Human PEX19:: cDNA cloning by functional complementation, mutation analysis in a patient with Zellweger syndrome, and potential role in peroxisomal membrane assembly
Human PEX19:: cDNA cloning by functional complementation, mutation analysis in a patient with Zellweger syndrome, and potential role in peroxisomal membrane assembly
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DOI：
10.1073/pnas.96.5.2116
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发表时间：
1999-03-02
影响因子：
11.1
通讯作者：
Fujiki, Y
中科院分区：
文献类型：
--
作者：
Matsuzono, Y;Kinoshita, N;Fujiki, Y
至少有11个互补组（CG）已被确定为过氧化物酶体生物合成障碍（PBD），如齐薇格综合征，其中7个致病基因已被阐明。我们已经分离出一个人PEX 19的cDNA（HsPEX 19）的功能互补的过氧化物酶体缺陷的突变中国仓鼠卵巢细胞系，ZP 119，在进口的基质和膜蛋白的缺陷。该cDNA编码包含299个氨基酸的亲水性蛋白（Pex 19 p），在C末端具有异戊烯化基序CAAX盒。法尼基化的Pex 19 p部分（如果不是全部）锚定在过氧化物酶体膜上，将其N-末端部分暴露于胞质溶胶。ZP 119与HsPEX 19的稳定结合在形态学和生物化学上恢复用于过氧化物酶体生物合成。HsPEX 19表达也恢复了CG-J Zellweger综合征患者（PBDJ-01）成纤维细胞中过氧化物酶体蛋白的输入。该患者（PBDJ-01）具有纯合的失活突变：在Met（255）密码子中插入1个碱基A（764），导致移码，诱导完全不同于正常Pex 19 p的24-aa序列。这些结果表明，PEX 19是CG-J PBD的致病基因，并表明C-末端部分，包括CAAX同源盒，是Pex 19 p的生物学功能所必需的。此外，Pex 19 p显然是参与在过氧化物酶体膜组装的初始阶段，在输入的基质蛋白。
At least 11 complementation groups (CGs) have been identified for the peroxisome biogenesis disorders (PBDs) such as Zellweger syndrome, for which seven pathogenic genes have been elucidated. We have isolated a human PEX19 cDNA (HsPEX19) by functional complementation of peroxisome deficiency of a mutant Chinese hamster ovary cell line, ZP119, defective in import of both matrix and membrane proteins. This cDNA encodes a hydrophilic protein (Pex19p) comprising 299 amino acids, with a prenylation motif, CAAX box, at the C terminus. Farnesylated Pex19p is partly, if not all, anchored in the peroxisomal membrane, exposing its N-terminal part to the cytosol. A stable transformant of ZP119 with HsPEX19 was morphologically and biochemically restored for peroxisome biogenesis. HsPEX19 expression also restored peroxisomal protein import in fibroblasts from a patient (PBDJ-01) with Zellweger syndrome of CG-J. This patient (PBDJ-01) possessed a homozygous, inactivating mutation: a 1-base insertion, A(764), in a codon for Met(255), resulted in a frameshift, inducing a 24-aa sequence entirely distinct from normal Pex19p. These results demonstrate that PEX19 is the causative gene for CG-J PBD and suggest that the C-terminal part, including the CAAX homology box, is required for the biological function of Pex19p. Moreover, Pex19p is apparently involved at the initial stage in peroxisome membrane assembly, before the import of matrix protein.