Laboratorio de Micología Médica, Depto. de Microbiología, Escuela Nacional de Ciencias Biológicas (ENCB) , Instituto Politécnico Nacional, Prolongación de Carpio y Plan de Ayala s/n, Col. Casco de Santo Tomás, Del. Miguel Hidalgo, CP 11340, Ciudad de México, Mexico.
Laboratorio de Producción y Control de Biológicos ENCB, Instituto Politécnico Nacional, Carpio y Plan de Ayala s/n, Col. Casco de Santo Tomás, Del. Miguel Hidalgo, CP 11340, Ciudad de México, Mexico.
J Mol Model. 2017 Dec 16;24(1):13. doi: 10.1007/s00894-017-3545-z.
Signaling systems allow microorganisms to sense and respond to different stimuli through the modification of gene expression. The phosphorelay signal transduction system in eukaryotes involves three proteins: a sensor protein, an intermediate protein and a response regulator, and requires the transfer of a phosphate group between two histidine-aspartic residues. The SLN1-YPD1-SSK1 system enables yeast to adapt to hyperosmotic stress through the activation of the HOG1-MAPK pathway. The genetic sequences available from Saccharomyces cerevisiae were used to identify orthologous sequences in Candida glabrata, and putative genes were identified and characterized by in silico assays. An interactome analysis was carried out with the complete genome of C. glabrata and the putative proteins of the phosphorelay signal transduction system. Next, we modeled the complex formed between the sensor protein CgSln1p and the intermediate CgYpd1p. Finally, phosphate transfer was examined by a molecular dynamic assay. Our in silico analysis showed that the putative proteins of the C. glabrata phosphorelay signal transduction system present the functional domains of histidine kinase, a downstream response regulator protein, and an intermediate histidine phosphotransfer protein. All the sequences are phylogenetically more related to S. cerevisiae than to C. albicans. The interactome suggests that the C. glabrata phosphorelay signal transduction system interacts with different proteins that regulate cell wall biosynthesis and responds to oxidative and osmotic stress the same way as similar systems in S. cerevisiae and C. albicans. Molecular dynamics simulations showed complex formation between the response regulator domain of histidine kinase CgSln1 and intermediate protein CgYpd1 in the presence of a phosphate group and interactions between the aspartic residue and the histidine residue. Overall, our research showed that C. glabrata harbors a functional SLN1-YPD1-SSK1 phosphorelay system.
信号系统允许微生物通过基因表达的修饰来感知和响应不同的刺激。真核生物中的磷酸接力信号转导系统涉及三种蛋白质：传感器蛋白、中间蛋白和反应调节剂，并且需要在两个组氨酸-天冬氨酸残基之间转移磷酸基团。SLN1-YPD1-SSK1 系统通过激活 HOG1-MAPK 途径使酵母适应高渗应激。利用酿酒酵母的遗传序列，在光滑假丝酵母中鉴定出同源序列，并通过计算机模拟试验鉴定和表征了假定基因。对光滑假丝酵母的全基因组和磷酸接力信号转导系统的假定蛋白进行了互作组分析。接下来，我们构建了传感器蛋白 CgSln1p 和中间蛋白 CgYpd1p 形成的复合物模型。最后，通过分子动力学试验检查了磷酸转移。我们的计算机分析表明，光滑假丝酵母磷酸接力信号转导系统的假定蛋白具有组氨酸激酶、下游反应调节剂蛋白和中间组氨酸磷酸转移蛋白的功能域。所有序列在系统发育上与酿酒酵母的亲缘关系比与白色念珠菌的亲缘关系更密切。互作组表明，光滑假丝酵母的磷酸接力信号转导系统与不同的蛋白相互作用，这些蛋白调节细胞壁生物合成，并以与酿酒酵母和白色念珠菌相似系统相同的方式响应氧化应激和渗透压应激。分子动力学模拟显示，在存在磷酸基团的情况下，组氨酸激酶 CgSln1 的反应调节域与中间蛋白 CgYpd1 形成复合物，并显示出天冬氨酸残基与组氨酸残基之间的相互作用。总的来说，我们的研究表明，光滑假丝酵母具有功能性的 SLN1-YPD1-SSK1 磷酸接力系统。
