title: A dynamic scaffold of pre-snoRNP factors facilitates human box C/D snoRNP assembly.
abstract: The box C/D small nucleolar RNPs (snoRNPs) are essential for the processing and modification of rRNA. The core box C/D proteins are restructured during human U3 box C/D snoRNP biogenesis; however, the molecular basis of this is unclear. Here we show that the U8 snoRNP is also restructured, suggesting that this may occur with all box C/D snoRNPs. We have characterized four novel human biogenesis factors (BCD1, NOP17, NUFIP, and TAF9) which, along with the ATPases TIP48 and TIP49, are likely to be involved in the formation of the pre-snoRNP. We have analyzed the in vitro protein-protein interactions between the assembly factors and core box C/D proteins. Surprisingly, this revealed few interactions between the individual core box C/D proteins. However, the novel biogenesis factors and TIP48 and TIP49 interacted with one or more of the core box C/D proteins, implying that they mediate the assembly of the pre-snoRNP. Consistent with this, we show that NUFIP bridges interactions between the core box C/D proteins in a partially reconstituted pre-snoRNP. Restructuring of the core complex probably reflects the conversion of the pre-snoRNP, where core protein-protein interactions are maintained by the bridging biogenesis factors, to the mature snoRNP.
authors.affiliation: Institute for Cell and Molecular Biosciences, University of Newcastle upon Tyne, Newcastle upon Tyne, UK.
authors.forename: Kenneth Scott
authors.initials: KS
authors.lastname: McKeegan
authors.forename: Charles Maurice
authors.initials: CM
authors.lastname: Debieux
authors.forename: Séverine
authors.initials: S
authors.lastname: Boulon
authors.forename: Edouard
authors.initials: E
authors.lastname: Bertrand
authors.forename: Nicholas James
authors.initials: NJ
authors.lastname: Watkins
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002466:Cell Nucleolus / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism; D051379:Mice; D046912:Multiprotein Complexes; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics / Q000378:metabolism; D020718:Ribonucleoproteins, Small Nucleolar / Q000235:genetics / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics / Q000378:metabolism; D035362:Transcription Factor TFIID / Q000235:genetics / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D002868:Chromosomal Proteins, Non-Histone; C105465:KLF6 protein, human; D000075723:Kruppel-Like Factor 6; D051741:Kruppel-Like Transcription Factors; D046912:Multiprotein Complexes; C403092:NUFIP1 protein, human; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D012322:RNA Precursors; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D017411:Ribonucleoproteins, Small Nuclear; D020718:Ribonucleoproteins, Small Nucleolar; C402291:Snu13 protein, human; C106849:TAF9 protein, human; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; C047458:fibrillarin; D000251:Adenosine Triphosphatases; C525849:TIP48 protein, mouse; C525850:TIP49 protein, mouse; D004265:DNA Helicases