What is the silencing mechanism of AGO1,AGO3 and AGO4?
Paper by Zinovyev and colleagues in the paper &quot;Mathematical modeling of microRNA‐mediated mechanisms of translation repression&quot; find that there are reports to 9 different mechanisms of miRNA-regulation.

Here we are reviewing available experimental data on all reported mechanisms of microRNA action, grouping them in a way which elucidates the main details supporting each of these proposed mechanisms.

Here is a list of the mentioned mechanisms:

M1: Cap-40S Initiation Inhibition
M2: 60S Ribosomal Unit Joining Inhibition
M3: Elongation Inhibition
M4: Ribosome Drop-Off
M5: Co-translational Nascent Protein Degradation
M6: Sequestration in P-Bodies
M7: mRNA Decay
M8:  mRNA Cleavage
M9: Transcriptional Inhibition Through microRNA-Mediated Chromatin Reorganization Following by Gene Silencing

Also here is a link to the Pubmed entry of the article: