Properties of p20, a yeast eIF4E¿binding protein

The yeast phosphoprotein p20 is a modulator of translation and shares with mammalian 4EBPs a conserved eIF4E-binding motif. In this book, six more phosphorylation sites have been found on p20 by means of proteomics and a non-phosphorylatable p20 isoform has been established. Moreover, a phenotype of p20 is demonstrated while differences between derivates of two genetically diverse laboratory yeast strains became visible. Investigation of p20 mutants under several stress conditions leads to the conclusion that mutations in p20 affecting its eIF4E binding result in p20 degradation and to a phenotype in a filamentous strain. Furthermore the influence of non-phosphorylatable or several other p20 mutants on translation of reporter mRNAs as well as p20¿s effect on localisation of eIF4E are shown in this work.