DELETIONS AFFECTING HEMOLYTIC AND TOXIN ACTIVITIES OF BORDETELLA-PERTUSSIS ADENYLATE-CYCLASE
DELETIONS AFFECTING HEMOLYTIC AND TOXIN ACTIVITIES OF BORDETELLA-PERTUSSIS ADENYLATE-CYCLASE
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DOI：
10.1128/iai.58.10.3242-3247.1990
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发表时间：
1990-10-01
影响因子：
3.1
通讯作者：
ULLMANN, A
中科院分区：
文献类型：
--
作者：
BELLALOU, J;SAKAMOTO, H;ULLMANN, A
百日咳杆菌Cyaa ene编码一种毒力因子，它是一种双功能蛋白，具有钙调素敏感的腺苷环化酶和溶血活性(P.Gaser，H.Sakamoto，J.Bellahov，A.Ullmann和A.Danchin，EMBO J.7：3997-4004,1988)。我们对200 kDa双功能蛋白(CyaA)的溶血和毒素活性进行了表征，结果表明，无论是细胞结合还是分泌，200 kDa的CyaA蛋白都具有溶血和毒素功能。200 kDa的CyaA蛋白经蛋白水解酶消化后，释放出具有催化活性的45 kDa的腺苷环化酶，既不显示溶血活性，也不显示毒素活性。我们在CyaA基因的3‘’区域构建了同相缺失，推测该基因携带溶血决定簇，并表明所产生的蛋白具有野生型腺苷环化酶活性，并且不经处理就能分泌到培养上清中。这些突变的CyaA蛋白的溶血活性严重降低，其毒素活性被取消。这些结果表明，200 kDa的CyaA蛋白的结构完整性是毒素活性所必需的，并且CyaA蛋白的不同结构决定因素参与了分泌、孔形成和进入靶细胞的过程。
The Bordetella pertussis cyaA ene encodes a virulence factor which is a bifunctional protein exhibiting calmodulin-sensitive adenylate cyclase and hemolytic activities (P. Glaser, H. Sakamoto, J. Bellahov, A. Ullmann, and A. Danchin, EMBO J. 7:3997-4004, 1988). We characterized the hemolytic and toxin activities of the 200-kilodalton (kDa) bifunctional (CyaA) protein and showed that, whether cell associated or secreted, the 200-kDa CyaA protein carries hemolytic and toxin functions. The catalytically active 45-kDa form of adenylate cyclase released by proteolytic digestion of the 200-kDa CyaA protein displayed neither hemolytic nor toxin activities. We constructed in-phase deletions in the 3'' region of the cyaA gene, which presumably carries the hemolytic determinant, and showed that the resulting proteins exhibited wild-type adenylate cyclase activity and were secreted without processing into culture supernatants. The hemolytic activities of these mutant CyaA proteins were severely reduced, and their toxin activities were abolished. These results suggest that the structural integrity of the 200-kDa CyaA protein is necessary for toxin activity and that distinct structural determinants with the CyaA protein are involved in secretion, pore formation, and entry into target cells.