Laboratory of Epigenetic Regulations

D-FENS Project

Dicer-Dependent Defense in Mammals

eu-erc

ERC Consolidator Grant 2014

Name of the Principal Investigator (PI)	Petr Svoboda
Name of the PI’s host institution for the project	Institute of Molecular Genetics of the CAS
Proposal duration in months	60 (07/2015 – 06/2020)

Viral infection or retrotransposon expansion in the genome often result in production of double-stranded RNA (dsRNA). dsRNA can be intercepted by RNase III Dicer acting in the RNA interference (RNAi) pathway, an ancient eukaryotic defense mechanism. Notably, endogenous mammalian RNAi appears dormant while its common and unique physiological roles remain poorly understood. A factor underlying mammalian RNAi dormancy is inefficient processing of dsRNA by the full-length Dicer. Yet, a simple truncation of Dicer leads to hyperactive RNAi, which is naturally present in mouse oocytes.

The D-FENS project will use genetic animal models to define common, cell-specific and species-specific roles of mammalian RNAi. D-FENS has three complementary and synergizing objectives:

(1) Explore consequences of hyperactive RNAi in vivo. A mouse expressing a truncated Dicer will reveal at the organismal level any negative effect of hyperactive RNAi, the relationship between RNAi and mammalian immune system, and potential of RNAi to suppress viral infections in mammals.

(2) Define common and species-specific features of RNAi in the oocyte. Functional and bioinformatics analyses in mouse, bovine, and hamster oocytes will define rules and exceptions concerning endogenous RNAi roles, including RNAi contribution to maternal mRNA degradation and co-existence with the miRNA pathway.

(3) Uncover relationship between RNAi and piRNA pathways in suppression of retrotransposons. We hypothesize that hyperactive RNAi in mouse oocytes functionally complements the piRNA pathway, a Dicer-independent pathway suppressing retrotransposons in the germline. Using genetic models, we will explore unique and redundant roles of both pathways in the germline.

D-FENS will uncover physiological significance of the N-terminal part of Dicer, fundamentally improve understanding RNAi function in the germline, and provide a critical in vivo assessment of antiviral activity of RNAi with implications for human therapy.

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Laboratory of Epigenetic Regulations, Institute of Molecular Genetics
https://www.img.cas.cz/research/petr-svoboda/

Virology Department, Slovak Medical University (SMU)
http://www.szu.sk/index.php?id=100&menu=56&kgid=156&idpart=4&iddp=2

Dr. Shubhada Bopegamage

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Kataruka S, Modrak M, Kinterova V, Malik R, Zeitler DM, Horvat F, Kanka J, Meister G, Svoboda P: MicroRNA dilution during oocyte growth disables the microRNA pathway in mammalian oocytes. Nucleic Acids Res 2020 48(14): 8050-8062. (PDF)
Demeter T, Vaskovicova M, Malik R, Horvat F, Pasulka J, Svobodova E, Flemr M, Svoboda P: Main constraints for RNAi induced by expressed long dsRNA in mouse cells. Life Sci Alliance 2019 2(1). (PDF)
Taborska E, Pasulka J, Malik R, Horvat F, Jenickova I, Jelić Matošević Z, Svoboda P: Restricted and non-essential redundancy of RNAi and piRNA pathways in mouse oocytes. PLoS Genet 2019 15(12): e1008261. (PDF)
Franke V, Ganesh S, Karlic R, Malik R, Pasulka J, Horvat F, Kuzman M, Fulka H, Cernohorska M, Urbanova J, Svobodova E, Ma J, Suzuki Y, Aoki F, Schultz RM, Vlahovicek K, Svoboda P: Long terminal repeats power evolution of genes and gene expression programs in mammalian oocytes and zygotes. Genome Res 2017 27(8): 1384-1394. (PDF)
Ganesh S, Svoboda P: Retrotransposon-associated long non-coding RNAs in mice and men. Pflugers Arch 2016 468(6): 1049-60. (PDF)
Svobodova E, Kubikova J, Svoboda P: Production of small RNAs by mammalian Dicer. Pflugers Arch 2016 468(6): 1089-102. (PDF)
Bopegamage S: Enterovirus infections: Pivoting role of the adaptive immune response. Virulence 2016 Jul 3;7(5):495-7. (PDF)