title: Identification of genes that function in the biogenesis and localization of small nucleolar RNAs in Saccharomyces cerevisiae.
abstract: Small nucleolar RNAs (snoRNAs) orchestrate the modification and cleavage of pre-rRNA and are essential for ribosome biogenesis. Recent data suggest that after nucleoplasmic synthesis, snoRNAs transiently localize to the Cajal body (in plant and animal cells) or the homologous nucleolar body (in budding yeast) for maturation and assembly into snoRNPs prior to accumulation in their primary functional site, the nucleolus. However, little is known about the trans-acting factors important for the intranuclear trafficking and nucleolar localization of snoRNAs. Here, we describe a large-scale genetic screen to identify proteins important for snoRNA transport in Saccharomyces cerevisiae. We performed fluorescence in situ hybridization analysis to visualize U3 snoRNA localization in a collection of temperature-sensitive yeast mutants. We have identified Nop4, Prp21, Tao3, Sec14, and Htl1 as proteins important for the proper localization of U3 snoRNA. Mutations in genes encoding these proteins lead to specific defects in the targeting or retention of the snoRNA to either the nucleolar body or the nucleolus. Additional characterization of the mutants revealed impairment in specific steps of U3 snoRNA processing, demonstrating that snoRNA maturation and trafficking are linked processes.
authors: Department of Biochemistry and Molecular Biology, University of Georgia, Davison Life Sciences Complex, Green Street, Athens, GA 30602, USA.
authors: Hui
authors: H
authors: Qiu
authors: Julia
authors: J
authors: Eifert
authors: Ludivine
authors: L
authors: Wacheul
authors: Marc
authors: M
authors: Thiry
authors: Adam C
authors: AC
authors: Berger
authors: Jelena
authors: J
authors: Jakovljevic
authors: John L
authors: JL
authors: Woolford
authors: Anita H
authors: AH
authors: Corbett
authors: Denis L J
authors: DL
authors: Lafontaine
authors: Rebecca M
authors: RM
authors: Terns
authors: Michael P
authors: MP
authors: Terns
mesh_terms: D000483:Alleles; D002466:Cell Nucleolus / Q000737:chemistry / Q000378:metabolism; D005800:Genes, Fungal; D006358:Hot Temperature; D009154:Mutation; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism; D012331:RNA, Fungal / Q000032:analysis / Q000378:metabolism*; D020537:RNA, Small Nucleolar / Q000032:analysis / Q000378:metabolism*; D020718:Ribonucleoproteins, Small Nucleolar / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*
chemical_list: C064793:NOP1 protein, S cerevisiae; D009687:Nuclear Proteins; D012322:RNA Precursors; D012331:RNA, Fungal; D020537:RNA, Small Nucleolar; C117378:RNA, U3 small nucleolar; D020718:Ribonucleoproteins, Small Nucleolar; D029701:Saccharomyces cerevisiae Proteins