Human Kelch-like Protein 20 (KLHL20); A Target Enabling Package

The BTB-Kelch protein KLHL20 is a hypoxia-induced CUL3-dependent E3 ligase linked to autophagy, Alzheimer’s disease and cancer. KLHL20 acts to terminate autophagy by promoting the ubiquitination and degradation of ULK1. KLHL20 is also reported as a top 20 biomarker for Alzheimer’s disease progression. Inhibition of KLHL20 may be neuroprotective by extending autophagy for the clearance of neurotoxic proteins aggregates. KLHL20 also promotes cancer through the ubiquitination and degradation of tumour suppressors including PML and DAPK1. We have solved the 1.1 Å structure of the Kelch domain of KLHL20 in complex with a DAPK1 peptide. We have used biophysical and cellular studies to validate this peptide site as a degron site for DAPK1 degradation. Using this peptide, we have also established alpha screen and HTRF assays to identify potent small molecule covalent inhibitors that compete with DAPK1 for binding to the Kelch domain of KLHL20.