Ramírez-Aguirre Erandi, Nava-Ramírez Teresa Beatriz, Covarrubias Alejandra A, Garay-Arroyo Adriana
Laboratorio de Genética Molecular, Desarrollo y Evolución de Plantas, Depto. de Ecología Funcional, Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, México.
Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, México.
PLoS One. 2025 Aug 22;20(8):e0330098. doi: 10.1371/journal.pone.0330098. eCollection 2025.
Plants have acquired the ability to adapt and respond to varying environmental conditions through modifications in their developmental programs. This adaptability relies on the plant's capacity to sense environmental cues and respond via diverse signal transduction pathways and transcriptional regulation. Transcription factors are central in these processes, orchestrating specific gene expression in both developmental and stress responses. In Arabidopsis thaliana, 91% of transcription factors contain large intrinsically disordered regions (IDRs). The structural flexibility in these regions is critical in protein-protein interactions and contributes to functional versatility across different cell types. MADS-domain transcription factors constitute an eukaryotic protein family involved in a diversity of developmental processes and stress responses. Using bioinformatic tools, we found that most Arabidopsis MADS-domain proteins contain IDRs (≥30 residues) in their C-terminal region, with a higher proportion of global disorder in Type II compared to Type I MADS-domain proteins. Remarkably orthologous proteins from non-plant species in the Eukarya domain (Drosophila melanogaster, Saccharomyces cerevisiae, and Homo sapiens) also present disordered C-terminal regions, containing longer IDRs than those found in Arabidopsis, or other analyzed plant species. Additionally, conserved motifs were identified within the C-terminal IDRs of Arabidopsis Type I and Type II MADS-domain proteins, suggesting interactions with co-regulatory partners. We also identified putative activation domains in the C-terminal region of Type I and Type II MADS-domain proteins. The involvement of IDRs in selecting co-regulators is further supported by the identification of Molecular Recognition Features (MoRFs) in Type II MADS-domain proteins. The conserved structural disorder in the C-terminal region of MADS-domain proteins, which includes specific motifs, across diverse domains of life provides valuable insights into their structural properties and mechanisms of action as transcriptional regulators.
植物通过改变其发育程序获得了适应和响应不同环境条件的能力。这种适应性依赖于植物感知环境线索并通过多种信号转导途径和转录调控做出响应的能力。转录因子在这些过程中起着核心作用，在发育和应激反应中协调特定基因的表达。在拟南芥中，91%的转录因子含有大的内在无序区域（IDR）。这些区域的结构灵活性在蛋白质-蛋白质相互作用中至关重要，并有助于不同细胞类型间的功能多样性。MADS结构域转录因子构成了一个真核蛋白家族，参与多种发育过程和应激反应。使用生物信息学工具，我们发现大多数拟南芥MADS结构域蛋白在其C端区域含有IDR（≥30个残基），与I型MADS结构域蛋白相比，II型MADS结构域蛋白的整体无序比例更高。值得注意的是，真核域中非植物物种（黑腹果蝇、酿酒酵母和智人）的直系同源蛋白也存在无序的C端区域，其IDR比拟南芥或其他分析的植物物种中的更长。此外，在拟南芥I型和II型MADS结构域蛋白的C端IDR中鉴定出了保守基序，表明它们与共调节伙伴存在相互作用。我们还在I型和II型MADS结构域蛋白的C端区域鉴定出了推定的激活域。II型MADS结构域蛋白中分子识别特征（MoRF）的鉴定进一步支持了IDR在选择共调节因子中的作用。MADS结构域蛋白C端区域保守的结构无序，包括特定基序，在不同生命域中存在，这为其作为转录调节因子的结构特性和作用机制提供了有价值的见解。
