Argonaute 1 (AGO1)

Argonaute 1 (AGO1) is a highly conserved RNA-binding protein and core component of the RNA-induced silencing complex (RISC), which mediates gene silencing by microRNAs (miRNAs) and, in some organisms, small interfering RNAs (siRNAs). AGO1 binds to single-stranded guide RNAs and associates with complementary sequences on target mRNAs, resulting in translational repression, mRNA deadenylation, and decay. While the best-studied endonuclease (slicing) catalytic activity among Argonaute proteins belongs to AGO2 in mammals, AGO1 functions primarily in miRNA-mediated translational inhibition. In Drosophila and plants, AGO1 is essential for normal development and cell growth regulation and may have additional roles in direct transcriptional control, such as repressing the Myc gene. Mutations in AGO1 lead to severe developmental defects, highlighting its critical function in post-transcriptional regulation. Argonaute proteins do not act as classic therapeutic targets or receptors but constitute an essential part of the RNA interference machinery fundamental to eukaryotic gene expression control.

Other names

AGO1Argonaute-1Argonaute RISC catalytic subunit 1 (human context)ARGONAUTE1AtAGO1 (in *Arabidopsis*)rde-1 (in *C. elegans*)piwi (related Drosophila family member)QDE-2 (in *Neurospora*)miRNP protein

Not directly targeted by drugs; molecular mechanisms include: - Formation of RISC with miRNA for translational repression or mRNA decay - Sequence-specific binding to target mRNAs via small RNA guides - In some contexts (e.g. mammals: AGO2), endonuclease ("slicer") activity