Ubiquitin-associated protein 1 is a protein that in humans is encoded by the UBAP1 gene.

This gene is a member of the UBA domain family, whose members include proteins having connections to ubiquitin and the ubiquitination pathway. The ubiquitin associated domain is thought to be a non-covalent ubiquitin binding domain consisting of a compact three helix bundle. This particular protein originates from a gene locus in a refined region on chromosome 9 undergoing loss of heterozygosity in nasopharyngeal carcinoma (NPC). Taking into account its cytogenetic location, this UBA domain family member is being studies as a putative target for mutation in nasopharyngeal carcinomas. Multiple alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq].