DELLA proteins recruit the Mediator complex subunit MED15 to coactivate transcription in land plants

• 成果类型: Article
• 署名作者: Hernandez-Garcia, Jorge; Serrano-Mislata, Antonio; Lozano-Quiles, Maria; Urbez, Cristina; Nohales, Maria A.; Blanco-Tourinan, Noel; Peng, Huadong; Ledesma-Amaro, Rodrigo; Blazquez, Miguel A.
• 署名单位: Consejo Superior de Investigaciones Cientificas (CSIC); Universitat Politecnica de Valencia; CSIC-UPV - Instituto de Biologia Molecular y Celular de Plantas (IBMCP); Wageningen University & Research; Imperial College London; Imperial College London
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10024
• DOI: 10.1073/pnas.2319163121
• 发表日期: 2024-05-07
• 关键词: kix domain; gibberellin; activation; rice; performance; expression; EVOLUTION; alignment; sequence; MODULE

摘要

DELLA proteins are negative regulators of the gibberellin response pathway in angiosperms, acting as central hubs that interact with hundreds of transcription factors (TFs) and regulators to modulate their activities. While the mechanism of TF sequestration by DELLAs to prevent DNA binding to downstream targets has been extensively documented, the mechanism that allows them to act as coactivators remains to be understood. Here, we demonstrate that DELLAs directly recruit the Mediator complex to specific loci in Arabidopsis, facilitating transcription. This recruitment involves DELLA amino - terminal domain and the conserved MED15 KIX domain. Accordingly, partial loss of MED15 function mainly disrupted processes known to rely on DELLA coactivation capacity, including cytokinin - dependent regulation of meristem function and skotomorphogenic response, gibberellin metabolism feedback, and flavonol production. We have also found that the single DELLA protein in the liverwort Marchantia polymorpha is capable of recruiting MpMED15 subunits, contributing to transcriptional coactivation. The conservation of Mediator - dependent transcriptional coactivation by DELLA between Arabidopsis and Marchantia implies that this mechanism is intrinsic to the emergence of DELLA in the last common ancestor of land plants.