The role of Kin3p in the fidelity of chromosome transmission in Saccharomyces cerevisiae Die Rolle des Kin3p bei der Genauigkeit der Chromosomensegregation in Saccharomyces cerevisiae

• Applicant: Dr. Tillmann Schuster
• Subject Area: Basic Research in Biology and Medicine
• Term: from 1999 to 2002
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5194282

KIN3 codes for a Ser/Thr protein kinase in Saccharomyces cerevisiae which shows highest sequence homology to nimA of Aspergillus nidulans and the human gene Nek2. While nimA plays an essential role in the transition from G2-phase of the cell cycle to mitosis, Nek2 is thought to be important for centrosome integrity. We have been able to show that KIN3 is expressed in a cell cycle dependent manner with transcript levels peaking in mitosis. It is a non-essential gene, and deletion mutants do not show an obvious phenotype. Like Nek2 in human cells Kin3p localises near the spindle pole bodies. In the view of these results we tested whether deleton of KIN3 impairs chromosome segregation. Employing a chromosomal fragment stability assay we have been able to show that Kin3p, in conjunction with the mitotic checkpoint, controls the fidelity of chromosome transmission. These data suggest that Kin3p and Nek2 share similar functions. To elucidate the molecular function of Kin3p we plan next to undertake a search for proteins which interact with this kinase. The study of the relationship between Kin3p and its interaction partners should help us to understand how Kin3p acts on the molecular level to ensure high fidelity of chromosome transmission.

• DFG Programme: Priority Programmes
• Subproject of: SPP 314: Kontrolle des Zellzyklus bei Eukaryonten