Ectopic production of guanosine penta- and tetraphosphate can initiate early developmental gene expression in Myxococcus xanthus.
Ectopic production of guanosine penta- and tetraphosphate can initiate early developmental gene expression in Myxococcus xanthus.
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DOI：
10.1101/gad.9.13.1633
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发表时间：
1995-07
影响因子：
10.5
通讯作者：
Mitchell Singer;Dale Kaiser
中科院分区：
文献类型：
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作者：
Mitchell Singer;Dale Kaiser
氨基酸或碳限制足以启动黄色粘球菌子实体的发育。在大肠杆菌和M.当细胞缺乏氨基酸或碳时，鸟苷3'-二-5'-（三）二磷酸核苷酸[（p）ppGpp]的水平瞬时升高。在M中实现了（p）ppGpp的细胞内浓度的异位增加。通过引入E. coli relA基因，其产物催化焦磷酸从ATP-转移到GTP-形成pppGpp。急诊coliRelA蛋白在这些M. xanthus菌株，并在色谱上观察到（p）ppGpp的上升。这种细胞内（p）ppGpp水平的增加足以激活发育特异性基因表达。虽然（p）ppGpp由GTP制成，但来自这些菌株的细胞内GTP库没有显著减少。此外，当GTP池被降低的两个具体的抑制剂GTP合成，霉酚酸或decoyinine，发展没有诱导。这些结果表明M.通过（p）ppGpp水平监测氨基酸的内部可用性，xanthus细胞可以评估它们的营养状况。
Amino acid or carbon limitation is sufficient to initiate fruiting body development in Myxococcus xanthus. In both Escherichia coli and M. xanthus the levels of guanosine 3'-di-5'-(tri)di-phosphate nucleotides [(p)ppGpp] rise transiently when cells are starved for amino acids or carbon. Ectopic increase in the intracellular concentration of (p)ppGpp was achieved in M. xanthus by introducing a copy of the E. coli relA gene, whose product catalyzes pyrophosphate transfer from ATP- to GTP-forming pppGpp. The E. coli RelA protein was detected in these M. xanthus strains, and a rise in (p)ppGpp was observed chromatographically. This increase in the intracellular (p)ppGpp levels was sufficient to activate developmentally specific gene expression. Although (p)ppGpp is made from GTP, the intracellular GTP pool from these strains was not significantly decreased. Moreover, when the GTP pool was lowered by either of two specific inhibitors of GTP synthesis, mycophenolic acid or decoyinine, development was not induced. These results suggest that M. xanthus cells can assess their nutritional status by monitoring the internal availability of amino acids through (p)ppGpp levels.