Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
Holiferm, Manchester, UK.
Nat Plants. 2022 Jun;8(6):670-681. doi: 10.1038/s41477-022-01164-4. Epub 2022 Jun 9.
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 characterized, largely as a result of the lack of basic information regarding which proteins are S-acylated and where in the proteins the modification occurs. To address this gap in our knowledge, we used an optimized acyl-resin-assisted capture assay to perform a comprehensive analysis of plant protein S-acylation from six separate tissues. In our high- and medium-confidence groups, we identified 1,849 cysteines modified by S-acylation, which were located in 1,640 unique peptides from 1,094 different proteins. This represents around 6% of the detectable 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 the S-acylation of a number of 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 and are all predicted to possess a RING-type zinc finger at their amino terminus composed of eight cysteines. For CESA8, we find evidence for S-acylation of these cysteines 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 CESA8 appears to have evolved a very different structure. Together, the data suggest that 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 demonstrating the importance of further work in this area.
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改变蛋白质的行为，但它对植物蛋白功能的影响仍然知之甚少，主要是因为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哪个位置的基本信息。为了填补我们知识中的这一空白，我们使用了优化的酰-resin 辅助捕获测定法，从六个单独的组织中对植物蛋白 S-酰化进行了全面分析。在我们的高可信度和中可信度组中，我们鉴定了 1,849 个被 S-酰化修饰的半胱氨酸，它们位于 1,094 种不同蛋白质的 1,640 个独特肽段中。这约占可检测拟南芥蛋白质组的 6%，表明 S-酰化在许多重要的细胞功能中发挥重要作用，包括运输、信号转导和代谢。为了说明这个数据集的潜力，我们重点关注纤维素合成，并证实了一些已知参与纤维素合成和纤维素合酶复合物运输的蛋白质的 S-酰化。在次生细胞壁中，纤维素合成需要三个不同的催化亚基（CESA4、CESA7 和 CESA8），它们都表现出惊人的序列相似性，并且都预测在其氨基末端具有一个由八个半胱氨酸组成的 RING 型锌指结构。对于 CESA8，我们发现这些半胱氨酸发生 S-酰化的证据与任何协调金属离子的作用都不兼容。我们表明，虽然 CESA7 可能具有 RING 型结构域，但 CESA8 的相同区域似乎已经进化出非常不同的结构。总之，这些数据表明，这项研究代表了拟南芥 S-酰化的图谱，将促进对植物中这种难以捉摸的翻译后修饰的更广泛研究，并证明在该领域进一步工作的重要性。
