Exome Sequencing and cis-Regulatory Mapping Identify Mutations in MAK, a Gene Encoding a Regulator of Ciliary Length, as a Cause of Retinitis Pigmentosa
Exome Sequencing and cis-Regulatory Mapping Identify Mutations in MAK, a Gene Encoding a Regulator of Ciliary Length, as a Cause of Retinitis Pigmentosa
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DOI：
10.1016/j.ajhg.2011.07.005
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发表时间：
2011-08-12
影响因子：
9.8
通讯作者：
Corbo, Joseph C.
中科院分区：
文献类型：
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作者：
Ozgul, Riza Koksal;Siemiatkowska, Anna M.;Corbo, Joseph C.
分析外显子组序列数据的一个基本挑战是将致病突变与背景多态性区分开来。为了在遗传异质性疾病色素性视网膜炎 (RP) 的背景下解决这个问题，我们设计了一种称为顺式调控映射的候选基因优先策略，该策略利用光感受器转录因子 CRX 的 ChIP-seq 数据对候选基因进行排序。外显子组测序与这种方法相结合，在患有 RP 的土耳其近亲家庭的单个受影响成员中发现了男性生殖细胞相关激酶 (MA K) 的纯合无义突变。 MAK 编码一种纤毛相关丝裂原激活蛋白激酶，其功能从纤毛藻莱茵衣藻到人类都是保守的。小鼠和其他模型生物体中 MAK 直系同源物的突变会导致纤毛异常长，并导致小鼠的光感受器快速变性。随后对其他 RP 个体的序列分析发现了 5 名先证者的 MAK 存在错义突变。其中两个突变改变了所有已知激酶中保守的氨基酸，体外激酶测定表明这些突变导致激酶活性丧失。因此，激酶活性似乎对于人类 MAK 功能至关重要。这项研究强调了 CRX 作为光感受器中睫状基因的直接转录调节因子的先前未被充分认识的作用。此外，它证明了基于 CRX 的顺式调控作图在优先考虑外显子组数据中的候选基因方面的有效性，并表明该策略应普遍适用于一系列视网膜疾病。
A fundamental challenge in analyzing exome-sequence data is distinguishing pathogenic mutations from background polymorphisms. To address this problem in the context of a genetically heterogeneous disease, retinitis pigmentosa (RP), we devised a candidate-gene prioritization strategy called cis-regulatory mapping that utilizes ChIP-seq data for the photoreceptor transcription factor CRX to rank candidate genes. Exome sequencing combined with this approach identified a homozygous nonsense mutation in male germ cell-associated kinase (MA K) in the single affected member of a consanguineous Turkish family with RP. MAK encodes a cilium-associated mitogen-activated protein kinase whose function is conserved from the ciliated alga, Chlamydomonas reinhardtii, to humans. Mutations in MAK orthologs in mice and other model organisms result in abnormally long cilia and, in mice, rapid photoreceptor degeneration. Subsequent sequence analyses of additional individuals with RP identified five probands with missense mutations in MAK. Two of these mutations alter amino acids that are conserved in all known kinases, and an in vitro kinase assay indicates that these mutations result in a loss of kinase activity. Thus, kinase activity appears to be critical for MAK function in humans. This study highlights a previously underappreciated role for CRX as a direct transcriptional regulator of ciliary genes in photoreceptors. In addition, it demonstrates the effectiveness of CRX-based cis-regulatory mapping in prioritizing candidate genes from exome data and suggests that this strategy should be generally applicable to a range of retinal diseases.