Phosphorylation of mammalian mitochondrial EF-Tu by Fyn and c-Src kinases.
Phosphorylation of mammalian mitochondrial EF-Tu by Fyn and c-Src kinases.
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DOI：
10.1016/j.cellsig.2022.110524
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发表时间：
2022-11
影响因子：
4.8
通讯作者：
E. Koc;C. Hunter;H. Koc
中科院分区：
文献类型：
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作者：
E. Koc;C. Hunter;H. Koc
Src家族激酶（SFK）是已知调节哺乳动物线粒体中的葡萄糖和脂肪酸代谢以及氧化磷酸化（OXPHOS）的酪氨酸激酶。我们和其他人发现SFK激酶Fyn和c-Src与线粒体翻译组分的关联。该翻译系统负责合成OXPHOS复合物的13个线粒体（mt）编码亚基，因此对能量产生至关重要。线粒体核糖体蛋白和包括Tu（EF-Tumt）在内的各种翻译延伸因子已被鉴定为可能的Fyn和c-Src激酶靶标。然而，EF-Tumt中特定残基的磷酸化及其在蛋白质合成调控中的作用还有待探索。在这项研究中，我们报告了EF-Tumt与cSrc激酶的关联以及这些激酶对磷酸化Tyr（pTyr）残基的定位。我们确定了位于高度保守的c-Src共有基序中的EF-Tumtat位置266（EF-Tumt-Y266）中的特定Tyr残基是主要的磷酸化位点之一。通过定点突变研究EF-Tumt-Y266磷酸化在线粒体翻译调节中的潜在作用。其Glu残基的磷酸化模拟物（EF-Tumt-E266）在体外可抑制三元复合物（EF-Tumt·GTP·aatRNA）的形成和降解。我们的发现沿着c-Src基因敲除（KO）小鼠蛋白质组的数据挖掘分析表明，SFKs在动物线粒体蛋白质合成和氧化能量代谢的调节中具有可能的作用。
Src Family Kinases (SFKs) are tyrosine kinases known to regulate glucose and fatty acid metabolism as well as oxidative phosphorylation (OXPHOS) in mammalian mitochondria. We and others discovered the association of the SFK kinases Fyn and c-Src with mitochondrial translation components. This translational system is responsible for the synthesis of 13 mitochondrial (mt)-encoded subunits of the OXPHOS complexes and is, thus, essential for energy generation. Mitochondrial ribosomal proteins and various translation elongation factors including Tu (EF-Tumt) have been identified as possible Fyn and c-Src kinase targets. However, the phosphorylation of specific residues in EF-Tumtby these kinases and their roles in the regulation of protein synthesis are yet to be explored. In this study, we report the association of EF-Tumtwith cSrc kinase and mapping of phosphorylated Tyr (pTyr) residues by these kinases. We determined that a specific Tyr residue in EF-Tumtat position 266 (EF-Tumt-Y266), located in a highly conserved c-Src consensus motif is one of the major phosphorylation sites. The potential role of EF-Tumt-Y266 phosphorylation in regulation of mitochondrial translation investigated by site-directed mutagenesis. Its phosphomimetic to Glu residue (EF-Tumt-E266) inhibited ternary complex (EF-Tumt•GTP•aatRNA) formation and translationin vitro. Our findings along with data mining analysis of the c-Src knock out (KO) mice proteome suggest that the SFKs have possible roles for regulation of mitochondrial protein synthesis and oxidative energy metabolism in animals.