VicK激酶活性对变异链球菌的生物学影响  

Functional Analysis of VicK Kinase Activity in Streptococcus Mutans

作　　者：张琼[1] 王诗达 周学东[1] 程磊[1] 李雨庆[1] Dilani B.Senadheera Dennis G.Cvitkovitch 

机构地区：[1]口腔疾病研究国家重点实验室四川大学华西口腔医院牙体牙髓病科,成都610041 [2]多伦多大学牙学院牙学研究所

出　　处：《四川大学学报（医学版）》2013年第6期911-915,共5页Journal of Sichuan University(Medical Sciences)

基　　金：国家自然科学基金(No.81170959)资助

摘　　要：目的研究VicK蛋白的激酶活性对变异链球菌(S.mutans)生理及毒力因子的调控作用。方法使用PCR连接突变技术构建vicK基因敲出株,利用质粒搭载、表达VicK激酶活性废除蛋白。研究实验株菌落形态、隔夜培养菌液的变化、生物膜形成以及生物膜形成相关重要基因转录水平的改变。结果 VicKH217A的菌落表面较野生株UA159及互补株SMCVicK平滑,且菌落也较之高耸;VicKH217A隔夜培养的菌液中细胞共聚堆积在玻璃管底部;VicKH217A形成的生物膜未发生明显改变;gbpB、ftf、gtfD的表达受抑制而gtfB/C基因的表达上调(P<0.05)。结论 VicK的激酶活性对变异链球菌正常生长、生物膜形成及与编码生物膜形成相关蛋白基因的表达起着重要的调节作用。Objective To investigate the regulatory function on physiology and virulence of VicK kinase activity in Streptococcus mutans. Methods PCR ligation mutagenesis was used to construct a vicK knock-out mutant, and kinase activity abolished VicK was expressed by a streptococcal vector in this rick null mutant. Colony morphology, overnight culture, biofilm formation and gene expression involved in biofilm formation were analyzed. AVicK, strains harboring a complemented wild-type ricK, and a vector without insert were used as controls. Results Colonies of VicKH217A were smoother and more elevated than that of wild-type UA159 and complementary strain SMCVicK; cells from VicKH217A overnight culture coaggregated on the bottom of glass tubes; no obvious alteration was observed in VicKH217A hiofilm; expressions of gbpB, ftf, gtfD were repressed while gtfB/C were up-regulated （P〈0.05）. Conclusion VicK kinase activity is important for maintaining normal growth, biofilm formation and expression of genes involved in biofilm formation in Streptococcus mutans.

关 键 词：变异链球菌 双组分信号传导系统 VicK 生物学作用 

分 类 号：R378[医药卫生—病原生物学]