微生物所在PNAS发文揭示抗生素在微生物种间信号作用

微生物能够产生多种结构各异的抗生素，然而，对微生物产生抗生素的真正生物学意义的认识至今尚不明晰。目前，研究表明天然抗生素除了对非产生菌的抑杀作用外，还可能在微生物种间起信号作用;但是，迄今为止尚没有在分子层面上，对抗生素作为种间信号介导特定的生理行为及其机理有深入的阐释。

微生物所杨克迁课题组经过潜心研究，发现天蓝色链霉菌能够感应来源于委内瑞拉链霉菌产生的抗生素——杰多霉素(jadomycin B,JdB)信号，引起气生菌丝提前分化和十一烷基灵菌红素产生等一系列生理行为;并证明对种间JdB信号的感应和传导是通过受体ScbR2介导的一个复杂的调控网络实现的;该调控网络包含了一个由ScbR2-AdpA-RedD构成的前馈调控回路(feed-forward loop)，该调控回路可以感应JdB浓度变化、对不同浓度做出不同的生理响应。

该研究还进一步证明其它链霉菌产生的角蒽环化合物在天蓝色链霉菌也都能通过这一信号转导网络诱导相似的生理响应行为，说明角蒽环化合物作为种间信号具有普遍性。这一研究首次报道了角蒽环抗生素的种间信号作用及其分子机制，揭示了抗生素在调节微生物种群相互作用中的生态及进化意义。

相关文章发表在PNAS;文章发表后立即被Faculty of 1000推荐。该工作在杨克迁研究员的指导下，由王为善助理研究员，季俊杰博士和李肖同学等完成，受到基金委重点和科技部973项目的资助。

原文摘要：

Angucyclines as signals modulate the behaviors of Streptomyces coelicolor

Weishan Wang, Junjie Ji, Xiao Li,Juan Wang, Shanshan Li, Guohui Pan,Keqiang Fan, and Keqian Yang

The angucycline antibiotic jadomycin B (JdB) produced by Streptomyces venezuelae has been found here to induce complex survival responses in Streptomyces coelicolor at subinhibitory concentration. The receptor for JdB was identified as a “pseudo” gamma-butyrolactone receptor, ScbR2, which was shown to bind two previously unidentified target promoters, those of redD (redDp) and adpA (adpAp), thus directly regulating undecylprodigiosin (Red) production and morphological differentiation, respectively. Because AdpA also directly regulates the expression of redD, ScbR2, AdpA, and RedD together form a feed-forward loop controlling both differentiation and Red production phenotypes. Different signal strengths (i.e., JdB concentrations) were shown to induce the two different phenotypes by modulating the relative transcription levels of adpA vs. redD. The induction of morphological differentiation and endogenous antibiotic production by exogenous antibiotic exemplifies an important survival strategy more sophisticated than the induction of antibiotic resistance.

标签: 天蓝色链霉菌 角蒽环抗生素 微生物种群相互作用

作者：微生物所

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