PROTECTIVE PROTEIN GENE-MUTATIONS IN GALACTOSIALIDOSIS
PROTECTIVE PROTEIN GENE-MUTATIONS IN GALACTOSIALIDOSIS
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DOI：
10.1172/jci116472
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发表时间：
1993-06-01
影响因子：
15.9
通讯作者：
SUZUKI, Y
中科院分区：
文献类型：
--
作者：
SHIMMOTO, M;FUKUHARA, Y;SUZUKI, Y
在6名具有不同表型表现的日本半乳糖唾液酸沉积症患者中鉴定了4种不同的保护蛋白cDNA突变，146 A--> G（Q49 R）、193 T--> C（W 65 R）、268- 269 TC--> CT（S90 L）和1184 A--> G（Y395 C），另一种突变，746 T--> A（Y249 N），在具有非典型临床过程的法裔德国患者中。Y395 C是4例日本患者婴幼儿期常见突变; 2例青少年患者为Y395 C与另一常见突变SpDEx 7的复合杂合子，另外2例婴儿为Y395 C与SpDEx 7以外的突变等位基因的复合杂合子。我们通过直接序列分析或限制性酶切位点分析证实了基因组DNA中的这些突变。突变的cDNA克隆，瞬时表达转化的半乳糖唾液酸沉积症细胞系，没有恢复继发性缺陷的β-半乳糖苷酶或α-神经氨酸酶的活性，除了Y249 N突变，表达一些羧肽酶的活性和恢复两个溶酶体酶的活性。脉冲追踪分析在用Y249 N cDNA转染的细胞中检测到少量的成熟形式以及前体。只有前体蛋白被检测到，成熟的蛋白质没有出现的其他突变体的cDNA。
Four different protective protein cDNA mutations, 146A --> G (Q49R), 193T --> C (W65R), 268-269TC --> CT (S90L), and 1184A --> G (Y395C), were identified in six Japanese galactosialidosis patients with various phenotypic manifestations, and another mutation, 746T --> A (Y249N), in a patient of French-German origin with an atypical clinical course. Y395C was a common mutation in four Japanese patients in infancy and childhood; two juvenile patients were compound heterozygotes of Y395C and another common mutation, SpDEx7, and the other two infants were compound heterozygotes of Y395C and mutant alleles other than SpDEx7. We confirmed these mutations in genomic DNA by direct-sequence analysis or restriction-site analysis. The mutant cDNA clones, transiently expressed in a transformed galactosialidosis cell line, did not restore the secondarily deficient beta-galactosidase or alpha-neuraminidase activity except for the Y249N mutation that expressed some carboxypeptidase activity and restored the two lysosomal enzyme activities. Pulse-chase analysis detected a small amount of the mature form, as well as the precursor, in the cells transfected with the Y249N cDNA. Only precursor proteins were detected, mature proteins not appearing for the other mutant cDNAs.