FIGURE 10-23 Remodeling of mRNPs during nuclear export. Some mRNP proteins (rectangles) dissociate from nuclear mRNP complexes before their export through an NPC. Others (ovals) are exported through the NPC with the mRNP, but dissociate from it in the cytoplasm and are shuttled back into the nucleus through an NPC. In the cytoplasm, translation initiation factor eIF4E replaces CBC bound to the 5′ cap, and PABPC1 replaces PABPN1.