Common and distinct patterns of terminal modifications to mirtrons and canonical microRNAs Journal Article


Authors: Westholm, J. O.; Ladewig, E.; Okamura, K.; Robine, N.; Lai, E. C.
Article Title: Common and distinct patterns of terminal modifications to mirtrons and canonical microRNAs
Abstract: Nucleotide modifications to microRNAs or their precursors can influence their processing and/or activity. A challenge to their analysis is the lack of independent references for the termini generated by primary processing; typically, these are empirically assigned as the most abundant mapped reads. Mirtrons offer such an independent measure since these microRNA hairpins are defined by splicing. Consequently, mirtron-derived reads that deviate from splice sites reflect modification following primary processing. Analysis in Drosophila revealed multiple modification patterns, including select alterations of 5′ termini, many 3′resection events, and unexpectedly abundant 3′ untemplated monouridylation. Resections occur on mature AGO1-loaded species, whereas uridylation occurs on pre-miRNAs but is compatible with dicing and AGO1 loading. Strikingly, we found many mirtrons whose modified reads are more abundant than those produced by primary processing. In some cases, these abundant modified reads matched the genome owing to fortuitous uridines in downstream flanking exons, thus highlighting the value of an independent reference for the primary-processed sequence. We could further extend the principle of abundant and preferred uridylation of mirtrons, relative to canonical pre-miRNAs, to Caenorhabditis elegans, mouse, and human. Finally, we found that 3′ resection occurs broadly across AGO1-loaded canonical miRNA and star species. Altogether, these findings substantially broaden the complexity of terminal modification pathways acting upon small regulatory RNAs. Copyright © 2012 RNA Society.
Keywords: unclassified drug; nonhuman; mouse; microrna; drosophila; resection; caenorhabditis elegans; rna processing; uridine; rna splicing; argonaute 1 protein; chemical modification; uridylation; mirtron; uridine derivative
Journal Title: RNA
Volume: 18
Issue: 2
ISSN: 1355-8382
Publisher: Cold Spring Harbor Laboratory Press  
Date Published: 2012-01-01
Start Page: 177
End Page: 192
Language: English
DOI: 10.1261/rna.030627.111
PROVIDER: scopus
PMCID: PMC3264906
PUBMED: 22190743
DOI/URL:
Notes: --- - "Export Date: 1 March 2012" - "CODEN: RNARF" - "Source: Scopus"
Altmetric
Citation Impact
BMJ Impact Analytics
MSK Authors
  1. Eric C Lai
    159 Lai
  2. Nicolas Robine
    11 Robine
  3. Katsutomo Okamura
    26 Okamura
  4. Erik Manfred Ladewig
    16 Ladewig