UBX domain-containing protein 1 (UBXN1)

UBXN1 is a member of the UBX domain-containing protein family, characterized by the presence of a UBX domain at its C-terminus and a UBA (ubiquitin-associated) domain at the N-terminus[2][6]. UBXN1 acts as a cellular receptor for K6-linked polyubiquitin chains, particularly those attached to autoubiquitinated BRCA1, and through bipartite interactions both with ubiquitin and with protein substrates, UBXN1 serves as an inhibitor of BRCA1/BARD1 E3 ligase activity[1][3]. It is also recruited upon viral infection to regulate the RIG-I-like receptor and NF-kappa-B pathways, thus modulating the innate immune response[3][5]. UBXN1 is involved in the coupling of ER-associated protein deglycosylation to proteasome-mediated degradation, supporting protein quality control mechanisms in the cell[3]. There is no evidence that UBXN1 is conjugated in a ubiquitin-like fashion, despite its structural resemblance to ubiquitin; rather, it serves as a regulator and receptor for ubiquitin-mediated signaling[2][6]. Defects in ubiquitin pathway proteins are associated with diverse diseases, including cancer and inflammatory disorders, although UBXN1 itself is not currently a direct therapeutic target[1][3][5].

Other names

UBXN1SAKS1LOC510352B28UBXD10SAPK substrate protein 1UBA/UBX 33.3 kDa protein