Biology subjects

Queisser, M. A.

Publications and source records attributed to Queisser, M. A..

4 recordsLinked to original sources

bioRxiv2025

Optimization and evaluation of complementary degrader discovery assays for application in screening

Targeted protein degradation (TPD) mediated by molecular glues is an innovative pharmaceutical paradigm. By binding to and modulating the surface of an E3-ligase component, molecular glue degraders can facilitate the recruitment of a specific target protein (or vice versa) and, ultimately, invoke target degradation. This mode of action results in specific challenges for the development of rational discovery strategies, and complex hit validation workflows may be required to reliably eliminate compounds that elicit non-specific effects. With the aim to guide screening efforts, we optimized two orthogonal cell-based, target-centric assays for degrader discovery: (1) a time-resolved FRET assay directly quantifying levels of target protein and its degradation (signal inhibition), and (2) an assay coupling TPD to cell growth (signal rescue). To enable a deeper understanding of the individual assays strengths and limitations, we compared their statistical performance as well as respective hit populations by screening a specifically designed collection of about 1000 compounds containing well annotated reference compounds and known frequent hitters. We found that the signal rescue format reliably and specifically captured active target degraders while it efficiently filtered out interfering or frequent hitter compounds. Importantly, this format achieved to retrieve lower potency hits, which might be desirable in order to confidently include as many diverse chemical starting points as possible at the start of a drug discovery project.

pharmacology and toxicology↗

bioRxiv2024

Orthogonal IMiD-Degron Pairs Induce Selective Protein Degradation in Cells

Immunomodulatory imide drugs (IMiDs) including thalidomide, lenalidomide, and pomalidomide, can be used to induce degradation of a protein of interest that is fused to a short zinc finger (ZF) degron motif. These IMiDs, however, also induce degradation of endogenous neosubstrates, including IKZF1 and IKZF3. To improve degradation selectivity, we took a bump-and-hole approach to design and screen bumped IMiD analogs against 8380 ZF mutants. This yielded a bumped IMiD analog that induces efficient degradation of a mutant ZF degron, while not affecting other cellular proteins, including IKZF1 and IKZF3. In proof-of-concept studies, this system was applied to induce efficient degradation of TRIM28, a disease-relevant protein with no known small molecule binders. We anticipate that this system will make a valuable addition to the current arsenal of degron systems for use in target validation. One-Sentence SummaryEngineered zinc-finger-based degrons enable targeted protein degradation induced by selective molecular glues.

biochemistry↗

bioRxiv2023

Structure-guided design and optimization of covalent VHL-targeted sulfonyl fluoride PROTACs

O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/545773v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@da22e5org.highwire.dtl.DTLVardef@1290278org.highwire.dtl.DTLVardef@1611c0eorg.highwire.dtl.DTLVardef@7902d2_HPS_FORMAT_FIGEXP M_FIG C_FIG Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that have emerged as a therapeutic modality to induce targeted protein degradation (TPD) by harnessing cellular proteolytic degradation machinery. PROTACs which ligand the E3 ligase in a covalent manner have attracted intense interest, however, covalent PROTACs with a broad protein of interest (POI) scope have proven challenging to discover by design. Here, we report structure-guided design and optimization of Von Hippel-Lindau (VHL) protein-targeted sulfonyl fluorides which covalently bind Ser110 in the HIF1 binding site. We demonstrate that their incorporation in bifunctional degraders induces targeted protein degradation of BRD4 or androgen receptor (AR) without further linker optimization. Our study discloses the first covalent VHL ligands which can be implemented directly in bifunctional degrader design expanding the substrate scope of covalent E3 ligase PROTACs.

molecular biology↗

bioRxiv2019

Targeting endogenous K-RAS for degradation through the affinity-directed protein missile system

For over three decades, K-RAS has been known as the holy grail of cancer targets, one of the most frequently mutated oncogenes in cancer. Because the development of conventional small molecule K-RAS inhibitors has been extremely challenging, K-RAS has been dubbed as an undruggable target, and only recently a mutation specific inhibitor has reached clinical trials. Targeted protein degradation has emerged as a new modality in drug discovery to tackle undruggable targets. However, no degrader for K-RAS has been described thus far. Our laboratory has developed an Affinity-directed PROtein Missile (AdPROM) system for targeted proteolysis of endogenous proteins through the ubiquitin proteasome system. Here, we show that we can achieve degradation of endogenous K-RAS and H-RAS in different cell lines in a targeted manner using our AdPROM system. Our findings imply that endogenous RAS proteins can be targeted for proteolysis, thereby offering tantalising possibilities for an alternative therapeutic approach to these so-called undruggable targets in cancer.

molecular biology↗