MADS life on MAdLand II: Changes in DNA-binding specificity of MADS-domain transcription factors during the transition of plants to land

MAdLand II 上的 MADS 生命：植物向陆地过渡期间 MADS 结构域转录因子的 DNA 结合特异性的变化

• 批准号: 440291575
• 负责人: Professor Dr. Günter Theißen
• 金额: --
• 依托单位: Lehrstuhl für Genetik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/440291575?language=en
• 关键词: MADS; life; MAdLand; II; Changes

The overarching goal of our projects in both phases of MAdLand is to investigate the role of MIKC-type MADS-domain transcription factors (MTFs) during the transition of plants to land. MTFs constitute tetrameric proteins termed floral quartet-like complexes (FQCs) that control major developmental processes in land plants. The high combinatorial potential and cooperative DNA binding of FQCs enables the control of target gene activity in an especially efficient and specific way. This feature of FQCs is probably causally linked to the evolutionary origin of complex novelties in land plants and thus is of great biological interest. MTFs originated in the stem group of extant streptophytes, comprising all land plants and their closest relatives (charophyte algae). During the first phase of MAdLand we demonstrated that in the stem group of extant land plants important changes within the protein-protein interaction domain of MTFs occurred. These changes followed a gene duplication that led to two subfamilies of MTFs, termed MIKCC- and MIKC*-type proteins. MIKCC- and MIKC*-type proteins are major constituents of two largely independent gene regulatory networks that control important aspects of sporophyte and gametophyte development in land plants, respectively. In the second phase of MAdLand we want to study the biological relevance of FQC formation of the only MIKCC-type protein MpMADS2 in the liverwort M. polymorpha, reflecting the functional gain achieved by the ability of FQC formation during the transition of plants to land. We will do that by studying MpMADS2 mutants unable of FQC formation that we generated during the first phase. In addition, we want to determine the impact of FQC formation on genome-wide DNA-binding of MTFs for selected charophyte species. This will also provide useful insight into potential target genes of MIKC-type proteins in charophytes, for which no such data are available so far. Moreover, we want to complement our findings about the evolution of the protein-protein interaction domain by investigating major evolutionary changes within the DNA-binding MADS-domain of MTFs. Preliminary data suggest that ancestral MTFs that existed prior to the transition of plants to land, had a more promiscuous mode of DNA-binding than MIKCC- and MIKC*-type proteins. In our project we want to determine the mutations in the MADS-domain of MTFs that brought about these changes in DNA-recognition, and the consequences for the activity of those genes that are controlled by the different types of MTFs.

我们在MAdLand的两个阶段的项目的总体目标是研究mikc型mads结构域转录因子（MTFs）在植物向陆地过渡过程中的作用。MTFs由四聚体蛋白组成，称为花四聚体样复合物（fqc），控制着陆地植物的主要发育过程。fqc的高组合潜力和协同DNA结合使其能够以特别有效和特异性的方式控制靶基因的活性。fqc的这一特征可能与陆地植物复杂新物种的进化起源有因果关系，因此具有重要的生物学意义。mtf起源于现存链生植物的茎类，包括所有陆地植物及其近亲（绿藻）。在MAdLand的第一阶段，我们证明了在现存陆地植物的茎群中，MTFs的蛋白质-蛋白质相互作用域发生了重要的变化。这些变化发生在基因复制之后，导致mtf的两个亚家族，称为MIKCC-和MIKC*型蛋白。MIKCC-和MIKC*型蛋白是两个基本独立的基因调控网络的主要组成部分，它们分别控制着陆地植物孢子体和配子体发育的重要方面。在MAdLand的第二阶段，我们想要研究多形地茅（liverwort M. polymorpha）中唯一的mikcc型蛋白MpMADS2形成FQC的生物学相关性，以反映植物向陆地过渡过程中FQC形成能力所获得的功能增益。我们将通过研究在第一阶段产生的无法形成FQC的MpMADS2突变体来做到这一点。此外，我们想要确定FQC的形成对选定的蕨类植物mtf全基因组dna结合的影响。这也将提供有用的见解，以潜在的靶基因在蕨类植物的mikc型蛋白，目前还没有这样的数据。此外，我们希望通过研究MTFs dna结合mads结构域的主要进化变化来补充我们关于蛋白质-蛋白质相互作用结构域进化的发现。初步数据表明，在植物向陆地过渡之前就存在的mtf祖先比MIKCC-和MIKC*型蛋白具有更混杂的dna结合模式。在我们的项目中，我们想要确定mtf的mads结构域的突变，这些突变导致了dna识别的变化，以及由不同类型的mtf控制的那些基因活性的后果。