A novel mutation in DDR2 causing spondylo-meta-epiphyseal dysplasia with short limbs and abnormal calcifications (SMED-SL) results in defective intra-cellular trafficking.
A novel mutation in DDR2 causing spondylo-meta-epiphyseal dysplasia with short limbs and abnormal calcifications (SMED-SL) results in defective intra-cellular trafficking.
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DOI：
10.1186/1471-2350-15-42
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发表时间：
2014-04-11
影响因子：
--
通讯作者：
Ali BR
中科院分区：
文献类型：
--
作者：
Al-Kindi A;Kizhakkedath P;Xu H;John A;Sayegh AA;Ganesh A;Al-Awadi M;Al-Anbouri L;Al-Gazali L;Leitinger B;Ali BR
一种罕见的常染色体遗传疾病，伴短肢和异常钙化的脊椎骨-后骺发育不良（SMED-SL），据报道是由人类盘状蛋白结构域受体2 （DDR2）基因错义或剪接位点突变引起的。之前，我们的研究小组已经确定，运输缺陷和配体结合的丧失是几种SMED-SL引起突变的潜在细胞机制。在这里，我们报告了两名疑似患有SMED-SL的近亲婚姻兄弟姐妹的临床特征，并鉴定了一种新的DDR2基因致病突变。通过临床评价和x线摄影对患者进行评价。采用Sanger测序法对DDR2基因的所有编码外显子和剪接位点进行测序。通过共聚焦显微镜、去糖基化实验和Western blotting检测突变DDR2蛋白的亚细胞定位。采用胶原活化法和Western分析法测定DDR2活性。除了SMED-SL的典型特征外，其中一名患者的眼部表型包括视神经萎缩导致的视力障碍。DNA测序显示，两例患者的DDR2基因外显子18上出现了一种新的纯合二核苷酸缺失突变（c.2468_2469delCT）。该突变导致一个移码导致S823位点的氨基酸改变，并预测翻译的提前终止（p.S823Cfs*2）。在哺乳动物细胞系中分析了突变蛋白的亚细胞定位，发现其大部分保留在内质网（ER）中，其n -糖基化谱进一步支持了这一点。与其细胞错误定位一致，突变蛋白被发现缺乏胶原诱导的受体激活，这表明蛋白质运输缺陷是我们患者中DDR2功能丧失的主要细胞机制。我们的研究结果表明，这种新的突变导致DDR2蛋白的运输缺陷，导致功能丧失和疾病。这证实了我们之前的发现，即在激酶结构域发生的DDR2错义突变导致突变蛋白保留在内质网中。
The rare autosomal genetic disorder, Spondylo-meta-epiphyseal dysplasia with short limbs and abnormal calcifications (SMED-SL), is reported to be caused by missense or splice site mutations in the human discoidin domain receptor 2 (DDR2) gene. Previously our group has established that trafficking defects and loss of ligand binding are the underlying cellular mechanisms of several SMED-SL causing mutations. Here we report the clinical characteristics of two siblings of consanguineous marriage with suspected SMED-SL and identification of a novel disease-causing mutation in the DDR2 gene. Clinical evaluation and radiography were performed to evaluate the patients. All the coding exons and splice sites of the DDR2 gene were sequenced by Sanger sequencing. Subcellular localization of the mutated DDR2 protein was determined by confocal microscopy, deglycosylation assay and Western blotting. DDR2 activity was measured by collagen activation and Western analysis. In addition to the typical features of SMED-SL, one of the patients has an eye phenotype including visual impairment due to optic atrophy. DNA sequencing revealed a novel homozygous dinucleotide deletion mutation (c.2468_2469delCT) on exon 18 of the DDR2 gene in both patients. The mutation resulted in a frameshift leading to an amino acid change at position S823 and a predicted premature termination of translation (p.S823Cfs*2). Subcellular localization of the mutant protein was analyzed in mammalian cell lines, and it was found to be largely retained in the endoplasmic reticulum (ER), which was further supported by its N-glycosylation profile. In keeping with its cellular mis-localization, the mutant protein was found to be deficient in collagen-induced receptor activation, suggesting protein trafficking defects as the major cellular mechanism underlying the loss of DDR2 function in our patients. Our results indicate that the novel mutation results in defective trafficking of the DDR2 protein leading to loss of function and disease. This confirms our previous findings that DDR2 missense mutations occurring at the kinase domain result in retention of the mutant protein in the ER.
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DOI：
10.1016/b978-0-12-800180-6.00002-5
发表时间：
2014
影响因子：
--
作者：
Leitinger, Birgit
通讯作者：
Leitinger, Birgit
影响因子：
33.6
作者：
Guerriero CJ;Brodsky JL
通讯作者：
Brodsky JL
DOI：
10.1016/j.str.2009.10.012
发表时间：
2009-12-09
期刊：
Structure (London, England : 1993)
影响因子：
--
作者：
Carafoli F;Bihan D;Stathopoulos S;Konitsiotis AD;Kvansakul M;Farndale RW;Leitinger B;Hohenester E
通讯作者：
Hohenester E
影响因子：
5.7
作者：
Carafoli, Federico;Mayer, Marie Cathrin;Shiraishi, Kazushige;Pecheva, Mira Anguelova;Chan, Lai Yi;Nan, Ruodan;Leitinger, Birgit;Hohenester, Erhard
通讯作者：
Hohenester, Erhard
影响因子：
9.8
作者：
Bargal, Ruth;Cormier-Daire, Valerie;Raas-Rothschild, Annick
通讯作者：
Raas-Rothschild, Annick