Ubinuclein-1 (UBN1)

Ubinuclein-1 (UBN1) is a ubiquitously expressed nuclear protein that functions as part of the HIRA histone chaperone complex, together with HIRA and CABIN1. Its most clearly defined role is as a determinant of histone H3.3-specific binding within this complex, conferring specificity for deposition of the H3.3 histone variant into chromatin—a crucial aspect of epigenetic regulation in non-replicative chromatin assembly. Structurally, UBN1 contains alternating acidic and basic domains capable of interacting with DNA and protein partners, and has been shown to directly interact with the basic region of bZIP transcription factors and viral protein domains, suggesting regulatory potential over transcriptional activity. UBN1 is widely expressed in tissues, and incorporates structural motifs that are related to other nuclear proteins such as nucleolin. There are currently no known drugs that target UBN1, nor is there evidence for its use as a clinical biomarker or therapeutic target.

Other names

HIRA-binding proteinProtein VT4Ubiquitously expressed nuclear proteinVTVT4ubinuclein-1