Figure 1.

eIF6 in ribosome biogenesis and translational control. In the nucleolus, eIF6 associates with immature large ribosomal subunits (pre-60S) and other regulatory proteins (trans-acting factors). eIF6 is found during pre-60S subunit maturation in the nucleoplasm and is exported to the cytosol. Here, eIF6 release allows the 60S to join the 40S subunit, and the active, translating 80S complex is formed. eIF6 shuttling between the nucleus and cytoplasm allows the proper formation of pre-60S. Whether eIF6 joins the 60S and prevents its premature association with 40S after the termination of translation is unknown. eIF6, eukaryotic initiation factor 6; PABP, polyA-binding protein.