Fig. 1
From: miRTissue: a web application for the analysis of miRNA-target interactions in human tissues
Mechanism of miRNA-target interaction. a mRNA degradation and b translation inhibition schema. a mRNA degradation: after binding miRISC complex, there is a recruitment of a deadenylase complex (CAF1-CCR4-NOT) acting on 3’UTR region of mRNA. Poli A tail is then removed [47, 48]. After deadenylation, decapping of 5’UTR may occur through a synergistic action of different protein factors (DCP1, DCP2, DDX6, EDC4) [47]. Finally 5’-3’ exonucleases lead mRNA degradation [49]. b Translation inhibition: Translation repression is due to miRNA intervention in different steps of translation. AGO protein has been showed to compete with 5’capping protein factors [50], blocking translation at initiation step. Other mechanisms of miRNA action involve elongation step, causing a premature protein termination [51]