Molecular analysis of acid ceramidase deficiency in patients with Farber disease
Molecular analysis of acid ceramidase deficiency in patients with Farber disease
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DOI：
10.1002/humu.5
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发表时间：
2001-01-01
期刊：
影响因子：
3.9
通讯作者：
Sandhoff, K
中科院分区：
文献类型：
--
作者：
Bär, J;Linke, T;Sandhoff, K
法伯病是一种罕见的常染色体隐性遗传性鞘脂贮积症，由于溶酶体酸性神经酰胺酶活性不足，导致神经酰胺在细胞和组织中蓄积。在这里，我们报告的鉴定六个新的突变的酸性神经酰胺酶基因引起法伯病：三个点突变导致单个氨基酸取代，一个内含子剪接位点突变导致外显子跳跃，两个点突变也导致偶尔或完全外显子跳跃。有趣的是，后两种突变发生在相邻的核苷酸中，并导致同一外显子的异常剪接。突变的酸性神经酰胺酶cDNA在COS-1细胞中的表达和随后的酸性神经酰胺酶残留酶活性的测定表明，这些突变中的每一个都是相应患者中酸性神经酰胺酶缺乏的直接原因。相反，两个已知的多态性对酸性神经酰胺酶活性没有影响。4例患者成纤维细胞的代谢标记研究表明，即使在这些个体中合成酸性神经酰胺酶前体蛋白，但溶酶体内发生突变的成熟酸性神经酰胺酶的快速蛋白水解。Mutat 17：199-209，2001. (C)2001 Wiley利斯公司
Farber disease is a rare, autosomal recessively inherited sphingolipid storage disorder due to the deficient activity of lysosomal acid ceramidase, leading to the accumulation of ceramide in cells and tissues. Here we report the identification of six novel mutations in the acid ceramidase gene causing Farber disease: three point mutations resulting in single amino acid substitutions, one intronic splice site mutation resulting in exon skipping, and two point mutations also leading to occasional or complete exon skipping. Of interest, these latter two mutations occurred in adjacent nucleotides and led to abnormal splicing of the same exon. Expression of the mutated acid ceramidase cDNAs in COS-1 cells and subsequent determination of acid ceramidase residual enzyme activity demonstrated that each of these mutations was the direct cause of the acid ceramidase deficiency in the respective patients. In contrast, two known polymorphisms had no effect on acid ceramidase activity. Metabolic labeling studies in fibroblasts of four patients showed that even though acid ceramidase precursor protein was synthesized in these individuals, rapid proteolysis of the mutated, mature acid ceramidase occurred within the lysosome. Hum Mutat 17:199-209, 2001. (C) 2001 Wiley Liss, Inc.