Proteolysis targeting chimera

Last updated
TL 12-186, a thalidomide-based PROTAC targeting the protein GSPT1, a translation termination factor TL 12-186 skeletal.svg
TL 12-186, a thalidomide-based PROTAC targeting the protein GSPT1, a translation termination factor

A proteolysis targeting chimera (PROTAC) [2] is a heterobifunctional molecule composed of two active domains and a linker, capable of removing specific unwanted proteins. Rather than acting as a conventional enzyme inhibitor, a PROTAC works by inducing selective intracellular proteolysis. PROTACs consist of two covalently linked protein-binding molecules: one capable of engaging an E3 ubiquitin ligase, and another that binds to a target protein meant for degradation. Recruitment of the E3 ligase to the target protein results in ubiquitination and subsequent degradation of the target protein via the proteasome. Because PROTACs need only to bind their targets with high selectivity (rather than inhibit the target protein's enzymatic activity), there are currently many efforts to retool previously ineffective inhibitor molecules as PROTACs for next-generation drugs. [3] [4]

Contents

Initially described by Kathleen Sakamoto, Craig Crews and Ray Deshaies in 2001, [5] the PROTAC technology has been applied by a number of drug discovery labs using various E3 ligases, [6] including pVHL, [7] [8] [9] CRBN, [10] [11] Mdm2, [12] beta-TrCP1, [5] DCAF15, [13] DCAF16, [13] RNF114, [13] and c-IAP1. [14] Yale University licensed the PROTAC technology to Arvinas in 2013–14. [15] [16]

In 2019, Arvinas put two PROTACs into clinical trials: bavdegalutamide (ARV-110), an androgen receptor degrader, and vepdegestrant (ARV-471), an estrogen receptor degrader. [17] [18]

Mechanism of action

Mechanism. E1, E2, E3: ubiquitination enzymes; Ub = ubiquitin; target = protein to be degraded Proteolysis targeting chimera mechanism.svg
Mechanism. E1, E2, E3: ubiquitination enzymes; Ub = ubiquitin; target = protein to be degraded

PROTACs achieve degradation through "hijacking" the cell's ubiquitin–proteasome system (UPS) by bringing together the target protein and an E3 ligase. [19]

First, the E1 activates and conjugates the ubiquitin to the E2. [13] The E2 then forms a complex with the E3 ligase. The E3 ligase targets proteins and covalently attaches the ubiquitin to the protein of interest. [19] Eventually, after a ubiquitin chain is formed, the protein is recognized and degraded by the 26S proteasome. [17] PROTACs take advantage of this cellular system by putting the protein of interest in close proximity to the E3 ligase to catalyze degradation. [17]

Unlike traditional inhibitors, PROTACs have a catalytic mechanism, with the PROTAC itself being recycled after the target protein is degraded. [17]

Design and development

The protein targeting warhead, E3 ligase, and linker must all be considered for PROTAC development. Formation of a ternary complex between the protein of interest, PROTAC, and E3 ligase may be evaluated to characterize PROTAC activity because it often leads to ubiquitination and subsequent degradation of the targeted protein. [13] A hook effect is commonly observed with high concentrations of PROTACs due to the bifunctional nature of the degrader. [13]

Currently, pVHL and CRBN have been used in preclinical trials as E3 ligases. [13] However, there still remains hundreds of E3 ligases to be explored, with some giving the opportunity for cell specificity.

Benefits

Compared to traditional inhibitors, PROTACs display multiple benefits that make them desirable drug candidates. Due to their catalytic mechanism, PROTACs can be administered at lower doses compared to their inhibitor analogues. [18] Some PROTACs have been shown to be more selective than their inhibitor analogues, reducing off-target effects. [18] PROTACs have the ability to target previously undruggable proteins, as they do not need to target catalytic pockets. [18] This also helps prevent mutation-driven drug resistance often found with enzymatic inhibitors.

PROTAC databases

BioGRID is an open public resource containing manually curated molecular interaction data. [20] In addition to its extensive catalogue of genetic and protein interactions, BioGRID also curates chemical interactions including experimentally-determined PROTACs and PROTAC-related molecules with accompanying target and E3 information. Additional resources include PROTACpedia, a manually curated and user-contributed PROTAC-specific public access database, and E3 Atlas, a comprehensive E3 database that characterizes the potential for specific E3 ligases to be employed for PROTAC design. [21]

Related Research Articles

<span class="mw-page-title-main">Proteasome</span> Protein complexes which degrade unnecessary or damaged proteins by proteolysis

Proteasomes are protein complexes which degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds. Enzymes that help such reactions are called proteases.

<span class="mw-page-title-main">Ubiquitin</span> Regulatory protein found in most eukaryotic tissues

Ubiquitin is a small regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ubiquitously. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 1980s. Four genes in the human genome code for ubiquitin: UBB, UBC, UBA52 and RPS27A.

<span class="mw-page-title-main">Ubiquitin ligase</span> Protein

A ubiquitin ligase is a protein that recruits an E2 ubiquitin-conjugating enzyme that has been loaded with ubiquitin, recognizes a protein substrate, and assists or directly catalyzes the transfer of ubiquitin from the E2 to the protein substrate. In simple and more general terms, the ligase enables movement of ubiquitin from a ubiquitin carrier to another thing by some mechanism. The ubiquitin, once it reaches its destination, ends up being attached by an isopeptide bond to a lysine residue, which is part of the target protein. E3 ligases interact with both the target protein and the E2 enzyme, and so impart substrate specificity to the E2. Commonly, E3s polyubiquitinate their substrate with Lys48-linked chains of ubiquitin, targeting the substrate for destruction by the proteasome. However, many other types of linkages are possible and alter a protein's activity, interactions, or localization. Ubiquitination by E3 ligases regulates diverse areas such as cell trafficking, DNA repair, and signaling and is of profound importance in cell biology. E3 ligases are also key players in cell cycle control, mediating the degradation of cyclins, as well as cyclin dependent kinase inhibitor proteins. The human genome encodes over 600 putative E3 ligases, allowing for tremendous diversity in substrates.

<span class="mw-page-title-main">SCF complex</span>

Skp, Cullin, F-box containing complex is a multi-protein E3 ubiquitin ligase complex that catalyzes the ubiquitination of proteins destined for 26S proteasomal degradation. Along with the anaphase-promoting complex, SCF has important roles in the ubiquitination of proteins involved in the cell cycle. The SCF complex also marks various other cellular proteins for destruction.

<span class="mw-page-title-main">Ubiquitin-activating enzyme</span> Class of enzymes

Ubiquitin-activating enzymes, also known as E1 enzymes, catalyze the first step in the ubiquitination reaction, which can target a protein for degradation via a proteasome. This covalent bond of ubiquitin or ubiquitin-like proteins to targeted proteins is a major mechanism for regulating protein function in eukaryotic organisms. Many processes such as cell division, immune responses and embryonic development are also regulated by post-translational modification by ubiquitin and ubiquitin-like proteins.

Ubiquitin-conjugating enzymes, also known as E2 enzymes and more rarely as ubiquitin-carrier enzymes, perform the second step in the ubiquitination reaction that targets a protein for degradation via the proteasome. The ubiquitination process covalently attaches ubiquitin, a short protein of 76 amino acids, to a lysine residue on the target protein. Once a protein has been tagged with one ubiquitin molecule, additional rounds of ubiquitination form a polyubiquitin chain that is recognized by the proteasome's 19S regulatory particle, triggering the ATP-dependent unfolding of the target protein that allows passage into the proteasome's 20S core particle, where proteases degrade the target into short peptide fragments for recycling by the cell.

<span class="mw-page-title-main">SKP2</span> Protein-coding gene in the species Homo sapiens

S-phase kinase-associated protein 2 is an enzyme that in humans is encoded by the SKP2 gene.

<span class="mw-page-title-main">CUL4A</span> Protein-coding gene in humans

Cullin-4A is a protein that in humans is encoded by the CUL4A gene. CUL4A belongs to the cullin family of ubiquitin ligase proteins and is highly homologous to the CUL4B protein. CUL4A regulates numerous key processes such as DNA repair, chromatin remodeling, spermatogenesis, haematopoiesis and the mitotic cell cycle. As a result, CUL4A has been implicated in several cancers and the pathogenesis of certain viruses including HIV. A component of a CUL4A complex, Cereblon, was discovered to be a major target of the teratogenic agent thalidomide.

<span class="mw-page-title-main">Ubiquitin D</span> Protein-coding gene in the species Homo sapiens

Ubiquitin D is a protein that in humans is encoded by the UBD gene, also known as FAT10. UBD acts like ubiquitin, by covalently modifying proteins and tagging them for destruction in the proteasome.

<span class="mw-page-title-main">CUL4B</span> Protein-coding gene in humans

Cullin-4B is a protein that in humans is encoded by the CUL4B gene which is located on the X chromosome. CUL4B has high sequence similarity with CUL4A, with which it shares certain E3 ubiquitin ligase functions. CUL4B is largely expressed in the nucleus and regulates several key functions including: cell cycle progression, chromatin remodeling and neurological and placental development in mice. In humans, CUL4B has been implicated in X-linked intellectual disability and is frequently mutated in pancreatic adenocarcinomas and a small percentage of various lung cancers. Viruses such as HIV can also co-opt CUL4B-based complexes to promote viral pathogenesis. CUL4B complexes containing Cereblon are also targeted by the teratogenic drug thalidomide.

<span class="mw-page-title-main">CUL3</span> Protein-coding gene in humans

Cullin 3 is a protein that in humans is encoded by the CUL3 gene.

<span class="mw-page-title-main">PSMD14</span> Protein-coding gene in the species Homo sapiens

26S proteasome non-ATPase regulatory subunit 14, also known as 26S proteasome non-ATPase subunit Rpn11, is an enzyme that in humans is encoded by the PSMD14 gene. This protein is one of the 19 essential subunits of the complete assembled 19S proteasome complex. Nine subunits Rpn3, Rpn5, Rpn6, Rpn7, Rpn8, Rpn9, Rpn11, SEM1, and Rpn12 form the lid sub complex of the 19S regulatory particle of the proteasome complex.

<span class="mw-page-title-main">Cereblon</span>

Cereblon is a protein that in humans is encoded by the CRBN gene. The gene that encodes the cereblon protein is found on the human chromosome 3, on the short arm at position p26.3 from base pair 3,190,676 to base pair 3,221,394. CRBN orthologs are highly conserved from plants to humans.

<span class="mw-page-title-main">Cell division control protein 4</span>

Cdc4 is a substrate recognition component of the SCF ubiquitin ligase complex, which acts as a mediator of ubiquitin transfer to target proteins, leading to their subsequent degradation via the ubiquitin-proteasome pathway. Cdc4 targets primarily cell cycle regulators for proteolysis. It serves the function of an adaptor that brings target molecules to the core SCF complex. Cdc4 was originally identified in the model organism Saccharomyces cerevisiae. CDC4 gene function is required at G1/S and G2/M transitions during mitosis and at various stages during meiosis.

Craig M. Crews is an American scientist at Yale University known for his contributions to chemical biology. He is known for his contributions to the field of induced proximity through his work in creating heterobifunctional molecules that "hijack" cellular processes by inducing the interaction of two proteins inside a living cell. His initial work focused on the discovery of PROteolysis-TArgeting Chimeras (PROTACs) to trigger degradation of disease-causing proteins, a process known as targeted protein degradation (TPD), and he has since developed new versions of -TACs to leverage other cellular processes and protein families to treat disease.

Raymond Joseph Deshaies is an American biochemist and cell biologist. He is senior vice president of global research at Amgen and a visiting associate at the California Institute of Technology (Caltech). Prior to that, he was a professor of biology at Caltech and an investigator of the Howard Hughes Medical Institute. He is also the co-founder of the biotechnology companies Proteolix and Cleave Biosciences. His research focuses on mechanisms and regulation of protein homeostasis in eukaryotic cells, with a particular focus on how proteins are conjugated with ubiquitin and degraded by the proteasome.

<span class="mw-page-title-main">Daniel Nomura</span> American chemical biologist

Daniel K. Nomura is an American chemical biologist and Professor of Chemical Biology and Molecular Therapeutics at the University of California, Berkeley, in the Departments of Chemistry and Molecular & Cell Biology. His work employs chemoproteomic approaches to develop small molecule therapeutics and therapeutic modalities against traditionally "undruggable" proteins.

Alessio Ciulli is an Italian British biochemist. Currently, he is the Professor of Chemical & Structural Biology at the School of Life Sciences, University of Dundee, where he founded and directs Dundee' new Centre for Targeted Protein Degradation (CeTPD). He is also the scientific co-founder and advisor of Amphista Therapeutics.

Molecular glue refers to a class of chemical compounds or molecules that play a crucial role in binding and stabilizing protein-protein interactions in biological systems. These molecules act as "glue" by enhancing the affinity between proteins, ultimately influencing various cellular processes. Molecular glue compounds have gained significant attention in the fields of drug discovery, chemical biology, and fundamental research due to their potential to modulate protein interactions, and thus, impact various cellular pathways. They have unlocked avenues in medicine previously thought to be "undruggable".

Chimeric small molecule therapeutics are a class of drugs designed with multiple active domains to operate outside of the typical protein inhibition model. While most small molecule drugs inhibit target proteins by binding their active site, chimerics form protein-protein ternary structures to induce degradation or, less frequently, other protein modifications.

References

  1. 1 2 Ishoey, Mette; Chorn, Someth; Singh, Natesh; Jaeger, Martin G.; Brand, Matthias; Paulk, Joshiawa; Bauer, Sophie; Erb, Michael A.; Parapatics, Katja; Müller, André C.; Bennett, Keiryn L.; Ecker, Gerhard F.; Bradner, James E.; Winter, Georg E. (2018). "Translation Termination Factor GSPT1 is a Phenotypically Relevant Off-Target of Heterobifunctional Phthalimide Degraders". ACS Chemical Biology. 13 (3): 553–560. doi:10.1021/acschembio.7b00969. PMID   29356495.
  2. Luh, Laura M.; Scheib, Ulrike; Juenemann, Katrin; Wortmann, Lars; Brands, Michael; Cromm, Philipp M. (2020). "Prey for the Proteasome: Targeted Protein Degradation—A Medicinal Chemist's Perspective". Angewandte Chemie International Edition. 59 (36): 15448–15466. doi:10.1002/anie.202004310. PMC   7496094 . PMID   32428344.
  3. Cermakova K, Hodges HC (August 2018). "Next-Generation Drugs and Probes for Chromatin Biology: From Targeted Protein Degradation to Phase Separation". Molecules. 23 (8): 1958. doi: 10.3390/molecules23081958 . PMC   6102721 . PMID   30082609.
  4. Noblejas-López, María del Mar; Tébar-García, David; López-Rosa, Raquel; Alcaraz-Sanabria, Ana; Cristóbal-Cueto, Pablo; Pinedo-Serrano, Alejandro; Rivas-García, Lorenzo; Galán-Moya, Eva M. (October 2023). "TACkling Cancer by Targeting Selective Protein Degradation". Pharmaceutics. 15 (10): 2442. doi: 10.3390/pharmaceutics15102442 . ISSN   1999-4923. PMC   10610449 . PMID   37896202.
  5. 1 2 Sakamoto KM, Kim KB, Kumagai A, Mercurio F, Crews CM, Deshaies RJ (July 2001). "Protacs: chimeric molecules that target proteins to the Skp1-Cullin-F box complex for ubiquitination and degradation". Proceedings of the National Academy of Sciences of the United States of America. 98 (15): 8554–9. Bibcode:2001PNAS...98.8554S. doi: 10.1073/pnas.141230798 . PMC   37474 . PMID   11438690.
  6. Chi KR (May 2016). "Drug developers delve into the cell's trash-disposal machinery". Nature Reviews. Drug Discovery. 15 (5): 295–7. doi:10.1038/nrd.2016.86. PMID   27139985. S2CID   34652880.
  7. Zengerle M, Chan KH, Ciulli A (August 2015). "Selective Small Molecule Induced Degradation of the BET Bromodomain Protein BRD4". ACS Chemical Biology. 10 (8): 1770–7. doi:10.1021/acschembio.5b00216. PMC   4548256 . PMID   26035625.
  8. Bondeson DP, Mares A, Smith IE, Ko E, Campos S, Miah AH, et al. (August 2015). "Catalytic in vivo protein knockdown by small-molecule PROTACs". Nature Chemical Biology. 11 (8): 611–7. doi:10.1038/nchembio.1858. PMC   4629852 . PMID   26075522.
  9. Buckley DL, Raina K, Darricarrere N, Hines J, Gustafson JL, Smith IE, Miah AH, Harling JD, Crews CM (August 2015). "HaloPROTACS: Use of Small Molecule PROTACs to Induce Degradation of HaloTag Fusion Proteins". ACS Chemical Biology. 10 (8): 1831–7. doi:10.1021/acschembio.5b00442. PMC   4629848 . PMID   26070106.
  10. Lu J, Qian Y, Altieri M, Dong H, Wang J, Raina K, Hines J, Winkler JD, Crew AP, Coleman K, Crews CM (June 2015). "Hijacking the E3 Ubiquitin Ligase Cereblon to Efficiently Target BRD4". Chemistry & Biology. 22 (6): 755–63. doi:10.1016/j.chembiol.2015.05.009. PMC   4475452 . PMID   26051217.
  11. Winter GE, Buckley DL, Paulk J, Roberts JM, Souza A, Dhe-Paganon S, Bradner JE (June 2015). "Drug Development. Phthalimide conjugation as a strategy for in vivo target protein degradation". Science. 348 (6241): 1376–81. doi:10.1126/science.aab1433. PMC   4937790 . PMID   25999370.
  12. Schneekloth AR, Pucheault M, Tae HS, Crews CM (November 2008). "Targeted intracellular protein degradation induced by a small molecule: En route to chemical proteomics". Bioorganic & Medicinal Chemistry Letters. 18 (22): 5904–8. doi:10.1016/j.bmcl.2008.07.114. PMC   3175619 . PMID   18752944.
  13. 1 2 3 4 5 6 7 Ocaña, Alberto; Pandiella, Atanasio (2020-09-15). "Proteolysis targeting chimeras (PROTACs) in cancer therapy". Journal of Experimental & Clinical Cancer Research. 39 (1): 189. doi: 10.1186/s13046-020-01672-1 . ISSN   1756-9966. PMC   7493969 . PMID   32933565.
  14. Itoh Y, Kitaguchi R, Ishikawa M, Naito M, Hashimoto Y (November 2011). "Design, synthesis and biological evaluation of nuclear receptor-degradation inducers". Bioorganic & Medicinal Chemistry. 19 (22): 6768–78. doi:10.1016/j.bmc.2011.09.041. PMID   22014751.
  15. "Connecticut to support New Haven biotech to the tune of $4.25 million". New Haven Register. 2013-09-26. Retrieved 2016-05-13.
  16. "Scientist wants to hijack cells' tiny garbage trucks to fight cancer". Boston Globe. Retrieved 2016-05-21.
  17. 1 2 3 4 Schneider, Melanie; Radoux, Chris J.; Hercules, Andrew; Ochoa, David; Dunham, Ian; Zalmas, Lykourgos-Panagiotis; Hessler, Gerhard; Ruf, Sven; Shanmugasundaram, Veerabahu; Hann, Michael M.; Thomas, Pam J. (July 2021). "The PROTACtable genome". Nature Reviews. Drug Discovery. 20 (10): 789–797. doi:10.1038/s41573-021-00245-x. ISSN   1474-1784. PMID   34285415. S2CID   236157200.
  18. 1 2 3 4 Cecchini, Carlotta; Pannilunghi, Sara; Tardy, Sébastien; Scapozza, Leonardo (2021). "From Conception to Development: Investigating PROTACs Features for Improved Cell Permeability and Successful Protein Degradation". Frontiers in Chemistry. 9: 672267. Bibcode:2021FrCh....9..215C. doi: 10.3389/fchem.2021.672267 . ISSN   2296-2646. PMC   8093871 . PMID   33959589.
  19. 1 2 Bondeson, Daniel P.; Crews, Craig M. (2017-01-06). "Targeted Protein Degradation by Small Molecules". Annual Review of Pharmacology and Toxicology. 57: 107–123. doi:10.1146/annurev-pharmtox-010715-103507. ISSN   0362-1642. PMC   5586045 . PMID   27732798.
  20. Oughtred, Rose; Rust, Jennifer; Chang, Christie; Breitkreutz, Bobby-Joe; Stark, Chris; Willems, Andrew; Boucher, Lorrie; Leung, Genie; Kolas, Nadine; Zhang, Frederick; Dolma, Sonam; Coulombe-Huntington, Jasmin; Chatr-Aryamontri, Andrew; Dolinski, Kara; Tyers, Mike (January 2021). "The BioGRID database: A comprehensive biomedical resource of curated protein, genetic, and chemical interactions". Protein Science. 30 (1): 187–200. doi:10.1002/pro.3978. ISSN   1469-896X. PMC   7737760 . PMID   33070389.
  21. Liu, Yuan; Yang, Jingwen; Wang, Tianlu; Luo, Mei; Chen, Yamei; Chen, Chengxuan; Ronai, Ze'ev; Zhou, Yubin; Ruppin, Eytan; Han, Leng (2023-10-16). "Expanding PROTACtable genome universe of E3 ligases". Nature Communications. 14 (1): 6509. Bibcode:2023NatCo..14.6509L. doi: 10.1038/s41467-023-42233-2 . ISSN   2041-1723. PMC   10579327 . PMID   37845222.