Anti-HECT, UBA and WWE domain containing E3 ubiquitin protein ligase 1 antibodies are used for the immunodetection of the protein encoded by the HUWE1 gene. In humans, the canonical protein has a reported length of 4374 amino acid residues and a mass of 481.9 kDa. Its subcellular localization is in the nucleus, mitochondria, and cytoplasm. Alternative splicing is reported to yield 3 different isoforms for this protein. It is reported to be weakly expressed in the heart, brain and placenta but not in other tissues. A member of the UPL protein family, it is known to be involved with cell differentiation and protein ubiquitination. Post-translational modifications have been described, including phosphorylation. The gene encoding this protein is implicated in Intellectual developmental disorder. Other names for this target antigen include HECTH9, HSPC272, Ib772, LASU1, MRXST, MULE, URE-B1, and ARF-BP1. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish and chimpanzee species.