Okumoto K, Itoh R, Shimozawa N, Suzuki Y, Tamura S, Kondo N, Fujiki Y
Department of Biology, Faculty of Science, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Hum Mol Genet. 1998 Sep;7(9):1399-405. doi: 10.1093/hmg/7.9.1399.
Peroxisome biogenesis disorders (PBD), such as Zellweger syndrome, are autosomal recessive diseases caused by a deficiency in peroxisome assembly as well as a malfunction of the peroxisomes, where at least 10 genotypes have been reported. We have isolated a human PEX10 cDNA (HsPEX10) by an expressed sequence tag homology search on a human DNA database using yeast PEX10 from Hansenula polymorpha, followed by screening of a human liver cDNA library. This cDNA encodes a peroxisomal protein (a peroxin Pex10p) comprising 326 amino acids, with two putative transmembrane segments and a C3HC4zinc finger RING motif. Both the N- and C-terminal regions of Pex10p are exposed to the cytosol, as assessed by an expression study of epitope-tagged Pex10p. HsPEX10 expression morphologically and biochemically restored peroxisome biogenesis in fibroblasts from Zellweger patients of complementation group B in Japan (complementation group VII in the USA). One patient (PBDB-01) possessed a homozygous, inactivating mutation, a 2 bp deletion immediately upstream of the RING motif, which resulted in a frameshift, altering 65 amino acids from the normal. This implies that the C-terminal part, including the RING finger, is required for biological function of Pex10p. PEX10 cDNA derived from patient PBDB-01 was defective in peroxisome-restoring activity when expressed in patient fibroblasts. These results demonstrate that mutation in PEX10 is the genetic cause of complementation group B PBD.
过氧化物酶体生物发生障碍（PBD），如泽尔韦格综合征，是由过氧化物酶体组装缺陷以及过氧化物酶体功能异常引起的常染色体隐性疾病，已报道至少有10种基因型。我们利用多形汉逊酵母的酵母PEX10在人类DNA数据库中通过表达序列标签同源性搜索，随后筛选人类肝脏cDNA文库，分离出了人类PEX10 cDNA（HsPEX10）。该cDNA编码一种包含326个氨基酸的过氧化物酶体蛋白（过氧化物酶体蛋白Pex10p），有两个假定的跨膜区段和一个C3HC4锌指RING基序。通过对表位标记的Pex10p进行表达研究评估，Pex10p的N端和C端区域都暴露于胞质溶胶中。HsPEX10的表达在形态学和生物化学上恢复了日本B互补组（美国VII互补组）泽尔韦格患者成纤维细胞中的过氧化物酶体生物发生。一名患者（PBDB - 01）有一个纯合的失活突变，即RING基序上游紧邻的2bp缺失，这导致了移码，使65个氨基酸与正常情况不同。这意味着包括RING指在内的C端部分是Pex10p生物学功能所必需的。当在患者成纤维细胞中表达时，源自患者PBDB - 01的PEX10 cDNA在过氧化物酶体恢复活性方面存在缺陷。这些结果表明，PEX10中的突变是B互补组PBD的遗传原因。
