Human phytanoyl-CoA hydroxylase: resolution of the gene structure and the molecular basis of Refsum's disease
Human phytanoyl-CoA hydroxylase: resolution of the gene structure and the molecular basis of Refsum's disease
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DOI：
10.1093/hmg/9.8.1195
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发表时间：
2000-05-01
影响因子：
3.5
通讯作者：
Wanders, RJA
中科院分区：
文献类型：
--
作者：
Jansen, GA;Hogenhout, EM;Wanders, RJA
Refsum病(RD)是一种遗传性神经综合征，生化特征是植酸在血浆和组织中积聚。RD患者由于植酰辅酶A羟基酶(PHYH)活性不足而不能降解植酸，这是一种催化植酸α氧化第一步的过氧化物酶。为了能够在基因组水平上进行RD的突变分析，我们已经阐明了PHYH基因的基因组组织。该基因与21kb相似，包含9个外显子和8个内含子。对22例RD患者的PHYH基因进行突变分析，共发现14个错义突变，其中3个碱基插入，1个碱基缺失，均在基因组水平得到证实。在几例RD患者的PHYH基因中发现了111个碱基的缺失，这是由于同一剪接受体位点上的两个不同突变之一导致了外显子3的跳过。为了研究它们对PhyH活性的影响，在酿酒酵母中表达了6个突变，包括1个大的框内缺失和5个错义突变。结果表明，所有这些突变都导致了一种酶失活的PhyH蛋白。
Refsum's disease (RD) is an inherited neurological syndrome biochemically characterized by the accumulation of phytanic acid in plasma and tissues. Patients with RD are unable to degrade phytanic acid due to a deficient activity of phytanoyl-CoA hydroxylase (PhyH), a peroxisomal enzyme catalysing the first step of phytanic acid alpha-oxidation. To enable mutation analysis of RD at the genome level, we have elucidated the genomic organization of the PHYH gene. The gene is similar to 21 kb and contains nine exons and eight introns. Mutation analysis of PHYH cDNA from 22 patients with RD revealed 14 different missense mutations, a 3 bp insertion, and a 1 bp deletion, which were all confirmed at the genome level. A 111 bp deletion identified in the PHYH cDNA of several patients with RD was due to either one of two different mutations in the same splice acceptor site, which result in skipping of exon 3. Six mutations, including a large in-frame deletion and five missense mutations, were expressed in the yeast Saccharomyces cerevisiae to study their effect on PhyH activity. The results showed that all these mutations lead to an enzymatically inactive PhyH protein.