Transcriptional adaptor and histone acetyltransferase proteins in Arabidopsis and their interactions with CBF1, a transcriptional activator involved in cold-regulated gene expression

Abstract

The ARABIDOPSIS CBF transcriptional activators bind to the CRT/DRE regulatory element present in the promoters of many cold-regulated genes and stimulate their transcription. Expression of the CBF1 proteins in yeast activates reporter genes carrying a minimal promoter with the CRT/DRE as an upstream regulatory element. Here we report that this ability of CBF1 is dependent upon the activities of three key components of the yeast Ada and SAGA complexes, namely the histone acetyltransferase (HAT) Gcn5 and the transcriptional adaptor proteins Ada2 and Ada3. This result suggested that CBF1 might function through the action of similar complexes in ARABIDOPSIS In support of this hypothesis we found that ARABIDOPSIS has a homolog of the GCN5 gene and two homologs of ADA2, the first report of multiple ADA2 genes in an organism. The ARABIDOPSIS GCN5 protein has intrinsic HAT activity and can physically interact in vitro with both the ARABIDOPSIS ADA2a and ADA2b proteins. In addition, the CBF1 transcriptional activator can interact with the ARABIDOPSIS GCN5 and ADA2 proteins. We conclude that ARABIDOPSIS encodes HAT-containing adaptor complexes that are related to the Ada and SAGA complexes of yeast and propose that the CBF1 transcriptional activator functions through the action of one or more of these complexes.

RNA Expression Profiles and Data Mining of Sugarcane Response to Low Temperature

“…These proteins can stimulate transcription (Stockinger et al, 2001). These complexes consist of the proteins GCN5 and ADA (Grant et al, 1997).…”

“…These complexes consist of the proteins GCN5 and ADA (Grant et al, 1997). The GCN5 protein has HAT activity, whereas the ADA protein may function as a transcriptional adapter for some activation domains (Marcus et al, 1994;Stockinger et al, 2001). We identified SUCESTassembled sequences similar to Arabidopsis GCN5 and ADA2b proteins (Table III).…”

“…These results provide preliminary evidence for the existence of HAT-containing adapter complexes in sugarcane. The existence of this complex in plants was believed to be restricted to Arabidopsis (Stockinger et al, 2001). As in Arabidopsis (Stockinger et al, 2001), sugarcane GCN5 and ADA2b proteins may interact physically with each other and with CBF1, thereby stimulating the transcription of CBF1 target genes (Fig.…”

The Arabidopsis transcription factor bZIP11 activates auxin-mediated transcription by recruiting the histone acetylation machinery

“…To date, a few direct physical interactions between plant ADA2 homologues and transcriptional activators could be identified. Arabidopsis ADA2b interacts with the AP2 TF CBF1, which promotes expression of several cold-responsive genes 27,28 , whereas ADA2 from maize binds the basic leucine zipper (bZIP) factor OPAQUE2 (O2), which is involved in regulating seed storage genes during maize endosperm development 29,30 .…”

Dynamics of the Plant Nuclear Envelope and Nuclear Pore

“…In yeast, a connection between the chromatin-bound Spt-Ada-Gcn5 acetyltransferase (SAGA) transcriptional coactivator complex, the nuclear pore protein Mlp1, and the RNA export complex TREX-2 (also known as the Thp1-Sac3-Cdc31-Sus1 complex) is implied in this activation. The SAGA histone acetyl transferase component Gcn5, the plant Mlp1 homolog NUA, and subunits of TREX-2 have all been identified in Arabidopsis, making it worthwhile to test if a similar connection might be involved in regulating plant gene expression (Stockinger et al, 2001;Xu et al, 2007b;Lu et al, 2010;Yelina et al, 2010). Nucleoporins are bound to hundreds of genomic sites, as identified by chromatin immunoprecipitation experiments and fusion of Nups to micrococcal nuclease (Schmid et al, 2006;Capelson et al, 2010;Vaquerizas et al, 2010;Wälde and Kehlenbach, 2010).…”