Research Projects

Plants have developed a complex small RNA-mediated post-transcriptional gene silencing mechanism (RNAi) in A. thaliana, which requires four Dicer-like enzymes and seven auxiliary dsRNA Binding Domain (dsRBD) containing Proteins (dsRBPs). These proteins are essential for plant regulation due to their lack of an adaptive immune system. DRB5, one of the least studied proteins, is among the seven dsRBPs and contains two N-terminal dsRBDs and a long unstructured C-terminus. Bioinformatics analysis shows that DRB5 has a higher degree of sequence similarity with DRB2 and DRB3 than DRB4 and DRB1. DRB2, DRB3, and DRB5 express only in developmentally active shoot apical meristem regions in plants. They are thought to either inhibit DCL1 activity or participate in the viral defence mechanism in germline tissues. DRB2, DRB3, and DRB5 localize and form punctae at the viral replication complex (VRC), a defense strategy developed by plants against viral infections. DRB5 interacts with DCL1, DCL3, DRB1, DRB2, and dsRNA, suggesting a multifaceted role in inhibiting viral replication and miRNA biogenesis. However, DRB5's role in the plant RNAi pathway remains enigmatic, as it is associated with two tangential yet equally important processes: recognition and trapping of viral RNA and interaction with DRB2. The study proposes investigating the molecular basis of RNA recognition by DRB5 using biophysical and biochemical methods to expand our understanding of the plant's viral defense mechanism.