Viral Infection and Stress Affect Protein Levels of Dicer 2 and Argonaute 2 in Drosophila melanogaster

Front Immunol. 2020 Mar 4;11:362. doi: 10.3389/fimmu.2020.00362. eCollection 2020.


The small interfering RNA (siRNA) pathway of Drosophila melanogaster, mainly characterized by the activity of the enzymes Dicer 2 (Dcr-2) and Argonaute 2 (Ago-2), has been described as the major antiviral immune response. Several lines of evidence demonstrated its pivotal role in conferring resistance against viral infections at cellular and systemic level. However, only few studies have addressed the regulation and induction of this system upon infection and knowledge on stability and turnover of the siRNA pathway core components transcripts and proteins remains scarce. In the current work, we explore whether the siRNA pathway is regulated following viral infection in D. melanogaster. After infecting different fly strains with two different viruses and modes of infection, we observed changes in Dcr-2 and Ago-2 protein concentrations that were not related with changes in gene expression. This response was observed either upon viral infection or upon stress-related experimental procedure, indicating a bivalent function of the siRNA system operating as a general gene regulation rather than a specific antiviral system.

Keywords: RNA interference; antiviral response; gene regulation; insect immunity; protein regulation; viral infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Argonaute Proteins / analysis*
  • Argonaute Proteins / genetics
  • Disease Susceptibility
  • Drosophila Proteins / analysis*
  • Drosophila Proteins / genetics
  • Drosophila melanogaster / immunology*
  • Female
  • RNA Helicases / analysis*
  • RNA Helicases / genetics
  • RNA, Small Interfering / physiology
  • Ribonuclease III / analysis*
  • Ribonuclease III / genetics
  • Stress, Physiological
  • Virus Diseases / immunology*
  • Virus Diseases / metabolism


  • AGO2 protein, Drosophila
  • Argonaute Proteins
  • Drosophila Proteins
  • RNA, Small Interfering
  • DCR-2 protein, Drosophila
  • Ribonuclease III
  • RNA Helicases