miRNAs Get an Early Start on Translational Silencing

MicroRNAs (miRNAs) control gene expression by regulating mRNA stability and translation. Using cell-free in vitro systems, several labs have recently reported insights into the molecular mechanisms underlying miRNA-guided translational repression (Kiriakidou et al., 2007, Mathonnet et al., 2007, Thermann and Hentze, 2007 and Wakiyama et al., 2007). These new findings indicate that miRNAs inhibit translation at early steps of initiation.