Identification of responsible amino acid residues in staphylococcal superantigen-like 12 for the activation of mast cells
Identification of responsible amino acid residues in staphylococcal superantigen-like 12 for the activation of mast cells
复制标题
鉴定葡萄球菌类超抗原 12 中负责肥大细胞激活的氨基酸残基
DOI：
10.1111/gtc.12973
复制
发表时间：
2022
期刊：
影响因子：
2.1
通讯作者：
Hida S.
中科院分区：
文献类型：
--
作者：
Kim G.;Itoh S.;Itoh Y.;Ohya S.;Hida S.
据报道，葡萄球菌超抗原样12 （SSL12）可引起小鼠肥大细胞的脱颗粒。参考菌株NCTC8325基因组的SSL12等位基因变异诱导小鼠肥大细胞脱粒，MRSA252株没有，但序列相似性较高（82%）。为了确定与肥大细胞活化有关的SSL12氨基酸残基，我们在激活和非活性变体之间创建了一系列结构域交换突变体和氨基酸替代突变体。含有寡核苷酸/寡糖结合（OB）折叠结构域的突变体激活了肥大细胞。OB‐fold结构域56位（L56F）的替换降低了肥大细胞的刺激活性，L56F/K92E、L56F/D95S和L56F/S100V的组合替换消除了含有OB‐fold结构域的活性变体和完整活性变体的突变体的刺激活性。这表明，SSL12对肥大细胞激活的响应元件位于SSL12的OB - fold中，而L56可能是肥大细胞激活的必需氨基酸残基。这一发现将有助于理解SSL12在肥大细胞活化和类毒素发展中的分子机制，防止与金黄色葡萄球菌相关的过敏性炎症。
Staphylococcal superantigen‐like 12 (SSL12) is reported to evoke the degranulation in murine mast cells. The allelic variant of SSL12 in the genome of reference strain NCTC8325 induced the degranulation of murine mast cells, that of MRSA252 strain did not, nevertheless relatively high sequence similarity (82%). To identify responsible amino acid residues of SSL12 for mast cell activation, we created a series of domain swap mutants and amino acid substitution mutants between the active and inactive variants. The mutants that harbored oligonucleotide/oligosaccharide binding (OB)‐fold domain of the active variant activated mast cells. The replacement at position 56 (L56F) in the OB‐fold domain diminished the mast cell stimulatory activity, and the combinatorial substitutions L56F/K92E, L56F/D95S, and L56F/S100V abolished the stimulatory activities of the mutant that harbored OB‐fold domain of the active variant and the intact active variant. These indicate that the responsive elements of SSL12 for mast cell activation are in the OB‐fold of SSL12, and L56 would be an essential amino acid residue for the activation of mast cells. The findings would contribute to the understanding of the molecular mechanism of SSL12 for mast cell activation and the development of toxoids preventing allergic inflammations associated withStaphylococcus aureus.