A common mechanism underpinning the cell’s proteostasis network is the recognition of specific protein substrates by components of the quality-control machineries. The Polyproxin® platform exploits our understanding of these interactions. By combining libraries of target-engagement modules and degradation-inducing modules in a mix-and-match format, we identify the best combination for efficient knockdown of the target. The platform can be applied to diverse targets by co-opting the broadest range of degradation machineries including, but not limited to, the ubiquitin-proteasome system.

Recent innovations in PROTAC functionality assays for target affinity, ternary complex stability and cellular potency have enabled significant progress towards a screening toolkit that guides rational PROTAC design. Exemplified by SMARCA PROTAC optimisation, this talk will outline the key profiling parameters to consider within a structure-guided approach to PROTAC drug discovery. It will also provide an overview of the assay platforms at hand to facilitate PROTAC development towards potential cancer therapeutics of the future.

The AdPROM system utilizes small, polypeptide binders of intracellular proteins of interest (POIs) linked to specific enzymes as “payload” to target intracellular proteins for desired outcomes; for instance, the use of an E3 ligase targets POI for ubiquitination and destruction. The AdPROM system achieves rapid and efficient modifications of target POIs and is extremely versatile. Therefore, it has the potential to not only reveal the functions of specific modifications within POIs, but to also rapidly inform various intervention strategies to develop heterofunctional molecules.

Current methods for PROTAC drug discovery are inefficient and limited in information. We developed a plate-based methodology for rapid screening of PROTAC-mediated protein poly-ubiquitination, a true measure of PROTAC drug effect. This method is faster, more reproducible and adaptable to in vitro and cell-based approaches.

In this lecture, I will summarize our efforts to discover small-molecule inhibitors, activators, and hijackers for HECT/RBR E3s ligases. To do so, we have developed two complimentary technologies: UbFluor and covalent fragments. UbFluor allows the ability to discover reversible inhibitors and activators of E3s, while covalent fragment technology allows the ability to discover covalent inhibitors.

Targeted protein degradation is a novel chemical modality using pharmacological agents to alter protein abundance. While there are a lack of tools to perturb majority of the proteome, we developed the degradation tag (dTAG) system to selectively dispose of any target protein using small molecule degraders. This talk will summarize the dTAG technology platform and highlight studies demonstrating utility for preclinical target validation and biological investigation in cellular and mouse models.

The rapid spread of SARS-CoV-2 has underscored the need to quickly develop antiviral countermeasures. Here, we present our work using engineered ubiquitin to first identify inhibitory sites on a virally encoded enzyme that is absolutely required for host infection. We then use this information to screen for small molecule antiviral leads. Broadly, our versatile strategy can be used to identify lead compounds in response to future outbreaks.

Nature synthesizes multiple poly-ubiquitin chains that extend from seven lysines on the ubiquitin surface. Lys 48 and Lys 63 poly-ubiquitin are primary degradation signals for PROTACs, driven by ubiquitin ligases cerebelon, VHL and HDM2. Little is known about the roles of mono-ubiquitin or atypical poly-ubiquitin chains or their cognitive ubiquitin ligases. The roles of classic ubiquitin ligases and atypical ubiquitylation will be discussed with the aim of expanding the horizon of PROTAC drugs beyond protein degradation.

Testis-restricted melanoma antigen (MAGE) proteins are frequently hijacked in cancer and play a critical role in tumorigenesis. MAGEs assemble with E3 ubiquitin ligases and function as substrate adaptors (‘protein glue’) that direct the ubiquitination of novel targets. Here, I will discuss how MAGE-A11 promotes tumorigenesis through reprogramming the HUWE1 ubiquitin ligase to ubiquitinate the mRNA 3' end processing complex protein, PCF11. This leads to alternative polyadenylation of many transcripts affecting core oncogenic and tumor suppressors.

We will present recent data from CETSA profiles on both PROTACs and molecular glue molecules. The CETSA HT technology allows parallel quantification of the degradation specificity and efficacy. The CETSA MS profiling of degraders allow simultaneous study of direct binding both its intended protein target, involved E3-ligase and off-targets. 

A major hurdle in tumor immunotherapy is understanding how immunosuppression is mediated by regulatory T (Treg) cells, that suppress the function of effector T cells. However, current approaches in targeting Treg to activate antitumor immune responses have shown only transient efficacy and are highly unspecific. Herein we identified USP22 as a potential therapeutic target and its suppression partially diminishes Treg-suppressive functions without impairing effector T cell immunity.

Alzheimer’s disease is a tauopathy and the leading cause of dementia worldwide with no disease-modified treatments currently available; however, an emerging therapeutic approach is anti-tau immunotherapies. While conventional immunotherapies are promising, they are limited to targeting extracellular proteins, whereas the majority of pathological tau remain in the cytosol of cells. Therefore, we have engineered anti-tau intrabodies for expression intracellularly that contain distinct tags that shuttle tau to either the proteasome or lysosome for degradation.

Pharmaceutical research teams rely on SciFinder-n, the most advanced research solution in the SciFinder family, to help improve productivity, inspire innovation and feel confident in advancing projects and programs forward. This talk will demonstrate, with practical examples, how SciFinder-n helps solve problems and inspire ideas in protein degradation technology.