Non-coding RNAs from the rDNA intergenic repeat are transcribed by RNA polymerase I and II and have different functions
(English)Manuscript (preprint) (Other academic)
Long intergenic non-coding RNA, linc RNA, are often produced from intergenic sequences and have been ascribed diverse functions, such as regulating mRNA levels and being involved in the formation of heterochromatin. We show here that the intergenic spacer region (IGS) of the ribosomal DNA gene repeat in human cells is transcribed. Three ncRNAs, the IGS19asRNA, the IGS32asRNA and the IGS38RNA, of 500, 800 and 1300 bases, respectively, were isolated and investigated. Two of them, the IGS19asRNA and the IGS32asRNA, were transcribed in the antisense direction with respect to the rRNA and in the sense direction for the IGS38RNA. We also showed that the ncRNAs were transcribed by different RNA polymerases; the IGS19asRNA and the IGS38RNA were transcribed by RNA polymerase II and the IGS32asRNA were transcribed by RNA polymerase I. The three ncRNAs were also differentially regulated; IGS19asRNA induced upon heat shock and the level of the IGS32asRNA increased upon glucose feeding, similar to the 45S rRNA. In addition, the ncRNAs IGS19asRNA and IGS32asRNA were found at different locations in the nucleus, with IGS19asRNA located in a speckled pattern in the nucleus and IGS32asRNA associated with chromatin bound to heterochromatin protein 1. This suggests that the IGS32asRNA has a role in heterochromatin formation.
IdentifiersURN: urn:nbn:se:su:diva-103001OAI: oai:DiVA.org:su-103001DiVA: diva2:714263