Deciphering the non-conserved function and regulation of the Anaphase promoting complex/Cyclosome in plants

后期促进复合体，又称环体(APC/C)，是真核细胞周期中最重要的调节因子之一。它最突出的功能是在有丝分裂和减数分裂中分离姐妹染色单体，以及在第一次减数分裂中分离同源染色体。有了这一点，APC/C在通过防止染色体异常来保护基因组完整性方面发挥了重要作用；这是通过称为纺锤体(组装)检查点(SAC)的专用检查点来完成的，该检查点抑制APC/C，如果细胞条件威胁到染色体向子细胞的不均匀分布，APC/C通过有丝分裂和减数分裂进行。尽管APC/C和SAC核心成分的氨基酸序列在动物、酵母和植物中是保守的，但我们和其他团队最近的证据表明，与其他真核生物相比，植物中的APC/C调控有惊人的不同。有丝分裂细胞中SAC的激活或APC/C活性的丧失至少在某些情况下会导致内复制，而不是细胞周期停滞。此外，植物的减数分裂是进行的，尽管染色体并不平均地分配给子细胞。此外，来自我们和其他研究小组的最新证据表明，APC/C在植物发育和生长中具有额外的功能，这些功能与细胞周期调节没有直接关系。因此，了解APC/C的植物特有功能和调控不仅具有根本的意义，而且对生物技术的应用也具有重要的意义，例如通过调整减数分裂来开发新的育种策略，寻找新的增产途径和解决农业中现有的缺点。在巴西和德国合作伙伴大量准备工作的基础上，包括鉴定新的APC/C相互作用子和新开发的一套SAC报告系，我们将在这里探索APC/C在孢子体生长和减数分裂过程中的非典型功能和植物特有的控制。为此，我们将探索APC/C调控蛋白在胁迫条件下的表达和定位，并测试新发现的APC/C相互作用蛋白与已知调控机制组件相比的功能重要性。最后，我们将确定更多的监管机构作为巴西和德国合作伙伴之间的长期合作项目。

The Anaphase promoting complex, also known as the cyclosome (APC/C), has been identified as one of the most important regulators of the eukaryotic cell cycle. Its most prominent function is the separation of sister chromatids in mitosis and meiosis as well as the parting of homologous chromosomes in the first meiotic division. With this, the APC/C plays a major role in safeguarding genome integrity by preventing chromosome aberrations; this is accomplished by a dedicated checkpoint, called the spindle (assembly) checkpoint (SAC), that inhibits the APC/C and with that progression through mitosis and meiosis if the cellular conditions threaten an unequal distribution of the chromosomes to the daughter cells. Although the amino acid sequence of the core components of the APC/C and the SAC is conserved between animals, yeasts and plants, recent evidence from us and other teams has demonstrated that the APC/C regulation is surprisingly different in plants when compared to other eukaryotes. The activation of the SAC or loss of APC/C activity in mitotic cells leads, at least in some cases, to endoreplication, and not to cell cycle arrest. Moreover, meiosis in plants progresses although chromosomes are not equally distributed to the daughter cells. Furthermore, recent evidence from us and other groups suggests that the APC/C has additional functions in plant development and growth that are not directly related to cell cycle regulation. Thus, understanding the plant-specific function and regulation of the APC/C is not only of fundamental interest but also has important implications for biotechnological applications such as developing new breeding strategies by tuning meiosis, identifying new avenues to increase yield and tackling existing shortcomings in agriculture. Based on substantial preparatory work of the Brazilian and German partner that includes the identification of novel APC/C interactors and a newly developed set of SAC reporter lines, we will explore here the non-canonical function and plant-specific control of the APC/C during sporophytic growth and meiosis. To this end we will explore the expression and localization of APC/C regulatory proteins under stress conditions and test the functional importance of the newly identified APC/C interactors in comparison to components of the known regulatory machinery. Finally, we will identify additional regulators as a long-term collaborative project between the Brazilian and the German partner.