PUBLICATION

The Warsaw Breakage Syndrome-related protein DDX11 is required for ribosomal RNA synthesis and embryonic development

Authors
Sun, X., Chen, H., Deng, Z., Bo, H., Luo, H., Zeng, X., Han, L., Cai, G., Ma, L.
ID
ZDB-PUB-150620-6
Date
2015
Source
Human molecular genetics   24(17): 4901-15 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Animals
  • Cell Nucleolus/metabolism
  • Cell Proliferation
  • DEAD-box RNA Helicases/chemistry
  • DEAD-box RNA Helicases/genetics*
  • DEAD-box RNA Helicases/metabolism*
  • DNA Helicases/chemistry
  • DNA Helicases/genetics*
  • DNA Helicases/metabolism*
  • Embryonic Development/genetics*
  • Gene Expression Regulation
  • Gene Knockdown Techniques
  • HeLa Cells
  • Humans
  • Mutation
  • Pol1 Transcription Initiation Complex Proteins/metabolism
  • Promoter Regions, Genetic
  • Protein Binding
  • Protein Transport
  • RNA, Ribosomal/biosynthesis*
  • RNA, Small Interfering/genetics
  • Transcription, Genetic
  • Zebrafish
PubMed
26089203 Full text @ Hum. Mol. Genet.
Abstract
DDX11 was recently identified as a cause of Warsaw breakage syndrome (WABS). However, the functional mechanism of DDX11 and the contribution of clinically described mutations to the pathogenesis of WABS are elusive. Here, we show that DDX11 is a novel nucleolar protein that preferentially binds to hypomethylated active ribosomal DNA (rDNA) gene loci, where it interacts with upstream binding factor (UBF) and the RNA polymerase I (Pol I). DDX11 knockdown changed the epigenetic state of rDNA loci from euchromatic structures to more heterochromatic structures, reduced the activity of UBF, decreased the recruitment of UBF and RPA194 (a subunit of Pol I) to rDNA promoter, suppressed rRNA transcription, and thereby inhibited growth and proliferation of HeLa cells. Importantly, two indentified WABS-derived mutants, R263Q and K897del, and a Fe-S deletion construct demonstrated significantly reduced binding abilities to rDNA promoters and lowered DNA-dependent ATPase activities compared with wild-type DDX11. Knockdown of the zebrafish ortholog of human DDX11 by mopholinos resulted in growth retardation and vertebral and craniofacial malformations in zebrafish, concomitant with the changes in histone epigenetic modifications at rDNA loci, the reduction of Pol I recruitment to the rDNA promoter and a significant decrease in nascent pre-RNA levels. These growth disruptions in zebrafish in response to DDX11 reduction showed similarities to the clinically described developmental abnormalities found in WABS patients for the first time in any vertebrate. Thus, our results indicate that DDX11 functions as a positive regulator of rRNA transcription and provides a novel insight into the pathogenesis of WABS.
Genes / Markers
Figures
Show all Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping