Evolution and function of Marchantia BBR/BPC proteins

本短期研究项目旨在探讨BBR/BPC蛋白的分子生化功能是否已在雌雄异株地钱草中确立，并在整个进化过程中保持不变。由于MpBBR1和MpBBR2的保守的三段结构域结构，有可能与MpLHP1形成同源二聚体和异源二聚体。根据我们从拟南芥同源蛋白中获得的数据，MpLHP1可能会被MpBBR1或MpBBR2招募到含有DNA探针的GAGA基序中。MpBBR-MpLHP1复合体的协同作用可能针对同源异型基因，因此对生殖器官的发育可能是重要的。在拟南芥LHP1或第二组BBR/BPC与Marchantia LHP1或第四组BBR/BPC成员之间的跨物种异源二聚体形成将揭示分子功能能力是否在陆地植物进化过程中保持。作为我的假设的背景，我将解决以下核心问题：·MpBBR1和MpBBR2在体内形成同源二聚体吗？这些蛋白质在细胞核内定位在哪里？作为配子体雌雄异株的结果，重要的是知道MpBBR1-MpBBR2是否能在受精卵中形成同型异二聚体。·MpBBR1和MpBBR2都能与MpLHP1相互作用吗？这种相互作用是否局限于核质，类似于它们的拟南芥同源蛋白？·拟南芥和地钱草的同源蛋白是否能够在体内形成二聚体？·MpBBR1和MpBBR2是否与GagA-DNA基序结合？如果是这样的话，重要的是要知道MpLHP1是否能被MpBBR1或MpBBR2招募到GagA基序。·MpBBR1和MpBBR2是否以MADS-box基因启动子为靶标--与它们的拟南芥同源基因相似？

This short term project addresses the question whether the molecular biochemical functions of BBR/BPC proteins were already established in the dioecious liverwort Marchantia, as one of the earliest land plants, and maintained throughout evolution, or not.Because of the conserved tripartide domain structure, it might be possible that Marchantia MpBBR1 and MpBBR2 can form homodimers and heterodimers with MpLHP1. Based on our data from the orthologous proteins in Arabidopsis, it might be possible that MpLHP1 can be recruited by MpBBR1 or MpBBR2 to GAGA-motif containing DNA-probes. The concerted action of the MpBBR-MpLHP1 complex will presumably target homeotic genes and, hence, might be important for the development of reproductive organs. Cross-species heterodimer formation between Arabidopsis LHP1 or group II BBR/BPCs and Marchantia LHP1 or group IV BBR/BPC members will disclose whether the molecular functional capacities were maintained throughout land plant evolution.Against the background of my hypotheses, I will address the following central questions:• Are MpBBR1 and MpBBR2 forming homodimers in vivo? Where do the proteins localize inside the nucleus? As a consequence of gametophytic dioecy, it is important to know whether MpBBR1 - MpBBR2 homotypic heterodimers can form in the zygote.• Are both MpBBR1 and MpBBR2 able to interact with MpLHP1? Is this interaction restricted to the nucleoplasm, similar to their Arabidopsis othologs?• Are orthologous proteins from Arabidopsis and Marchantia able to form dimers in vivo?• Are MpBBR1 and MpBBR2 binding to GAGA-DNA-motifs? If so, it is important to know whether MpLHP1 can be recruited by MpBBR1 or MpBBR2 to GAGA-motifs.• Are MpBBR1 and MpBBR2 targeting MADS-box gene promoters - similar to their Arabidopsis orthologs?