MicroRNAs represent a large class of non-coding RNAs that regulate gene expression by interacting with the 3'-untranslated region of target mRNAs. In addition to being essential regulators of development, differentiation and many other basic cellular processes, microRNA expression is associated with the progression of cancer and other chronic diseases, suggesting that regulation of specific microRNAs could have significant therapeutic benefits. Our objective is to investigate the mechanism by which pre-mRNA splicing factors regulate processing of a subset of miRNA precursors. Since we have also identified peptide mimetics that inhibit processing of an oncogenic miRNA (miR- 21) by the RNase III enzyme Dicer, we also propose to investigate the mechanism of inhibition of microRNA processing by this new class of molecules and to further develop their activity. We specifically propose to: 1) Study the regulation of microRNA processing by the Fox-1 family of splicing factors. We will investigate the structural and biochemical mechanism of regulation and the physiological consequences of downregulation of miR-20b expression by Fox-1 and Fox-2. 2) Study the structural and biochemical mechanism of inhibition of microRNA processing by a new class of peptide mimetics and by engineered RNA- binding proteins we have identified. 3) Improve the activity of the peptide inhibitors we have discovered. By conducting this project, we will investigate how processing of microRNA precursors is regulated by endogenous RNA-binding proteins and by exogenous inhibitors. This will provide information critical to understand post-transcriptional regulation of microRNA production, and new approach to inhibiting the activity of oncogenic microRNAs and to improve the potency of the inhibitors.
This project aims to investigate how individual microRNAs are post-transcriptionally regulated, to clarify an essential biological process critical to the regulaion of a majority of eukaryotic genes, and to provide information needed for the discovery of new inhibitors of specific microRNAs overexpressed in cancer or other chronic diseases.
|Hosseinzadeh, Parisa; Bhardwaj, Gaurav; Mulligan, Vikram Khipple et al. (2017) Comprehensive computational design of ordered peptide macrocycles. Science 358:1461-1466|
|Pisignano, Giuseppina; Napoli, Sara; Magistri, Marco et al. (2017) A promoter-proximal transcript targeted by genetic polymorphism controls E-cadherin silencing in human cancers. Nat Commun 8:15622|
|Shortridge, Matthew D; Walker, Matthew J; Pavelitz, Tom et al. (2017) A Macrocyclic Peptide Ligand Binds the Oncogenic MicroRNA-21 Precursor and Suppresses Dicer Processing. ACS Chem Biol 12:1611-1620|
|Barnwal, Ravi P; Yang, Fan; Varani, Gabriele (2017) Applications of NMR to structure determination of RNAs large and small. Arch Biochem Biophys 628:42-56|
|Chen, Yu; Yang, Fan; Zubovic, Lorena et al. (2016) Targeted inhibition of oncogenic miR-21 maturation with designed RNA-binding proteins. Nat Chem Biol 12:717-23|
|Barnwal, Ravi Pratap; Loh, Edmund; Godin, Katherine S et al. (2016) Structure and mechanism of a molecular rheostat, an RNA thermometer that modulates immune evasion by Neisseria meningitidis. Nucleic Acids Res 44:9426-9437|
|Chen, Yu; Zubovic, Lorena; Yang, Fan et al. (2016) Rbfox proteins regulate microRNA biogenesis by sequence-specific binding to their precursors and target downstream Dicer. Nucleic Acids Res 44:4381-95|
|Shortridge, Matthew D; Varani, Gabriele (2015) Structure based approaches for targeting non-coding RNAs with small molecules. Curr Opin Struct Biol 30:79-88|
|Chen, Yu; Varani, Gabriele (2013) Engineering RNA-binding proteins for biology. FEBS J 280:3734-54|