Characterization of target RNAs of the tumor suppressor protein Pdcd4

点击翻译按钮获取中文摘要

Pdcd4 is an evolutionarily highly conserved RNA-binding protein, that suppresses the translation of specific mRNAs and has been implicated as a tumor suppressor in the development of different kinds of tumors. The mechanisms by which Pdcd4 influences the translation of specific mRNAs and how the function of Pdcd4 as a translation regulator contributes to tumor suppression are still elusive because only very few mRNAs have been identified as translational targets of Pdcd4. Based on the analysis of the known Pdcd4 target RNAs it appears that Pdcd4 affects the translation of specific mRNAs by different mechanisms acting on the level of translational initiation or translational elongation and that direct Pdcd4-RNA-interactions play an key role in the targeting of Pdcd4 to specific mRNAs. In this project we will use PAR-CLIP and ribosome profiling to gain insight into the role of Pdcd4 as a translational regulator on a transcriptome-wide level. PAR-CLIP and Ribosome profiling are new methods that allow to determine the binding sites of an RNA-binding protein on all cellular RNAs, and to map the positions of all ribosomes on all mRNAs in the cell, thereby providing a transcriptome-wide view of the translation process. By comparing Pdcd4-expressing and -deficient cells we will be able to identify all Pdcd4-regulated mRNAs and to study the molecular mechanisms underlying their regulation by Pdcd4 in a systematic way. This project will provide fundamental insight into the biological and molecular processes regulated by Pdcd4 and their relevance for tumorigenesis.