BRING-SynBio: Dynamic cooperative binders for endogenously gated cellular control

About This Grant

Cells sense and respond to their environments. Immune system cells sense and respond to viruses, bacteria, and even cancer cells. Most sense and response circuits involve several intermediate molecules acting as a cascade. This takes time and makes it difficult to engineer these circuits to respond to new inputs or to generate new responses. Existing circuits often overlap and interact. This makes efforts to modify them subject to possible negative side effects. To avoid these problems, it is proposed to develop a class of molecules that sense and respond directly to environmental cues that can be engineered and can infiltrate existing cells to change their responses. For example, this might be a way that cells in an existing tumor could be directed to break apart and die. This effort will focus on a class of proteins referred to as intrinsically disordered proteins (IDPs). Unlike most other proteins, they do not have a fixed conformation and can rapidly and dramatically change shape in response to stimuli. Because they can be designed to interact with signal molecules and cellular proteins, they could act as a rapid switch for cell metabolism in response to a specific signal. Outreach at the local Southside Chicago Science Festival will make science relatable and help attract students to STEM careers. Supporting undergraduate researchers will grow the synthetic biology workforce. Molecules that drive cell-specific responses based on defined inputs can increase the safety and efficacy of bioengineering and biomedical technologies. This synthetic biology project will establish a new class of dynamic molecules that drive defined, gated output signals based on endogenous, cell-specific input triggers, where the sensing and output functions are entirely contained within a single molecule. Binary interactions between these “smart molecules” and either one of two targets – an effector and sensing target - are weak, but cooperative interactions in the ternary complex are strong; thus, if a function is linked to any of the binary interactions, dependence on cooperative ternary complex formation creates an AND gate for that function. This project will establish this new mechanism by developing dynamic cooperative molecules that elicit a controlled response (i.e., apoptosis) in mammalian cells based on the coincidence of two binding targets – either an exogenously expressed model protein or endogenous proteins specific to a target cell type, such as HIF1a. The novel AND gate-induced molecular technology will define a new mechanism for cell engineering and molecular design and pave the way for a new class of therapeutics with broad potential to impact human health. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.