Translational control of gene expression in maturing erythroid cells

• Applicant: Professorin Dr. Antje Ostareck-Lederer
• Subject Area: Cell Biology
• Term: from 2007 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 33442413

Regulation of mRNA translation is essential for erythroid cells because their precursors loose mRNA synthesis capacity with nuclear exclusion. Temporal translational silencing of reticulocyte 15-Lipoxygenase (r15-LOX) mRNA, which we have studied is representative for that. Recently, based on human K562 cells we set up an inducible erythroid cell system, which exhibits changes in morphology and protein expression that are characteristic for terminal erythroid cell maturation: nuclear exclusion, expression of hr15-LOX regulated by hnRNP K and hnRNP E1 and loss of mitochondria. Employing this system we identified new interacting factors involved in 80S ribosome formation and so far unknown proteins cooperating with hnRNP K and hnRNP E1 in maintaining hr15-LOX mRNA silencing, which will now be characterized. Furthermore, besides hr15-LOX- and c-Src mRNA we identified new mRNAs, which are differentially enriched in hnRNP K-containing mRNPs during maturation. The functional relevance of this interaction for protein expression will be studied. We could show that hnRNP K and hnRNP E1 are degraded during K562 cell induction and detected a specific peptide for hnRNP K. We will identify and characterize the hnRNP K cleaving activity and investigate how hnRNP E1 is processed in erythroid cell maturation.

• DFG Programme: Research Units
• Subproject of: FOR 855: Cytoplasmic Regulation of Gene Expression
• Participating Person: Professor Dr. Dirk Ostareck