The Use of High-Quality Chemical Tools to Rescue TBK1 Function and Identify Novel ATP-Competitive Targets in ALS
Abstract
We are developing chemical tools and biological reagents to interrogate the regulation of kinase-mediated biological pathways as new avenues to combat the accumulation of toxic protein and RNA aggregates in ALS. TDP-43 is an example of the most commonly misfolded and deposited protein in ALS. Failure of the autophagy system is one mechanism that allows protein aggregates accrue. TBK1 is a human protein kinase that plays an essential role in autophagy and which, through multiple genetic studies, has surfaced as a protein that suffers from inactivating mutations in ALS patients. We have identified linkable compounds that potently engage TBK1 in cells and a putative TRAF3-recruiting warhead. These will be covalently linked to produce the first TBK1-activating activation-targeting chimera. As an alternative approach, we have identified the best available chemical probe targeting casein kinase 2 (CK2), which indirectly activates TBK1. We have and will continue to improve the physical properties of this scaffold to make it suitable for in vivo use. We have also selected a potent, cell-activeback-up compound from the CK2-targeting naphthyridine series for further optimization. Furthermore, through development of a novel TDP-43 aggregation assay in motor neurons derived from stem cells, we aim to identify additional protein kinases that, when modulated, reduce the deposition of misfolded proteins. We have generated motor neurons harboring ALS-relevant TDP-43 and characterized expression of mutant versus wild-type (WT) TDP-43 during differentiation. We have confirmed that ethacrynic acid elicits mutant and WT TDP-43 translocation and have developed a methodology to quantify this movement.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2021
- Accession Number
- AD1136217
Entities
People
- Alison D Axtman
- Carrow Wells
- Lenore Beitel
- Mathilde M. Chaineau
- Sarah Lepine
- Thomas Durcan
Organizations
- McGill University
- University of North Carolina at Chapel Hill