title: hUTP24 is essential for processing of the human rRNA precursor at site A1, but not at site A0.
abstract: Production of ribosomes relies on more than 200 accessory factors to ensure the proper sequence of steps and faultless assembly of ribonucleoprotein machinery. Among trans-acting factors are numerous enzymes, including ribonucleases responsible for processing the large rRNA precursor synthesized by RNA polymerase I that encompasses sequences corresponding to mature 18S, 5.8S, and 25/28S rRNA. In humans, the identity of most enzymes responsible for individual processing steps, including endoribonucleases that cleave pre-rRNA at specific sites within regions flanking and separating mature rRNA, remains largely unknown. Here, we investigated the role of hUTP24 in rRNA maturation in human cells. hUTP24 is a human homolog of the Saccharomyces cerevisiae putative PIN domain-containing endoribonuclease Utp24 (yUtp24), which was suggested to participate in the U3 snoRNA-dependent processing of yeast pre-rRNA at sites A0, A1, and A2. We demonstrate that hUTP24 interacts to some extent with proteins homologous to the components of the yeast small subunit (SSU) processome. Moreover, mutation in the putative catalytic site of hUTP24 results in slowed growth of cells and reduced metabolic activity. These effects are associated with a defect in biogenesis of the 40S ribosomal subunit, which results from decreased amounts of 18S rRNA as a consequence of inaccurate pre-rRNA processing at the 5'-end of the 18S rRNA segment (site A1). Interestingly, and in contrast to yeast, site A0 located upstream of A1 is efficiently processed upon UTP24 dysfunction. Finally, hUTP24 inactivation leads to aberrant processing of 18S rRNA 2 nucleotides downstream of the normal A1 cleavage site.
authors.affiliation: a Institute of Biochemistry and Biophysics; Polish Academy of Sciences ; Warsaw , Poland.|b Institute of Genetics and Biotechnology; Faculty of Biology; University of Warsaw ; Warsaw , Poland.
authors.forename: Rafal
authors.initials: R
authors.lastname: Tomecki
authors.affiliation: a Institute of Biochemistry and Biophysics; Polish Academy of Sciences ; Warsaw , Poland.|b Institute of Genetics and Biotechnology; Faculty of Biology; University of Warsaw ; Warsaw , Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Labno
authors.affiliation: a Institute of Biochemistry and Biophysics; Polish Academy of Sciences ; Warsaw , Poland.|b Institute of Genetics and Biotechnology; Faculty of Biology; University of Warsaw ; Warsaw , Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Drazkowska
authors.affiliation: a Institute of Biochemistry and Biophysics; Polish Academy of Sciences ; Warsaw , Poland.|b Institute of Genetics and Biotechnology; Faculty of Biology; University of Warsaw ; Warsaw , Poland.
authors.forename: Dominik
authors.initials: D
authors.lastname: Cysewski
authors.affiliation: a Institute of Biochemistry and Biophysics; Polish Academy of Sciences ; Warsaw , Poland.|b Institute of Genetics and Biotechnology; Faculty of Biology; University of Warsaw ; Warsaw , Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Dziembowski
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000378:metabolism; D020134:Catalytic Domain / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics; D053487:DEAD-box RNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D020459:Genes, rRNA; D005816:Genetic Complementation Test; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping; D012322:RNA Precursors / Q000235:genetics* / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012337:RNA, Ribosomal, 18S / Q000235:genetics / Q000378:metabolism; D020537:RNA, Small Nucleolar; D054682:Ribosome Subunits, Small, Eukaryotic / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D002352:Carrier Proteins; D053487:DEAD-box RNA Helicases; D009687:Nuclear Proteins; D012322:RNA Precursors; D012337:RNA, Ribosomal, 18S; D020537:RNA, Small Nucleolar; D029701:Saccharomyces cerevisiae Proteins; C117378:RNA, U3 small nucleolar; C512357:Fcf1 protein, S cerevisiae; C000609024:FCF1 protein, human
keywords: Endoribonuclease; SSU processome; U3 snoRNA; UTP24; rRNA; rRNA processing