Identification and Functional Consequences of a Recurrent NLRP12 Missense Mutation in Periodic Fever Syndromes
Identification and Functional Consequences of a Recurrent NLRP12 Missense Mutation in Periodic Fever Syndromes
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DOI：
10.1002/art.30241
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发表时间：
2011-05-01
影响因子：
--
通讯作者：
Amselem, Serge
中科院分区：
文献类型：
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作者：
Jeru, Isabelle;Le Borgne, Gaelle;Amselem, Serge
Objective.通过筛选NLRP 12（一个迄今为止只发现了一个无义和一个剪接位点突变的基因），深入了解遗传原因不明的周期性发热综合征（PFS）的分子基础，并评估所发现的错义变异的功能后果。通过直接测序筛选NLRP 12的突变。为了确定正常和突变的NLRP 12蛋白对斑点形成、半胱天冬酶1信号传导和NF-κ B激活的影响，在稳定表达促凋亡蛋白ASC和半胱天冬酶1的HEK 293 T细胞中进行功能测定。在编码蛋白质核苷酸结合位点（NBS）的外显子3中，在来自不同国家并携带不同NLRP 12单倍型的2名患者中鉴定出涉及CpG位点（c.1054C>T; p.Arg352Cys）的杂合NLRP 12错义突变。该突变不改变NLRP 12对NF-κ B激活的抑制作用，增加斑点形成并激活半胱天冬酶1信号传导。为了定义这种新的PFS类别，我们提出术语NLRP 12相关疾病（NLRP 12 AD）。鉴于已知NLRP 12相关疾病的罕见性，该NLRP 12分子缺陷的鉴定有助于描绘与该基因突变相关的临床谱，并强调了在出现原因不明的PFS的患者中筛查NLRP 12的重要性。本研究还通过功能测定证明了这种复发性错义突变的有害作用;与这种NBS突变相关的斑点形成和半胱天冬酶1信号传导的功能获得与PFS的炎症表型一致。
Objective. To gain insight into the molecular bases of genetically unexplained periodic fever syndromes (PFS) by screening NLRP12, a gene in which only a nonsense and a splice site mutation have so far been identified, and to assess the functional consequences of the identified missense variation.Methods. NLRP12 was screened for mutations by direct sequencing. Functional assays were performed in HEK 293T cells stably expressing the proapoptotic protein ASC and procaspase 1, in order to determine the effects of normal and mutated NLRP12 proteins on speck formation, caspase 1 signaling, and NF-kappa B activation.Results. A heterozygous NLRP12 missense mutation involving a CpG site (c.1054C>T; p. Arg352Cys) was identified in exon 3, which encodes the nucleotide-binding site (NBS) of the protein, in 2 patients from different countries and carrying different NLRP12 haplotypes. The mutation, which does not alter the inhibitory effect of NLRP12 on NF-kappa B activation, increases speck formation and activates caspase 1 signaling. To define this new class of PFS, we propose the term NLRP12-associated disorders (NLRP12AD).Conclusion. Given the rarity of known NLRP12-associated disorders, the identification of this NLRP12 molecular defect contributes to the delineation of the clinical spectrum associated with mutations in this gene and highlights the importance of screening NLRP12 in patients presenting with unexplained PFS. This study also demonstrates, by means of functional assays, the deleterious effect of this recurrent missense mutation; the gain of function for speck formation and caspase 1 signaling associated with this NBS mutation is consistent with the inflammatory phenotype of PFS.