Is an ortholog of human UBQLN1 (ubiquilin 1) and UBQLN4 (ubiquilin 4). Is predicted to have polyubiquitin modification-dependent protein binding activity. Is involved in positive regulation of transcription from RNA polymerase II promoter in response to endoplasmic reticulum stress and ubiquitin-dependent ERAD pathway. Human ortholog(s) of this gene are implicated in amyotrophic lateral sclerosis type 15.