Cap-Independent Translation

Peter Sarnow (Curatore)

Springer-Verlag Berlin and Heidelberg GmbH & Co. KG, 2011

Whether or not an mRNA is translated is often thought to be a simple function of its steady-state concentration and the ab- sence of inhibitory proteins or RNA structures in the 5' and 3' noncoding regions. The articles presented in this volume show an unexpected flexibility of the eukaryotic translational appara- tus in the mechanism of translational initiation and provide new opportunities for regulation. Most or all mRNA molecules synthesized by RNA poly- 7 merase II in eukaryotic cells contain a 5' terminal mGpppG dinucleotide, also known as the "cap structure. " RNAs carrying a cap structure have been shown to be more resistant to attack by exoribonucleases than their uncapped counterparts. Further- more, the cap facilitates transport of the RNAs from the nucleus to the cytoplasm. In the cytoplasm, the cap functions as a binding site for the cap binding protein complex eIF-4, which enhances the translation of the RNAs by the eukaryotic trans- lational apparatus. Specifically, it has been postulated that bind- ing of e1F-4 to the 5' terminal cap facilitates the recruitment of ribosomal subunits onto the mRNAs via their free 5' ends (cap- dependent translation). Accordingly, uncapped RNAs are generally translated more poorly than capped RNAs. However, during the past 6 years both viral and cellular mRNAs have been discovered that can be translated cap-independently.

• Curatore: Peter Sarnow
• Editore: Springer-Verlag Berlin and Heidelberg GmbH & Co. KG
• Collana: Current Topics in Microbiology and Immunology
• Anno: 2011
• Rilegatura: Paperback / softback
• Pagine: 183 p.
• Dimensioni: 235 x 155 mm
• EAN: 9783642796654

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