As a new type of post-translational modifications (PTMs), lysine 2-hydroxyisobutyrylation (Khib) was firstly identified in histones and functioned as a regulator of transactivation in mammals. However, the role of Khib proteins remains to be investigated. Here, we firstly identified 10,367 Khib sites on 2,325 modified proteins in seven patients with pancreatic cancer by applying liquid chromatography with tandem mass spectrometry (LC-MS/MS) qualitative proteomics techniques. Among them, 27 Khib modified sites were identified in histones. Bioinformatics analysis revealed that the Khib-modified proteins were mainly distributed in the cytoplasm and enhanced in metabolic pathways including glycolysis/gluconeogenesis, the citrate cycle (TCA cycle) and fatty acid degradation. In an overlapping comparison of lysine 2-hydroxyisobutyrylation, succinylation and acetylation in humans, 105 proteins with 80 sites were modified by all three PTMs, suggesting there may be a complex network among the different modified proteins and sites. Furthermore, MG149, which was identified as Tip60 inhibitor, significantly decreased the total Khib modification level in pancreatic cancer (PC), and strongly suppressed proliferation, migration and invasion ability of PC. Overall, our study is the first profiling of lysine 2-hydroxyisobutyrylome and provides a new database for better investigating Khib in PC.

作为一种新型的翻译后修饰 (PTM)，赖氨酸 2-羟基异丁酰化 (Khib) 首次在组蛋白中被发现，并在哺乳动物中起反式激活调节剂的作用。然而，Khib 蛋白的作用仍有待研究。在这里，我们首先通过应用液相色谱和串联质谱 (LC-MS/MS) 定性蛋白质组学技术在 7 名胰腺癌患者的 2,325 个修饰蛋白上鉴定了 10,367 个 Khib 位点。其中，在组蛋白中鉴定出27个Khib修饰位点。生物信息学分析表明，Khib修饰蛋白主要分布在细胞质中，并在糖酵解/糖异生、柠檬酸循环（TCA循环）和脂肪酸降解等代谢途径中得到增强。在赖氨酸 2-羟基异丁酰化的重叠比较中，在人类的琥珀酰化和乙酰化中，所有三个 PTM 都修饰了 105 个具有 80 个位点的蛋白质，这表明不同修饰的蛋白质和位点之间可能存在复杂的网络。此外，被鉴定为Tip60抑制剂的MG149显着降低了胰腺癌（PC）中的总Khib修饰水平，并强烈抑制了PC的增殖、迁移和侵袭能力。总体而言，我们的研究是对赖氨酸 2-羟基异丁酰脲的首次分析，并为更好地研究 PC 中的 Khib 提供了一个新数据库。显着降低胰腺癌（PC）中的总Khib修饰水平，并强烈抑制PC的​​增殖，迁移和侵袭能力。总体而言，我们的研究是对赖氨酸 2-羟基异丁酰脲的首次分析，并为更好地研究 PC 中的 Khib 提供了一个新数据库。显着降低胰腺癌（PC）中的总Khib修饰水平，并强烈抑制PC的​​增殖，迁移和侵袭能力。总体而言，我们的研究是对赖氨酸 2-羟基异丁酰脲的首次分析，并为更好地研究 PC 中的 Khib 提供了一个新数据库。