Carabetta Valerie J, Greco Todd M, Tanner Andrew W, Cristea Ileana M, Dubnau David
Public Health Research Center at New Jersey Medical School, Rutgers University, Newark, New Jersey, USA.
Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
mSystems. 2016 May;1(3). doi: 10.1128/mSystems.00005-16. Epub 2016 May 31.
-Lysine acetylation has been recognized as a ubiquitous regulatory posttranslational modification that influences a variety of important biological processes in eukaryotic cells. Recently, it has been realized that acetylation is also prevalent in bacteria. Bacteria contain hundreds of acetylated proteins, with functions affecting diverse cellular pathways. Still, little is known about the regulation or biological relevance of nearly all of these modifications. Here we characterize the cellular growth-associated regulation of the acetylome. Using acetylation enrichment and quantitative mass spectrometry, we investigate the logarithmic and stationary growth phases, identifying over 2,300 unique acetylation sites on proteins that function in essential cellular pathways. We determine an acetylation motif, EK(ac)(D/Y/E), which resembles the eukaryotic mitochondrial acetylation signature, and a distinct stationary-phase-enriched motif. By comparing the changes in acetylation with protein abundances, we discover a subset of critical acetylation events that are temporally regulated during cell growth. We functionally characterize the stationary-phase-enriched acetylation on the essential shape-determining protein MreB. Using bioinformatics, mutational analysis, and fluorescence microscopy, we define a potential role for the temporal acetylation of MreB in restricting cell wall growth and cell diameter.
The past decade highlighted -lysine acetylation as a prevalent posttranslational modification in bacteria. However, knowledge regarding the physiological importance and temporal regulation of acetylation has remained limited. To uncover potential regulatory roles for acetylation, we analyzed how acetylation patterns and abundances change between growth phases in . To demonstrate that the identification of cell growth-dependent modifications can point to critical regulatory acetylation events, we further characterized MreB, the cell shape-determining protein. Our findings led us to propose a role for MreB acetylation in controlling cell width by restricting cell wall growth.
赖氨酸乙酰化已被公认为一种普遍存在的调节性翻译后修饰，影响真核细胞中的多种重要生物学过程。最近，人们意识到乙酰化在细菌中也很普遍。细菌含有数百种乙酰化蛋白，其功能影响多种细胞途径。然而，对于几乎所有这些修饰的调节或生物学相关性仍知之甚少。在这里，我们描述了乙酰化蛋白质组与细胞生长相关的调节。利用乙酰化富集和定量质谱技术，我们研究了对数生长期和稳定期，在参与基本细胞途径的蛋白质上鉴定出超过2300个独特的乙酰化位点。我们确定了一个乙酰化基序EK(ac)(D/Y/E)，它类似于真核线粒体乙酰化特征，以及一个独特的稳定期富集基序。通过比较乙酰化变化与蛋白质丰度，我们发现了一组在细胞生长过程中受时间调节的关键乙酰化事件。我们在功能上表征了基本形状决定蛋白MreB上稳定期富集的乙酰化。利用生物信息学、突变分析和荧光显微镜，我们确定了MreB的时间乙酰化在限制细胞壁生长和细胞直径方面的潜在作用。
过去十年强调了赖氨酸乙酰化是细菌中普遍存在的翻译后修饰。然而，关于乙酰化的生理重要性和时间调节的知识仍然有限。为了揭示乙酰化的潜在调节作用，我们分析了[具体细菌名称]生长阶段之间乙酰化模式和丰度的变化。为了证明鉴定细胞生长依赖性修饰可以指向关键的调节性乙酰化事件，我们进一步表征了细胞形状决定蛋白MreB。我们的发现使我们提出MreB乙酰化在通过限制细胞壁生长来控制细胞宽度方面的作用。
