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Gorostiola González M, Rakers PRJ, Jespers W, IJzerman AP, Heitman LH, van Westen GJP. Computational Characterization of Membrane Proteins as Anticancer Targets: Current Challenges and Opportunities. Int J Mol Sci 2024; 25:3698. [PMID: 38612509 PMCID: PMC11011372 DOI: 10.3390/ijms25073698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/21/2024] [Accepted: 03/21/2024] [Indexed: 04/14/2024] Open
Abstract
Cancer remains a leading cause of mortality worldwide and calls for novel therapeutic targets. Membrane proteins are key players in various cancer types but present unique challenges compared to soluble proteins. The advent of computational drug discovery tools offers a promising approach to address these challenges, allowing for the prioritization of "wet-lab" experiments. In this review, we explore the applications of computational approaches in membrane protein oncological characterization, particularly focusing on three prominent membrane protein families: receptor tyrosine kinases (RTKs), G protein-coupled receptors (GPCRs), and solute carrier proteins (SLCs). We chose these families due to their varying levels of understanding and research data availability, which leads to distinct challenges and opportunities for computational analysis. We discuss the utilization of multi-omics data, machine learning, and structure-based methods to investigate aberrant protein functionalities associated with cancer progression within each family. Moreover, we highlight the importance of considering the broader cellular context and, in particular, cross-talk between proteins. Despite existing challenges, computational tools hold promise in dissecting membrane protein dysregulation in cancer. With advancing computational capabilities and data resources, these tools are poised to play a pivotal role in identifying and prioritizing membrane proteins as personalized anticancer targets.
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Affiliation(s)
- Marina Gorostiola González
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
- Oncode Institute, 2333 CC Leiden, The Netherlands
| | - Pepijn R. J. Rakers
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
| | - Willem Jespers
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
| | - Adriaan P. IJzerman
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
| | - Laura H. Heitman
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
- Oncode Institute, 2333 CC Leiden, The Netherlands
| | - Gerard J. P. van Westen
- Leiden Academic Centre of Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands; (M.G.G.); (P.R.J.R.); (W.J.); (A.P.I.); (L.H.H.)
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2
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Rygiel KA, Elkins JM. Recent advances in the structural biology of tyrosine kinases. Curr Opin Struct Biol 2023; 82:102665. [PMID: 37562149 DOI: 10.1016/j.sbi.2023.102665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 07/08/2023] [Accepted: 07/10/2023] [Indexed: 08/12/2023]
Abstract
The past few years have seen exciting discoveries in the area of tyrosine kinase structural biology including the first high resolution models of full-length receptor tyrosine kinases and new mechanistic insights into the structural mechanisms of receptor tyrosine kinase activation. Despite being a mature area of research, the application of new technologies continues to advance our understanding. In this article we highlight a selection of recent studies that illustrate the current areas of research interest, focussing in particular on the exciting progress made possible by cryo-electron-microscopy. These new discoveries may herald a wave of new design ideas for therapeutics acting through novel mechanisms.
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Affiliation(s)
- Karolina A Rygiel
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, NDM Research Building, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Jonathan M Elkins
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, NDM Research Building, Roosevelt Drive, Oxford, OX3 7FZ, UK.
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3
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Jiang H, Zhou S, Li G. Novel biomarkers used for early diagnosis and tyrosine kinase inhibitors as targeted therapies in colorectal cancer. Front Pharmacol 2023; 14:1189799. [PMID: 37719843 PMCID: PMC10502318 DOI: 10.3389/fphar.2023.1189799] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/14/2023] [Indexed: 09/19/2023] Open
Abstract
Colorectal cancer (CRC) is the third most common and second most lethal type of cancer worldwide, presenting major health risks as well as economic costs to both people and society. CRC survival chances are significantly higher if the cancer is diagnosed and treated early. With the development of molecular biology, numerous initiatives have been undertaken to identify novel biomarkers for the early diagnosis of CRC. Pathological disorders can be diagnosed at a lower cost with the help of biomarkers, which can be detected in stool, blood, and tissue samples. Several lines of evidence suggest that the gut microbiota could be used as a biomarker for CRC screening and treatment. CRC treatment choices include surgical resection, chemotherapy, immunotherapy, gene therapy, and combination therapies. Targeted therapies are a relatively new and promising modality of treatment that has been shown to increase patients' overall survival (OS) rates and can inhibit cancer cell development. Several small-molecule tyrosine kinase inhibitors (TKIs) are being investigated as potential treatments due to our increasing awareness of CRC's molecular causes and oncogenic signaling. These compounds may inhibit critical enzymes in controlling signaling pathways, which are crucial for CRC cells' development, differentiation, proliferation, and survival. On the other hand, only one of the approximately 42 TKIs that demonstrated anti-tumor effects in pre-clinical studies has been licensed for clinical usage in CRC. A significant knowledge gap exists when bringing these tailored medicines into the clinic. As a result, the emphasis of this review is placed on recently discovered biomarkers for early diagnosis as well as tyrosine kinase inhibitors as possible therapy options for CRC.
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Arglabin, an EGFR receptor tyrosine kinase inhibitor, suppresses proliferation and induces apoptosis in prostate cancer cells. Biomed Pharmacother 2022; 156:113873. [DOI: 10.1016/j.biopha.2022.113873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/10/2022] [Accepted: 10/13/2022] [Indexed: 12/09/2022] Open
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Diwanji D, Trenker R, Jura N, Verba KA. Efficient expression, purification, and visualization by cryo-EM of unliganded near full-length HER3. Methods Enzymol 2022; 667:611-632. [PMID: 35525556 PMCID: PMC9288109 DOI: 10.1016/bs.mie.2022.03.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Biochemical analyses of membrane receptor kinases have been limited by challenges in obtaining sufficient homogeneous receptor samples for downstream structural and biophysical characterization. Here, we report a suite of methods for the efficient expression, purification, and visualization by cryo-electron microscopy (cryo-EM) of near full-length Human Epidermal Growth Factor Receptor 3 (HER3), a receptor tyrosine pseudokinase, in the unliganded state. Through transient mammalian cell expression, a two-step purification with detergent exchange into lauryl maltose neopentyl glycol (LMNG), and freezing devoid of background detergent micelle, we obtained ~6Å reconstructions of the ~60kDa fully-glycosylated unliganded extracellular domain of HER3 from just 30mL of suspension culture. The reconstructions reveal previously unappreciated extracellular domain dynamics and glycosylation sites.
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Affiliation(s)
- Devan Diwanji
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States; Medical Scientist Training Program, University of California San Francisco, San Francisco, CA, United States
| | - Raphael Trenker
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States
| | - Natalia Jura
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States; Quantitative Biosciences Institute (QBI), University of California San Francisco, San Francisco, CA, United States; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, United States.
| | - Kliment A Verba
- Quantitative Biosciences Institute (QBI), University of California San Francisco, San Francisco, CA, United States; Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, United States.
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Trenker R, Diwanji D, Verba KA, Jura N. An effective strategy for ligand-mediated pulldown of the HER2/HER3/NRG1β heterocomplex and cryo-EM structure determination at low sample concentrations. Methods Enzymol 2022; 667:633-662. [PMID: 35525557 PMCID: PMC9288110 DOI: 10.1016/bs.mie.2022.03.049] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Obtaining high-resolution structures of Receptor Tyrosine Kinases that visualize extracellular, transmembrane and intracellular kinase regions simultaneously is an eagerly pursued but still unmet challenge of structural biology. The Human Epidermal Growth Factor Receptor 3 (HER3) that has a catalytically inactive kinase domain (pseudokinase) forms a potent signaling complex upon binding of growth factor neuregulin 1β (NRG1β) and upon dimerization with a close homolog, the HER2 receptor. The HER2/HER3/NRG1β complex is often referred to as an oncogenic driver in breast cancer and is an attractive target for anti-cancer therapies. After overcoming significant hurdles in isolating sufficient amounts of the HER2/HER3/NRG1β complex for structural studies by cryo-electron microscopy (cryo-EM), we recently obtained the first high-resolution structures of the extracellular portion of this complex. Here we describe a step-by-step protocol for obtaining a stable and homogenous HER2/HER3/NRG1β complex for structural studies and our recommendation for collecting and processing cryo-EM data for this sample. We also show improved EM density for the transmembrane and kinase domains of the receptors, which continue to evade structural determination at high resolution. The discussed strategies are tunable and applicable to other membrane receptor complexes.
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Affiliation(s)
- Raphael Trenker
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States
| | - Devan Diwanji
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States; Medical Scientist Training Program, University of California San Francisco, San Francisco, CA, United States
| | - Kliment A Verba
- Quantitative Biosciences Institute (QBI), University of California San Francisco, San Francisco, CA, United States; Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, United States.
| | - Natalia Jura
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, United States; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, United States.
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7
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Tan Y, Fu S, Yang T, Xie Y, Shen G, Yan J, Zhao Y, Ni F. Evaluation of Site-Diversified, Fully Functionalized Diazirine Probes for Chemical Proteomic Applications. Chem Commun (Camb) 2022; 58:9532-9535. [DOI: 10.1039/d2cc03868d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of site-diversified, fully functionalized diazirine probes are constructed based on a scaffold shared by several marketed EGFR-targeted drugs. The integrated analysis of protein targets of site-diversified probe toolkit...
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Mechanism for the activation of the anaplastic lymphoma kinase receptor. Nature 2021; 600:153-157. [PMID: 34819673 PMCID: PMC8639797 DOI: 10.1038/s41586-021-04140-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 10/14/2021] [Indexed: 01/09/2023]
Abstract
Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase (RTK) that regulates important functions in the central nervous system1,2. The ALK gene is a hotspot for chromosomal translocation events that result in several fusion proteins that cause a variety of human malignancies3. Somatic and germline gain-of-function mutations in ALK were identified in paediatric neuroblastoma4-7. ALK is composed of an extracellular region (ECR), a single transmembrane helix and an intracellular tyrosine kinase domain8,9. ALK is activated by the binding of ALKAL1 and ALKAL2 ligands10-14 to its ECR, but the lack of structural information for the ALK-ECR or for ALKAL ligands has limited our understanding of ALK activation. Here we used cryo-electron microscopy, nuclear magnetic resonance and X-ray crystallography to determine the atomic details of human ALK dimerization and activation by ALKAL1 and ALKAL2. Our data reveal a mechanism of RTK activation that allows dimerization by either dimeric (ALKAL2) or monomeric (ALKAL1) ligands. This mechanism is underpinned by an unusual architecture of the receptor-ligand complex. The ALK-ECR undergoes a pronounced ligand-induced rearrangement and adopts an orientation parallel to the membrane surface. This orientation is further stabilized by an interaction between the ligand and the membrane. Our findings highlight the diversity in RTK oligomerization and activation mechanisms.
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9
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Margiotta A. All Good Things Must End: Termination of Receptor Tyrosine Kinase Signal. Int J Mol Sci 2021; 22:ijms22126342. [PMID: 34198477 PMCID: PMC8231876 DOI: 10.3390/ijms22126342] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/10/2021] [Accepted: 06/11/2021] [Indexed: 12/28/2022] Open
Abstract
Receptor tyrosine kinases (RTKs) are membrane receptors that regulate many fundamental cellular processes. A tight regulation of RTK signaling is fundamental for development and survival, and an altered signaling by RTKs can cause cancer. RTKs are localized at the plasma membrane (PM) and the major regulatory mechanism of signaling of RTKs is their endocytosis and degradation. In fact, RTKs at the cell surface bind ligands with their extracellular domain, become active, and are rapidly internalized where the temporal extent of signaling, attenuation, and downregulation are modulated. However, other mechanisms of signal attenuation and termination are known. Indeed, inhibition of RTKs’ activity may occur through the modulation of the phosphorylation state of RTKs and the interaction with specific proteins, whereas antagonist ligands can inhibit the biological responses mediated by the receptor. Another mechanism concerns the expression of endogenous inactive receptor variants that are deficient in RTK activity and take part to inactive heterodimers or hetero-oligomers. The downregulation of RTK signals is fundamental for several cellular functions and the homeostasis of the cell. Here, we will review the mechanisms of signal attenuation and termination of RTKs, focusing on FGFRs.
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Affiliation(s)
- Azzurra Margiotta
- Department of Biology, Faculty of Medicine, Masaryk University, 62500 Brno, Czech Republic;
- International Clinical Research Center, St. Anne’s University Hospital, 65691 Brno, Czech Republic
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10
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Mattoso Miskulin Cardoso AP, Tavares Pereira M, Dos Santos Silva R, Medeiros de Carvalho Sousa LM, Giometti IC, Kowalewski MP, de Carvalho Papa P. Global transcriptome analysis implicates cholesterol availability in the regulation of canine cyclic luteal function. Gen Comp Endocrinol 2021; 307:113759. [PMID: 33771531 DOI: 10.1016/j.ygcen.2021.113759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 01/06/2021] [Accepted: 03/10/2021] [Indexed: 12/24/2022]
Abstract
Considering the key role of the corpus luteum in the regulation of the canine diestrus, the present study aimed to investigate changes in the luteal transcriptome of pseudopregnant dogs (n = 18) from days (D) 10, 20, 30, 40, 50 and 60 post-ovulation. After RNAsequencing was performed, data was analyzed by resorting to several informatic tools. A total of 3300 genes were differently expressed among all samples (FDR < 0.01). By comparing different time points, enriched biological processes as response to estradiol and lipids (D20 vs D10) and intracellular cholesterol transport (D40 vs D60) were observed. Moreover, LXR/RXR (liver X receptor- retinoid X receptor) signaling appeared as an overrepresented pathway in all comparisons. Thus, the expression of 19 genes involved in intracellular cholesterol availability was further evaluated; most were affected by time (P < 0.05). Adding to the deep transcriptomic analysis, presented data implies the importance of cholesterol regulation in luteal physiology of pseudopregnant dogs.
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Affiliation(s)
| | - Miguel Tavares Pereira
- Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Renata Dos Santos Silva
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil
| | | | - Ines Cristina Giometti
- Faculty of Veterinary Medicine, University of Western São Paulo, Presidente Prudente, Brazil
| | | | - Paula de Carvalho Papa
- School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo, Brazil; Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
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11
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State of the structure address on MET receptor activation by HGF. Biochem Soc Trans 2021; 49:645-661. [PMID: 33860789 DOI: 10.1042/bst20200394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 12/12/2022]
Abstract
The MET receptor tyrosine kinase (RTK) and its cognate ligand hepatocyte growth factor (HGF) comprise a signaling axis essential for development, wound healing and tissue homeostasis. Aberrant HGF/MET signaling is a driver of many cancers and contributes to drug resistance to several approved therapeutics targeting other RTKs, making MET itself an important drug target. In RTKs, homeostatic receptor signaling is dependent on autoinhibition in the absence of ligand binding and orchestrated set of conformational changes induced by ligand-mediated receptor dimerization that result in activation of the intracellular kinase domains. A fundamental understanding of these mechanisms in the MET receptor remains incomplete, despite decades of research. This is due in part to the complex structure of the HGF ligand, which remains unknown in its full-length form, and a lack of high-resolution structures of the complete MET extracellular portion in an apo or ligand-bound state. A current view of HGF-dependent MET activation has evolved from biochemical and structural studies of HGF and MET fragments and here we review what these findings have thus far revealed.
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12
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Casey GR, Zhou X, Lesiak L, Xu B, Fang Y, Becker DF, Stains CI. An Evolutionary Strategy for Identification of Higher Order, Green Fluorescent Host-Guest Pairs Compatible with Living Systems. Chemistry 2020; 26:16721-16726. [PMID: 32725914 DOI: 10.1002/chem.202002423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/26/2020] [Indexed: 11/09/2022]
Abstract
Engineered miniprotein host-small-molecule guest pairs could be utilized to design new processes within cells as well as investigate fundamental aspects of cell signaling mechanisms. However, the development of host-guest pairs capable of functioning in living systems has proven challenging. Moreover, few examples of host-guest pairs with stoichiometries other than 2:1 exist, significantly hindering the ability to study the influence of oligomerization state on signaling fidelity. Herein, we present an approach to identify host-guest systems for relatively small green fluorescent guests by incorporation into cyclic peptides. The optimal host-guest pair produced a 10-fold increase in green fluorescence signal upon binding. Biophysical characterization clearly demonstrated higher order supramolecular assembly, which could be visualized on the surface of living yeast cells using a turn-on fluorescence readout. This work further defines evolutionary design principles to afford host-guest pairs with stoichiometries other than 2:1 and enables the identification of spectrally orthogonal host-guest pairs.
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Affiliation(s)
- Garrett R Casey
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.,Department of Chemistry and Physics, Southeast Missouri State University, Cape Girardeau, MO, 63701, USA
| | - Xinqi Zhou
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Lauren Lesiak
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Bi Xu
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Yuan Fang
- Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA
| | - Donald F Becker
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Cliff I Stains
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.,Department of Chemistry, University of Virginia, Charlottesville, VA, 22904, USA.,Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA.,Cancer Genes and Molecular Regulation Program, Fred & Pamela Buffet Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA.,University of Virginia Cancer Center, University of Virginia, Charlottesville, VA, 22904, USA
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13
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Structural studies of full-length receptor tyrosine kinases and their implications for drug design. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2020; 124:311-336. [PMID: 33632469 DOI: 10.1016/bs.apcsb.2020.10.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Receptor tyrosine kinases (RTKs) are important drug targets for cancer and immunological disorders. Crystal structures of individual RTK domains have contributed greatly to the structure-based drug design of clinically used drugs. Low-resolution structures from electron microscopy are now available for the RTKs, EGFR, PDGFR, and Kit. However, there are still no high-resolution structures of full-length RTKs due to the technical challenges of working with these complex, membrane proteins. Here, we review what has been learned from structural studies of these three RTKs regarding their mechanisms of ligand binding, activation, oligomerization, and inhibition. We discuss the implications for drug design. More structural data on full-length RTKs may facilitate the discovery of druggable sites and drugs with improved specificity and effectiveness against resistant mutants.
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14
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Cell Communications among Microorganisms, Plants, and Animals: Origin, Evolution, and Interplays. Int J Mol Sci 2020; 21:ijms21218052. [PMID: 33126770 PMCID: PMC7663094 DOI: 10.3390/ijms21218052] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/17/2020] [Accepted: 10/27/2020] [Indexed: 02/06/2023] Open
Abstract
Cellular communications play pivotal roles in multi-cellular species, but they do so also in uni-cellular species. Moreover, cells communicate with each other not only within the same individual, but also with cells in other individuals belonging to the same or other species. These communications occur between two unicellular species, two multicellular species, or between unicellular and multicellular species. The molecular mechanisms involved exhibit diversity and specificity, but they share common basic features, which allow common pathways of communication between different species, often phylogenetically very distant. These interactions are possible by the high degree of conservation of the basic molecular mechanisms of interaction of many ligand-receptor pairs in evolutionary remote species. These inter-species cellular communications played crucial roles during Evolution and must have been positively selected, particularly when collectively beneficial in hostile environments. It is likely that communications between cells did not arise after their emergence, but were part of the very nature of the first cells. Synchronization of populations of non-living protocells through chemical communications may have been a mandatory step towards their emergence as populations of living cells and explain the large commonality of cell communication mechanisms among microorganisms, plants, and animals.
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15
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Hajdu T, Váradi T, Rebenku I, Kovács T, Szöllösi J, Nagy P. Comprehensive Model for Epidermal Growth Factor Receptor Ligand Binding Involving Conformational States of the Extracellular and the Kinase Domains. Front Cell Dev Biol 2020; 8:776. [PMID: 32850868 PMCID: PMC7431817 DOI: 10.3389/fcell.2020.00776] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/23/2020] [Indexed: 12/03/2022] Open
Abstract
The epidermal growth factor (EGF) receptor (EGFR) undergoes ligand-dependent dimerization to initiate transmembrane signaling. Although crystallographic structures of the extracellular and kinase domains are available, ligand binding has not been quantitatively analyzed taking the influence of both domains into account. Here, we developed a model explicitly accounting for conformational changes of the kinase and extracellular domains, their dimerizations and ligand binding to monomeric and dimeric receptor species. The model was fitted to ligand binding data of suspended cells expressing receptors with active or inactive kinase conformations. Receptor dimers with inactive, symmetric configuration of the kinase domains exhibit positive cooperativity and very weak binding affinity for the first ligand, whereas dimers with active, asymmetric kinase dimers are characterized by negative cooperativity and subnanomolar binding affinity for the first ligand. The homodimerization propensity of EGFR monomers with active kinase domains is ∼100-times higher than that of dimers with inactive kinase domains. Despite this fact, constitutive, ligand-independent dimers are mainly generated from monomers with inactive kinase domains due to the excess of such monomers in the membrane. The experimental finding of increased positive cooperativity at high expression levels of EGFR was recapitulated by the model. Quantitative prediction of ligand binding to different receptor species revealed that EGF binds to receptor monomers and dimers in an expression-level dependent manner without significant recruitment of monomers to dimers upon EGF stimulation below the phase transition temperature of the membrane. Results of the fitting offer unique insight into the workings of the EGFR.
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Affiliation(s)
- Tímea Hajdu
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tímea Váradi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - István Rebenku
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Kovács
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Szöllösi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,MTA-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Peter Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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16
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Byrne PO, Hristova K, Leahy DJ. EGFR forms ligand-independent oligomers that are distinct from the active state. J Biol Chem 2020; 295:13353-13362. [PMID: 32727847 DOI: 10.1074/jbc.ra120.012852] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/27/2020] [Indexed: 01/15/2023] Open
Abstract
The human epidermal growth factor receptor (EGFR/ERBB1) is a receptor tyrosine kinase (RTK) that forms activated oligomers in response to ligand. Much evidence indicates that EGFR/ERBB1 also forms oligomers in the absence of ligand, but the structure and physiological role of these ligand-independent oligomers remain unclear. To examine these features, we use fluorescence microscopy to measure the oligomer stability and FRET efficiency for homo- and hetero-oligomers of fluorescent protein-labeled forms of EGFR and its paralog, human epidermal growth factor receptor 2 (HER2/ERBB2) in vesicles derived from mammalian cell membranes. We observe that both receptors form ligand-independent oligomers at physiological plasma membrane concentrations. Mutations introduced in the kinase region at the active state asymmetric kinase dimer interface do not affect the stability of ligand-independent EGFR oligomers. These results indicate that ligand-independent EGFR oligomers form using interactions that are distinct from the EGFR active state.
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Affiliation(s)
- Patrick O Byrne
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, Texas, USA
| | - Kalina Hristova
- Department of Materials Science and Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Daniel J Leahy
- Department of Molecular Biosciences, College of Natural Sciences, The University of Texas at Austin, Austin, Texas, USA.
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Trenker R, Jura N. Receptor tyrosine kinase activation: From the ligand perspective. Curr Opin Cell Biol 2020; 63:174-185. [PMID: 32114309 PMCID: PMC7813211 DOI: 10.1016/j.ceb.2020.01.016] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/27/2020] [Accepted: 01/27/2020] [Indexed: 02/06/2023]
Abstract
Receptor tyrosine kinases (RTKs) are single-span transmembrane receptors in which relatively conserved intracellular kinase domains are coupled to divergent extracellular modules. The extracellular domains initiate receptor signaling upon binding to either soluble or membrane-embedded ligands. The diversity of extracellular domain structures allows for coupling of many unique signaling inputs to intracellular tyrosine phosphorylation. The combinatorial power of this receptor system is further increased by the fact that multiple ligands can typically interact with the same receptor. Such ligands often act as biased agonists and initiate distinct signaling responses via activation of the same receptor. Mechanisms behind such biased agonism are largely unknown for RTKs, especially at the level of receptor-ligand complex structure. Using recent progress in understanding the structures of active RTK signaling units, we discuss selected mechanisms by which ligands couple receptor activation to distinct signaling outputs.
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Affiliation(s)
- Raphael Trenker
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Natalia Jura
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, 94158, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, 94158, USA.
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