Wu Jiangbin, Hollinger Jared, Bonanno Emily, Jiang Feng, Yao Peng
Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642 USA.
Undergraduate Program in Biology and Medicine, Department of Biological Sciences: Biochemistry, University of Rochester, Rochester, New York 14620 USA.
bioRxiv. 2023 Sep 22:2023.09.19.558539. doi: 10.1101/2023.09.19.558539.
Glutamyl-prolyl-tRNA synthetase (EPRS1), an aminoacyl-tRNA synthetase (ARS) ligating glutamic acid and proline to their corresponding tRNAs, plays an essential role in decoding proline codons during translation elongation. The physiological function of EPRS1 in cardiomyocytes (CMs) and the potential effects of CM-specific loss of EPRS1 remain unknown. Here, we found that heterozygous knockout in CMs does not cause any significant changes in CM hypertrophy induced by pressure overload, while homozygous knockout leads to dilated cardiomyopathy, heart failure, and lethality at around 1 month after deletion. Transcriptomic profiling of early-stage knockout hearts suggests a significantly decreased expression of multiple ion channel genes and an increased gene expression in proapoptotic pathways and integrated stress response. Proteomic analysis shows decreased protein expression of multi-aminoacyl-tRNA synthetase complex components, fatty acid, and branched-chain amino acid metabolic enzymes, as well as a compensatory increase in cytosolic translation machine-related proteins. Immunoblot analysis indicated that multiple proline-rich proteins were reduced at the early stage, which might contribute to cardiac dysfunction of knockout mice. Taken together, this study demonstrates the physiological and molecular outcome of loss-of-function of EPRS1 and provides valuable insights into the potential side effects on CMs resulting from the EPRS1-targeting therapeutic approach.
谷氨酰胺-脯氨酰-tRNA合成酶（EPRS1）是一种氨酰-tRNA合成酶（ARS），可将谷氨酸和脯氨酸连接到它们相应的tRNA上，在翻译延伸过程中解码脯氨酸密码子方面发挥着至关重要的作用。EPRS1在心肌细胞（CMs）中的生理功能以及CM特异性缺失EPRS1的潜在影响仍不清楚。在这里，我们发现CMs中的杂合敲除不会导致压力过载诱导的CM肥大发生任何显著变化，而纯合敲除则会导致扩张型心肌病、心力衰竭，并在缺失后约1个月致死。早期敲除心脏的转录组分析表明，多个离子通道基因的表达显著降低，促凋亡途径和综合应激反应中的基因表达增加。蛋白质组学分析显示，多氨酰-tRNA合成酶复合体成分、脂肪酸和支链氨基酸代谢酶的蛋白质表达降低，以及与胞质翻译机器相关的蛋白质有代偿性增加。免疫印迹分析表明，多个富含脯氨酸的蛋白质在早期减少，这可能导致敲除小鼠的心脏功能障碍。综上所述，本研究证明了EPRS1功能丧失的生理和分子结果，并为靶向EPRS1的治疗方法对CMs产生的潜在副作用提供了有价值的见解。
