The guanosine nucleotide (p)ppGpp initiates development and A-factor production in Myxococcus xanthus
The guanosine nucleotide (p)ppGpp initiates development and A-factor production in Myxococcus xanthus
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DOI：
10.1101/gad.12.7.1022
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发表时间：
1998-04-01
影响因子：
10.5
通讯作者：
Singer, M
中科院分区：
文献类型：
--
作者：
Harris, BZ;Kaiser, D;Singer, M
鸟苷3′-二-5′-（三）二磷酸核苷酸[(p)ppGpp]是在氨基酸限制下合成的，可诱导黄粘球菌早期基因表达，导致多细胞子实体形成。在饥饿反应中不能积累ppGpp的突变体（DK527）被发现在聚集前发育受阻。通过使用一系列发育调控的Tn5lac转录融合报告基因，DK527的发育停滞时间被缩小到发育后的几个小时内，即饥饿识别期。突变体在a因子的产生上也有缺陷，a因子是一种早期的细胞外细胞密度信号。来自大肠杆菌的relA基因编码核糖体依赖性(p)ppGpp合成酶，拯救了这个突变体。我们还证明了黄顶菌a同源物的失活会阻碍(p)ppGpp的发育和积累。此外，粘球菌relA的野生型等位基因拯救了DK527。这些观察结果支持了一个模型，在这个模型中，(p)PPGPP的积累，作为对饥饿的反应，启动了子实体发育程序，包括a因子的产生。
Guanosine 3'-di-5'-(tri)di-phosphate nucleotides [(p)ppGpp], synthesized in response to amino acid limitation, induce early gene expression leading to multicellular fruiting body formation in Myxococcus xanthus. A mutant (DK527) that fails to accumulate (p)ppGpp in response to starvation was found to be blocked in development prior to aggregation. By use of a series of developmentally regulated Tn5lac transcriptional fusion reporters, the time of developmental arrest in DK527 was narrowed to within the few hours of development, the period of starvation recognition. The mutant is also defective in the production of A-factor, an early extracellular cell-density signal. The relA gene from Escherichia coli, which encodes a ribosome-dependent (p)ppGpp synthetase, rescues this mutant. We also demonstrate that inactivation of the M. xanthus relA homolog blocks development and the accumulation of (p)ppGpp. Moreover, the wild-type allele of Myxococcus relA rescues DK527. These observations support a model in which accumulation of (p)PPGPP, in response to starvation, initiates the program of fruiting body development, including the production of A-factor.