Lysine acetylation of ribosomal proteins during poliovirus infection limits viral translation

核糖体蛋白包含许多翻译后修饰，但这些核糖体修饰在mRNA翻译过程中所起的作用目前尚不清楚。我们的长期目标是研究这些翻译后修饰的功能，特别是它们如何调节蛋白质的生物合成。我们发现，在感染脊髓灰质炎病毒的过程中，核糖体蛋白的乙酰化发生了变化。突变eS25中的一些乙酰化赖氨酸残基对病毒有利，这表明一些乙酰化可能具有抗病毒功能。这笔赠款的目的是确定在脊髓灰质炎病毒感染期间修饰核糖体蛋白的乙酰转移酶。中心假设是同一种酶可能以多种核糖体蛋白为靶标，因此，我们预计乙酰基转移酶的过度表达或缺失可能会对脊髓灰质炎病毒的翻译产生累积和显著的影响。我们的特定目标将通过耗尽或过度表达不同的乙酰转移酶来检验我们的中心假设，并通过免疫印迹和质谱分析来确定其对脊髓灰质炎病毒翻译和核糖体修饰的影响。我们的建议描述了一个重大的范式转变，从核糖体作为非歧视的翻译机器，无防御到病毒接管，到具有抗病毒功能的蛋白质生物合成的主动调节以保护细胞。

Ribosomal proteins contain numerous posttranslational modifications, but the functions these ribosome modifications play during mRNA translation are currently unknown. Our long-term goal is to study the function of these posttranslational modifications, specifically how they regulate protein biosynthesis. We have found that ribosomal protein acetylations are altered during infection with poliovirus. Mutagenesis of some acetylated lysine residues in eS25, a protein required for poliovirus translation, benefits the virus, suggesting that some acetylations might have antiviral function. The objective of this grant is to identify the acetyltransferase, which modifies ribosomal proteins during poliovirus infection. The central hypothesis is that the same enzyme might target multiple ribosomal proteins, thus, we expect that overexpression or depletion of the acetyltransferase may have a cumulative and pronounced effect on poliovirus translation. Our specific aim will test our central hypothesis by depleting or overexpressing different acetyltransferases and determining the effect on poliovirus translation and ribosome modifications by immunoblotting and mass spectrometry analysis. Our proposal describes a significant paradigm shift from ribosomes as non-discriminatory translation machines, defenseless to viral takeover, to active regulators of protein biosynthesis with antiviral function to protect cells.