Open AccessHuman PEX1 cloned by functional complementation on a CHO cell mutant is responsible for peroxisome-deficient Zellweger syndrome of complementation group I
Author(s) -
Shigehiko Tamura,
Kanji Okumoto,
Ryusuke Toyama,
Nobuyuki Shimozawa,
Tomoko Tsukamoto,
Yasuyuki Suzuki,
Takashi Osumi,
Naomi Kondo,
Yukio Fujiki
Publication year - 1998
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.95.8.4350
Subject(s) - zellweger syndrome , complementation , biology , peroxisomal disorder , peroxisome , chinese hamster ovary cell , microbiology and biotechnology , mutant , genetics , gene , cell culture
The peroxisome biogenesis disorders (PBDs), including Zellweger syndrome (ZS) and neonatal adrenoleukodystrophy (NALD), are autosomal recessive diseases caused by defects in peroxisome assembly, for which at least 10 complementation groups have been reported. We have isolated a humanPEX1 cDNA (HsPEX1 ) by functional complementation of peroxisome deficiency of a mutant Chinese hamster ovary (CHO) cell line, ZP107, transformed with peroxisome targeting signal type 1-tagged “enhanced” green fluorescent protein. This cDNA encodes a hydrophilic protein (Pex1p) comprising 1,283 amino acids, with high homology to the AAA-type ATPase family. A stable transformant of ZP107 withHsPEX1 was morphologically and biochemically restored for peroxisome biogenesis.HsPEX1 expression restored peroxisomal protein import in fibroblasts from three patients with ZS and NALD of complementation group I (CG-I), which is the highest-incidence PBD. A CG-I ZS patient (PBDE-04) possessed compound heterozygous, inactivating mutations: a missense point mutation resulting in Leu-664 → Pro and a deletion of the sequence from Gly-634 to His-690 presumably caused by missplicing (splice site mutation). Both PBDE-04PEX1 cDNAs were defective in peroxisome-restoring activity when expressed in the patient fibroblasts as well as in ZP107 cells. These results demonstrate thatPEX1 is the causative gene for CG-I peroxisomal disorders.