RNAi screening for kinases and phosphatases identifies FoxO regulators.
Forkhead box class O (FoxO) transcription factors are key regulators of growth, metabolism, life span, and stress resistance. FoxOs integrate signals from different pathways and guide the cellular response to varying energy and stress conditions. FoxOs are modulated by several signaling pathways, e.g., the insulin-TOR signaling pathway and the stress induced JNK signaling pathway. Here, we report a genome wide RNAi screen of kinases and phosphatases aiming to find regulators of dFoxO activity in Drosophila S2 cells. By using a combination of transcriptional activity and localization assays we identified several enzymes that modulate dFoxO transcriptional activity, intracellular localization and/or protein stability. Importantly, several currently known dFoxO regulators were found in the screening, confirming the validity of our approach. In addition, several interesting new regulators were identified, including protein kinase C and glycogen synthase kinase 3beta, two proteins with important roles in insulin signaling. Furthermore, several mammalian orthologs of the proteins identified in Drosophila also regulate FOXO activity in mammalian cells. Our results contribute to a comprehensive understanding of FoxO regulatory processes.
Mattila
Jaakko
J
Institute of Biotechnology, University of Helsinki, Viikinkaari 9, 00014 Helsinki, Finland.
Kallijärvi
Jukka
J
Puig
Oscar
O
D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D004330:Drosophila / Q000235:genetics / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D015723:Gene Library; D049750:Genome, Insect; D038362:Glycogen Synthase Kinase 3 / Q000235:genetics / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D014158:Transcription, Genetic
D051858:Forkhead Transcription Factors; D011494:Protein Kinases; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D011493:Protein Kinase C; D038362:Glycogen Synthase Kinase 3; D010744:Phosphoric Monoester Hydrolases