UBXN1 is a widely expressed protein containing an N-terminal ubiquitin-associated (UBA) domain, a coiled-coil region, and a C-terminal ubiquitin-like (UBX) domain. It binds polyubiquitin and valosin-containing protein (VCP), and has been identified as a substrate for stress-activated protein kinases (SAPKs) []. UBXN1 specifically binds to Homer2b []. It may also interact with ubiquitin (Ub) and may be involved in the Ub-proteasome proteolytic pathways. UBXN1 can associate with autoubiquitinated BRCA1 tumour suppressor and inhibit its enzymatic function through its UBA domain [].
