Evidence for multiple, distinct ADAR-containing complexes in Xenopus laevis

RNA. 2015 Feb;21(2):279-95. doi: 10.1261/rna.047787.114. Epub 2014 Dec 17.

Abstract

ADAR (adenosine deaminase acting on RNA) is an RNA-editing enzyme present in most metazoans that converts adenosines in double-stranded RNA targets into inosines. Although the RNA targets of ADAR-mediated editing have been extensively cataloged, our understanding of the cellular function of such editing remains incomplete. We report that long, double-stranded RNA added to Xenopus laevis egg extract is incorporated into an ADAR-containing complex whose protein components resemble those of stress granules. This complex localizes to microtubules, as assayed by accumulation on meiotic spindles. We observe that the length of a double-stranded RNA influences its incorporation into the microtubule-localized complex. ADAR forms a similar complex with endogenous RNA, but the endogenous complex fails to localize to microtubules. In addition, we characterize the endogenous, ADAR-associated RNAs and discover that they are enriched for transcripts encoding transcriptional regulators, zinc-finger proteins, and components of the secretory pathway. Interestingly, association with ADAR correlates with previously reported translational repression in early embryonic development. This work demonstrates that ADAR is a component of two, distinct ribonucleoprotein complexes that contain different types of RNAs and exhibit diverse cellular localization patterns. Our findings offer new insight into the potential cellular functions of ADAR.

Keywords: A-to-I editing; RNA editing; RNP; dsRNA.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adenosine Deaminase / metabolism*
  • Animals
  • Oocytes / enzymology
  • RNA Transport
  • RNA, Double-Stranded / metabolism*
  • Ribonucleoproteins / metabolism
  • Spindle Apparatus / metabolism
  • Xenopus Proteins / metabolism*
  • Xenopus laevis

Substances

  • RNA, Double-Stranded
  • Ribonucleoproteins
  • Xenopus Proteins
  • Adenosine Deaminase

Associated data

  • BioProject/PRJNA255991