Talk abstracts
Talk on Saturday 09:15-09:30am submitted by Benjamin Pastore
pre-piRNA trimming and 2′-O-methylation protect piRNAs from 3’ tailing and degradation in C. elegans
Benjamin Pastore (Department of Biological Chemistry and Pharmacology, Center for RNA Biology, Ohio State Biochemistry Program, The Ohio State University ), Hannah L. Hertz (Department of Biological Chemistry and Pharmacology, Center for RNA Biology, The Ohio State University ), Ian F. Price (Department of Biological Chemistry and Pharmacology, Center for RNA Biology, Ohio State Biochemistry Program, The Ohio State University ), Wen Tang (Department of Biological Chemistry and Pharmacology, Center for RNA Biology, The Ohio State University )
Abstract:
The Piwi/piRNA pathway suppresses transposable elements and promotes fertility in diverse organisms. Maturation of piRNAs involves pre-piRNA trimming followed by 2′-O-methylation at their 3’ termini. Here we report that 3’ termini of C. elegans piRNAs are subject to nontemplated nucleotide addition and piRNAs with 3’ addition exhibit extensive base-pairing interaction with their target RNAs. Animals deficient for PARN-1 (pre-piRNA trimmer) and HENN-1 (2′-O-methyltransferase) accumulate piRNAs with 3’ nontemplated nucleotides. In henn-1 mutants piRNAs are shortened prior to 3’ addition whereas long isoforms of untrimmed piRNAs are preferentially modified in parn-1 mutant animals. Loss of either PARN-1 or HENN-1 results in modest reduction in steady-state levels of piRNAs. Deletion of both enzymes leads to depletion of piRNAs, desilencing of piRNA targets, and impaired fecundity. Together, our findings suggest that pre-piRNA trimming and 2′-O-methylation act collaboratively to protect piRNAs from tailing and degradation.
References:
Ozata, D.M., Gainetdinov, I., Zoch, A., O'Carroll, D., and Zamore, P.D. (2019). PIWI-interacting RNAs: small RNAs with big functions. Nature reviews Genetics 20, 89-108.
Fuchs Wightman, F., Giono, L.E., Fededa, J.P., and de la Mata, M. (2018). Target RNAs Strike Back on MicroRNAs. Frontiers in genetics 9, 435.
Keywords: piRNA, nontemplated nucleotide addition, degradation