Fukuda S, Shimozawa N, Suzuki Y, Zhang Z, Tomatsu S, Tsukamoto T, Hashiguchi N, Osumi T, Masuno M, Imaizumi K, Kuroki Y, Fujiki Y, Orii T, Kondo N
Department of Pediatrics, Gifu University School of Medicine, Japan.
Am J Hum Genet. 1996 Dec;59(6):1210-20.
Peroxisome-biogenesis disorders (PBD) are genetically heterogeneous and can be classified into at least ten complementation groups. We recently isolated the cDNA for rat peroxisome assembly factor-2 (PAF-2) by functional complementation using the peroxisome-deficient Chinese-hamster-ovary cell mutant, ZP92. To clarify the novel pathogenic gene of PBD, we cloned the full-length human PAF-2 cDNA that morphologically and biochemically restores peroxisomes of group C Zellweger fibroblasts (the same as group 4 in the Kennedy-Krieger Institute) and identified two pathogenic mutations in the PAF-2 gene in two patients with group C Zellweger syndrome. The 2,940-bp open reading frame of the human PAF-2 cDNA encodes a 980-amino-acid protein that shows 87.1% identity with rat PAF-2 and also restored the peroxisome assembly after gene transfer to fibroblasts of group C patients. Direct sequencing of the PAF-2 gene revealed a homozygous 1-bp insertion at nucleotide 511 (511 insT) in one patient with group C Zellweger syndrome (ZS), which introduces a premature termination codon in the PAF-2 gene, and, in the second patient, revealed a splice-site mutation in intron 3 (IVS3+1G-->A), which skipped exon 3, an event that leads to peroxisome deficiency. Chromosome mapping utilizing FISH indicates that PAF-2 is located on chromosome 6p21.1. These results confirm that human PAF-2 cDNA restores peroxisome of group C cells and that defects in the PAF-2 produce peroxisome deficiency of group C PBD.
过氧化物酶体生物发生障碍（PBD）具有遗传异质性，可分为至少十个互补组。我们最近通过功能互补，利用过氧化物酶体缺陷的中国仓鼠卵巢细胞突变体ZP92分离出大鼠过氧化物酶体组装因子2（PAF-2）的cDNA。为了阐明PBD的新致病基因，我们克隆了全长人PAF-2 cDNA，其在形态学和生物化学上可恢复C组泽尔韦格综合征成纤维细胞（与肯尼迪-克里格研究所的4组相同）的过氧化物酶体，并在两名C组泽尔韦格综合征患者的PAF-2基因中鉴定出两个致病突变。人PAF-2 cDNA的2940 bp开放阅读框编码一个980个氨基酸的蛋白质，与大鼠PAF-2的同源性为87.1%，并且在基因转移到C组患者的成纤维细胞后也恢复了过氧化物酶体组装。对PAF-2基因的直接测序显示，一名C组泽尔韦格综合征（ZS）患者在核苷酸511处有一个纯合的1 bp插入（511 insT），这在PAF-2基因中引入了一个提前终止密码子，在第二名患者中，在内含子3中发现了一个剪接位点突变（IVS3+1G→A），该突变跳过了外显子3，这一事件导致过氧化物酶体缺乏。利用荧光原位杂交（FISH）进行的染色体定位表明，PAF-2位于6号染色体p21.1上。这些结果证实，人PAF-2 cDNA可恢复C组细胞的过氧化物酶体，并且PAF-2的缺陷会导致C组PBD的过氧化物酶体缺乏。
