Polypurine-repeat-containing RNAs: a novel class of long non-coding RNA in mammalian cells

R. Zheng, Z. Shen, V. Tripathi, Z. Xuan, S. M. Freier, C. F. Bennett, S. G. Prasanth, K. V. Prasanth
2010 Journal of Cell Science  
In higher eukaryotic cells, long non-protein-coding RNAs (lncRNAs) have been implicated in a wide array of cellular functions. Cellor tissue-specific expression of lncRNA genes encoded in the mammalian genome is thought to contribute to the complex gene networks needed to regulate cellular function. Here, we have identified a novel species of polypurine triplet repeat-rich lncRNAs, designated as GAA repeat-containing RNAs (GRC-RNAs), that localize to numerous punctate foci in the mammalian
more » ... phase nuclei. GRC-RNAs consist of a heterogeneous population of RNAs, ranging in size from ~1.5 kb to ~4 kb and localize to subnuclear domains, several of which associate with GAA.TTC-repeat-containing genomic regions. GRC-RNAs are components of the nuclear matrix and interact with various nuclear matrix-associated proteins. In mitotic cells, GRC-RNAs form distinct cytoplasmic foci and, in telophase and G1 cells, localize to the midbody, a structure involved in accurate cell division. Differentiation of tissue culture cells leads to a decrease in the number of GRC-RNA nuclear foci, albeit with an increase in size as compared with proliferating cells. Conversely, the number of GRC-RNA foci increases during cellular transformation. We propose that nuclear GRC-RNAs represent a novel family of mammalian lncRNAs that might play crucial roles in the cell nucleus. Journal of Cell Science 32 P-labeled (TTC) 15 probe from total RNA revealed that GRC-RNAs represent heterogeneous transcripts. Actin RNA was used as a loading control. (D)Northern blot using a 32 P-labeled (TTC) 15 probe in nuclear and cytoplasmic RNA fractions from EpH4 cells revealed nuclear enrichment of GRC-RNA. MALAT1 and lysine tRNA were used as markers for nuclear and cytoplasmic RNA fractionation, respectively. Journal of Cell Science Supplementary material available online at
doi:10.1242/jcs.070466 pmid:20940252 pmcid:PMC4481618 fatcat:yx2oojdufvg7jmhkptkzjyxpha