PXD067909-1

PXD067909 is an original dataset announced via ProteomeXchange.

Title	Sni445 recruits box C/D snoRNPs snR4 and snR45 to guide ribosomal RNA acetylation by Kre33
Description	Eukaryotic ribosome synthesis is a highly complex, multistep process that is best characterized in the yeast Saccharomyces cerevisiae. It is orchestrated by over 200 ribosome assembly factors and 75 small nucleolar ribonucleoproteins (snoRNPs), which guide site-specific chemical modifications of precursor ribosomal RNA (pre-rRNA). While canonical box C/D snoRNPs direct 2?-O-methylation, the atypical box C/D snoRNPs snR4 and snR45 mediate acetylation of 18S rRNA residues C1280 and C1773, respectively, catalyzed by the acetyltransferase Kre33. Here, we identify and characterize Ynl050c/Sni445 as a novel ribosome assembly factor and previously unrecognized auxiliary component of the snR4 and snR45 box C/D snoRNPs. Sni445 associates with snR4 and snR45 in their free form and is required for their stable incorporation into 90S pre-ribosomes. Genetic interactions link Sni445 and the snR4 and snR45 snoRNAs to ribosomal proteins Rps20 (uS10) and Rps14 (uS11), which are positioned near the respective acetylation sites in the 40S subunit. Moreover, Sni445 physically interacts with Kre33 within the 90S pre-ribosome, and its absence abolishes acetylation of C1280 and C1773. Our findings suggest that Sni445 facilitates the recruitment of snR4 and snR45 snoRNPs to 90S particles and might promote their interaction with Kre33, thereby enabling the site-specific acetylation of 18S rRNA by Kre33.
HostingRepository	PRIDE
AnnounceDate	2026-01-30
AnnouncementXML	Submission_2026-01-30_05:35:54.873.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Michael Stumpe
SpeciesList	scientific name: Saccharomyces cerevisiae (Baker's yeast); NCBI TaxID: NEWT:4932;
ModificationList	monohydroxylated residue; iodoacetamide derivatized residue
Instrument	Q Exactive Plus

Revision	Datetime	Status	ChangeLog Entry
0	2025-08-31 02:26:39	ID requested
⏵ 1	2026-01-30 05:35:55	announced

10.1093/nar/gkag030;

Hafner J, Zierler I, Hamze H, Favre S, Thoms M, Kunowska N, Rimser S, Albert B, Caetano T, Aguirrebengoa M, Beckmann R, Stelzl U, Kressler D, Henras AK, Pertschy B, Sni445 recruits box C/D snoRNPs snR4 and snR45 to guide ribosomal RNA acetylation by Kre33. Nucleic Acids Res, 54(3):(2026) [pubmed]

submitter keyword: box C/D snoRNP, yeast,Kre33, cytidine acetylation, ribosome biogenesis

Dieter Kressler
contact affiliation	Departement of Biology University of Fribourg
contact email	dieter.kressler@unifr.ch
lab head
Michael Stumpe
contact affiliation	Department of Biology, University of Fribourg
contact email	michael.stumpe@unifr.ch
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD067909
     1. Label: PRIDE project
     2. Name: Sni445 recruits box C/D snoRNPs snR4 and snR45 to guide ribosomal RNA acetylation by Kre33