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Analysis of Wild Type and Variant B Cystatin C Interactome in Retinal Pigment Epithelium Cells Reveals Variant B Interacting Mitochondrial Proteins. Cells 2023; 12:cells12050713. [PMID: 36899848 PMCID: PMC10001352 DOI: 10.3390/cells12050713] [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: 12/01/2022] [Revised: 02/09/2023] [Accepted: 02/21/2023] [Indexed: 03/05/2023] Open
Abstract
Cystatin C, a secreted cysteine protease inhibitor, is abundantly expressed in retinal pigment epithelium (RPE) cells. A mutation in the protein's leader sequence, corresponding to formation of an alternate variant B protein, has been linked with an increased risk for both age-related macular degeneration (AMD) and Alzheimer's disease (AD). Variant B cystatin C displays intracellular mistrafficking with partial mitochondrial association. We hypothesized that variant B cystatin C interacts with mitochondrial proteins and impacts mitochondrial function. We sought to determine how the interactome of the disease-related variant B cystatin C differs from that of the wild-type (WT) form. For this purpose, we expressed cystatin C Halo-tag fusion constructs in RPE cells to pull down proteins interacting with either the WT or variant B form, followed by identification and quantification by mass spectrometry. We identified a total of 28 interacting proteins, of which 8 were exclusively pulled down by variant B cystatin C. These included 18 kDa translocator protein (TSPO) and cytochrome B5 type B, both of which are localized to the mitochondrial outer membrane. Variant B cystatin C expression also affected RPE mitochondrial function with increased membrane potential and susceptibility to damage-induced ROS production. The findings help us to understand how variant B cystatin C differs functionally from the WT form and provide leads to RPE processes adversely affected by the variant B genotype.
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2
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Stafford JM, Wyatt MD, McInnes C. Inhibitors of the PLK1 polo-box domain: drug design strategies and therapeutic opportunities in cancer. Expert Opin Drug Discov 2023; 18:65-81. [PMID: 36524399 DOI: 10.1080/17460441.2023.2159942] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Polo Like Kinase 1 (PLK1) is a key regulator of mitosis and its overexpression is frequently observed in a wide variety of human cancers, while often being associated with poor survival rates. Therefore, it is considered a potential and attractive target for cancer therapeutic development. The Polo like kinase family is characterized by the presence of a unique C terminal polobox domain (PBD) involved in regulating kinase activity and subcellular localization. Among the two functionally essential, druggable sites with distinct properties that PLK1 offers, targeting the PBD presents an alternative approach for therapeutic development. AREAS COVERED Significant progress has been made in progressing from the peptidic PBD inhibitors first identified, to peptidomimetic and recently drug-like small molecules. In this review, the rationale for targeting the PBD over the ATP binding site is discussed, along with recent progress, challenges, and outlook. EXPERT OPINION The PBD has emerged as a viable alternative target for the inhibition of PLK1, and progress has been made in using compounds to elucidate mechanistic aspects of activity regulation and in determining roles of the PBD. Studies have resulted in proof of concept of in vivo efficacy suggesting promise for PBD binders in clinical development.
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Affiliation(s)
- Jessy M Stafford
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA
| | - Michael D Wyatt
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA
| | - Campbell McInnes
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, USA
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3
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Sharifi Tabar M, Francis H, Yeo D, Bailey CG, Rasko JEJ. Mapping oncogenic protein interactions for precision medicine. Int J Cancer 2022; 151:7-19. [PMID: 35113472 PMCID: PMC9306658 DOI: 10.1002/ijc.33954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 11/10/2022]
Abstract
Normal protein‐protein interactions (normPPIs) occur with high fidelity to regulate almost every physiological process. In cancer, this highly organised and precisely regulated network is disrupted, hijacked or reprogrammed resulting in oncogenic protein‐protein interactions (oncoPPIs). OncoPPIs, which can result from genomic alterations, are a hallmark of many types of cancers. Recent technological advances in the field of mass spectrometry (MS)‐based interactomics, structural biology and drug discovery have prompted scientists to identify and characterise oncoPPIs. Disruption of oncoPPI interfaces has become a major focus of drug discovery programs and has resulted in the use of PPI‐specific drugs clinically. However, due to several technical hurdles, studies to build a reference oncoPPI map for various cancer types have not been undertaken. Therefore, there is an urgent need for experimental workflows to overcome the existing challenges in studying oncoPPIs in various cancers and to build comprehensive reference maps. Here, we discuss the important hurdles for characterising oncoPPIs and propose a three‐phase multidisciplinary workflow to identify and characterise oncoPPIs. Systematic identification of cancer‐type‐specific oncogenic interactions will spur new opportunities for PPI‐focused drug discovery projects and precision medicine.
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Affiliation(s)
- Mehdi Sharifi Tabar
- Gene & Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Cancer & Gene Regulation Laboratory Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Faculty of Medicine & Health, The University of Sydney, Sydney, NSW, Australia
| | - Habib Francis
- Gene & Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Cancer & Gene Regulation Laboratory Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Faculty of Medicine & Health, The University of Sydney, Sydney, NSW, Australia
| | - Dannel Yeo
- Faculty of Medicine & Health, The University of Sydney, Sydney, NSW, Australia.,Li Ka Shing Cell & Gene Therapy Program, The University of Sydney, Camperdown, NSW, Australia.,Cell & Molecular Therapies, Royal Prince Alfred Hospital, Sydney Local Health District, Camperdown, NSW, Australia
| | - Charles G Bailey
- Gene & Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Cancer & Gene Regulation Laboratory Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Faculty of Medicine & Health, The University of Sydney, Sydney, NSW, Australia
| | - John E J Rasko
- Gene & Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.,Faculty of Medicine & Health, The University of Sydney, Sydney, NSW, Australia.,Li Ka Shing Cell & Gene Therapy Program, The University of Sydney, Camperdown, NSW, Australia.,Cell & Molecular Therapies, Royal Prince Alfred Hospital, Sydney Local Health District, Camperdown, NSW, Australia
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4
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Craig SN, Baxter M, Chapagai D, Stafford JM, Nurmemmedov E, Altomare D, Wyatt MD, McInnes C. Structure-activity and mechanistic studies of non-peptidic inhibitors of the PLK1 polo box domain identified through REPLACE. Eur J Med Chem 2022; 227:113926. [PMID: 34735919 PMCID: PMC9137042 DOI: 10.1016/j.ejmech.2021.113926] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/06/2021] [Accepted: 10/13/2021] [Indexed: 01/07/2023]
Abstract
Polo-like kinase 1 (PLK1) is a serine/threonine-protein kinase involved in cell cycle regulation and mitotic progression. Studies have shown that PLK1 is upregulated in many tumors and high levels are adversely related to a poor prognosis. Knocking down or inhibiting PLK1 results in synthetic lethality in PTEN deficient prostate tumors and Kras mutant colorectal tumors, further validating PLK1 as an oncotarget. Substrate recognition by PLK1 occurs through the Polo-Box Domain (PBD), which is a phospho-peptide binding site also responsible for subcellular localization. Much effort has been directed to target this kinase therapeutically through the ATP-binding site, and a few such inhibitors have advanced to clinical trials however with limited clinical efficacy. Moreover, it has been shown that a point mutation in PLK1 (C67V) confers dramatic cellular resistance to catalytic site inhibitors. An alternative approach to target PLK1 potently and selectively is through the PBD to block its protein-protein interactions. Through the REPLACE strategy, for converting peptide inhibitors into more drug-like non peptidic compounds, a PBD targeting compound series ("ABBAs"), has been identified and the key determinants of potency and selectivity elucidated through structure-activity relationship studies. In cellular experiments, the ABBAs were shown to lead to profound effects on the cell cycle, to inhibit tumor proliferation and overcome resistance of cells expressing the PLK1 C67V mutant to ATP-based inhibitors. These non-ATP competitive inhibitors of PLK1 were also used chemical biology probes to investigate the gene regulatory effects of PLK1, known to act on transcription factors such as p53.
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Affiliation(s)
- Sandra N Craig
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA.
| | - Merissa Baxter
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA.
| | - Danda Chapagai
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Jessy M Stafford
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Elmar Nurmemmedov
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Diego Altomare
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Michael D Wyatt
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA
| | - Campbell McInnes
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, SC, 29208, USA.
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5
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Aurora A and AKT Kinase Signaling Associated with Primary Cilia. Cells 2021; 10:cells10123602. [PMID: 34944109 PMCID: PMC8699881 DOI: 10.3390/cells10123602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 02/07/2023] Open
Abstract
Dysregulation of kinase signaling is associated with various pathological conditions, including cancer, inflammation, and autoimmunity; consequently, the kinases involved have become major therapeutic targets. While kinase signaling pathways play crucial roles in multiple cellular processes, the precise manner in which their dysregulation contributes to disease is dependent on the context; for example, the cell/tissue type or subcellular localization of the kinase or substrate. Thus, context-selective targeting of dysregulated kinases may serve to increase the therapeutic specificity while reducing off-target adverse effects. Primary cilia are antenna-like structures that extend from the plasma membrane and function by detecting extracellular cues and transducing signals into the cell. Cilia formation and signaling are dynamically regulated through context-dependent mechanisms; as such, dysregulation of primary cilia contributes to disease in a variety of ways. Here, we review the involvement of primary cilia-associated signaling through aurora A and AKT kinases with respect to cancer, obesity, and other ciliopathies.
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Gao Y, Kabotyanski EB, Shepherd JH, Villegas E, Acosta D, Hamor C, Sun T, Montmeyor-Garcia C, He X, Dobrolecki LE, Westbrook TF, Lewis MT, Hilsenbeck SG, Zhang XHF, Perou CM, Rosen JM. Tumor suppressor PLK2 may serve as a biomarker in triple-negative breast cancer for improved response to PLK1 therapeutics. CANCER RESEARCH COMMUNICATIONS 2021; 1:178-193. [PMID: 35156101 PMCID: PMC8827906 DOI: 10.1158/2767-9764.crc-21-0106] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Polo-like kinase (PLK) family members play important roles in cell cycle regulation. The founding member PLK1 is oncogenic and preclinically validated as a cancer therapeutic target. Paradoxically, frequent loss of chromosome 5q11-35 which includes PLK2 is observed in basal-like breast cancer. In this study, we found that PLK2 was tumor suppressive in breast cancer, preferentially in basal-like and triple-negative breast cancer (TNBC) subtypes. Knockdown of PLK1 rescued phenotypes induced by PLK2-loss both in vitro and in vivo. We also demonstrated that PLK2 directly interacted with PLK1 at prometaphase through the kinase but not the polo-box domains of PLK2, suggesting PLK2 functioned at least partially through the interaction with PLK1. Furthermore, an improved treatment response was seen in both Plk2-deleted/low mouse preclinical and PDX TNBC models using the PLK1 inhibitor volasertib alone or in combination with carboplatin. Re-expression of PLK2 in an inducible PLK2-null mouse model reduced the therapeutic efficacy of volasertib. In summary, this study delineates the effects of chromosome 5q loss in TNBC that includes PLK2, the relationship between PLK2 and PLK1, and how this may render PLK2-deleted/low tumors more sensitive to PLK1 inhibition in combination with chemotherapy.
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Affiliation(s)
- Yang Gao
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Elena B. Kabotyanski
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
| | | | | | - Deanna Acosta
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
| | - Clark Hamor
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
| | - Tingting Sun
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Verna & Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas
| | | | - Xiaping He
- The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Lacey E. Dobrolecki
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Thomas F. Westbrook
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Verna & Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas
| | - Michael T. Lewis
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Susan G. Hilsenbeck
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
| | - Xiang H.-F. Zhang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
- Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas
- McNair Medical Institute, Baylor College of Medicine, Houston, Texas
| | - Charles M. Perou
- The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jeffrey M. Rosen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas
- Corresponding Author: Jeffrey M. Rosen, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030. Phone: 832-215-9503; E-mail:
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7
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Sad K, Parashar P, Tripathi P, Hungyo H, Sistla R, Soni R, Tandon V. Prochlorperazine enhances radiosensitivity of non-small cell lung carcinoma by stabilizing GDP-bound mutant KRAS conformation. Free Radic Biol Med 2021; 177:299-312. [PMID: 34742922 DOI: 10.1016/j.freeradbiomed.2021.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/21/2021] [Accepted: 11/01/2021] [Indexed: 12/25/2022]
Abstract
Lung cancer is considered as leading cancer with the highest mortality. The KRAS-oncogenic mutations are dominant in lung carcinoma leading to poor prognosis and radioresistance, which is a major impediment to radiotherapy. Thus, KRAS mutant inhibitors that synergistically sensitize tumours to radiation are urgently needed. In pursuance of the search for a novel radiosensitizer, high-throughput screening of FDA-approved drugs was performed at active site of K-Ras. Prochlorperazine (PCZ), an antipsychotic drug, showed good binding affinity with KRAS-mutant proteins. PCZ binds to the GTP-binding pocket of KRAS-mutant protein and inhibits its constitutive activation by stabilizing the GDP-bound conformation of K-Ras mutants by 9 kcal/mol compared to WT. PCZ alongwith radiation decreased the clonogenic survival of KRAS-mutant NSCLC but not KRAS-WT cells. The combination treatment activates p-ATM, p53, and p21 proteins, leading to cell cycle arrest. PCZ with increasing radiation caused a linear increase in γH2AX foci, suggesting enhanced DSBs-associated apoptosis in radioresistant A549 cells. Pharmacokinetics study showed Cmax = 526 ng/ml at 30min, 4.6h half-life in plasma, and highest accumulation in tumours. PCZ and 10Gy irradiation synergistically radiosensitize mice xenografts via downregulation of Ras/Raf/MEK/ERK pathway. Our efforts have led to the discovery of PCZ as a lead compound. In preclinical analyses, treatment with PCZ alone and in combination with radiation led to regression of KRAS-G12S tumours.
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Affiliation(s)
- Kirti Sad
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Palak Parashar
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Pragya Tripathi
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Hungharla Hungyo
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ramesh Sistla
- Think Molecular Technologies Pvt. Ltd., Bengaluru, Karnataka, 560102, India
| | - Ravi Soni
- Institute of Nuclear Medicine & Allied Sciences, New Delhi, 110054, India
| | - Vibha Tandon
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India.
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8
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Chapagai D, Ramamoorthy G, Varghese J, Nurmemmedov E, McInnes C, Wyatt MD. Nonpeptidic, Polo-Box Domain-Targeted Inhibitors of PLK1 Block Kinase Activity, Induce Its Degradation and Target-Resistant Cells. J Med Chem 2021; 64:9916-9925. [PMID: 34210138 PMCID: PMC10451095 DOI: 10.1021/acs.jmedchem.1c00133] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PLK1, polo-like kinase 1, is a central player regulating mitosis. Inhibition of the subcellular localization and kinase activity of PLK1 through the PBD, polo-box domain, is a viable alternative to ATP-competitive inhibitors, for which the development of resistance and inhibition of related PLK family members are concerns. We describe novel nonpeptidic PBD-binding inhibitors, termed abbapolins, identified through successful application of the REPLACE strategy and demonstrate their potent antiproliferative activity in prostate tumors and other cell lines. Furthermore, abbapolins show PLK1-specific binding and inhibitory activity, as measured by a cellular thermal shift assay and an ability to block phosphorylation of TCTP, a validated target of PLK1-mediated kinase activity. Additional evidence for engagement of PLK1 was obtained through the unique observation that abbapolins induce PLK1 degradation in a manner that closely matches antiproliferative activity. Moreover, abbapolins demonstrate antiproliferative activity in cells that are dramatically resistant to ATP-competitive PLK1 inhibitors.
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Affiliation(s)
- Danda Chapagai
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Gurusankar Ramamoorthy
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Jessy Varghese
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Elmar Nurmemmedov
- John Wayne Cancer Institute and Pacific Neuroscience Institute at Providence Saint John's Health Center, Santa Monica, California 90404-2312, United States
| | - Campbell McInnes
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Michael D Wyatt
- Drug Discovery and Biomedical Sciences, College of Pharmacy, University of South Carolina, Columbia, South Carolina 29208, United States
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9
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Target identification for small-molecule discovery in the FOXO3a tumor-suppressor pathway using a biodiverse peptide library. Cell Chem Biol 2021; 28:1602-1615.e9. [PMID: 34111400 PMCID: PMC8610377 DOI: 10.1016/j.chembiol.2021.05.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 03/03/2021] [Accepted: 05/14/2021] [Indexed: 12/12/2022]
Abstract
Genetic screening technologies to identify and validate macromolecular interactions (MMIs) essential for complex pathways remain an important unmet need for systems biology and therapeutics development. Here, we use a library of peptides from diverse prokaryal genomes to screen MMIs promoting the nuclear relocalization of Forkhead Box O3 (FOXO3a), a tumor suppressor more frequently inactivated by post-translational modification than mutation. A hit peptide engages the 14-3-3 family of signal regulators through a phosphorylation-dependent interaction, modulates FOXO3a-mediated transcription, and suppresses cancer cell growth. In a crystal structure, the hit peptide occupies the phosphopeptide-binding groove of 14-3-3ε in a conformation distinct from its natural peptide substrates. A biophysical screen identifies drug-like small molecules that displace the hit peptide from 14-3-3ε, providing starting points for structure-guided development. Our findings exemplify “protein interference,” an approach using evolutionarily diverse, natural peptides to rapidly identify, validate, and develop chemical probes against MMIs essential for complex cellular phenotypes. We describe protein interference, an approach to identify and validate new drug targets A genetic screen identifies a protein interference probe inducing FOXO3a reactivation The probe defines a druggable binding site in the 14-3-3 signal regulator family We illustrate a workflow to parse complex cellular pathways for new drug targets
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10
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Tsuji K, Hymel D, Burke TR. A new genre of fluorescence recovery assay to evaluate polo-like kinase 1 ATP-competitive inhibitors. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2020; 12:4418-4421. [PMID: 32970049 PMCID: PMC7523589 DOI: 10.1039/d0ay01223h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Using a probe consisting of a fluorescein-labeled variant of the potent polo-like kinase 1 (Plk1) inhibitor BI2536 [FITC-PEG-Lys(BI2536) 4], we were able to determine half maximal inhibitory concentration (IC50) of ATP-competitive Type 1 inhibitors of Plk1 by means of a fluorescence recovery assay. This methodology represents a cost-effective and simple alternative to traditional kinase assays for initial screening of potential Plk1 inhibitors.
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Affiliation(s)
- Kohei Tsuji
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, 21702 USA.
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11
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Pavlinov I, Salkovski M, Aldrich LN. Beclin 1-ATG14L Protein-Protein Interaction Inhibitor Selectively Inhibits Autophagy through Disruption of VPS34 Complex I. J Am Chem Soc 2020; 142:8174-8182. [PMID: 32320221 DOI: 10.1021/jacs.9b12705] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Autophagy, a catabolic recycling process, has been implicated as a critical pathway in cancer. Its role in maintaining cellular homeostasis helps to nourish hypoxic, nutrient-starved tumors and protects them from chemotherapy-induced death. Recent efforts to target autophagy in cancer have focused on kinase inhibition, which has led to molecules that lack specificity due to the multiple roles of key kinases in this pathway. For example, the lipid kinase VPS34 is present in two multiprotein complexes responsible for the generation of phosphatidylinositol-3-phosphate. Complex I generates the autophagosome, and Complex II is crucial for endosomal trafficking. Molecules targeting VPS34 inhibit both complexes, which inhibits autophagy but causes undesirable defects in vesicle trafficking. The lack of specific autophagy modulators has limited the utility of autophagy inhibition as a therapeutic strategy. We hypothesize that disruption of the Beclin 1-ATG14L protein-protein interaction, which is required for the formation, proper localization, and function of VPS34 Complex I but not Complex II, will disrupt Complex I formation and selectively inhibit autophagy. To this end, a high-throughput, cellular NanoBRET assay was developed targeting this interaction. An initial screen of 2560 molecules yielded 19 hits that effectively disrupted the interaction, and it was confirmed that one hit disrupted VPS34 Complex I formation and inhibited autophagy. In addition, the molecule did not disrupt the Beclin 1-UVRAG interaction, critical for VPS34 Complex II, and thus had little impact on vesicle trafficking. This molecule is a promising new tool that is critical for understanding how modulation of the Beclin 1-ATG14L interaction affects autophagy. More broadly, its discovery demonstrates that targeting protein-protein interactions found within the autophagy pathway is a viable strategy for the discovery of autophagy-specific probes and therapeutics.
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Affiliation(s)
- Ivan Pavlinov
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago Illinois 60607, United States
| | - Maryna Salkovski
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago Illinois 60607, United States
| | - Leslie N Aldrich
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago Illinois 60607, United States
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12
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A programmable polymer library that enables the construction of stimuli-responsive nanocarriers containing logic gates. Nat Chem 2020; 12:381-390. [DOI: 10.1038/s41557-020-0426-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 01/22/2020] [Indexed: 12/14/2022]
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13
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Huggins DJ, Hardwick BS, Sharma P, Emery A, Laraia L, Zhang F, Narvaez AJ, Roberts-Thomson M, Crooks AT, Boyle RG, Boyce R, Walker DW, Mateu N, McKenzie GJ, Spring DR, Venkitaraman AR. Development of a Novel Cell-Permeable Protein-Protein Interaction Inhibitor for the Polo-box Domain of Polo-like Kinase 1. ACS OMEGA 2020; 5:822-831. [PMID: 31956833 PMCID: PMC6964520 DOI: 10.1021/acsomega.9b03626] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 12/13/2019] [Indexed: 05/10/2023]
Abstract
Polo-like kinase 1 (PLK1) is a key regulator of mitosis and a recognized drug target for cancer therapy. Inhibiting the polo-box domain of PLK1 offers potential advantages of increased selectivity and subsequently reduced toxicity compared with targeting the kinase domain. However, many if not all existing polo-box domain inhibitors have been shown to be unsuitable for further development. In this paper, we describe a novel compound series, which inhibits the protein-protein interactions of PLK1 via the polo-box domain. We combine high throughput screening with molecular modeling and computer-aided design, synthetic chemistry, and cell biology to address some of the common problems with protein-protein interaction inhibitors, such as solubility and potency. We use molecular modeling to improve the solubility of a hit series with initially poor physicochemical properties, enabling biophysical and biochemical characterization. We isolate and characterize enantiomers to improve potency and demonstrate on-target activity in both cell-free and cell-based assays, entirely consistent with the proposed binding model. The resulting compound series represents a promising starting point for further progression along the drug discovery pipeline and a new tool compound to study kinase-independent PLK functions.
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Affiliation(s)
- David J. Huggins
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
- TCM
Group, Cavendish Laboratory, University
of Cambridge, 19 JJ Thomson
Avenue, Cambridge CB3 0HE, United Kingdom
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
| | - Bryn S. Hardwick
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
| | - Pooja Sharma
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
| | - Amy Emery
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
| | - Luca Laraia
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
| | - Fengzhi Zhang
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
| | - Ana J. Narvaez
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
| | - Meredith Roberts-Thomson
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
| | - Alex T. Crooks
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
| | - Robert G. Boyle
- Sentinel
Oncology Ltd., Cambridge Science Park, Milton Road, Cambridge CB4 0EY, United Kingdom
| | - Richard Boyce
- Sentinel
Oncology Ltd., Cambridge Science Park, Milton Road, Cambridge CB4 0EY, United Kingdom
| | - David W. Walker
- Sentinel
Oncology Ltd., Cambridge Science Park, Milton Road, Cambridge CB4 0EY, United Kingdom
| | - Natalia Mateu
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
| | - Grahame J. McKenzie
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
| | - David R. Spring
- Department
of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United
Kingdom
| | - Ashok R. Venkitaraman
- Medical
Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, United Kingdom
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14
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Sharma P, Mahen R, Rossmann M, Stokes JE, Hardwick B, Huggins DJ, Emery A, Kunciw DL, Hyvönen M, Spring DR, McKenzie GJ, Venkitaraman AR. A cryptic hydrophobic pocket in the polo-box domain of the polo-like kinase PLK1 regulates substrate recognition and mitotic chromosome segregation. Sci Rep 2019; 9:15930. [PMID: 31685831 PMCID: PMC6828814 DOI: 10.1038/s41598-019-50702-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 07/26/2019] [Indexed: 11/25/2022] Open
Abstract
The human polo-like kinase PLK1 coordinates mitotic chromosome segregation by phosphorylating multiple chromatin- and kinetochore-binding proteins. How PLK1 activity is directed to specific substrates via phosphopeptide recognition by its carboxyl-terminal polo-box domain (PBD) is poorly understood. Here, we combine molecular, structural and chemical biology to identify a determinant for PLK1 substrate recognition that is essential for proper chromosome segregation. We show that mutations ablating an evolutionarily conserved, Tyr-lined pocket in human PLK1 PBD trigger cellular anomalies in mitotic progression and timing. Tyr pocket mutations selectively impair PLK1 binding to the kinetochore phosphoprotein substrate PBIP1, but not to the centrosomal substrate NEDD1. Through a structure-guided approach, we develop a small-molecule inhibitor, Polotyrin, which occupies the Tyr pocket. Polotyrin recapitulates the mitotic defects caused by mutations in the Tyr pocket, further evidencing its essential function, and exemplifying a new approach for selective PLK1 inhibition. Thus, our findings support a model wherein substrate discrimination via the Tyr pocket in the human PLK1 PBD regulates mitotic chromosome segregation to preserve genome integrity.
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Affiliation(s)
- Pooja Sharma
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge, CB2 0XZ, United Kingdom
| | - Robert Mahen
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge, CB2 0XZ, United Kingdom
| | - Maxim Rossmann
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, United Kingdom
| | - Jamie E Stokes
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Bryn Hardwick
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge, CB2 0XZ, United Kingdom
| | - David J Huggins
- Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, United Kingdom
| | - Amy Emery
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge, CB2 0XZ, United Kingdom
| | - Dominique L Kunciw
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Marko Hyvönen
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, United Kingdom
| | - David R Spring
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom
| | - Grahame J McKenzie
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge, CB2 0XZ, United Kingdom
| | - Ashok R Venkitaraman
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge, CB2 0XZ, United Kingdom.
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15
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Trinh AL, Ber S, Howitt A, Valls PO, Fries MW, Venkitaraman AR, Esposito A. Fast single-cell biochemistry: theory, open source microscopy and applications. Methods Appl Fluoresc 2019; 7:044001. [PMID: 31422954 PMCID: PMC7000240 DOI: 10.1088/2050-6120/ab3bd2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Fluorescence lifetime sensing enables researchers to probe the physicochemical environment of a fluorophore providing a window through which we can observe the complex molecular make-up of the cell. Fluorescence lifetime imaging microscopy (FLIM) quantifies and maps cell biochemistry, a complex ensemble of dynamic processes. Unfortunately, typical high-resolution FLIM systems exhibit rather limited acquisition speeds, often insufficient to capture the time evolution of biochemical processes in living cells. Here, we describe the theoretical background that justifies the developments of high-speed single photon counting systems. We show that systems with low dead-times not only result in faster acquisition throughputs but also improved dynamic range and spatial resolution. We also share the implementation of hardware and software as an open platform, show applications of fast FLIM biochemical imaging on living cells and discuss strategies to balance precision and accuracy in FLIM. The recent innovations and commercialisation of fast time-domain FLIM systems are likely to popularise FLIM within the biomedical community, to impact biomedical research positively and to foster the adoption of other FLIM techniques as well. While supporting and indeed pursuing these developments, with this work we also aim to warn the community about the possible shortcomings of fast single photon counting techniques and to highlight strategies to acquire data of high quality.
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16
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Stratmann JA, Sebastian M. Polo-like kinase 1 inhibition in NSCLC: mechanism of action and emerging predictive biomarkers. LUNG CANCER-TARGETS AND THERAPY 2019; 10:67-80. [PMID: 31308774 PMCID: PMC6612950 DOI: 10.2147/lctt.s177618] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Accepted: 05/24/2019] [Indexed: 12/16/2022]
Abstract
Non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. Due to often unspecific disease symptoms, locally advanced or metastatic disease is diagnosed in the majority of all cases. Palliative treatment options comprise of conventional cytotoxic agents, immunotherapy with checkpoint inhibitors and the use of specific small-molecule tyrosine kinase inhibitors (TKI). However, these TKIs are mainly restricted to a small proportion of patients with lung cancer that harbor activating driver mutations. Still, the effectiveness and favorable safety profile of these compounds have prompted a systematic search for specific driver mechanisms of tumorigenesis and moreover the development of corresponding kinase inhibitors. In recent years, the Polo-like kinase (PLK) family has emerged as a key regulator in mitotic regulation. Its role in cell proliferation and the frequently observed overexpression in various tumor entities have raised much interest in basic and clinical oncology aiming to attenuate tumor growth by targeting the PLK. In this review, we give a comprehensive summary on the (pre-) clinical development of the different types of PLK inhibitors in lung cancer and summarize their mechanisms of action, safety and efficacy data and give an overview on translational research aiming to identify predictive biomarkers for a rational use of PLK inhibitors.
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Affiliation(s)
- Jan A Stratmann
- Department of Internal Medicine II, University Clinic of Frankfurt, 60596 Frankfurt, Germany
| | - Martin Sebastian
- Department of Internal Medicine II, University Clinic of Frankfurt, 60596 Frankfurt, Germany
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17
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Singh R, Peng S, Viswanath P, Sambandam V, Shen L, Rao X, Fang B, Wang J, Johnson FM. Non-canonical cMet regulation by vimentin mediates Plk1 inhibitor-induced apoptosis. EMBO Mol Med 2019; 11:e9960. [PMID: 31040125 PMCID: PMC6505578 DOI: 10.15252/emmm.201809960] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 02/28/2019] [Accepted: 03/12/2019] [Indexed: 12/26/2022] Open
Abstract
To address the need for improved systemic therapy for non-small-cell lung cancer (NSCLC), we previously demonstrated that mesenchymal NSCLC was sensitive to polo-like kinase (Plk1) inhibitors, but the mechanisms of resistance in epithelial NSCLC remain unknown. Here, we show that cMet was differentially regulated in isogenic pairs of epithelial and mesenchymal cell lines. Plk1 inhibition inhibits cMet phosphorylation only in mesenchymal cells. Constitutively active cMet abrogates Plk1 inhibitor-induced apoptosis. Likewise, cMet silencing or inhibition enhances Plk1 inhibitor-induced apoptosis. Cells with acquired resistance to Plk1 inhibitors are more epithelial than their parental cells and maintain cMet activation after Plk1 inhibition. In four animal NSCLC models, mesenchymal tumors were more sensitive to Plk1 inhibition alone than were epithelial tumors. The combination of cMet and Plk1 inhibition led to regression of tumors that did not regrow when drug treatment was stopped. Plk1 inhibition did not affect HGF levels but did decrease vimentin phosphorylation, which regulates cMet phosphorylation via β1-integrin. This research defines a heretofore unknown mechanism of ligand-independent activation of cMet downstream of Plk1 and an effective combination therapy.
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Affiliation(s)
- Ratnakar Singh
- Department of Thoracic/Head & Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Shaohua Peng
- Department of Thoracic/Head & Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Pavitra Viswanath
- Department of Thoracic/Head & Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- The University of Texas MD Anderson Cancer Center Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Vaishnavi Sambandam
- Department of Thoracic/Head & Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Li Shen
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Xiayu Rao
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Bingliang Fang
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jing Wang
- The University of Texas MD Anderson Cancer Center Graduate School of Biomedical Sciences, Houston, TX, USA
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Faye M Johnson
- Department of Thoracic/Head & Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- The University of Texas MD Anderson Cancer Center Graduate School of Biomedical Sciences, Houston, TX, USA
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18
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Rubner S, Schubert S, Berg T. Poloxin-2HT+: changing the hydrophobic tag of Poloxin-2HT increases Plk1 degradation and apoptosis induction in tumor cells. Org Biomol Chem 2019; 17:3113-3117. [PMID: 30848278 DOI: 10.1039/c9ob00080a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We report the hydrophobically-tagged Plk1 PBD inhibitor Poloxin-2HT+, which selectively degrades the tumor target Plk1 and induces apoptosis in human tumor cells with higher potency than the hydrophobically-tagged inhibitor Poloxin-2HT. Our data provide further evidence that hydrophobically tagged inhibitors of protein-protein interactions can target and destroy disease-relevant proteins.
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Affiliation(s)
- Stefan Rubner
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, 04103 Leipzig, Germany.
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19
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Rubner S, Scharow A, Schubert S, Berg T. Selective Degradation of Polo-like Kinase 1 by a Hydrophobically Tagged Inhibitor of the Polo-Box Domain. Angew Chem Int Ed Engl 2018; 57:17043-17047. [PMID: 30351497 DOI: 10.1002/anie.201809640] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/09/2018] [Indexed: 12/18/2022]
Abstract
Hydrophobic tagging (HT) of bioactive compounds can induce target degradation via the proteasomal pathway. The first application of hydrophobic tagging to an existing inhibitor of protein-protein interactions is now presented. We developed Poloxin-2HT by fusing an adamantyl tag to Poloxin-2, an inhibitor of the polo-box domain of the protein kinase Plk1, which is a target for tumor therapy. Poloxin-2HT selectively reduced the protein levels of Plk1 in HeLa cells and had a significantly stronger effect on cell viability and the induction of apoptosis than the untagged PBD inhibitor Poloxin-2. The change in cellular phenotype associated with the addition of the hydrophobic tag to Poloxin-2 demonstrated that Poloxin-2HT targets Plk1 in living cells. Our data validate hydrophobic tagging of selective inhibitors of protein-protein interactions as a novel strategy to target and destroy disease-relevant proteins.
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Affiliation(s)
- Stefan Rubner
- Leipzig University, Institute of Organic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Andrej Scharow
- Leipzig University, Institute of Organic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Sabine Schubert
- Leipzig University, Institute of Organic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
| | - Thorsten Berg
- Leipzig University, Institute of Organic Chemistry, Johannisallee 29, 04103, Leipzig, Germany
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20
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Rubner S, Scharow A, Schubert S, Berg T. Selective Degradation of Polo‐like Kinase 1 by a Hydrophobically Tagged Inhibitor of the Polo‐Box Domain. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201809640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Stefan Rubner
- Leipzig University Institute of Organic Chemistry Johannisallee 29 04103 Leipzig Germany
| | - Andrej Scharow
- Leipzig University Institute of Organic Chemistry Johannisallee 29 04103 Leipzig Germany
| | - Sabine Schubert
- Leipzig University Institute of Organic Chemistry Johannisallee 29 04103 Leipzig Germany
| | - Thorsten Berg
- Leipzig University Institute of Organic Chemistry Johannisallee 29 04103 Leipzig Germany
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21
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Abstract
Mitosis is controlled by reversible protein phosphorylation involving specific kinases and phosphatases. A handful of major mitotic protein kinases, such as the cyclin B-CDK1 complex, the Aurora kinases, and Polo-like kinase 1 (PLK1), cooperatively regulate distinct mitotic processes. Research has identified proteins and mechanisms that integrate these kinases into signaling cascades that guide essential mitotic events. These findings have important implications for our understanding of the mechanisms of mitotic regulation and may advance the development of novel antimitotic drugs. We review collected evidence that in vertebrates, the Aurora kinases serve as catalytic subunits of distinct complexes formed with the four scaffold proteins Bora, CEP192, INCENP, and TPX2, which we deem "core" Aurora cofactors. These complexes and the Aurora-PLK1 cascades organized by Bora, CEP192, and INCENP control crucial aspects of mitosis and all pathways of spindle assembly. We compare the mechanisms of Aurora activation in relation to the different spindle assembly pathways and draw a functional analogy between the CEP192 complex and the chromosomal passenger complex that may reflect the coevolution of centrosomes, kinetochores, and the actomyosin cleavage apparatus. We also analyze the roles and mechanisms of Aurora-PLK1 signaling in the cell and centrosome cycles and in the DNA damage response.
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Affiliation(s)
- Vladimir Joukov
- N.N. Petrov National Medical Research Center of Oncology, Saint-Petersburg 197758, Russian Federation.
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22
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Periasamy J, Kurdekar V, Jasti S, Nijaguna MB, Boggaram S, Hurakadli MA, Raina D, Kurup LM, Chintha C, Manjunath K, Goyal A, Sadasivam G, Bharatham K, Padigaru M, Potluri V, Venkitaraman AR. Targeting Phosphopeptide Recognition by the Human BRCA1 Tandem BRCT Domain to Interrupt BRCA1-Dependent Signaling. Cell Chem Biol 2018; 25:677-690.e12. [PMID: 29606576 PMCID: PMC6015222 DOI: 10.1016/j.chembiol.2018.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/24/2017] [Accepted: 02/22/2018] [Indexed: 02/06/2023]
Abstract
Intracellular signals triggered by DNA breakage flow through proteins containing BRCT (BRCA1 C-terminal) domains. This family, comprising 23 conserved phosphopeptide-binding modules in man, is inaccessible to small-molecule chemical inhibitors. Here, we develop Bractoppin, a drug-like inhibitor of phosphopeptide recognition by the human BRCA1 tandem (t)BRCT domain, which selectively inhibits substrate binding with nanomolar potency in vitro. Structure-activity exploration suggests that Bractoppin engages BRCA1 tBRCT residues recognizing pSer in the consensus motif, pSer-Pro-Thr-Phe, plus an abutting hydrophobic pocket that is distinct in structurally related BRCT domains, conferring selectivity. In cells, Bractoppin inhibits substrate recognition detected by Förster resonance energy transfer, and diminishes BRCA1 recruitment to DNA breaks, in turn suppressing damage-induced G2 arrest and assembly of the recombinase, RAD51. But damage-induced MDC1 recruitment, single-stranded DNA (ssDNA) generation, and TOPBP1 recruitment remain unaffected. Thus, an inhibitor of phosphopeptide recognition selectively interrupts BRCA1 tBRCT-dependent signals evoked by DNA damage. Bractoppin selectively blocks phosphopeptide recognition by the BRCA1 tBRCT domain Bractoppin engages tBRCT residues recognizing pSer, plus an adjacent pocket Bractoppin interrupts BRCA1 tBRCT-dependent cellular signals evoked by DNA damage This work opens avenues to inhibit intracellular signaling by the tBRCT domain family
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Affiliation(s)
- Jayaprakash Periasamy
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Vadiraj Kurdekar
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Subbarao Jasti
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Mamatha B Nijaguna
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Sanjana Boggaram
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Manjunath A Hurakadli
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Dhruv Raina
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Lokavya Meenakshi Kurup
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Chetan Chintha
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Kavyashree Manjunath
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Aneesh Goyal
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Gayathri Sadasivam
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Kavitha Bharatham
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Muralidhara Padigaru
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Vijay Potluri
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India
| | - Ashok R Venkitaraman
- Center for Chemical Biology & Therapeutics, InSTEM, Bellary Road, Bangalore, Karnataka 560065, India; Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK.
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23
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Ran X, Gestwicki JE. Inhibitors of protein-protein interactions (PPIs): an analysis of scaffold choices and buried surface area. Curr Opin Chem Biol 2018; 44:75-86. [PMID: 29908451 DOI: 10.1016/j.cbpa.2018.06.004] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/04/2018] [Indexed: 12/17/2022]
Abstract
Protein-protein interactions (PPI) were once considered 'undruggable', but clinical successes, driven by advanced methods in drug discovery, have challenged that notion. Here, we review the last three years of literature on PPI inhibitors to understand what is working and why. From the 66 recently reported PPI inhibitors, we found that the average molecular weight was significantly greater than 500Da, but that this trend was driven, in large part, by the contribution of peptide-based compounds. Despite differences in average molecular weight, we found that compounds based on small molecules or peptides were almost equally likely to be potent inhibitors (KD<1μM). Finally, we found PPIs with buried surface area (BSA) less than 2000Å2 were more likely to be inhibited by small molecules, while PPIs with larger BSA values were typically inhibited by peptides. PPIs with BSA values over 4000Å2 seemed to create a particular challenge, especially for orthosteric small molecules. Thus, it seems important to choose the inhibitor scaffold based on the properties of the target interaction. Moreover, this survey suggests a (more nuanced) conclusion to the question of whether PPIs are good drug targets; namely, that some PPIs are readily 'druggable' given the right choice of scaffold, while others still seem to deserve the 'undruggable' moniker.
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Affiliation(s)
- Xu Ran
- Institute for Neurodegenerative Diseases and Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, United States
| | - Jason E Gestwicki
- Institute for Neurodegenerative Diseases and Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, United States.
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