Poster abstracts
Poster number 9 submitted by Sumirtha Balaratnam
G-quadruplex driven functional modulation in the human piwiinteracting RNAs
Sumirtha Balaratnam (Department of Chemistry and Biochemistry, Kent State University), MadaraHettiArachchilage (Department of Biological Science,Kent State University,)
Abstract:
The piwi interacting RNAs (piRNAs) are small non-coding RNAs mostly 24-32 nucleotides in length. Among all types of non-coding RNAs, piRNAs are by far the most numerous, existing only in animals. The piRNAs are defined by their specific binding to the PIWI proteins, a requirement for their function. The piRNAs do not have conserved secondary structure, because piRNA sequences are not known to contain any conserved motifs. Using bioinformatics analysis, we discovered the presence of putative G-quadruplex (GQ)-forming sequences in human piRNAs that is higher in number compared to the piRNA pools of other organisms that were analyzed (exclude Chicken). We investigated the propensity to form the G-quadruplex structure in one (piRNA 48164) of the potential GQ forming sequence in human. Circular dichroism and RNase T1 footprinting data confirmed the formation of stable G-quadruplex structure by piRNA 48164. GQ formation led to inhibiting the piRNA-target complementary base pairing which consequently affects target gene silencing. Further studies are underway to analyze the effect of PIWI protein binding on GQ forming piRNAs. These studies begin to unravel the role of GQ in piRNA function.
References:
PengZhang, et al, piRBase: a web resource assisting piRNA functional study, Database, 2014, 1–7
Oleg Kikin,et al, QGRS Mapper: a web-based server for predicting G-quadruplexesin nucleotide sequences, Nucleic Acids Res, 2006,676-682.
MikikoC. Siomi, et al, PIWI-interacting small RNAs: the vanguard of genome defence, Nat Rev Mol Cell Bio,2011,246-258
Keywords: piRNAs, G-quadruplex, function modulation