A phylogenetic analysis reveals an unusual sequence conservation within introns involved in RNA editing - PubMed (original) (raw)

Comparative Study

A phylogenetic analysis reveals an unusual sequence conservation within introns involved in RNA editing

P J Aruscavage et al. RNA. 2000 Feb.

Abstract

Adenosine deaminases that act on RNA (ADARs) are RNA editing enzymes that convert adenosines to inosines within cellular and viral RNAs. Certain glutamate receptor (gluR) pre-mRNAs are substrates for the enzymes in vivo. For example, at the R/G editing site of gluR-B, -C, and -D RNAs, ADARs change an arginine codon (AGA) to a glycine codon (IGA) so that two protein isoforms can be synthesized from a single encoded mRNA; the highly related gluR-A sequence is not edited at this site. To gain insight into what features of an RNA substrate are important for accurate and efficient editing by an ADAR, we performed a phylogenetic analysis of sequences required for editing at the R/G site. We observed highly conserved sequences that were shared by gluR-B, -C, and -D, but absent from gluR-A. Surprisingly, in contrast to results obtained in phylogenetic analyses of tRNA and rRNA, it was the bases in paired, helical regions whose identity was conserved, whereas bases in nonhelical regions varied, but maintained their nonhelical state. We speculate this pattern in part reflects constraints imposed by ADAR's unique specificity and gained support for our hypotheses with mutagenesis studies. Unexpectedly, we observed that some of the gluR introns were conserved beyond the sequences required for editing. The approximately 600-nt intron 13 of gluR-C was particularly remarkable, showing >94% nucleotide identity between human and chicken, organisms estimated to have diverged 310 million years ago.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Microbiol Rev. 1994 Mar;58(1):10-26 - PubMed
    1. J Mol Biol. 1999 Aug 6;291(1):1-13 - PubMed
    1. EMBO J. 1994 Dec 1;13(23):5701-11 - PubMed
    1. Science. 1994 Dec 9;266(5191):1709-13 - PubMed
    1. Trends Genet. 1995 Sep;11(9):367-71 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources