Peroxisome assembly factor 1 is a protein encodes an integral peroxisomal membrane protein required for peroxisome biogenesis. The protein is thought to be involved in peroxisomal matrix protein import. Mutations in this gene result in one form of Zellweger syndrome and infantile Refsum disease. Alternative splicing results in multiple transcript variants encoding the same protein.Shimozawa et al. (1992) demonstrated a point mutation in peroxisome assembly factor-1 (PAF1), a 35-kD peroxisomal membrane protein (PMP35) for which the cDNA had been cloned by Tsukamoto et al. (1991). They had previously shown that this protein corrected the Zellweger-like defect in peroxisome assembly in a peroxisome-deficient Chinese hamster ovary mutant cell line (Z65).