Poster abstracts
Poster number 35 submitted by Chrishan Fernando
Performing a genetic screen to identify factors that promote lncRNA-dependent gene repression
Chrishan Fernando (Department of Biochemistry, Purdue University), Cecilia Yiu (Department of Biochemistry, Purdue University), Sara Cloutier (Department of Biochemistry, Purdue University), Siwen Wang (Department of Biochemistry, Purdue University), Elizabeth Tran (Department of Biochemistry, Purdue University)
Abstract:
Long non-coding RNAs (lncRNAs) were once thought not to have useful functions in organisms but rather to be products of aberrant transcription. However, roles are being found for lncRNAs in beneficial processes such as controlling gene expression. In some of these cases, lncRNAs form R-loops in vivo. R-loops are nucleic acid structures consisting of hybridized strands of single-stranded DNA (ssDNA) and single-stranded RNA (ssRNA) as well as the displaced strand of ssDNA. Formation of these R-loops is important for gene regulation by the lncRNAs. However, factors that promote formation of lncRNA R-loops are not known. The gene PHO84 is being used to study this matter. PHO84 encodes a phosphate transporter in Saccharomyces cerevisiae. Two lncRNAs are transcribed in the antisense direction across PHO84 and repress PHO84 gene expression. This phenomenon may be due to the formation of R-loops. A genetic screen has been designed in S. cerevisiae using a HIS3 reporter to identify genes that suppress gene expression on the PHO84 locus when overexpressed. The HIS3 reporter is currently being evaluated for ability to identify factors promoting R-loop formation.
Keywords: R-loop, RNA-DNA hybrid, lncRNA