Article
- The EMBO Journal (2006) 25, 3565 - 3575
- doi:10.1038/sj.emboj.7601245
Published online: 27 July 2006
Subject Categories:
The imprinted Air ncRNA is an atypical RNAPII transcript that evades splicing and escapes nuclear export
Christine IM Seidla, Stefan H Strickera and Denise P Barlow
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, c/o Institute of Genetics, Max F Perutz Laboratories, Vienna Biocenter, Dr Bohr-Gasse 9/4, A-1030 Vienna, Austria
Correspondence to:
Denise P Barlow, CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, c/o Institute of Genetics, Max F Perutz Laboratories, Vienna Biocenter, Dr Bohr-Gasse 9/4, 1030 Vienna, Austria. Tel.: +43 1 4277 54 610; Fax: +43 1 4277 9546; E-mail: denise.barlow@univie.ac.at
aThese authors contributed equally to this work
Received 4 April 2006; Accepted 28 June 2006
Abstract
Expression of the Air ncRNA is necessary to silence multiple genes in cis in the imprinted Igf2r cluster. However, its mode of action is unknown. Here, we characterize co- and post-transcriptional features of Air that identify it as a new member of the class of nuclear regulatory RNAs. We show that Air is transcribed from a DNA methylation-sensitive promoter by RNA polymerase II (RNAPII). However, although it is capped and polyadenylated similar to other RNAPII transcripts, the majority of Air transcripts evade cotranscriptional splicing resulting in a mature 108 kb ncRNA. As a consequence, the mature unspliced Air is nuclear localized and highly unstable. These features show that Air is an atypical RNAPII transcript whose properties indicate that its mode of action in gene silencing may not depend on the RNA per se but instead is related to its actual transcription.
Keywords:
- genomic imprinting,
- ncRNA,
- nuclear export,
- RNA stability,
- transcription interference
