The NUD1 Gene of Yeast Saccharomyces Cerevisiae Complements a Thermosensitive Lytic Mutation

Temperature sensitive (ts) yeast strains have been obtained by ethyl methane sulfonate (EMS) mutagenesis. They have a normal growth at low temperature and releases of intracellular proteins in the culture medium at 37oC. The ts mutation was localized in the NUD1 gene, which codes for a component of the yeast spindle pole body (SPB). Construction of a frame shift mutation in the wild type gene demonstrated that the correct sequence of the NUD1 gene only could complement the ts phenotype. Further analysis showed that the ts mutation deprived the cells of a normal termination of mitosis, thus causing death at restrictive temperature and a consequence cell lysis. Abreviations: EMS, ethyl methane sulfonate; LRR, Leucine – Rich Repeats; SPB, spindle pole body; ts, temperature sensitive phenotype; ALP, alkaline phosphatase; MEN, mitotic exit network; SDS-PAGE, sodium dodecyl phosphate polyacrilamide gel; Da, Daltons; ATP, adenosine triphosphate