The PAZ domain of Aedes aegypti Dicer 2 is critical for accurate and high-fidelity size determination of virus-derived small interfering RNAs.

Reuter, Melinda, Parry, Rhys H., McDonald, Melanie, Gestuveo, Rommel J., Arif, Rozeena, Khromykh, Alexander A., Brennan, Benjamin, Varjak, Margus, Castello, Alfredo, Redecke, Lars, Schnettler, Esther and Kohl, Alain (2025) 'The PAZ domain of Aedes aegypti Dicer 2 is critical for accurate and high-fidelity size determination of virus-derived small interfering RNAs.'. RNA, rna.080149.124. (In Press)

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Abstract

The exogenous siRNA (exo-siRNA) pathway is a critical RNA interference response involved in controlling arbovirus replication in mosquito cells. It is initiated by the detection of viral long double-stranded RNA (dsRNA) by the RNase III enzyme Dicer 2 (Dcr2), which is processed into predominantly 21 nucleotide (nt) virus-derived small interfering RNAs, or vsiRNAs that are taken up by the Argonaute 2 (Ago2) protein to target viral single-stranded RNAs. The detailed understanding of Dicer structure, function and domains owes much to studies outside the context of viral infection and studies in model organisms, and as such how Dcr2 domains contribute to detecting viral dsRNA to mount antiviral responses in infected mosquito cells remains less well understood. Here, we used a Dcr2 reconstitution system in Aedes aegypti derived Dcr2 KO cells to assess the contribution of the PAZ domain to induction of the exo-siRNA pathway following infection with Semliki Forest virus (SFV; Togaviridae, Alphavirus). Amino acids critical for PAZ activity were identified, and loss of PAZ function affected the production of 21 nt vsiRNAs -with enrichment of 22 nt SFV-derived small RNAs observed- and silencing activity. This study establishes PAZ domain’s functional contribution to Dcr2 processing of viral dsRNA to 21 nt vsiRNAs.

Item Type:	Article
Subjects:	QX Parasitology > Insects. Other Parasites > QX 510 Mosquitoes WA Public Health > Preventive Medicine > WA 108 Preventive health services. Preventive medicine. Travel Medicine. WC Communicable Diseases > Virus Diseases > Viral Hemorrhagic Fevers. Other Virus Diseases > WC 556 Prevention and control WC Communicable Diseases > Tropical and Parasitic Diseases > WC 765 Prevention and control
Faculty: Department:	Biological Sciences > Department of Tropical Disease Biology
Digital Object Identifer (DOI):	https://doi.org/10.1261/rna.080149.124
Depositing User:	Rachael Kedge
Date Deposited:	26 Feb 2025 08:21
Last Modified:	26 Feb 2025 08:21
URI:	https://archive.lstmed.ac.uk/id/eprint/26241

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