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Biology subjects

Czerwonka, A.

Publications and source records attributed to Czerwonka, A..

2 recordsLinked to original sources

TANGO-Light - optogenetic control of transcriptional modulators

Cell signalling pathways, in particular downstream receptor activation, frequently converge in the activation of transcriptional modulators. Yet, cells are able to differentiate the stimulation of each receptor. It has become clear that transcriptional modulators, such as transcription factors, do not work in on or off states but rather in patterns of active/inactivate conformations. Thus, it is the intensity and duration of such fluctuating activity that result in differential cellular and genes expression changes, and this is challenging to replicate using traditional methods such as inhibitors or genetic constructs. Optogenetics, which is based on the use of light-responsive proteins, offers precise control over biological processes, in a spatio-temporal manner, allowing targeted fine-tuned modulation of specific proteins or signalling pathways. Here, we engineered an optogenetic system to control transcriptional modulators, by fusing a photoactivatable receptor and the TANGO system. By this mean we show that we are able to control a plethora of transcriptional modulators by light. And by doing so, changing cells fate - inducing cells to acquire a more mesenchymal or epithelial phenotype. This optogenetic system was also adapted to mimic signalling pathways such as Notch and Wnt in a light-dose dependent manner. Finally, we show that this light-responsive system can be induced by natural light sources upon cell-cell contact/proximity.

cell biology↗

Optogenetic control of NOTCH1 signalling

The Notch signalling pathway is a crucial regulator of cell differentiation as well as tissue organisation. Dysregulation of Notch signalling has been linked to the pathogenesis of different diseases. Notch plays a key role in breast cancer progression by controlling the interaction between the tumour cells and the microenvironment as well as by increasing cell motility and invasion. NOTCH1 is a mechanosensitive receptor, where mechanical force is required to activate the proteolytic cleavage and release of the Notch intracellular domain (NICD). Here, we circumvent this step by regulating Notch activity by light. To achieve this, we have engineered a membrane-bound optogenetic NOTCH1 receptor (optoNotch) to control the activation of NOTCH1 intracellular domain (N1ICD) and its downstream transcriptional activities. Using optoNotch we confirm that NOTCH1 activation increases cell proliferation in MCF7 and MDA-MB-468 breast cancer cells in 2D and spheroid 3D cultures. OptoNotch allows fine-tuning ligand-independent regulation of N1ICD to understand the spatiotemporal complexity of Notch signalling.

cell biology↗