Anti-DDX21 Rabbit Polyclonal Antibody for WB, IHC-P, IF/ICC, ELISA - Q9NR30

Core Product Specifications and Parameters

Biological Background: DDX21 Function and Localization

• DDX21, also known as nucleolar RNA helicase 2, Gu-alpha, and DEAD box protein 21, is a member of the DEAD-box RNA helicase family, with a predicted molecular weight of ~87 kDa (UniProt: Q9NR30).
• In the nucleolus, DDX21 localizes to ribosomal DNA loci and directly binds rRNAs and small nucleolar RNAs (snoRNAs), promoting rRNA transcription, processing, and 2'-O-methylation by facilitating snoRNA recruitment. Related references: PMID:25470060 , PMID:25477391
• In the nucleoplasm, DDX21 binds 7SK RNA and is recruited to RNA polymerase II-transcribed gene promoters, where it facilitates P-TEFb release from the inhibitory 7SK snRNP complex in a helicase-dependent manner, thereby enhancing transcription. Related references: PMID:25470060
• DDX21 acts as a transcriptional cofactor for JUN, being required for the phosphorylation of JUN at Ser-77. Related references: PMID:11823437 , PMID:25260534
• The protein exhibits ATP-dependent RNA helicase activity (unwinding double-stranded RNA) and RNA foldase activity (introducing secondary structure into single-stranded RNA). Related references: PMID:9461305
• Deacetylation by SIRT7 activates DDX21 helicase function, enabling it to overcome R-loop-mediated RNA polymerase stalling and prevent transcription-associated DNA damage. Related references: PMID:28790157
• DDX21 is a component of a cytoplasmic multi-helicase–TICAM1 complex that senses viral double-stranded RNA, contributing to innate antiviral immunity.
• Subcellularly, DDX21 is primarily nucleolar and nucleoplasmic but can also localize to the cytoplasm, cytosol, and mitochondria under certain conditions.

Experimental Guidance and Technical Tips

• The immunogen spans amino acids 1–180 near the N-terminus of DDX21. As a rabbit polyclonal antibody generated against a recombinant fusion protein, it may recognize multiple epitopes within this region.
• For western blot (WB) under denaturing conditions, a band corresponding to the full-length protein at approximately 87 kDa is expected. Lysates from human or mouse cell lines with confirmed DDX21 expression should be used as positive controls.
• DDX21’s predominant nucleolar and nucleoplasmic localization makes it suitable for immunofluorescence (IF/ICC) and immunohistochemistry (IHC-P). Nuclear enrichment and nucleolar punctate staining may be observed; inclusion of appropriate organelle markers is recommended for verification.
• Given the broad RNA-binding and multi-domain nature of DDX21, antibody performance may vary with fixation, permeabilization, and antigen retrieval protocols. It is advisable to optimize these parameters for the specific cell or tissue type.
• For ELISA applications, the antibody can be used as a capture or detection reagent following standard titration to determine optimal working concentrations.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio serves as a comprehensive one-stop sourcing platform for IVD raw materials, providing validated antibody pairs, optimized monoclonal and polyclonal antibodies, and bulk ancillary reagents. For researchers focusing on DDX21-mediated rRNA processing, transcriptional regulation, and antiviral innate immunity, we offer reliable access to this anti-DDX21 rabbit polyclonal antibody and can assist with sourcing related reagents and assay development support from concept to clinic.