Exon mutations uncouple 5' splice site selection from U1 snRNA pairing.
It has previously been shown that a mutation of yeast 5' splice junctions at position 5 (GUAUGU) causes aberrant pre-mRNA cleavages near the correct 5' splice site. We show here that the addition of exon mutations to an aberrant cleavage site region transforms it into a functional 5' splice site both in vivo and in vitro. The aberrant mRNAs are translated in vivo. The results suggest that the highly conserved G at the 5' end of introns is necessary for the second step of splicing. Further analyses indicate that the location of the U1 snRNA-pre-mRNA pairing is not affected by the exon mutations and that the precise 5' splice site is selected independent of this pairing.
Séraphin
B
B
Howard Hughes Medical Institute, Brandeis University, Waltham, Massachusetts 02254.
Rosbash
M
M
D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics; D005091:Exons; D016368:Frameshift Mutation; D007438:Introns; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010957:Plasmids; D012322:RNA Precursors / Q000235:genetics*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics*; D012342:RNA, Small Nuclear / Q000235:genetics*; D016364:Reading Frames; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D015345:Oligonucleotide Probes; D012322:RNA Precursors; D012333:RNA, Messenger; D012342:RNA, Small Nuclear