RESUMO
The STING pathway is critical to innate immunity and is being investigated as a potential therapeutic target. Existing agents targeting STING suffer from several undesirable effects, particularly the possibility of systematic activation, which increases the risk of autoimmune disorders. In this proof-of-concept study, we report the development of a light-activated STING agonist, based on the potent compound SR-717. We first screened the activity of the non-caged agonist toward 5 human STING variants to identify the most viable target. A photocaged agonist was designed and synthesized in order to block an essential interaction between the carboxy acid group of the ligand with the R238 residue of the STING protein. We then investigated the selective activation of STING with the photocaged agonist, demonstrating an irradiation-dependent response. The development and characterization of this selective agonist expands the growing toolbox of conditionally controlled STING agonists to avoid systematic immune activation.
Assuntos
Imunidade Inata , Proteínas de Membrana , Humanos , Proteínas de Membrana/agonistasRESUMO
The strategic placement of unnatural amino acids into the active site of kinases and phosphatases has allowed for the generation of photocaged signaling proteins that offer spatiotemporal control over activation of these pathways through precise light exposure. However, deploying this technology to study cell signaling in the context of embryo development has been limited. The promise of optical control is especially useful in the early stages of an embryo where development is driven by tightly orchestrated signaling events. Here, we demonstrate light-induced activation of Protein Kinase A and a RASopathy mutant of NRAS in the zebrafish embryo using a new light-activated amino acid. We applied this approach to gain insight into the roles of these proteins in gastrulation and heart development and forge a path for further investigation of RASopathy mutant proteins in animals.