Chromosome segregation and cyclin degradation in the cell cycle of eukaryotic microorganisms Chromosomen-Segregation und Cyclin-Degradation im Zellzyklus eukaryontischer Mikroorganismen

• Applicant: Privatdozent Dr. Stefan Irniger
• Subject Area: Cell Biology
• Term: from 2001 to 2004
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5083437

Proteolytic degradation initiated by the anaphase- promoting complex (APC), a ubiquitin-ligase, is a crucial and highly conserved mechanism during mitosis in eukaryotes. The activity of the APC needs to be precisely regulated during the cell cycle. Its activation at metaphase triggers sister chromatid separation and later in mitosis proteolysis of mitotic cyclins, resulting in cyclin-dependent kinase inactivation and mitotic exit. In this project we will analyse factors and mechanisms involved in the regulation of APC function in dividing yeast cells. We are mainly focused on a further characterisation of how the Ras/cAMP/PKA pathway mediates inhibition of APC activity, the role of nuclear transport for APC function and how late mitotic genes are activated at telophase, thereby inducing the APC to trigger cyclin proteolysis. We will also study the role of the APC and its regulation in different cellular differentiation processes, particularily during sporulation and pseudohyphae formation in yeast. In addition, we extend our experiments to the filamentous fungus Aspergillus nidulans to analyse the function of the APC and its regulation in more complex cellular differentiation processes like fruitbody formation.

• DFG Programme: Research Grants
• Participating Person: Professor Dr. Gerhard H. Braus