Protein Argonaute (AGO)

Argonaute proteins are the central catalytic components of the RNA-induced silencing complex (RISC), playing a fundamental role in the RNA interference (RNAi) and microRNA (miRNA) pathways [1][2]. In humans, the family comprises four members (AGO1, AGO2, AGO3, and AGO4), among which Argonaute 2 (AGO2) is uniquely characterized by its endonucleolytic 'slicer' activity [1][4]. These proteins function by loading small non-coding RNAs, such as siRNAs or miRNAs, which serve as guides to recognize complementary messenger RNA (mRNA) sequences through base-pairing [2]. Upon binding, Argonaute proteins mediate gene silencing either by direct cleavage of the target mRNA or by inducing translational repression and subsequent mRNA decay [3]. Because they regulate a vast array of genes involved in cell proliferation, differentiation, and apoptosis, their dysregulation is frequently linked to oncogenesis and viral pathogenesis [4]. In the pharmaceutical industry, Argonaute proteins—specifically AGO2—are the essential intracellular targets for siRNA-based therapeutics, such as Patisiran and Inclisiran, which leverage the endogenous RNAi machinery to silence specific disease-causing genes [3].

Other names

Argonaute protein familyEukaryotic translation initiation factor 2CEIF2CSlicerRISC catalytic componentArgonaute-2AGO2PAZ Piwi domain proteinPPD

Argonaute proteins, particularly AGO2, serve as the catalytic core of the RNA-induced silencing complex (RISC). They bind small interfering RNAs (siRNAs) or microRNAs (miRNAs), which guide the complex to complementary mRNA sequences. Once bound, AGO2 facilitates the endonucleolytic cleavage of the target mRNA (slicer activity) or recruits additional factors to induce translational repression and mRNA decay [1][2][3].