Desensitisation of Notch signalling through dynamic adaptation in the nucleus

다국어 초록 (Multilingual Abstract)

During embryonic development, signalling pathways orchestrate organogenesis by controlling tissue‐specific gene expression programmes and differentiation. Although the molecular components of many common developmental signalling systems are known, our current understanding of how signalling inputs are translated into gene expression outputs in real‐time is limited. Here we employ optogenetics to control the activation of Notch signalling during Drosophila embryogenesis with minute accuracy and follow target gene expression by quantitative live imaging. Light‐induced nuclear translocation of the Notch Intracellular Domain (NICD) causes a rapid activation of target mRNA expression. However, target gene transcription gradually decays over time despite continuous photo‐activation and nuclear NICD accumulation, indicating dynamic adaptation to the signalling input. Using mathematical modelling and molecular perturbations, we show that this adaptive transcriptional response fits to known motifs capable of generating near‐perfect adaptation and can be best explained by state‐dependent inactivation at the target cis‐regulatory region. Taken together, our results reveal dynamic nuclear adaptation as a novel mechanism controlling Notch signalling output during tissue differentiation.










Precise control of Notch signalling activation using optogenetics uncovers adaptation of target gene expression to continuous Notch stimulation. Mathematical modelling and genetic perturbations suggest state‐dependent inactivation at the target promoter as the underlying mechanism.



Light‐mediated activation of Notch IntraCellular Domain (NICD) nuclear translocation induces sim expression in the Drosophila ectoderm.

Over time, sim expression in the ectoderm ends despite continuous NICD nuclear accumulation.

The transcription factor Twist or pulsatile optogenetic activation can prevent adaptation, allowing persistent sim expression.

Notch signalling can dynamically self‐terminate or persist in a context‐dependent fashion.


Precise continuous optogenetic activation of Notch in vivo leads to gradual decay of target gene expression through state‐dependent inactivation of cis‐regulatory regions.