Fu Qianyun, Nguyen Terry, Kumar Bhoj, Azadi Parastoo, Zheng Y George
Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia, USA.
Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia, USA.
bioRxiv. 2024 Oct 31:2024.10.31.621296. doi: 10.1101/2024.10.31.621296.
Short chain fatty acylations establish connections between cell metabolism and regulatory pathways. Lysine acetoacetylation (Kacac) was recently identified as a new histone mark. However, regulatory elements, substrate proteins, and epigenetic functions of Kacac remain unknown, hindering further in-depth understanding of acetoacetate modulated (patho)physiological processes. Here, we created a chemo-immunological approach for reliable detection of Kacac, and demonstrated that acetoacetate serves as the primary precursor for histone Kacac. We report the enzymatic addition of the Kacac mark by the acyltransferases GCN5, p300, and PCAF, and its removal by deacetylase HDAC3. Furthermore, we establish acetoacetyl-CoA synthetase (AACS) as a key regulator of cellular Kacac levels. A comprehensive proteomic analysis has identified 139 Kacac sites on 85 human proteins. Bioinformatics analysis of Kacac substrates and RNA-seq data reveal the broad impacts of Kacac on multifaceted cellular processes. These findings unveil pivotal regulatory mechanisms for the acetoacetate-mediated Kacac pathway, opening a new avenue for further investigation into ketone body functions in various pathophysiological states.
短链脂肪酰化作用在细胞代谢与调控途径之间建立了联系。赖氨酸乙酰乙酸化修饰（Kacac）最近被鉴定为一种新的组蛋白标记。然而，Kacac的调控元件、底物蛋白及表观遗传功能仍不清楚，这阻碍了对乙酰乙酸酯调节的（病理）生理过程的进一步深入理解。在此，我们创建了一种化学免疫方法用于可靠检测Kacac，并证明乙酰乙酸酯是组蛋白Kacac的主要前体。我们报道了酰基转移酶GCN5、p300和PCAF对Kacac标记的酶促添加，以及去乙酰化酶HDAC3对其的去除。此外，我们确定乙酰乙酰辅酶A合成酶（AACS）是细胞Kacac水平的关键调节因子。一项全面的蛋白质组学分析已在85种人类蛋白质上鉴定出139个Kacac位点。对Kacac底物和RNA测序数据的生物信息学分析揭示了Kacac对多方面细胞过程的广泛影响。这些发现揭示了乙酰乙酸酯介导的Kacac途径的关键调控机制，为进一步研究酮体在各种病理生理状态下的功能开辟了一条新途径。
