The B30.2 domain of pyrin, the familial Mediterranean fever protein, interacts directly with caspase-1 to modulate IL-1β production
The B30.2 domain of pyrin, the familial Mediterranean fever protein, interacts directly with caspase-1 to modulate IL-1β production
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DOI：
10.1073/pnas.0602081103
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发表时间：
2006-06-27
影响因子：
11.1
通讯作者：
Kastner, Daniel L.
中科院分区：
文献类型：
--
作者：
Chae, Jae Jin;Wood, Geryl;Kastner, Daniel L.
家族性地中海热（FMF）是中东地区一种携带者频率较高的复发性遗传性自身炎症性疾病。FMF中突变的蛋白质Pyrin通过其N-末端PYRIN基序与ASC衔接蛋白的同源相互作用调节半胱天冬酶-1活化，并因此调节IL-1 β产生。然而，绝大多数突变位于pyrin的C-末端B30.2结构域。在这里，我们证明了这个结构域与caspase-1的直接相互作用。在不表达ASC的细胞的裂解物中，GST的相互下拉证明了pyrin与caspase-1的p20和p10催化亚基的相互作用。从THP-1人单核细胞的pyrin和caspase-1的免疫共沉淀与内源性蛋白质的相互作用是一致的。Pyrin的C-末端B30.2结构域对于相互作用是必要和充分的，并且结合被FMF相关的B30.2突变降低。全长pyrin在用半胱天冬酶-1/IL-1 β构建体转染的细胞中减弱了IL-1 β的产生，FMF相关的B30.2突变和B30.2缺失突变体减弱了这种作用。半胱天冬酶-1的晶体结构与推导出的结构的pyrin B30.2域的建模证实了M694 V和M680 I pyrin突变的相互作用和重要性。与pyrin对IL-1 β激活的净抑制作用一致，THP-1细胞中小干扰RNA（siRNA）介导的pyrin敲除增加了响应细菌LPS的IL-1 β产生。此外，IL-1受体拮抗剂阿那白滞素抑制FMF和淀粉样变性患者的急性期蛋白。我们的数据支持pyrin对IL-1 β激活的直接的、ASC独立的作用，并表明提高的IL-1反应性是pyrin突变的一个选择因素。
Familial Mediterranean fever (FMF) is a recessively inherited autoinflammatory disorder with high carrier frequencies in the Middle East. Pyrin, the protein mutated in FMF, regulates caspase-1 activation and consequently IL-1 beta production through cognate interaction of its N-terminal PYRIN motif with the ASC adaptor protein. However, the preponderance of mutations reside in pyrin's C-terminal B30.2 domain. Here we demonstrate direct interaction of this domain with caspase-1. In lysates from cells not expressing ASC, reciprocal GST pull-downs demonstrated the interaction of pyrin with the p20 and p10 catalytic subunits of caspase-1. Coimmunoprecipitations of pyrin and caspase-1 from THP-1 human monocytic cells were consistent with the interaction of endogenous proteins. The C-terminal B30.2 domain of pyrin is necessary and sufficient for the interaction, and binding was reduced by FMF-associated B30.2 mutations. Full-length pyrin attenuated IL-1 beta production in cells transfected with a caspase-1/IL-1 beta construct, an effect diminished by FMF-associated B30.2 mutations and in B30.2 deletion mutants. Modeling of the crystal structure of caspase-1 with the deduced structure of the pyrin B30.2 domain corroborated both the interaction and the importance of M694V and M680I pyrin mutations. Consistent with a net inhibitory effect of pyrin on IL-1 beta activation, small interfering RNA (siRNA)-mediated pyrin knockdown in THP-1 cells augmented IL-1 beta production in response to bacterial LPS. Moreover, the IL-1 receptor antagonist anakinra suppressed acute-phase proteins in a patient with FMF and amyloidosis. Our data support a direct, ASC-independent effect of pyrin on IL-1 beta activation and suggest heightened IL-1 responsiveness as one factor selecting for pyrin mutations.