渗透压对痢疾志贺菌水通道蛋白glpF基因表达的影响

The effect of osmotic pressure on the expression of aquaporin gene glpF in S. dysenteriae

目的探讨细菌水-甘油通道蛋白(GlpF)的生理功能及其对生长繁殖的影响。方法将用简并PCR发现表达水通道蛋白glpF基因的痢疾志贺菌接种于不同渗透压的液体培养基和添加了GlpF功能抑制剂的相应培养基中,培养不同时间后取培养液检测其生长繁殖量,RT-PCR分析其GlpF的表达。结果痢疾志贺菌GlpF的表达随培养基渗透压的改变而变化,在低渗培养基中的表达低于在等渗环境中;在高渗透压的培养基中,其表达显著高于在等渗培养基中。在加入Hg2+抑制剂抑制GlpF的表达后,在低渗培养基中,未明显影响细菌的生长繁殖,但在较高渗透压的培养基中,细菌的繁殖量显著少于在未加Hg2+抑制剂的同样渗透压培养基中。结论在非等渗环境中,细菌GlpF的表达对细菌细胞内外水分的调节,维持胞内环境稳定起到重要作用,尤其在高渗透压环境中更为明显。

Objective To explore the physiologic function of bacterial GlpF aquaporin and its contribution to the growth and multiplication.Method S.dysenteriae which was discovered to express glpF by the method of degeneracy PCR was inoculated in the liquid media with different osmotic pressures and in the liquid media added with the Hg2＋ inhibitors of GlpF respectively. The bacterial amounts were detected; the expression of GlpF was analyzed by RT-PCR after cultured for different time periods. Result The expression of GlpF in S.dysenteriae altered along with the change of the osmotic conditions in the liquid media.It was lower in the hypotonic media and significantly higher in the hypertonic media than in the isotonic medium.After the Hg2＋inhibitor of GlpF was added in the media,the growth and multiplication of the bacteria were not effected obviously in the hypotonic media,but the bacteria amounts were decreased significantly in the more hypertonic media contrasting in the media with the same osmotic pressure but without Hg2＋inhibitor of GlpF. Conclusion The expression of GlpF in S.dysenteriae play a significant role in regulating water in the exterior and interior of cells and in retaining homeostasis of bacteria,especially in the hypertonic environment.