RT Journal Article
SR Electronic
T1 Regulatory RNPs: A novel class of ribonucleoproteins that contribute to ribosome heterogeneity
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 128090
DO 10.1101/128090
A1 Aaron R. Poole
A1 Ian Vicino
A1 Hiro Adachi
A1 Yi-Tao Yu
A1 Michael D. Hebert
YR 2017
UL http://biorxiv.org/content/early/2017/04/18/128090.abstract
AB Ribonucleoproteins (RNPs), which are comprised of non-coding RNA and associated proteins, are involved in essential cellular processes such as translation and pre-mRNA splicing. One class of RNP is the small Cajal body-specific RNP (scaRNP), which contributes to the biogenesis of small nuclear RNPs (snRNPs) that are central components of the spliceosome. Interestingly, three scaRNAs are internally processed, generating stable nucleolus-enriched RNAs of unknown function. Here we provide evidence that these RNAs become part of novel RNPs we term regulatory RNPs (regRNPs). We postulate that regRNPs can impact rRNA modifications via interactions with the guide RNA component of small nucleolar RNPs (snoRNPs). Most modifications within rRNA (predominantly pseudouridylation and ribose 2’-O-methylation) are conducted by snoRNPs, and we hypothesize that the activity of at least some of these snoRNPs is under the control of regRNPs. Ribosome heterogeneity leading to specialized ribosomes is an exciting emerging concept. Because modifications within rRNA can vary in different physiological or pathological situations, rRNA modifications are thought to be the major source of ribosome heterogeneity. Our identification of regRNPs thus provides important and timely insight into how ribosome heterogeneity may be accomplished. This work also provides additional functional connections between the Cajal body and the nucleolus.Summary Statement Processed scaRNAs give rise to a novel regulatory RNP which regulates the modification of ribosomal RNA. These findings provide insight into the mechanisms governing ribosome heterogeneity.