Untersuchung der Mechanotransduktion durch den Hippo Signalweg mittels Optogenetik
Biophysik
Zusammenfassung der Projektergebnisse
The Hippo pathway is one of main cellular mechanosensors that converts mechanical information into a cellular response. It primarily senses signals from the actin cytoskeleton and acts through the transcriptional co-activator YAP and TAZ to control gene expression involved in important cellular decisions such as proliferation, differentiation, pluripotency and apoptosis. How the pathway distinguishes between the different upstream signals to drive the appropriate gene expression programs is however unclear. To probe this question, I leveraged CRISPR editing and optogenetics to perturb and control Hippo signaling in mESCs. The optogenetic tools allow light-gated nuclear import and export of YAP at the minute timescale. The system was combined with live-imaging reporters of endogenous gene expression of YAP target genes to understand the logic of YAP signaling for gene regulation. The approach enables the temporal control of YAP signaling and simultaneous quantitative readout of target gene transcription. Preliminary results suggest differential decoding of YAP target genes to steady-state nuclear YAP levels, suggesting that nuclear YAP concentrations may encode information about the upstream signal. The established tools are currently used to study YAP target genes expression to different nuclear YAP dynamics. In the future, I plan to use a genome-wide RNAseq screen to identify further gene that decode YAP concentrations and/or dynamics and will use differentiation assays to verify the logic of YAP signaling for mESC fate decisions.
