Inspired by our time-course measurement for the KaiABC oscillatory system, we realized the importance of the sensitivity of reporter genes when used to characterize the variation in our engineering strains.
With the knowledge that the instability of proteins is associated with the existence of the so-called PEST regions, which control the ubiquitination of regulatory short-lived proteins, we decided to optimize our NanoLuc with the potentially degrading sequence PSET to shorten its intracellular lifetime.
Function of PEST
The covalent linkage of ubiquitin to lysine residues of substrate proteins is a common means used by eucaryotic cells to signal their degradation by the 26S proteasome, a multiprotease complex located in the cytoplasm and the nucleus. Decades ago it had been demonstrated that the PEST regions, enriched with Pro, Glu, Ser, and Thr, were identified to indeed control the ubiquitination of regulatory short-lived proteins , such as transactivator Gcn4 and G1 cyclins in yeast and mammalian cells. Phosphorylation of particular Ser or Thr residues in the PEST regions of these G1 cyclins specifies their recognition and processing by the ubiquitin-proteasome pathway.
Sequence and features
Features: shortener NanoLuc lifetime contributes to the higher sensitivity
PEST sequence can be found in variety of eukaryotic cells and the sequence we used was from the literature Engineered Luciferase Reporter from a Deep Sea Shrimp Utilizing a Novel Imidazopyrazinone Substrate.
We compare the degradation of the origin with improved NanoLuc in 3 hours.
Anna E. Masser, Ganapathi Kandasamy, Jayasankar Mohanakrishnan Kaimal and Claes Andréasson.Luciferase NanoLuc as a reporter for gene expression and protein levels in Saccharomyces cerevisiae.YEAST 2016. DOI: 10.1002/yea.3155