Argonaute Proteins and Small RNA Interference

Argonaute proteins are evolutionarily conserved effectors that mediate sequence-specific gene silencing through association with small RNAs. Upon biogenesis by the Dicer family of RNase III enzymes, microRNAs (miRNAs) and small interfering RNAs (siRNAs) are loaded into Argonaute to form the RNA-induced silencing complex (RISC). Guide strands within RISC recognise complementary sites on target transcripts, leading either to endonucleolytic cleavage (‘slicing’) or translational repression followed by decay. The PIWI and MID domains of Argonaute position the guide-target duplex, while the PAZ domain anchors the 3′ end of the small RNA. This modular architecture enables diverse modes of target recognition and regulatory outcomes. Argonaute-mediated interference shapes developmental programmes, maintains cellular identity and responds to environmental cues. Dysregulation of Argonaute function or its post-translational modifications can contribute to disease, including cancer and neurological disorders. Advances in structural biology and real-time biochemistry have elucidated key determinants of slicing kinetics, guide-target pairing fidelity and target release, informing strategies for therapeutic RNAi and genome-wide functional screening.

Research from Nature Portfolio

Recent studies have uncovered germline mutations in AGO2 that impair RNA interference and perturb neuronal development. Single-amino-acid substitutions within the PIWI domain compromise either RISC assembly or target-release kinetics, leading to aberrant dendritic P-body formation and widespread transcriptomic alterations in patient-derived cells. Reduced phosphorylation of a conserved C-terminal serine cluster diminishes mRNA release, emphasising the dynamic AGO2–RNA interaction as essential for human neurodevelopment.

Argonaute Proteins and Small RNA Interference publication trend

The graph below shows the total number of articles in argonaute proteins and small rna interference across all publications each year (not limited to Nature Index journals).

Technical terms

Argonaute protein: Core RISC component that binds small RNAs and mediates target recognition and silencing.

RNA-induced silencing complex (RISC): Multimeric assembly of Argonaute and guide RNA responsible for RNA interference.

MicroRNA (miRNA): Endogenous ~22-nucleotide non-coding RNA that directs translational repression and mRNA decay.

Small interfering RNA (siRNA): Exogenous or endogenous ~21-nucleotide duplex that guides endonucleolytic cleavage of complementary RNA.

Slicing: Endonucleolytic cleavage of a target RNA strand by the catalytic PIWI domain of Argonaute.

Guide strand: The single-stranded small RNA within RISC that base-pairs with target transcripts.

References

1. Germline AGO2 mutations impair RNA interference and human neurological development. Nature Communications (2020).
2. Catalytic residues of microRNA Argonautes play a modest role in microRNA star strand destabilization in C. elegans. Nucleic Acids Research (2024).
3. The guide-RNA sequence dictates the slicing kinetics and conformational dynamics of the Argonaute silencing complex. Molecular Cell (2024).
4. Phosphorylation of AGO2 by TBK1 Promotes the Formation of Oncogenic miRISC in NSCLC. Advanced Science (2024).