Howard S P, Buckley J T
J Bacteriol. 1983 Apr;154(1):413-8. doi: 10.1128/jb.154.1.413-418.1983.
Pleiotropic export mutants of Aeromonas hydrophila were obtained which are unable to release protease, hemolysin, and glycerophospholipid:cholesterol acyltransferase. The synthesis of the proteins was not impaired; they were accumulated in active forms inside the mutant cells. The hemolysin could be isolated from cell contents by immunoprecipitation in a form with the same apparent molecular weight as the wild-type extracellular product, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Because both the protease and the hemolysin could be released from the mutant cells by osmotic shock, it was concluded that they were accumulated in the periplasmic space. Some mutants were missing two major outer membrane proteins, both of which reappeared in revertants with the wild-type excretory phenotype. Another mutant class had a normal outer membrane protein profile. That two different mutant classes could be obtained indicates that at least two gene products may be needed for export after protein translocation through the inner membrane. The accumulation of proteins which can be released by osmotic shock suggests that the periplasm may be part of the normal route for protein export.
获得了嗜水气单胞菌的多效性分泌突变体，这些突变体无法分泌蛋白酶、溶血素和甘油磷脂：胆固醇酰基转移酶。蛋白质的合成未受损害；它们以活性形式积累在突变体细胞内。通过免疫沉淀从细胞内容物中分离出的溶血素，经十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳测定，其表观分子量与野生型细胞外产物相同。由于蛋白酶和溶血素都可通过渗透压休克从突变体细胞中释放出来，因此得出结论，它们积累在周质空间。一些突变体缺失两种主要的外膜蛋白，而这两种蛋白在具有野生型分泌表型的回复突变体中重新出现。另一类突变体具有正常的外膜蛋白谱。能够获得两种不同的突变体类别表明，蛋白质通过内膜转运后，至少需要两种基因产物才能进行分泌。可通过渗透压休克释放的蛋白质的积累表明，周质可能是蛋白质分泌正常途径的一部分。
