induction, since GCN5 had been implicated in this process (Nagy et al 2010). As shown in Figure 3A (and Supplemental Fig.…”

Subunits of ADA-two-A-containing (ATAC) or Spt-Ada-Gcn5-acetyltrasferase (SAGA) Coactivator Complexes Enhance the Acetyltransferase Activity of GCN5

“…Metazoan GCN5 was identified also as a subunit of a second coactivator HAT complex in Drosophila (26) and mammals, named ATAC (Ada two A-containing) (26,27). Interestingly, the yAda2 protein has two paralogues in metazoans: ADA2a and ADA2b (28,29).…”