GENOMIC ORGANIZATION OF THE 70-KDA PEROXISOMAL MEMBRANE-PROTEIN GENE (PXMP1)

The 70-kDa peroxisomal membrane protein (PMP70) is a member of a famil y of half-ATP-binding cassette (ABC) transporter proteins located in t he human peroxisomal membrane. Other members include the PMP70-related peroxisomal membrane protein, the adrenoleukodystrophy protein (ALDP) , and the adrenoleukodystrophy-related protein. The functions of ABC t ransporters in the peroxisomal membrane are poorly understood, Evidenc e from yeast and human mutants suggests that they are involved in the peroxisomal import of fatty acids and/or fatty acyl-CoAs into the orga nelle. We report the cloning and characterization of the human PMP70 s tructural gene (gene symbol: PXMP1) localized on human chromosome 1p21 -p22. PXMP1 is approximately 65 kb in length, contains 23 exons, and i s quite different in structure from the gene (ALD) that encodes the re lated protein, ALDP. We also analyzed the 5' flanking region of the hu man PXMP1 gene and the corresponding region of murine Pxmp-1. Both pro moters have features of housekeeping genes, including a high GC conten t and multiple consensus Spl binding sequences. In more than 3 kb of P xmp-1 5' flanking sequence we did not identify a consensus peroxisomal proliferator responsive element. (C) 1998 Academic Press.