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Information × Registration Number 0225U001635, (0119U103634) , R & D reports Title Molecular mechanisms for quality control of translation with non-proteinogenic amino acids participation popup.stage_title Вивчення можливої токсичності D-аланіну на різних клітинних лініях людини. Вивчення методом сайт-спрямованого мутагенезу елементів АлаРС і тРНКАла T. thermophilus, які є найбільш важливими для аміноацилування та корекції помилок. Head Tukаlo Mykhаilo A., Доктор біологічних наук Registration Date 04-02-2025 Organization Institute of Molecular Biology and Genetics of NAS of Ukraine popup.description1 The goal of this project is to study the structural and conformational determinants of tRNAs, human leucyl-tRNA synthetase and alanyl-tRNA synthetases from various species that exclude the participation of non-proteinogenic amino acids such as norleucine, norvaline, homocysteine and D-alanine, in protein biosynthesis. The mechanisms of stereospecificity control in translation of genetic information have not yet been elucidated. Therefore, the ability of AlaRS and ProRS from different species (E. coli, Enterococcus faecalis and Homo sapiens) to edit D-amino acids will be studied. Additionally, separate trans-editing factor AlaX will be examined. The comprehensive approach, combining genetic engineering, biochemical, biophysical and molecular dynamics methods and quantum chemical calculations, will be applied. The study of the influence of incorporation of norvaline, norleucine and homocysteine into proteins on the growth of normal and cancer cells will be performed. The results of our investigations will be used for the search of new antibiotics against human pathogens and new drugs against cancer. Additionally, they also provide the basis for the creation of new orthologous tRNA-ARSase pairs for synthetic biology. popup.description2  The high accuracy of genetic code translation is critical for the cell, with aminoacyl-tRNA synthetases (AARSs) ensuring the specific attachment of amino acids to tRNA. Aminoacylation of tRNA is a key quality control step, and its disruption can have catastrophic consequences. Errors often involve the substitution of canonical amino acids, but the impact of non-proteinogenic amino acids (D-amino acids, metabolic products) remains poorly studied. Norvaline and norleucine accumulate in bacteria under low oxygen conditions, and more than half of AARSs can mistakenly activate them. These enzymes have evolved editing mechanisms to correct such errors. Recent studies have shown that in *E. coli*, LeuRS edits norvaline, which is crucial for bacterial survival. However, this mechanism is poorly understood in eukaryotes. Leucine regulates growth via mTORC1, and human LeuRS is a key mediator of this pathway. Some non-proteinogenic amino acids, such as norleucine, can also activate mTORC1. Norvaline, used as a dietary supplement, inhibits not only arginase but also S6K1, affecting signaling pathways. Dysregulation of mTORC1 is linked to cancer, diabetes, and neurodegenerative diseases. Studies have shown that human LeuRS does not sufficiently discriminate between L- and D-isomers, necessitating error correction. A substrate-assisted post-transfer editing mechanism has been identified, involving aspartic acid residue 399. Increased expression of *LARS, SARS,* and *HARS* genes in clear-cell renal carcinoma may serve as biomarkers for early diagnosis. The toxicity of norvaline, norleucine, and homocysteine in human cell lines revealed that norvaline most significantly suppresses cell growth, highlighting the importance of quality control in non-proteinogenic amino acid translation. Product Description popup.authors Ilchenko Mykola M. Gerashchenko Ganna V. Raievskyi Oleksii V. Yaremchuk Hanna D. Chernushyn Serhii Yu. Kovalenko Oksana P. Volodymyr А. Shablii Hudzera Olha Y. Kryklyvyi Ivan A. Rybak Mariia Yu. Skydanovych Oleksandra I. Hryshchenko Nataliia V. Polina O. Pikus popup.nrat_date 2025-02-04 Close