Slide 36 of 62
Notes:
This figure is a very recent drawing that was presented in 1997. It links poly A tail with regulation of initiation at the cap. Therefore, both the polyA tail and the cap, the two modifications that are made on eucaryotic messages, are used in protein synthesis.
eIF4E is cap-binding protein
eIF4E binds to G and A and is active only in this group (eIF4F)
eIFG is has binding sites for eIF3 (bound to 40S) and for polyA binding protein Pab1p, bridging the poly A tail and the cap.
Regulation: 4E-BP binds eIF4E to prevent initiation; phosphorylation of 4E-BP by growth factors inactivate 4E-BP
