Anti-BUD23 antibodies are used in the immunodetection of the protein BUD23 rRNA methyltransferase and ribosome maturation factor. In humans, the canonical protein has a reported length of 281 amino acid residues and a mass of 31.9 kDa. Its subcellular localization is in the nucleus and cytoplasm. Up to 3 different isoforms have been reported for this protein. It is found to be widely expressed, with high levels in the heart, skeletal muscle and kidney. A member of the BUD23/WBSCR22 protein family, BUD23 is reported to be a S-adenosyl-L-methionine-dependent methyltransferase that specifically methylates the N(7) position of a guanine in 18S rRNA. Post-translational modifications have been described, including ubiquitination. Synonyms for this target antigen include Williams-Beuren candidate region putative methyltransferase, Williams-Beuren syndrome chromosomal region 22 protein, Williams-Beuren syndrome chromosome region 22, and probable 18S rRNA (guanine-N(7))-methyltransferase. BUD23 gene orthologs have been reported in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.