Title: "RNA-Mediated Gene Regulation, One Molecule at a Time"
Jingyi Fei, Assistant Professor, Department of Biochemistry and Molecular Biology, University of Chicago
Single-molecule and super-resolution microscopies have significantly empowered our ability in probing biological activities with high spatial and temporal resolutions and in live cells. Regulatory RNAs play important roles in regulating gene expression in bacteria, in response to various external signals or stresses. Regulatory RNAs can act both in cis and trans. Cis-regulatory RNAs, specifically the riboswitches, are localized upstream of the controlled mRNAs, and can affect the transcription or translation of the mRNAs upon binding of specific ligands; whereas trans-regulatory RNAs, specifically small RNAs (sRNAs), recognize their target mRNAs through base-pairing interactions and affect the translation and the stability of the bound mRNAs. In my presentation, I will share our results on the ligand binding mechanism of a special riboswitch, the T-box element, which recognizes uncharged tRNAs as oppose to other small molecule binding riboswitches, using single-molecule fluorescence microscopy. In addition, I will present how Hfq proteins, one of the key effector proteins of sRNA, dynamically interact with mRNAs, sRNAs and the ribosomes in live cells, and regulate mRNA stability in addition to the sRNA-mediated pathways.