Inhibition of c-erbA mRNA splicing by a naturally occurring antisense RNA.
The rat erbA alpha locus encodes two overlapping mRNAs, alpha 1 and alpha 2, which are identical except for their most 3' exons. alpha 1 mRNA encodes a thyroid hormone receptor, while alpha 2 encodes an altered ligand binding domain of unknown function. Previous studies have shown that the ratio of alpha 1 to alpha 2 is highest in cells expressing a high level of a third RNA, Rev-ErbA alpha mRNA, which is transcribed in the opposite direction and is complementary to alpha 2 but not alpha 1 mRNA. It was hypothesized that base pairing with Rev-ErbA alpha blocks splicing of alpha 2 mRNA, thereby favoring formation of the non-overlapping alpha 1. To test this model, a system was developed in which alpha 2 pre-mRNAs were accurately spliced in vitro. Splicing was inhibited by the addition of a 5-fold excess of antisense RNAs containing the 3' end of Rev-ErbA alpha mRNA. Both an antisense RNA extending across the 3' splice site and a shorter RNA complementary only to exon sequences efficiently blocked splicing. However, splicing was only inhibited by complementary RNAs. These observations are consistent with a mechanism in which base pairing with a complementary RNA regulates alternative processing of alpha 1 and alpha 2 mRNAs.
Munroe
S H
SH
Department of Biology, Marquette University, Milwaukee, Wisconsin 53233.
Lazar
M A
MA
D000818:Animals; D002467:Cell Nucleus / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D007438:Introns; D008957:Models, Genetic; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D011519:Proto-Oncogenes; D012326:RNA Splicing; D016372:RNA, Antisense / Q000235:genetics* / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics*; D051381:Rats; D011988:Receptors, Thyroid Hormone; D015183:Restriction Mapping
D011518:Proto-Oncogene Proteins; D016372:RNA, Antisense; D012333:RNA, Messenger; D011988:Receptors, Thyroid Hormone; D011505:Protein-Tyrosine Kinases