The Saccharomyces cerevisiae RNase mitochondrial RNA processing is critical for cell cycle progression at the end of mitosis.

We have identified a cell cycle delay in Saccharomyces cerevisiae RNase MRP mutants. Mutants delay with large budded cells, dumbbell-shaped nuclei, and extended spindles characteristic of "exit from mitosis" mutants. In accord with this, a RNase MRP mutation can be suppressed by overexpressing the polo-like kinase CDC5 or by deleting the B-type cyclin CLB1, without restoring the MRP-dependent rRNA-processing step.