Structural Dynamics of Translation

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The Central Dogma of molecular biology is that DNA is used to make mRNA, which in turn is used to make proteins. Central to physiology of every live cell, translation of messenger RNAs (mRNAs) into proteins is catalyzed by the ribosome, structurally complex and dynamic macromolecular machine. Dysregulation of translation plays an important role in a number of human diseases including cancer. While some fundamentals of protein synthesis have been revealed, many molecular details of ribosomal translation remain unknown. For example, it is unclear why some mRNAs are translated orders of magnitude more efficiently than the others, and how mRNA structure regulates protein synthesis. My laboratory investigates molecular mechanisms of translation by studying structural dynamics of the ribosome, and the role of mRNA secondary structure in translation regulation. We use single-molecule microscopy and biochemical approaches to address the following questions: (i) How does the small ribosomal subunit move along mRNA in search for the start site for translation initiation in eukaryotes? (ii) How does the intrinsic compactness of mRNA and intramolecular basepairing interactions formed by the 5’ and 3’ untranslated regions (UTRs) of mRNA regulate the efficiency of protein synthesis in eukaryotes? (iii) How do mRNA stem-loop structures induce ribosome translation pauses, which control expression of a number of proteins in bacteria, eukaryotes and eukaryotic viruses, including Human Immunodeficiency Virus (HIV) and the cause of the COVID-19 pandemic, SARS-CoV-2? (iv) How are structural dynamics of eukaryotic ribosome (in particular, rotational movements between the small and the large ribosomal subunits) converted into the intricate process of protein synthesis? Our studies will substantially contribute to establishing the molecular mechanisms of protein synthesis, and provide the basis for the future development of antiviral and cancer therapies.