Skip to main content
. Author manuscript; available in PMC: 2007 Apr 27.
Published in final edited form as: Mol Cell. 2007 Feb 23;25(4):559–573. doi: 10.1016/j.molcel.2007.01.012

Figure 5. YRA1 Exon1 and Yra1p are cis- and trans-acting Negative Regulators of YRA1 Pre-mRNA Splicing.

Figure 5

(A-D) Effects on the levels of YRA1 pre-mRNA and mRNA engendered by: (A) internal deletions in YRA1 exon1; (B) substituting YRA1 exon1 coding sequences with their complementary sequences; (C) mutations in the 5’ splice site, the 3’ splice site, or the branchpoint region of the YRA1 intron; and (D) mutations in the translation initiation codon, 5’ splice site, 3’ splice site, and branchpoint region of the YRA1 intron in the presence or absence of Yra1p. Note that, in panel B, the replaced complementary sequence does not contain in-frame premature stop codons.

In panels A, B, C, and D plasmids carrying the wild-type YRA1 gene, or one of the mutant YRA1 alleles (depicted above the corresponding northern blots), were introduced into different yeast strains and the levels of the respective pre-mRNAs and mRNAs encoded by these alleles were analyzed by northern blotting. The relevant genotypes of yeast strains used in these experiments are indicated (panel A) or denoted by numbers in panels B, C, and D: 1: wild-type, 2: upf1Δ, 3: edc3Δ, 4: upf1Δ edc3Δ, 5:EDC3 yra1Δ yra2Δ (YEplac112-YRA2), and 6: edc3Δ yra1Δ yra2Δ (YEplac112-YRA2). In panel A, the levels of mutant YRA1 pre-mRNAs and mRNAs in edc3Δ cells were quantified, normalized to the corresponding wild-type pre-mRNA and mRNA levels, and graphed below the northern blot. Blots were hybridized to a SCR1 probe to serve as a loading control.