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Autoregulation of expression of the yeast Dbp2p ‘DEAD‐box’ protein is mediated by sequences in the conserved DBP2 intron.
Author(s) -
Barta I.,
Iggo R.
Publication year - 1995
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1995.tb00049.x
Subject(s) - biology , dead box , intron , genetics , conserved sequence , yeast , autoregulation , microbiology and biotechnology , gene , evolutionary biology , computational biology , base sequence , rna , helicase , blood pressure , endocrinology
The human p68, Saccharomyces cerevisiae DBP2 and Schizosaccharomyces pombe dbp2 genes are closely related members of the ‘DEAD‐box’ RNA helicase superfamily. All three genes contain an intron at a conserved site in RNA helicase motif V. The S.cerevisiae intron is unusual both for its position near the 3′‐end of the open reading frame and for its size, 1001 nucleotides. We show here that precise deletion of the intron has no effect on cell viability but leads to an increase in Dbp2p protein expression. Inefficient splicing due to the size of the intron can not account for this difference because the intron is efficiently spliced in Dbp2p‐deficient cells. Instead, there is a reciprocal relationship between the amount of Dbp2p in the cell and the efficiency with which DBP2 intron‐containing genes are expressed. Inactive Dbp2p mutants are efficiently expressed from DBP2 intron‐containing plasmids, and fragments of the DBP2 intron confer Dbp2p‐responsiveness on heterologous reporter introns. This suggest that there is an intron‐mediated negative feedback loop regulating DBP2 expression, and provides a possible explanation for the retention of such an unusual intron in S.cerevisiae.