Role of charged and hydrophobic residues in the oligomerization of the PYRIN domain of ASC
Role of charged and hydrophobic residues in the oligomerization of the PYRIN domain of ASC
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DOI：
10.1021/bi048374i
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发表时间：
2005-01-18
期刊：
影响因子：
2.9
通讯作者：
Sagara, J
中科院分区：
文献类型：
--
作者：
Moriya, M;Taniguchi, S;Sagara, J
含有半胱氨酸天冬氨酸氨基转移酶招募结构域(ASC)的凋亡相关斑点样蛋白是一种由两个同源蛋白相互作用结构域组成的适配蛋白，即吡林结构域(PYD)和半胱氨酸酶招募结构域(PYD)。依赖于PYD的ASC寡聚被认为在分子平台--炎症体的形成中发挥了关键作用，该分子平台激活了caspase-1。当在细胞中表达时，ASC的PYD通过自结合形成细胞质细丝。分析了70多个单点突变体在表达突变蛋白的细胞中的细丝形成。这组突变包括每个带有带电侧链(Arg、Lys、Asp和Glu)的氨基酸残基和一个大的疏水侧链(Ile、Leu、Met、Phe、Pro和Val)。通过螺旋2、3和4的Lys21、Leu25、Lys26、Pro40、Arg41、Asp48和Asp51突变，阻止了ASC PYD的细丝形成。这些数据识别了一个连贯的相互作用面，建立了对电荷相互作用具有重要作用的PYD-PYD络合物的分子模型。
Apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) is an adaptor protein composed of two homophilic protein-protein interaction domains, a PYRIN domain (PYD) and a caspase recruitment domain. PYD-dependent oligomerization of ASC is thought to play a crucial role in formation of a molecular platform, the inflammasome, which activates caspase-1. When expressed in cells, the PYD of ASC was shown to form cytoplasmic filaments through self-association. Over 70 single point mutants were analyzed for filament formation in cells expressing the mutant proteins. The set of mutations comprised every single amino acid residue with a charged side chain (Arg, Lys, Asp, and Glu) and a large hydrophobic side chain (Ile, Leu, Met, Phe, Pro, and Val). Filament formation of the ASC PYD was prevented by mutation of Lys21, Leu25, Lys26, Pro40, Arg41, Asp48, and Asp51 of helices 2, 3, and 4. These data identify a coherent interaction surface, establishing a molecular model of PYD-PYD complexes with an important role for charge-charge interactions.