如果細(xì)菌之間可以互相交流,，如果細(xì)菌之間還有觸覺，你是不是覺得不可思議呢,？近日,，加州大學(xué)圣芭芭拉分校的研究者表示細(xì)菌之間可以通過接觸進(jìn)行交流,，對(duì)于維持細(xì)菌群體的生長功能非常重要,。這項(xiàng)研究刊登在了近日的國際雜志The Journal Genes&Development上,。
研究者Christopher Hayes教授和他的研究生共同對(duì)尿路致病性大腸桿菌（UPEC）進(jìn)行了研究，UPEC可以引起人類的泌尿系統(tǒng)感染,，這項(xiàng)研究中,，研究者利用細(xì)菌表達(dá)出了一種接觸依賴性生長抑制系統(tǒng)（CDI），依賴此系統(tǒng)可以抑制細(xì)菌生長,，可是當(dāng)靶細(xì)菌中含有CysK代謝酶的時(shí)候,，便不受抑制，CysK是一種需要半胱氨酸合成的代謝酶,，可以結(jié)合至CDI毒素上面,，使得CDI系統(tǒng)作用喪失，而CDI毒素往往可以中斷RNA的ó 因子并且激活它,，CDI系統(tǒng)必須和抑制細(xì)胞一起才能的得到許可對(duì)靶細(xì)胞進(jìn)行抑制,，抑制細(xì)胞可以借助CDI系統(tǒng)與靶細(xì)胞進(jìn)行接觸從而達(dá)到抑制目的。
研究者Hayes表示,，這種CDI系統(tǒng)并不是單一的一個(gè)系統(tǒng),，而是由很多毒性細(xì)胞所構(gòu)成的，這些細(xì)胞可以殺死與其接觸的細(xì)胞,，而且可以利用CDI系統(tǒng)與同類細(xì)胞進(jìn)行交流,，并且組織起大部隊(duì)一塊進(jìn)行作用，例如,，細(xì)胞之間交流可以形成生物被膜,，從而可以形成更加強(qiáng)有力的生存能力。
這項(xiàng)研究的要點(diǎn)是CysK酶,，它可以作為細(xì)菌之間進(jìn)行正常交流溝通的潛在催化劑,，就好比是一種特殊的信息交換方式，或者一個(gè)密碼,。研究者表示,，盡管他們的研究中重點(diǎn)研究的是UPEC，但是很多發(fā)現(xiàn)為治療瘟疫引起的細(xì)菌性腦膜炎和植物病原菌感染也提供了一定的解決策略,。
研究者Low表示,，他們的發(fā)現(xiàn)表明細(xì)菌可以以一種接觸依賴性的語言進(jìn)行溝通交流，細(xì)菌依賴CDI系統(tǒng)和其它的遺傳因素,，通過不同的方式進(jìn)行接觸,，并且對(duì)別的細(xì)菌做出反應(yīng)，研究者們希望自己的研究工作能夠?yàn)榧?xì)菌感染的治療提供一些幫助,，尤其是針對(duì)阻礙致病菌之間進(jìn)行接觸交流的藥物開發(fā)提供一定的基礎(chǔ),，或者開發(fā)出一種藥物可以增強(qiáng)有益細(xì)菌之間的交流,。（生物谷：T.Shen編譯）
doi:10.1101/gad.182345.111
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PMID:
Identification of a target cell permissive factor required for contact-dependent growth inhibition (CDI)
Elie J. Diner1,2, Christina M. Beck1, Julia S. Webb1, David A. Low1,2 and Christopher S. Hayes1,2,3
Bacterial contact-dependent growth inhibition (CDI) is mediated by the CdiB/CdiA family of two-partner secretion proteins. CdiA effector proteins are exported onto the surface of CDI+ inhibitor cells, where they interact with susceptible bacteria and deliver effectors/toxins derived from their C-terminal regions (CdiA-CT). CDI+ cells also produce an immunity protein that binds the CdiA-CT and blocks its activity to prevent autoinhibition. Here, we show that the CdiA-CT from uropathogenic Escherichia coli strain 536 (UPEC536) is a latent tRNase that requires activation by the biosynthetic enzyme CysK (O-acetylserine sulfhydrylase A). UPEC536 CdiA-CT exhibits no nuclease activity in vitro, but cleaves within transfer RNA (tRNA) anti-codon loops when purified CysK is added. CysK and CdiA-CT form a stable complex, and their binding interaction appears to mimic that of the CysK/CysE cysteine synthase complex. CdiA-CT activation is also required for growth inhibition. Synthesis of CdiA-CT in E. coli cysK+ cells arrests cell growth, whereas the growth of ΔcysK mutants is unaffected by the toxin. Moreover, E. coli ΔcysK cells are completely resistant to inhibitor cells expressing UPEC536 CdiA, indicating that CysK is required to activate the tRNase during CDI. Thus, CysK acts as a permissive factor for CDI, providing a potential mechanism to modulate growth inhibition in target cells.
