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Chemical Society Reviews Jun 2022Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules consisting of one ligand that binds to a protein of interest (POI) and another that can recruit... (Review)
Review
Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules consisting of one ligand that binds to a protein of interest (POI) and another that can recruit an E3 ubiquitin ligase. The chemically-induced proximity between the POI and E3 ligase results in ubiquitination and subsequent degradation of the POI by the ubiquitin-proteasome system (UPS). The event-driven mechanism of action (MOA) of PROTACs offers several advantages compared to traditional occupancy-driven small molecule inhibitors, such as a catalytic nature, reduced dosing and dosing frequency, a more potent and longer-lasting effect, an added layer of selectivity to reduce potential toxicity, efficacy in the face of drug-resistance mechanisms, targeting nonenzymatic functions, and expanded target space. Here, we highlight important milestones and briefly discuss lessons learned about targeted protein degradation (TPD) in recent years and conjecture on the efforts still needed to expand the toolbox for PROTAC discovery to ultimately provide promising therapeutics.
Topics: Proteasome Endopeptidase Complex; Proteolysis; Ubiquitin-Protein Ligases; Ubiquitination
PubMed: 35671157
DOI: 10.1039/d2cs00193d -
Nature Reviews. Drug Discovery Mar 2022Targeted protein degradation (TPD) is an emerging therapeutic modality with the potential to tackle disease-causing proteins that have historically been highly... (Review)
Review
Targeted protein degradation (TPD) is an emerging therapeutic modality with the potential to tackle disease-causing proteins that have historically been highly challenging to target with conventional small molecules. In the 20 years since the concept of a proteolysis-targeting chimera (PROTAC) molecule harnessing the ubiquitin-proteasome system to degrade a target protein was reported, TPD has moved from academia to industry, where numerous companies have disclosed programmes in preclinical and early clinical development. With clinical proof-of-concept for PROTAC molecules against two well-established cancer targets provided in 2020, the field is poised to pursue targets that were previously considered 'undruggable'. In this Review, we summarize the first two decades of PROTAC discovery and assess the current landscape, with a focus on industry activity. We then discuss key areas for the future of TPD, including establishing the target classes for which TPD is most suitable, expanding the use of ubiquitin ligases to enable precision medicine and extending the modality beyond oncology.
Topics: Humans; Proteasome Endopeptidase Complex; Proteins; Proteolysis
PubMed: 35042991
DOI: 10.1038/s41573-021-00371-6 -
Signal Transduction and Targeted Therapy Apr 2022Traditional drug discovery mainly focuses on direct regulation of protein activity. The development and application of protein activity modulators, particularly... (Review)
Review
Traditional drug discovery mainly focuses on direct regulation of protein activity. The development and application of protein activity modulators, particularly inhibitors, has been the mainstream in drug development. In recent years, PROteolysis TArgeting Chimeras (PROTAC) technology has emerged as one of the most promising approaches to remove specific disease-associated proteins by exploiting cells' own destruction machinery. In addition to PROTAC, many different targeted protein degradation (TPD) strategies including, but not limited to, molecular glue, Lysosome-Targeting Chimaera (LYTAC), and Antibody-based PROTAC (AbTAC), are emerging. These technologies have not only greatly expanded the scope of TPD, but also provided fresh insights into drug discovery. Here, we summarize recent advances of major TPD technologies, discuss their potential applications, and hope to provide a prime for both biologists and chemists who are interested in this vibrant field.
Topics: Drug Discovery; Proteins; Proteolysis
PubMed: 35379777
DOI: 10.1038/s41392-022-00966-4 -
Journal of Hematology & Oncology May 2020Proteolysis-targeting chimera (PROTAC) has been developed to be a useful technology for targeted protein degradation. A bifunctional PROTAC molecule consists of a ligand... (Review)
Review
Proteolysis-targeting chimera (PROTAC) has been developed to be a useful technology for targeted protein degradation. A bifunctional PROTAC molecule consists of a ligand (mostly small-molecule inhibitor) of the protein of interest (POI) and a covalently linked ligand of an E3 ubiquitin ligase (E3). Upon binding to the POI, the PROTAC can recruit E3 for POI ubiquitination, which is subjected to proteasome-mediated degradation. PROTAC complements nucleic acid-based gene knockdown/out technologies for targeted protein reduction and could mimic pharmacological protein inhibition. To date, PROTACs targeting ~ 50 proteins, many of which are clinically validated drug targets, have been successfully developed with several in clinical trials for cancer therapy. This article reviews PROTAC-mediated degradation of critical oncoproteins in cancer, particularly those in hematological malignancies. Chemical structures, cellular and in vivo activities, pharmacokinetics, and pharmacodynamics of these PROTACs are summarized. In addition, potential advantages, challenges, and perspectives of PROTAC technology in cancer therapy are discussed.
Topics: Animals; Antineoplastic Agents; Drug Discovery; Humans; Ligands; Molecular Targeted Therapy; Neoplasms; Proteolysis; Ubiquitination
PubMed: 32404196
DOI: 10.1186/s13045-020-00885-3 -
Nature Communications Jan 2023Post-translational modifications (PTMs) can occur on specific amino acids localized within regulatory domains of target proteins, which control a protein's stability.... (Review)
Review
Post-translational modifications (PTMs) can occur on specific amino acids localized within regulatory domains of target proteins, which control a protein's stability. These regions, called degrons, are often controlled by PTMs, which act as signals to expedite protein degradation (PTM-activated degrons) or to forestall degradation and stabilize a protein (PTM-inactivated degrons). We summarize current knowledge of the regulation of protein stability by various PTMs. We aim to display the variety and breadth of known mechanisms of regulation as well as highlight common themes in PTM-regulated degrons to enhance potential for identifying novel drug targets where druggable targets are currently lacking.
Topics: Protein Processing, Post-Translational; Proteins; Proteolysis; Amino Acids; Protein Stability
PubMed: 36639369
DOI: 10.1038/s41467-023-35795-8 -
Chemical Society Reviews Oct 2022Targeted protein degradation (TPD) provides unprecedented opportunities for drug discovery. While the proteolysis-targeting chimera (PROTAC) technology has already... (Review)
Review
Targeted protein degradation (TPD) provides unprecedented opportunities for drug discovery. While the proteolysis-targeting chimera (PROTAC) technology has already entered clinical trials and changed the landscape of small-molecule drugs, new degrader technologies harnessing alternative degradation machineries, especially lysosomal pathways, have emerged and broadened the spectrum of degradable targets. We have recently proposed the concept of autophagy-tethering compounds (ATTECs) that hijack the autophagy protein microtubule-associated protein 1A/1B light chain 3 (LC3) for targeted degradation. Other groups also reported degrader technologies engaging lysosomal pathways through different mechanisms including AUTACs, AUTOTACs, LYTACs and MoDE-As. In this review, we analyse and discuss ATTECs along with other lysosomal-relevant degrader technologies. Finally, we will briefly summarize the current status of these degrader technologies and envision possible future studies.
Topics: Proteolysis; Drug Discovery; Proteins; Autophagy; Lysosomes
PubMed: 36218065
DOI: 10.1039/d2cs00624c -
Cell Jun 2022Hijacking the cellular protein degradation system offers unique opportunities for drug discovery, as exemplified by proteolysis-targeting chimeras. Despite their great...
Hijacking the cellular protein degradation system offers unique opportunities for drug discovery, as exemplified by proteolysis-targeting chimeras. Despite their great promise for medical chemistry, so far, it has not been possible to reprogram the bacterial degradation machinery to interfere with microbial infections. Here, we develop small-molecule degraders, so-called BacPROTACs, that bind to the substrate receptor of the ClpC:ClpP protease, priming neo-substrates for degradation. In addition to their targeting function, BacPROTACs activate ClpC, transforming the resting unfoldase into its functional state. The induced higher-order oligomer was visualized by cryo-EM analysis, providing a structural snapshot of activated ClpC unfolding a protein substrate. Finally, drug susceptibility and degradation assays performed in mycobacteria demonstrate in vivo activity of BacPROTACs, allowing selective targeting of endogenous proteins via fusion to an established degron. In addition to guiding antibiotic discovery, the BacPROTAC technology presents a versatile research tool enabling the inducible degradation of bacterial proteins.
Topics: Bacteria; Bacterial Proteins; Molecular Chaperones; Proteolysis
PubMed: 35662409
DOI: 10.1016/j.cell.2022.05.009 -
Cell Apr 2020New biological tools provide new techniques to probe fundamental biological processes. Here we describe the burgeoning field of proteolysis-targeting chimeras (PROTACs),... (Review)
Review
New biological tools provide new techniques to probe fundamental biological processes. Here we describe the burgeoning field of proteolysis-targeting chimeras (PROTACs), which are capable of modulating protein concentrations at a post-translational level by co-opting the ubiquitin-proteasome system. We describe the PROTAC technology and its application to drug discovery and provide examples where PROTACs have enabled novel biological insights. Furthermore, we provide a workflow for PROTAC development and use and discuss the benefits and issues associated with PROTACs. Finally, we compare PROTAC-mediated protein-level modulation with other technologies, such as RNAi and genome editing.
Topics: Drug Discovery; Humans; Proteasome Endopeptidase Complex; Proteolysis; Ubiquitin-Protein Ligases
PubMed: 31955850
DOI: 10.1016/j.cell.2019.11.031 -
Trends in Cell Biology Jan 2022Aberrancy in cell cycle progression is one of the fundamental mechanisms underlying tumorigenesis, making regulators of the cell cycle machinery rational anticancer... (Review)
Review
Aberrancy in cell cycle progression is one of the fundamental mechanisms underlying tumorigenesis, making regulators of the cell cycle machinery rational anticancer therapeutic targets. A growing body of evidence indicates that the cell cycle regulatory pathway integrates into other hallmarks of cancer, including metabolism remodeling and immune escape. Thus, therapies against cell cycle machinery components can not only repress the division of cancer cells, but also reverse cancer metabolism and restore cancer immune surveillance. Besides the ongoing effects on the development of small molecule inhibitors (SMIs) of the cell cycle machinery, proteolysis targeting chimeras (PROTACs) have recently been used to target these oncogenic proteins related to cell cycle progression. Here, we discuss the rationale of cell cycle targeting therapies, particularly PROTACs, to more efficiently retard tumorigenesis.
Topics: Carcinogenesis; Cell Cycle; Cell Transformation, Neoplastic; Humans; Neoplasms; Proteolysis
PubMed: 34304958
DOI: 10.1016/j.tcb.2021.07.001 -
Current Opinion in Chemical Biology Jun 2020Traditional approaches in the development of small-molecule drugs typically aim to inhibit the biochemical activity of functional protein domains. In contrast, targeted... (Review)
Review
Traditional approaches in the development of small-molecule drugs typically aim to inhibit the biochemical activity of functional protein domains. In contrast, targeted protein degradation aims to reduce overall levels of disease-relevant proteins. Mechanistically, this can be achieved via chemical ligands that induce molecular proximity between an E3 ubiquitin ligase and a protein of interest, leading to ubiquitination and degradation of the protein of interest. This paradigm-shifting pharmacology promises to address several limitations inherent to conventional inhibitor design. Most notably, targeted protein degradation has the potential not only to expand the druggable proteome beyond the reach of traditional competitive inhibitors but also to develop therapeutic strategies of unmatched selectivity. This review briefly summarizes key challenges that remain to be addressed to deliver on these promises and to realize the full therapeutic potential of pharmacologic modulation of protein degradation pathways.
Topics: Drug Design; Enzyme Inhibitors; Humans; Ligands; Molecular Targeted Therapy; Peptide Termination Factors; Protein Binding; Proteolysis; Proteome; Transcription Factors; Ubiquitin-Protein Ligases; Ubiquitination
PubMed: 31901786
DOI: 10.1016/j.cbpa.2019.11.012