Plant Elongator regulates auxin-related genes during RNA polymerase II transcription elongation

Abstract

In eukaryotes, transcription of protein-encoding genes is strongly regulated by posttranslational modifications of histones that affect the accessibility of the DNA by RNA polymerase II (RNAPII). The Elongator complex was originally identified in yeast as a histone acetyltransferase (HAT) complex that activates RNAPII-mediated transcription. In Arabidopsis thaliana, the Elongator mutants elo1, elo2, and elo3 with decreased leaf and primary root growth due to reduced cell proliferation identified homologs of components of the yeast Elongator complex, Elp4, Elp1, and Elp3, respectively. Here we show that the Elongator complex was purified from plant cell cultures as a six-component complex. The role of plant Elongator in transcription elongation was supported by colocalization of the HAT enzyme, ELO3, with euchromatin and the phosphorylated form of RNAPII, and reduced histone H3 lysine 14 acetylation at the coding region of the SHORT HYPOCOTYL 2 auxin repressor and the LAX2 auxin influx carrier gene with reduced expression levels in the elo3 mutant. Additional auxin-related genes were down-regulated in the transcriptome of elo mutants but not targeted by the Elongator HAT activity showing specificity in target gene selection. Biological relevance was apparent by auxin-related phenotypes and marker gene analysis. Ethylene and jasmonic acid signaling and abiotic stress responses were up-regulated in the elo transcriptome and might contribute to the pleiotropic elo phenotype. Thus, although the structure of Elongator and its substrate are conserved, target gene selection has diverged, showing that auxin signaling and influx are under chromatin control.Arabidopsis | chromatin | histone acetyltranferase complex | SHY2

Role of Elongator Subunit Elp3 in Drosophila melanogaster Larval Development and Immunity

“…that the effect of Elp3 deletion in the fly could also be due to alterations in chromatin regulation. In general, the Drosophila genome-wide expression data presented here complement gene expression analysis in Arabidopsis, mouse, and humans, further supporting a role for Elongator during transcript elongation and chromatin remodeling (Close et al 2006;Chen et al 2009;Nelissen et al 2010). Our data also reveal important roles for Elongator in ecdysone regulation, morphogenesis, and the suppression of melanotic nodules during development.…”

Elongator, a conserved complex required for wobble uridine modifications in Eukaryotes

“…3,[79][80][81][82][83][84][85] Consistent with yeast, mutations in Elongator genes in the mouse M. musculus, the worm C. elegans, the plant A. thaliana and human cause defects in formation of wobble uridine modifications ( Table 2). 82,[86][87][88] In vitro, Elongator complex purified from HeLa cells have histone H3 and H4 acetyltransferase activity and depletion of the human homolog hELP1, IKAP (I kappa B kinase complex associated protein) in fibroblasts, leads to hypoacetylation of histone H3, transcription impairment and cell migration defects.…”

Multi-probe in situ hybridization to whole mount Arabidopsis seedlings

“…elo mutants were originally identified as leaf mutants but also have auxin-related phenotypes (Nelissen et al 2005;. Recently, ISH has been applied to investigate tissue or domain specific expression pattern of ELO genes in Arabidopsis plants by using single probes (Nelissen et al 2010). Results showed that ELO genes were expressed predominantly in the meristematic tissues (shoot apical meristem, provascular strands of young seedlings, meristematic and elongation zone of the primary and lateral root tip) suggesting that Elongator complex formation is restricted to actively dividing tissues (Nelissen et al 2010).…”