Enzyme microRNA complexes, illustration - stock illustration

Illustration of three enzyme/microRNA (micro ribonucleic acid) complexes. At left is a pre-miRNA (precursor microRNA, red) complexed with the exportin-5(blue)/RanGTP(light violet) transport protein. Exportin-5/RanGTP transports pre-miRNAs from the cell nucleus to the cytoplasm via the nuclear pore complex. At centre is the dicer-2 enzyme (blue) bound to a pre-miRNA (red) and the cofactor TRBP (transactivation response element RNA-binding protein, violet). Dicer processes the pre-miRNA in the cytoplasm to produce double-stranded miRNA molecules. At right is an argonaute protein bound to a guide strand (red) of miRNA. The argonaute protein will incorporate the guide strand into the RNA-induced silencing complex (RISC), a multiprotein complex that acts to inhibit the expression of specific genes by regulating the expression of messenger RNA (mRNA)