Btc22 chaperone is required for secretion and stability of the type III secreted protein Bsp22 in Bordetella bronchiseptica
Btc22 chaperone is required for secretion and stability of the type III secreted protein Bsp22 in Bordetella bronchiseptica
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DOI：
10.1111/j.1574-6968.2012.02561.x
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发表时间：
2012-06-01
影响因子：
2.1
通讯作者：
Abe, Akio
中科院分区：
文献类型：
--
作者：
Kurushima, Jun;Kuwae, Asaomi;Abe, Akio
III型分泌系统（T3SS）是一种复杂的蛋白质分泌机制，将细菌毒力蛋白递送到宿主细胞中。针尖蛋白Bsp22是T3SS的分泌底物之一，在支气管败血波氏杆菌中T3SS的全部功能中起重要作用。在这项研究中，我们发现BB1618作为Bsp22的伴侣蛋白。BB1618的缺失导致Bsp22分泌到培养上清液中和Bsp22在细菌胞质溶胶中的稳定性的显著损害。相反，其他III型分泌蛋白的分泌不受BB1618突变的影响。此外，BB1618突变株不能诱导细胞毒性，并显示与Bsp22突变株相同的表型。免疫沉淀试验表明，BB1618与Bsp22相互作用，但不与BopB和BopD相互作用。因此，我们鉴定了BB1618作为Bsp 22的特异性III型分子伴侣。因此，我们建议将BB 1618重新命名为Btc22，以获得Bsp 22的III型博德特氏菌分子伴侣。
The type III secretion system (T3SS) is a sophisticated protein secretion machinery that delivers bacterial virulence proteins into host cells. A needle-tip protein, Bsp22 , is one of the secreted substrates of the T3SS and plays an essential role in the full function of the T3SS in Bordetella bronchiseptica. In this study, we found that BB1618 functions as a chaperone for Bsp22 . The deletion of BB1618 resulted in a dramatic impairment of Bsp22 secretion into the culture supernatants and Bsp22 stability in the bacterial cytosol. In contrast, the secretion of other type III secreted proteins was not affected by the BB1618 mutation. Furthermore, the BB1618 mutant strain could not induce cytotoxicity and displayed the same phenotypes as the Bsp22 mutant strain. An immunoprecipitation assay demonstrated that BB1618 interacts with Bsp22 , but not with BopB and BopD . Thus, we identified BB1618 as a specific type III chaperone for Bsp22 . Therefore, we propose that BB1618 be renamed Btc22 for the Bordetella type III chaperone for Bsp22 .