Mutational and biological analysis of α-actinin-4 in focal segmental glomerulosclerosis
Mutational and biological analysis of α-actinin-4 in focal segmental glomerulosclerosis
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DOI：
10.1681/asn.2005070706
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发表时间：
2005-12-01
影响因子：
13.6
通讯作者：
Pollak, MR
中科院分区：
文献类型：
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作者：
Weins, A;Kenlan, P;Pollak, MR
α-肌动蛋白-4 基因 (ACTN4) 突变会导致常染色体显性遗传的局灶节段性肾小球硬化症 (FSGS)。对具有 FSGS 家族史的先证者以及非家族 FSGS 个体的 DNA 中的 ACTN4 进行突变分析。还评估了 ACTN4 中非编码变异对 FSGS 发展的可能贡献。在编码和非编码序列中鉴定了多个核苷酸变体。在相关家族中检查了非同义编码序列变体的分离。仅发现了少量可能导致（或促成）疾病的核苷酸变化。确定了预测 I149del、W59R、V801M、R348Q、R837Q 和 R310Q 变化的序列变化。为了研究它们的生物学相关性及其在 FSGS 发病机制中的潜在作用，这些变体在培养的足细胞中表达为 GFP 融合蛋白。还进行了 F-肌动蛋白结合测定。其中三个变体（W59R、I149del 和 V801M）以邻近细胞核的聚集体的形式表现出明显的细胞错误定位。其中两个错误定位的变体（W59R 和 I149del）也显示出肌动蛋白结合活性增加。 I149del 突变与疾病分离； W59R被发现是先证者的新生突变。总共有 5 种被认为会导致疾病的 ACTN4 突变（其中 3 种是之前报道过的，2 种是新的），以及一些对疾病影响尚不清楚的变异体，现在已经被识别出来。不能排除其中一些其他变异增加 FSGS 易感性的可能性。 ACTN4 突变似乎约占家族 FSGS 的 4%。
Mutations in the alpha-actinin-4 gene (ACTN4) cause an autosomal dominant form of focal segmental glomerulosclerosis (FSGS). A mutational analysis was performed of ACTN4 in DNA from probands with a family history of FSGS as well as in individuals with nonfamilial FSGS. The possible contribution of noncoding variation in ACTN4 to the development of FSGS also was assessed. Multiple nucleotide variants were identified in coding and noncoding sequence. The segregation of nonsynonymous coding sequence variants was examined in the relevant families. Only a small number of nucleotide changes that seemed likely to be causing (or contributing to) disease were identified. Sequence changes that predicted I149del, W59R, V801M, R348Q, R837Q, and R310Q changes were identified. For studying their biologic relevance and their potential roles in the pathogenesis of FSGS, these variants were expressed as GFP-fusion proteins in cultured podocytes. F-actin binding assays also were performed. Three of these variants (W59R, I149del, and V801M) showed clear cellular mislocalization in the form of aggregates adjacent to the nucleus. Two of these mislocalized variants (W59R and I149del) also showed an increased actin-binding activity. The I149del mutation segregated with disease; W59R was found to be a de novo mutation in the proband. A total of five ACTN4 mutations that are believed to be disease causing (three reported previously and two novel) as well as a number of variants with unclear contribution to disease now have been identified. The possibility that some of these other variants increase the susceptibility to FSGS cannot be excluded. ACTN4 mutations seem to account for approximately 4% of familial FSGS.