Sandvig K, Dubinina E, Garred O, Prydz K, Kozlov J V, Hansen S H, Van Deurs B
Institute for Cancer Research, Norwegian Radium Hospital, Montebello, Oslo.
Zentralbl Bakteriol. 1993 Apr;278(2-3):296-305. doi: 10.1016/s0934-8840(11)80846-7.
The effect of Shiga toxin with mutations in the A fragment has been tested on cells in order to get more information about the processing of the A fragment during entry into the cytosol. A mutant with a deletion between the A1 and A2 domain in the A fragment is resistant to cleavage by trypsin and is less toxic than wild type toxin on both Vero and A431 cells. The results support the view that processing of the A fragment is important for the high toxicity of the wild type toxin. A number of cell lines are resistant to Shiga toxin although they bind the toxin. However, A431 cells can be sensitized by butyric acid treatment, and transport of Shiga toxin to the Golgi apparatus seems to be required for the intoxication in the sensitized cells. The role of retrograde transport through the Golgi apparatus to the endoplasmic reticulum (ER) will be discussed.
为了获取更多关于A片段进入胞质溶胶过程中加工情况的信息，已对具有A片段突变的志贺毒素对细胞的作用进行了测试。A片段中A1和A2结构域之间存在缺失的突变体对胰蛋白酶切割具有抗性，并且在Vero细胞和A431细胞上的毒性均低于野生型毒素。这些结果支持了这样一种观点，即A片段的加工对于野生型毒素的高毒性很重要。尽管许多细胞系能结合志贺毒素，但它们对志贺毒素具有抗性。然而，丁酸处理可使A431细胞致敏，并且志贺毒素向高尔基体的转运似乎是致敏细胞中毒所必需的。将讨论通过高尔基体向内质网（ER）逆行转运的作用。
