Controlling signal transduction with artificial designer receptors is a promising approach to realize future medicine for intractable diseases. Although several functional artificial receptors have been reported by domain engineering, more sophisticated engineering within domains has yet to be thoroughly investigated. Here we demonstrate motif-based engineering of a receptor tyrosine kinase for reprogramming signal transduction. We design a scaffold-less tyrosine kinase domain that does not recruit any signal transducers but retains its kinase function. The resultant scaffold-less tyrosine kinase domain is linked to a tyrosine motif that recruits a target signaling molecule upon its phosphorylation. The engineered tyrosine motif–kinase fusion protein is further connected to a small molecule- or light-dependent dimerizing domain that can switch on the kinase activity in response to an external stimulus.
Fig: Schematic illustration of designer receptors: A Ligand binding to the receptor tyrosine kinase (RTK) leads to activation of the intracellular kinase domain. The intracellular domain of c-KIT is engineered in this study. A tyrosine motif is a short sequence which is derived from another receptor. B The designer receptors in this study consist of 3 parts; (i) an engineered tyrosine kinase which has an ability to phosphorylate the tyrosine motif, (ii) a tyrosine motif, which specifically binds to a target signaling molecule when phosphorylated, and (iii) an external stimulus-responding dimerizing domain (e.g., AP20187-responsive FKBPF36V). C Illustration of the activation process of the designer receptor. FKBPF36V, a tyrosine motif, and the engineered c-KIT are linked together to create a designer receptor. The designer receptor dimerizes when stimulated by AP20187. D The kinase domain of wild-type c-KIT functions as a scaffold domain which recruits many intracellular signaling molecules. To obtain the domain which functions only as a kinase, the 7 tyrosine residues which are known as a scaffold for recruiting signaling molecules are mutated to phenylalanine.
The resultant designer receptors attain specific chemical- or photo-activation of signaling molecules of interest in mammalian cells. Thus, our designer receptor tyrosine kinase proves the possibility of rationally reprogramming intracellular signal transduction on a motif basis. The motif-based receptor engineering may realize tailor-made functional receptors useful in the fields of biology and medicine.
Kongkrongtong, T., Sumigama, Y., Nagamune, T. et al.Reprogramming signal transduction through a designer receptor tyrosine kinase. Commun Biol 4, 752 (2021). https://doi.org/10.1038/s42003-021-02287-8