Sebo P, Glaser P, Sakamoto H, Ullmann A
Unité de Biochimie des Régulations Cellulaires, Institut Pasteur, Paris, France.
Gene. 1991 Jul 31;104(1):19-24. doi: 10.1016/0378-1119(91)90459-o.
The Bordetella pertussis adenylate cyclase(Cya) toxin-encoding locus (cya) is composed of five genes. The cyaA gene encodes a virulence factor (CyaA), exhibiting adenylate cyclase, hemolytic and invasive activities. The cyaB, D and E gene products are necessary for CyaA transport, and the cyaC gene product is required to activate CyaA. We reconstructed, in Escherichia coli, the cya locus of B. pertussis by cloning the different genes on appropriate vectors under the control of strong promoters and E. coli-specific translation initiation signals. We show that in the absence of additional gene products, CyaA is synthesized at high levels, is endowed with adenylate cyclase activity, but is devoid of invasive and hemolytic activities. CyaC is sufficient to confer upon the adenylate cyclase holotoxin full invasive and partial hemolytic activities. Coexpression of the cyaB, D and E genes neither stimulates nor potentiates the activation brought about by CyaC. This reconstructed system should help to elucidate both the mechanism and the structural requirements of holotoxin activation.
百日咳博德特氏菌腺苷酸环化酶（Cya）毒素编码基因座（cya）由五个基因组成。cyaA基因编码一种毒力因子（CyaA），具有腺苷酸环化酶、溶血和侵袭活性。cyaB、D和E基因产物是CyaA转运所必需的，而cyaC基因产物是激活CyaA所必需的。我们通过将不同基因克隆到合适的载体上，并在强启动子和大肠杆菌特异性翻译起始信号的控制下，在大肠杆菌中重建了百日咳博德特氏菌的cya基因座。我们发现，在没有其他基因产物的情况下，CyaA能高水平合成，具有腺苷酸环化酶活性，但没有侵袭和溶血活性。CyaC足以赋予腺苷酸环化酶全毒素完全的侵袭活性和部分溶血活性。cyaB、D和E基因的共表达既不刺激也不增强CyaC所带来的激活作用。这个重建系统应该有助于阐明全毒素激活的机制和结构要求。
