1. Luminescence complementation assay for measurement of binding to protein C-termini in live cells.
- Author
-
Nadel, Cory M, Ran, Xu, and Gestwicki, Jason E
- Subjects
Humans ,Ubiquitin-Protein Ligases ,Protein Binding ,HSP70 Heat-Shock Proteins ,Luminescence ,HEK293 Cells ,Protein Domains ,C-termini ,Chaperones ,Hsp70 ,Protein-protein interactions ,TPR domains ,Biotechnology ,2.1 Biological and endogenous factors ,Aetiology ,Analytical Chemistry ,Other Chemical Sciences ,Biochemistry and Cell Biology ,Biochemistry & Molecular Biology - Abstract
Protein-protein interactions (PPIs) involving the extreme C-terminus serve important scaffolding and regulatory functions. Here, we leveraged NanoBiT technology to build a luminescent complementation assay for use in studying this subcategory of PPI. As a model system, we fused one component of NanoBiT to the disordered C-terminus of heat shock protein (Hsp70) and the other to its binding partner, the tetratricopeptide repeat (TPR) domain of CHIP/STUB1. We found that HEK293 cells that stably express these chimeras under a doxycycline promoter produced a robust luminescence signal. This signal was sensitive to mutations and it was further tuned by the expression of competitive C-termini. Using this system, we identified a promising, membrane permeable inhibitor of the Hsp70-CHIP interaction. More broadly, we anticipate that NanoBiT is well-suited for studying PPIs that involve C-termini.
- Published
- 2020