Anti-Fibrillarin/U3 RNP Rabbit Polyclonal Antibody for WB, IF/ICC, IP, ELISA - P22087

Core Product Specifications and Parameters

Biological Background: Fibrillarin/U3 RNP Function and Localization

• Fibrillarin, encoded by the FBL gene (also known as FIB1, FLRN), is a highly conserved nucleolar protein and was originally identified as the 34 kDa nucleolar scleroderma antigen.
• It functions as an S-adenosyl-L-methionine-dependent methyltransferase that catalyzes site-specific 2'-O-methylation of ribose moieties in pre-ribosomal RNA (pre-rRNA), guided by box C/D small nucleolar RNAs (snoRNAs) (By similarity). Related references: PMID:30540930
• Fibrillarin is a core component of the small subunit (SSU) processome, the earliest precursor of the small ribosomal subunit, assisting in pre-rRNA folding, modifications, and cleavage. Related references: PMID:34516797
• Beyond RNA methylation, fibrillarin acts as a protein methyltransferase, mediating methylation of histone H2A at glutamine 105 (H2AQ104me), which impairs FACT complex binding at the ribosomal DNA locus. Related references: PMID:24352239, PMID:30540930
• It also catalyzes 2'-O-methylation of U6 small nuclear RNA (snRNA) within box C/D RNP complexes, a modification critical for pre-mRNA splicing fidelity. Related references: PMID:32017898
• Subcellularly, fibrillarin predominantly resides in the nucleolus, with additional presence in the nucleoplasm, reflecting its roles in ribosomal RNA processing and splicing.
• Post-translational modifications of fibrillarin include acetylation, phosphorylation, and methylation, as well as isopeptide bond formation and ubiquitin-like conjugation, which may regulate its activity and localization.
• The protein has a molecular weight of 33784 Da and is widely studied as a marker for nucleolar structure and function.

Experimental Guidance and Technical Tips

• The immunogen (amino acids 100-321) covers a central region of fibrillarin, which is highly conserved across species; cross-reactivity with mouse, rat, and monkey is expected.
• In Western blot, a major band at approximately 34 kDa should be observed, corresponding to the full-length protein; additional bands may appear due to post-translational modifications or isoforms.
• For immunofluorescence, fibrillarin localizes to the nucleolus and nucleoplasm; co-staining with nucleolar markers such as nucleolin can validate specificity.
• For immunoprecipitation, optimize antibody concentration and incubation conditions; consider using nuclear extracts to enrich target protein.
• Perform appropriate controls (e.g., blocking peptide, knockout lysates) to confirm antibody specificity in your assay system.

CamelBio: Your One-Stop Sourcing Bridge

CamelBio provides diagnostic manufacturers, laboratories, and research institutes with comprehensive access to IVD raw materials, technical services, and consulting. This anti-Fibrillarin antibody is suitable for researchers studying ribosome biogenesis, nucleolar function, and related diseases. We offer validated antibody pairs, optimized monoclonal and polyclonal antibodies, bulk ancillary reagents, and rare target sourcing to support your assay development from concept to clinic.