Chawla, Geetanjali and Sapra, Aparna K and Surana, Uttam and Vijayraghavan, Usha (2003) Dependence of pre-mRNA introns on PRP17, a non-essential splicing factor: Implications for efficient progression through cell cycle transitions. In: Nucleic Acids Research, 31 (9). pp. 2333-2343.
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Saccharomyces cerevisiae PRP17 (CDC40) encodes a second-step pre-mRNA splicing factor with a role in cell division. The functions of Prp17 in specific cell cycle transitions were examined using temperature-sensitive alleles in arrest/release experiments. We find that $G_1/S$ and $G_2/M$ transitions depend on Prp17. $G_1$-synchronized prp17::LEU2 cells arrest at non-permissive temperatures as unbudded haploid cells with low levels of CLN1, CLB5 and RNR1 transcripts. This indicates a Prp17 execution point at or prior to Start. Reduced levels of alpha-tubulin protein, a mitotic spindle component, underlie the benomyl sensitivity of prp17 mutants and possibly their $G_2/M$ arrest. Splicing of TUB1 and TUB3 transcripts, which encode alpha-tubulin, was analyzed in prp17 and other second-step factor mutants. TUB1 splicing is inefficient in prp17, prp16 and prp22, and marginally affected in prp18, slu7-1 and psf1-1. TUB3 splicing is similarly affected. In vitro splicing with TUB3 pre-mRNA demonstrates a compromised second step in prp17::LEU2 extracts, implicating a direct role for Prp17 in its efficient splicing. Genomic replacement of an intronless TUB1 gene relieves the benomyl sensitivity of prp17 mutants; however, they remain temperature sensitive, implying multiple limiting factors for mitosis. The data suggest that integration of splicing with the cell cycle is important for $G_1/S$ and $G_2/M$ transitions.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Oxford University Press.|
|Department/Centre:||Division of Biological Sciences > Microbiology & Cell Biology|
|Date Deposited:||12 Oct 2007|
|Last Modified:||19 Sep 2010 04:40|
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