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Mutations in the large subunit of U2AF disrupt pre‐mRNA splicing, cell cycle progression and nuclear structure
Author(s) -
Beales Mitchell,
Flay Nina,
McKinney Ron,
Habara Yasuaki,
Ohshima Yasumi,
Tani Tokio,
Potashkin Judith
Publication year - 2000
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/1097-0061(200008)16:11<1001::aid-yea605>3.0.co;2-6
Subject(s) - biology , rna splicing , mutant , chromatin , genetics , splicing factor , rna binding protein , rna , precursor mrna , microbiology and biotechnology , cell nucleus , messenger rna , gene
The prp2 gene of fission yeast has previously been shown to encode the large subunit of the splicing factor spU2AF. SpU2AF 59 is an evolutionarily conserved protein that has an arginine/serine‐rich region and three RNA recognition motifs (RRMs). We have sequenced three temperature‐sensitive alleles of prp2 and determined that the mutations result in single amino acid changes within one of the RRMs or between RRMs. All mutant alleles of prp2 have pre‐mRNA splicing defects at the non‐permissive temperature. Although the mutant strains are growth‐arrested at 37°C, they do not elongate like typical fission yeast cell cycle mutants. The DNA of the prp2 − strains stains more intensely than a wild‐type strain, suggesting that the chromatin may be condensed. Ultrastructural studies show differences in the mutant nuclei including a prominent distinction between the chromatin‐ and non‐chromatin‐enriched regions compared to the more homogenous wild‐type nucleus. Two‐hybrid assays indicate that some of the wild‐type protein interactions are altered in the mutant strains. These results suggest that normal functioning of spU2AF 59 may be essential not only for pre‐mRNA splicing but also for the maintenance of proper nuclear structure and normal cell cycle progression. Copyright © 2000 John Wiley & Sons, Ltd.