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

• Applicant: Professor Dr. Arp Schnittger
• Subject Area: Plant Cell and Developmental Biology
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 274605654

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.

• DFG Programme: Research Grants
• International Connection: Brazil
• Partner Organisation: Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
• Cooperation Partner: Professor Paulo Cavalcanti Gomes Ferreira