Seawater-Regulated Genes for Two-Component Systems and Outer Membrane Proteins in Myxococcus
Seawater-Regulated Genes for Two-Component Systems and Outer Membrane Proteins in Myxococcus
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粘球菌二组分系统和外膜蛋白的海水调节基因
DOI：
10.1128/jb.01556-08
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发表时间：
2009-04-01
影响因子：
3.2
通讯作者：
Li, Yue-zhong
中科院分区：
文献类型：
--
作者：
Pan, Hong-wei;Liu, Hong;Li, Yue-zhong
摘要当耐盐粘球菌细胞迁移到海水环境中时，它们会改变它们的生长、形态和发育行为。外膜蛋白和信号转导通路可能在这一转变中发挥重要作用。针对黄曲霉DK1622编码226个双组分信号转导通路和74个外膜蛋白的基因进行芯片杂交，结果表明耐盐黄腐菌HW-1中55个相应基因的表达被海水显著上调(大部分下调)。测序显示，这些受海水调节的基因在两个菌株中高度同源，表明它们在粘球菌的生活方式中具有相似的作用。已报道的黄曲霉DK1622中的7个基因参与了不同的细胞过程，如子实体发育、孢子形成或运动。外膜(Om)基因Om031的表达变化最为显著(下调)，而双组分体系(TC)基因Tc105的表达上调幅度最大。它们的同源基因MXAN3106和MXAN4042在DK1622中被敲除，以分析它们对盐度变化的反应功能。与DK1622相比，MXAN3106突变体的耐盐性增强，产孢量增加，而突变基因MXAN4042产生相反的结果。这些结果表明，参与细胞过程的基因也可能与粘球菌细胞的耐盐性有关，这些基因对盐度的响应明显改变。调节这些多功能基因的表达水平可能会使细胞对沿海环境中不断变化的条件做出快速而有效的反应。
ABSTRACT When salt-tolerant Myxococcus cells are moved to a seawater environment, they change their growth, morphology, and developmental behavior. Outer membrane proteins and signal transduction pathways may play important roles in this shift. Chip hybridization targeting the genes predicted to encode 226 two-component signal transduction pathways and 74 outer membrane proteins of M. xanthus DK1622 revealed that the expression of 55 corresponding genes in the salt-tolerant strain M. fulvus HW-1 was significantly modified (most were downregulated) by the presence of seawater. Sequencing revealed that these seawater-regulated genes are highly homologous in both strains, suggesting that they have similar roles in the lifestyle of Myxococcus. Seven of the genes that had been reported in M. xanthus DK1622 are involved in different cellular processes, such as fruiting body development, sporulation, or motility. The outer membrane (Om) gene Om031 had the most significant change in expression (downregulated) in response to seawater, while the two-component system (Tc) gene Tc105 had the greatest increase in expression. Their homologues MXAN3106 and MXAN4042 were knocked out in DK1622 to analyze their functions in response to changes in salinity. In addition to having increased salt tolerance, sporulation of the MXAN3106 mutant was enhanced compared to that of DK1622, whereas mutating gene MXAN4042 produced contrary results. The results indicated that the genes that are involved in the cellular processes that are significantly changed in response to salinity may also be involved the salt tolerance of Myxococcus cells. Regulating the expression levels of these multifunctional genes may allow cells to quickly and efficiently respond to changing conditions in coastal environments.