Nop10p is a nucleolar protein that is specifically associated with H/ACA snoRNAs. It is essential for normal 18S rRNA production and rRNA pseudouridylation by the ribonucleoprotein particles containing H/ACA snoRNAs (H/ACA snoRNPs). Nop10p is probably necessary for the stability of these RNPs .
H/ACA ribonucleoprotein particles (RNPs) are a family of RNA pseudouridine synthases that specify modification sites through guide RNAs. The function of these H/ACA RNPs is essential for biogenesis of the ribosome, splicing of precursor mRNAs (pre-mRNAs), maintenance of telomeres and probably for additional cellular processes [PUBMED:16647858]. All H/ACA RNPs contain a specific RNA component (snoRNA or scaRNA) and at least four proteins common to all such particles: Cbf5, Gar1, Nhp2 and Nop10. These proteins are highly conserved from yeast to mammals and homologues are also present in archaea [PUBMED:10871366]. The H/ACA protein complex contains a stable core composed of Cbf5 and Nop10, to which Gar1 and Nhp2 subsequently bind [PUBMED:19917616].