回转器模拟微重力对大肠杆菌基因和蛋白表达的影响(英文)

Effects of Simulated Microgravity with Clinostat on Gene and Protein Expression in Escherichia coli

目的研究回转器模拟微重力对革兰氏阴性菌大肠杆菌(Escherichia coli)基因与蛋白表达的影响。方法采用回转器模拟微重力效应,连续2周作用于大肠杆菌ATCC 25922菌株,选取16个靶基因,RT-PCR反应检测处理菌株和对照菌株基因表达的变化;提取菌体蛋白进行双向电泳,电泳图谱采用ImageMaster 2D Platinum软件分析,找出差异表达蛋白,进行基质辅助激光解吸飞行时间质谱(MALDI TOF/TOF质谱)分析。结果在模拟微重力效应作用下,处理菌株与对照菌株相比,16个靶基因中有4个靶基因表达上调,5个下调;15个差异表达蛋白点,其中4个表达上调蛋白质谱鉴定为抗转录终止蛋白NusG、固氮铁蛋白、硫醇过氧化物酶,1个表达下调蛋白为未知蛋白,2个新增蛋白为谷氨酰胺ABC转运周质蛋白,1个表达消失蛋白为IclR转录调节蛋白家族。结论模拟微重力效应可引起大肠杆菌基因及功能蛋白表达的变化。

Abstract：Objective To study the effects of simulated microgravity with clinostat on expression of gene and protein in Escherichia coll. Methods Escherichia coli ATCC 25922 strain was treated by clinostat for 2 weeks, 16 target genes were selected, two-dimensional electrophoresis and mass spectrum were used to detect changes in protein expression and composition. RT-PCR was performed to detect different kinds of gene expressions in treated and untreated strains. Then total protein was extracted and used in two-dimensional electrophoresis a- nalysis. Matrix assisted laser desorption/ionization - time of flight mass spectrometry （MALDI TOF/TOF MS） was used to analyze differential expression of protein between treated and untreated strains. Results With the treatment of simulated microgravity, four kinds of gene expressions were significantly up-regulated and five gene expressions were significantly down-regulated among 16 target genes; For 15 differential expression of protein, transcription antitermination factor NusG, redoxin and thiol peroxidase were up-regulated, hypothet- ical protein was down-regulated. Newly emerged proteins included glutamine ABC transporter periplasmic pro- tein, and disappeared proteins were transcriptional regulator IclR family. Conclusion Simulated mierogravity with clinostat （ SMC ） can induce variations in expression of gene and functional protein in Escherichia coli.