Working on this project:
In the 2nd funding period, we were able to show that pre-miR181a is processed locally by Dicer upon local synaptic activity in neurons. This work demonstrated for the first time that miRNAs can be generated by extracellular signals (like neurotransmitters) in remote cellular regions like dendrites. In the upcoming funding period, we now want to fully understand this regulatory system – especially its spatio-temporal aspects. To this end, we want to develop a new method for the multiplexing, quantitative, super-resolution imaging of the constituent parts of this system together with the Heilemann group (A8). This technology will be based on what is so far known as DNA PAINT and will make use of our experience in the thermodynamic and kinetic aspects of oligonucleotide hybridization equilibria and complex light-regulation strategies obtained in the past funding period. By doing so we want to be able to examine, in a quantitative way, the regulatory relationship between a miRNA, its mRNA target and the resulting production of the protein. In a second part of the project, we want to understand a recently discovered process in which the 3’-UTR of several mRNAs appears to be actively shortened in neurons in a transcription-independent fashion. We want to use probes, which will allow us to actively interfere with this process in a light-controlled fashion in order to investigate the local functional consequences. In a second step, we want to devise probes that will allow us to image the stimulation-dependent 3’-UTR shortening process in real-time.