title: Noncoding RNAs of the H/ACA family.
abstract: The H/ACA RNAs are an abundant family of trans-acting, noncoding RNAs found in eukaryotes and archaea. More than 100 H/ACA RNAs are known to exist in humans. The function of the majority of the identified H/ACA RNAs is to guide sites-pecific pseudouridylation of ribosomal RNA. In eukaryotes, H/ACA RNAs also mediate the processing of pre-rRNA, provide the template for telomere synthesis, and guide pseudouridylation of other classes of target RNAs (e.g., small nuclear RNAs [snRNAs]). Thus, currently, the H/ACA RNAs are known to be integrally involved in the production of both ribosomes and spliceosomes, and in the maintenance of chromosome integrity. In addition, dozens of H/ACA RNAs have been identified for which no function has yet been determined. The H/ACA RNAs select and present substrate molecules via base pairing. All H/ACA RNAs contain conserved sequence elements (box H and box ACA) and assemble with a core set of four proteins to form functional ribonucleoprotein complexes (RNPs). Mutations in key RNA and protein components of H/ACA RNPs result in dyskeratosis congenita, a serious multisystem genetic disease. Impressive progress has been made very recently in understanding the biogenesis, trafficking, and function of H/ACA RNPs.
authors: Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA.
authors: M
authors: M
authors: Terns
authors: R
authors: R
authors: Terns
mesh_terms: D000818:Animals; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020541:Coiled Bodies / Q000378:metabolism; D019871:Dyskeratosis Congenita / Q000235:genetics / Q000378:metabolism; D042822:Genomic Instability; D006801:Humans; D046911:Macromolecular Substances; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D021122:Protein Subunits; D012322:RNA Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012326:RNA Splicing; D022661:RNA, Untranslated / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019098:Telomerase / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D019843:Archaeal Proteins; D046911:Macromolecular Substances; D021122:Protein Subunits; D012322:RNA Precursors; D022661:RNA, Untranslated; D012261:Ribonucleoproteins; D019098:Telomerase