Cleavage and polyadenylation factor, Rna14 is an essential protein required for the maintenance of genomic integrity in fission yeast Schizosaccharomyces pombe

Abstract

Faithful segregation of chromosomes is essential for the maintenance of genome integrity. In a genetic screen to identify genes related to checkpoint function, we have characterized the role of rna14, an essential gene in the maintenance of chromosome dynamics. We demonstrate that Rna14 localizes in the nucleus and in the absence of functional Rna14, the cells exhibit chromosomal segregation defects. The mutant allele of rna14 exhibits genetic interaction with key kinetochore components and spindle checkpoint proteins. Inactivation of rna14 leads to accumulation of Bub1-GFP foci, a protein required for spindle checkpoint activation that could be due to the defects in the attachment of mitotic spindle to the chromosome. Consistently, the double mutant of rna14-11 and bub1 knockout exhibits high degree of chromosome mis-segregation. At restrictive condition, the rna14-11 mutant cells exhibit defects in cell cycle progression with high level of septation. The orthologs of Rna14 in Saccharomyces cerevisiae (sc Rna14) and human (CstF3) contain similar domain architecture and are required for 3′-end processing of pre-mRNA. We have also demonstrated that the fission yeast Rna14 is required to prevent transcriptional read-through. These findings reveal the importance of transcription termination in the maintenance of genomic stability through the regulation of kinetochore function.