Recruitment to the Proteasome Is Necessary but Not Sufficient for Chemically Induced, Ubiquitin-Independent Degradation of Native Proteins
Year: 2024
Type: article
Abstract: Targeted protein degradation (TPD) is a promising strategy for drug development. Most degraders function by forcing the association of the target protein (TP) with an E3 Ubiquitin (Ub) ligase, which, in favorable cases, results in the polyubiquitylation of the TP and its subsequent degradation by the 26S proteasome. An alternative strategy would be to create chemical dimerizers that bypass the requirement for polyubiquitylation by recruiting the target protein directly to the proteasome. Direct-to-proteasome degraders (DPDs) may exhibit different characteristics than ubiquitin-dependent degraders, but few studies of this type of TPD have been published, largely due to the dearth of suitable proteasome ligands. To facilitate studies of DPDs, we report here a mammalian cell line in which the HaloTag protein is fused to the proteasome via Rpn13, one of the ubiquitin receptors. In these cells, a chloroalkane serves as a covalent proteasome ligand surrogate. We show that chimeric molecules comprised of a chloroalkane linked to a ligand for the BET family of proteins or the Cdk2/7/9 family of kinases result in ubiquitin-independent degradation of some of these target proteins. We use this system, the first that allows facile degradation of native proteins in a ubiquitin-independent fashion, to probe two issues: the effect of varying the length of the linker connecting the chloroalkane and the target ligand and the selectivity of degradation within the protein families engaged by the target ligand.
Source: ACS Chemical Biology
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Funder: National Cancer Institute
Awards: G2545484131, G3504372804
OpenAlex ID: W4403692699