Age is an important parameter underlying the regulation of fate decisions in biological systems. To study age related phenomenon, we have developed a reporter system that uses fluorescent proteins in order to report on the age of such labelled structures.

The basic component of the reporter system consists of a tandem fusion of two spectrally different fluorescent proteins. Fluorescent proteins require to undergo a chemical maturation step in order to acquire fluorescent properties. By using two fluorescent proteins with different maturation kinetics, such a tandem fusion protein constitutes a fluorescent timer, that is able to report on the age of a pool of labelled proteins by the relative amount of the fluorescence of the two fluorescent proteins (see figure). Therefore, we named them tandem fluorescent timer proteins (tFTs).

Fig 1.1 : this is an example of caption that could be way longer and should be modified before releasing the website.

Fluorescent timer proteins have already been developed earlier. Such fluorescent proteins however have been bade on the base of a single fluorescent proteins that change their color as a function of time, due to a chemical reaction of the chromophore that changes its spectral properties. This provides certain disadvantages. First, such proteins proteins are difficult to optimized to exhibit bright fluorescence in both channels and the optimal temporal resolution for the processes under investigation. In addition, they exhibit a relatively low temporal dynamic range. Still, they are supercool and – most importantly – brought the concept of ‘time’ into the field of fluorescent protein applications!

With our new tFTs based on state-of-the-art fluorescent proteins we have explored the concept of fluorescent timer for various different applications (see our paper on this).

Genomics/Proteomics
– Investigation of protein turnover and degradation
– High throughput screening for regulators of protein degradation

Cell Biology
– mapping the inheritance of protein structures during cell division and cellular aging
– analysis of protein turn over and stability with subcellular resolution