An atlas of Arabidopsis protein S-Acylation reveals its widespread role in plant cell organisation of and function
An atlas of Arabidopsis protein S-Acylation reveals its widespread role in plant cell organisation of and function
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DOI：
10.1101/2020.05.12.090415
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
M. Kumar;P. Carr;S. Turner
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文献类型：
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作者：
M. Kumar;P. Carr;S. Turner
S-酰化是将脂肪酸添加到蛋白质的半胱氨酸残基上。虽然这种修饰可能会深刻地改变蛋白质的行为，但其对植物蛋白功能的影响仍然很少被表征，这主要是由于缺乏关于哪些蛋白质被 S-酰化以及修饰发生在蛋白质中的位置的基本信息。为了弥补我们知识上的这一空白，我们对 6 个不同组织的植物蛋白 S-酰化进行了全面分析。在我们最高置信度组中，我们鉴定了 5185 个经过 S-酰化修饰的半胱氨酸，它们位于来自 2643 个不同蛋白质的 4891 个独特肽中。这约占整个拟南芥蛋白质组的 9%，表明 S-酰化在许多重要的细胞功能（包括运输、信号传导和代谢）中发挥着重要作用。为了说明该数据集的潜力，我们重点关注纤维素合成，并首次确认了已知参与纤维素合成和纤维素合酶复合物运输的所有蛋白质的 S-酰化。在次生细胞壁中，纤维素合成需要三种不同的催化亚基（CESA4、CESA7 和 CESA8），它们都表现出惊人的序列相似性。虽然所有三种蛋白质都被广泛预测在其 N 末端具有 RING 型锌指，但对于 CESA4 和 CESA8，我们发现了该区域半胱氨酸 S-酰化的证据，这与配位金属离子的任何作用都不相容。我们表明，虽然CESA7可能拥有RING型结构域，但CESA4和CESA8的相同区域似乎进化出了非常不同的结构。总之，数据表明这项研究代表了拟南芥中 S-酰化的图谱，这将有助于对植物中这种难以捉摸的翻译后修饰进行更广泛的研究，并证明在该领域开展进一步工作的重要性。
S-acylation is the addition of a fatty acid to a cysteine residue of a protein. While this modification may profoundly alter protein behaviour, its effects on the function of plant proteins remains poorly characterised, largely as a result to the lack of basic information regarding which proteins are S-acylated and where in the proteins the modification occurs. In order to address this gap in our knowledge, we have performed a comprehensive analysis of plant protein S-acylation from 6 separate tissues. In our highest confidence group, we identified 5185 cysteines modified by S-acylation, which were located in 4891 unique peptides from 2643 different proteins. This represents around 9% of the entire Arabidopsis proteome and suggests an important role for S-acylation in many essential cellular functions including trafficking, signalling and metabolism. To illustrate the potential of this dataset, we focus on cellulose synthesis and confirm for the first time the S-acylation of all proteins known to be involved in cellulose synthesis and trafficking of the cellulose synthase complex. In the secondary cell walls, cellulose synthesis requires three different catalytic subunits (CESA4, CESA7 and CESA8) that all exhibit striking sequence similarity. While all three proteins have been widely predicted to possess a RING-type zinc finger at their N-terminus, for CESA4 and CESA8, we find evidence for S-acylation of cysteines in this region that is incompatible with any role in coordinating metal ions. We show that while CESA7 may possess a RING type domain, the same region of CESA4 and CESA8 appear to have evolved a very different structure. Together, the data suggests this study represents an atlas of S-acylation in Arabidopsis that will facilitate the broader study of this elusive post-translational modification in plants as well as demonstrates the importance of undertaking further work in this area.