title: Protein Hit1, a novel box C/D snoRNP assembly factor, controls cellular concentration of the scaffolding protein Rsa1 by direct interaction.
abstract: Biogenesis of eukaryotic box C/D small nucleolar ribonucleoprotein particles (C/D snoRNPs) involves conserved trans-acting factors, which are proposed to facilitate the assembly of the core proteins Snu13p/15.5K, Nop58p/NOP58, Nop56p/NOP56 and Nop1p/Fibrillarin on box C/D small nucleolar RNAs (C/D snoRNAs). In yeast, protein Rsa1 acts as a platform, interacting with both the RNA-binding core protein Snu13 and protein Pih1 of the Hsp82-R2TP chaperone complex. In this work, a proteomic approach coupled with functional and structural studies identifies protein Hit1 as a novel Rsa1p-interacting partner involved in C/D snoRNP assembly. Hit1p contributes to in vivo C/D snoRNA stability and pre-RNA maturation kinetics. It associates with U3 snoRNA precursors and influences its 3'-end processing. Remarkably, Hit1p is required to maintain steady-state levels of Rsa1p. This stabilizing activity is likely to be general across eukaryotic species, as the human protein ZNHIT3(TRIP3) showing sequence homology with Hit1p regulates the abundance of NUFIP1, the Rsa1p functional homolog. The nuclear magnetic resonance solution structure of the Rsa1p317-352-Hit1p70-164 complex reveals a novel mode of protein-protein association explaining the strong stability of the Rsa1p-Hit1p complex. Our biochemical data show that C/D snoRNAs and the core protein Nop58 can interact with the purified Snu13p-Rsa1p-Hit1p heterotrimer.
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Rothé
authors.affiliation: Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), IPHC-DSA, Université de Strasbourg. CNRS, UMR 7178, 25 rue Becquerel, 67087 Strasbourg, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Saliou
authors.affiliation: FR CNRS-3209 Bioingénierie Moléculaire, Cellulaire et Thérapeutique (BMCT), CNRS, Université de Lorraine, Biopôle, Campus Biologie Santé, CS 50184, 54505 Vandœuvre-lès-Nancy Cedex, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Quinternet
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Back
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.
authors.forename: Decebal
authors.initials: D
authors.lastname: Tiotiu
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.
authors.forename: Clémence
authors.initials: C
authors.lastname: Jacquemin
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Loegler
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Schlotter
authors.affiliation: Max-Planck-Institut für biophysikalische Chemie, Abtl. Röntgenkristallographie, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Vlad
authors.initials: V
authors.lastname: Peña
authors.affiliation: Laboratoire d'Enzymologie et Biochimie Structurales (LEBS), CNRS, 1 Avenue de Terrasse, 91198 Gif-sur Yvette, France.
authors.forename: Kelvin
authors.initials: K
authors.lastname: Eckert
authors.affiliation: Laboratoire d'Enzymologie et Biochimie Structurales (LEBS), CNRS, 1 Avenue de Terrasse, 91198 Gif-sur Yvette, France.
authors.forename: Solange
authors.initials: S
authors.lastname: Moréra
authors.affiliation: Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), IPHC-DSA, Université de Strasbourg. CNRS, UMR 7178, 25 rue Becquerel, 67087 Strasbourg, France.
authors.forename: Alain Van
authors.initials: AV
authors.lastname: Dorsselaer
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France christiane.branlant@univ-lorraine.fr.
authors.forename: Christiane
authors.initials: C
authors.lastname: Branlant
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.
authors.forename: Séverine
authors.initials: S
authors.lastname: Massenet
authors.affiliation: Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), IPHC-DSA, Université de Strasbourg. CNRS, UMR 7178, 25 rue Becquerel, 67087 Strasbourg, France.
authors.forename: Sarah
authors.initials: S
authors.lastname: Sanglier-Cianférani
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Manival
authors.affiliation: Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS Université de Lorraine, Biopôle, Campus Biologie Santé, 9 avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France bruno.charpentier@univ-lorraine-nancy.fr.
authors.forename: Bruno
authors.initials: B
authors.lastname: Charpentier
mesh_terms: D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D026721:RNA 3' End Processing; D020537:RNA, Small Nucleolar / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020718:Ribonucleoproteins, Small Nucleolar / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: C000594604:Hit1 protein, S cerevisiae; C438199:NOP58 protein, S cerevisiae; D009687:Nuclear Proteins; C497702:PIH1 protein, S cerevisiae; D020537:RNA, Small Nucleolar; C117378:RNA, U3 small nucleolar; C402485:RSA1 protein, S cerevisiae; D017411:Ribonucleoproteins, Small Nuclear; D020718:Ribonucleoproteins, Small Nucleolar; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C440569:Snu13 protein, S cerevisiae