β-D-allose inhibits fruiting body formation and sporulation in Myxococcus xanthus
β-D-allose inhibits fruiting body formation and sporulation in Myxococcus xanthus
复制标题
DOI：
10.1128/jb.00792-06
复制
发表时间：
2007-01-01
影响因子：
3.2
通讯作者：
Shi, Wenyuan
中科院分区：
文献类型：
--
作者：
Chavira, Marielena;Cao, Nga;Shi, Wenyuan
黄色粘球菌是一种革兰氏阴性的土壤细菌，它对氨基酸饥饿的反应是进入多细胞发育过程，最终形成充满孢子的子实体。以前的研究利用发育抑制剂（如蛋氨酸，赖氨酸或苏氨酸）揭示了重要的线索，参与子实体形成的机制。我们使用Biolog表型微阵列来筛选384种化学物质，以完全抑制M. xanthus在这里，我们报告了一种新的子实体形成和孢子形成的抑制剂，P-D-阿洛糖的鉴定。β-D-阿洛糖是一种罕见的糖，是己醛糖家族的成员，是葡萄糖的C3差向异构体。我们的研究表明，R-D-阿洛糖不影响细胞生长，活力，凝集，或运动。然而，β-半乳糖苷酶报告基因表明，在发育4至14小时之间激活的基因在β-D-阿洛糖存在下显示出显著较低的表达水平。此外，抑制子实体的形成只发生在当P-D-阿洛糖添加到深层培养物之前12它的发展。在竞争研究中，高浓度的半乳糖和木糖拮抗对β-D-阿洛糖的非结果反应，而葡萄糖能够部分拮抗。最后，通过magellan-4转座子诱变筛选鉴定出了一种推定的葡糖激酶基因glcK，该基因是P-D-阿洛糖介导的子实体形成抑制所需的。随后的glcK突变体的葡萄糖激酶活性测定进一步支持了这种蛋白质在葡萄糖磷酸化中的作用。
Myxococcus xanthus, a gram-negative soil bacterium, responds to amino acid starvation by entering a process of multicellular development which culminates in the assembly of spore-filled fruiting bodies. Previous studies utilizing developmental inhibitors (such as methionine, lysine, or threonine) have revealed important clues about the mechanisms involved in fruiting body formation. We used Biolog phenotype microarrays to screen 384 chemicals for complete inhibition of fruiting body development in M. xanthus. Here, we report the identification of a novel inhibitor of fruiting body formation and sporulation, P-D-allose. P-D-Allose, a rare sugar, is a member of the aldohexose family and a C3 epimer of glucose. Our studies show that R-D-allose does not affect cell growth, viability, agglutination, or motility. However, beta-galactosidase reporters demonstrate that genes activated between 4 and 14 h of development show significantly lower expression levels in the presence Of P-D-allose. Furthermore, inhibition of fruiting body formation occurs only when P-D-allose is added to submerged cultures before 12 It of development. In competition studies, high concentrations of galactose and xylose antagonize the nonfruiting response to P-D-allose, while glucose is capable of partial antagonism. Finally, a magellan-4 transposon mutagenesis screen identified glcK, a putative glucokinase gene, required for P-D-allose-mediated inhibition of fruiting body formation. Subsequent glucokinase activity assays of the glcK mutant further supported the role of this protein in glucose phosphorylation.