Spo0A links de novo fatty acid synthesis to sporulation and biofilm development in Bacillus subtilis
Spo0A links de novo fatty acid synthesis to sporulation and biofilm development in Bacillus subtilis
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DOI：
10.1111/mmi.12102
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发表时间：
2013-01-01
影响因子：
3.6
通讯作者：
Grau, Roberto
中科院分区：
文献类型：
--
作者：
Pedrido, Maria E.;de Ona, Paula;Grau, Roberto
在枯草芽孢杆菌的孢子形成过程中，定型细胞经历大量的膜重排，产生两种不同大小和命运的细胞：母细胞和前孢子。在这里，我们证明主转录因子 Spo0A 在发育过程中重新激活脂质合成。最大的 Spo0A 依赖性脂质合成发生在不对称分裂和前孢子吞噬的关键阶段。 Spo0A 重新激活 accDA 操纵子，该操纵子编码乙酰辅酶 A 羧化酶的羧化酶成分，该酶催化脂质从头生物合成的第一步和限速步骤，即丙二酰辅酶 A 形成。 accDA 启动子区域 Spo0A 结合盒的破坏会损害其转录再激活并阻止脂质合成。 Spo0A 不敏感的 accDA(0A) 细胞擅长浮游生长，但在孢子形成（sigma(E) 激活）和生物膜发育（细胞簇形成和防水性）方面存在缺陷。向 accDA(0A) 细胞补充外源脂肪酸可以克服其在发育过程中合成脂质的能力，并恢复孢子形成和生物膜的能力。前孢子中脂质合成调节子的短暂排除以及母细胞中 Spo0A 和 ACP 的已知区室化表明脂质从头合成仅限于母细胞。讨论了枯草芽孢杆菌发育过程中 Spo0A 控制的脂质从头合成的重要性。
During sporulation in Bacillus subtilis, the committed-cell undergoes substantial membrane rearrangements to generate two cells of different sizes and fates: the mother cell and the forespore. Here, we demonstrate that the master transcription factor Spo0A reactivates lipid synthesis during development. Maximal Spo0A-dependent lipid synthesis occurs during the key stages of asymmetric division and forespore engulfment. Spo0A reactivates the accDA operon that encodes the carboxylase component of the acetylCoA carboxylase enzyme, which catalyses the first and rate-limiting step in de novo lipid biosynthesis, malonyl-CoA formation. The disruption of the Spo0A-binding box in the promoter region of accDA impairs its transcriptional reactivation and blocks lipid synthesis. The Spo0A-insensitive accDA(0A) cells were proficient in planktonic growth but defective in sporulation (sigma(E) activation) and biofilm development (cell cluster formation and water repellency). Exogenous fatty acid supplementation to accDA(0A) cells overcomes their inability to synthesize lipids during development and restores sporulation and biofilm proficiencies. The transient exclusion of the lipid synthesis regulon from the forespore and the known compartmentalization of Spo0A and ACP in the mother cell suggest that de novo lipid synthesis is confined to the mother cell. The significance of the Spo0A-controlled de novo lipid synthesis during B. subtilis development is discussed.