DDX21 RNA helicase that acts as a sensor of the transcriptional status of both RNA polymerase (Pol) I and II: promotes ribosomal RNA (rRNA) processing and transcription from polymerase II (Pol II). Binds various RNAs, such as rRNAs, snoRNAs, 7SK and, at lower extent, mRNAs. In the nucleolus, localizes to rDNA locus, where it directly binds rRNAs and snoRNAs, and promotes rRNA transcription, processing and modification. Required for rRNA 2'-O-methylation, possibly by promoting the recruitment of late-acting snoRNAs SNORD56 and SNORD58 with pre-ribosomal complexes. In the nucleoplasm, binds 7SK RNA and is recruited to the promoters of Pol II-transcribed genes: acts by facilitating the release of P-TEFb from inhibitory 7SK snRNP in a manner that is dependent on its helicase activity, thereby promoting transcription of its target genes. Functions as cofactor for JUN-activated transcription: required for phosphorylation of JUN at 'Ser-77'. Can unwind double-stranded RNA (helicase) and can fold or introduce a secondary structure to a single-stranded RNA (foldase). Involved in rRNA processing. May bind to specific miRNA hairpins. Component of a multi-helicase-TICAM1 complex that acts as a cytoplasmic sensor of viral double-stranded RNA (dsRNA) and plays a role in the activation of a cascade of antiviral responses including the induction of proinflammatory cytokines via the adapter molecule TICAM1. Belongs to the DEAD box helicase family. DDX21/DDX50 subfamily. 2 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: EC; Helicase; Nucleolus; RNA processing; RNA-binding
Chromosomal Location of human Ortholog: 10q22.1
Cellular Component:  cytosol; mitochondrion; nucleolus; nucleoplasm; nucleus
Molecular Function:  7SK snRNA binding; ATP binding; ATP-dependent RNA helicase activity; double-stranded RNA binding; identical protein binding; miRNA binding; protein binding; rRNA binding; snoRNA binding
Biological Process:  defense response to virus; innate immune response; positive regulation of gene expression, epigenetic; positive regulation of I-kappaB kinase/NF-kappaB signaling; positive regulation of myeloid dendritic cell cytokine production; response to exogenous dsRNA; rRNA processing; transcription by RNA polymerase II
Reference #:  Q9NR30 (UniProtKB)
Alt. Names/Synonyms: DDX21; DEAD (Asp-Glu-Ala-Asp) box helicase 21; DEAD (Asp-Glu-Ala-Asp) box polypeptide 21; DEAD box protein 21; DEAD-box helicase 21; DEAD/H (Asp-Glu-Ala-Asp/His) box polypeptide 21; DExD-box helicase 21; DKFZp686F21172; Gu protein; Gu-alpha; GUA; GURDB; Nucleolar RNA helicase 2; Nucleolar RNA helicase Gu; Nucleolar RNA helicase II; RH II/Gu; RH-II/GU; RH-II/GuA; RNA helicase II/Gu alpha
Gene Symbols: DDX21
Molecular weight: 87,344 Da
Basal Isoelectric point: 9.32  Predict pI for various phosphorylation states
Protein-Specific Antibodies, siRNAs or Recombinant Proteins from Cell Signaling Technology® Total Proteins
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Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  ENZYME  |  Phospho.ELM  |  NetworKIN  |  GeneCards  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene