1
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Babu Manoharan G, Guzmán C, Najumudeen AK, Abankwa D. Detection of Ras nanoclustering-dependent homo-FRET using fluorescence anisotropy measurements. Eur J Cell Biol 2023; 102:151314. [PMID: 37058825 DOI: 10.1016/j.ejcb.2023.151314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 03/10/2023] [Accepted: 04/10/2023] [Indexed: 04/16/2023] Open
Abstract
The small GTPase Ras is frequently mutated in cancer and a driver of tumorigenesis. The recent years have shown great progress in drug-targeting Ras and understanding how it operates on the plasma membrane. We now know that Ras is non-randomly organized into proteo-lipid complexes on the membrane, called nanoclusters. Nanoclusters contain only a few Ras proteins and are necessary for the recruitment of downstream effectors, such as Raf. If tagged with fluorescent proteins, the dense packing of Ras in nanoclusters can be analyzed by Förster/ fluorescence resonance energy transfer (FRET). Loss of FRET can therefore report on decreased nanoclustering and any process upstream of it, such as Ras lipid modifications and correct trafficking. Thus, cellular FRET screens employing Ras-derived fluorescence biosensors are potentially powerful tools to discover chemical or genetic modulators of functional Ras membrane organization. Here we implement fluorescence anisotropy-based homo-FRET measurements of Ras-derived constructs labelled with only one fluorescent protein on a confocal microscope and a fluorescence plate reader. We show that homo-FRET of both H-Ras- and K-Ras-derived constructs can sensitively report on Ras-lipidation and -trafficking inhibitors, as well as on genetic perturbations of proteins regulating membrane anchorage. By exploiting the switch I/II-binding Ras-dimerizing compound BI-2852, this assay is also suitable to report on the engagement of the K-Ras switch II pocket by small molecules such as AMG 510. Given that homo-FRET only requires one fluorescent protein tagged Ras construct, this approach has significant advantages to create Ras-nanoclustering FRET-biosensor reporter cell lines, as compared to the more common hetero-FRET approaches.
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Affiliation(s)
- Ganesh Babu Manoharan
- Cancer Cell Biology and Drug Discovery group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Camilo Guzmán
- Euro-BioImaging ERIC, Statutory Seat, Turku, Finland
| | - Arafath Kaja Najumudeen
- Institute of Biotechnology, HiLIFE Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
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2
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Pavic K, Gupta N, Omella JD, Derua R, Aakula A, Huhtaniemi R, Määttä JA, Höfflin N, Okkeri J, Wang Z, Kauko O, Varjus R, Honkanen H, Abankwa D, Köhn M, Hytönen VP, Xu W, Nilsson J, Page R, Janssens V, Leitner A, Westermarck J. Structural mechanism for inhibition of PP2A-B56α and oncogenicity by CIP2A. Nat Commun 2023; 14:1143. [PMID: 36854761 PMCID: PMC9974998 DOI: 10.1038/s41467-023-36693-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 02/09/2023] [Indexed: 03/02/2023] Open
Abstract
The protein phosphatase 2A (PP2A) heterotrimer PP2A-B56α is a human tumour suppressor. However, the molecular mechanisms inhibiting PP2A-B56α in cancer are poorly understood. Here, we report molecular level details and structural mechanisms of PP2A-B56α inhibition by an oncoprotein CIP2A. Upon direct binding to PP2A-B56α trimer, CIP2A displaces the PP2A-A subunit and thereby hijacks both the B56α, and the catalytic PP2Ac subunit to form a CIP2A-B56α-PP2Ac pseudotrimer. Further, CIP2A competes with B56α substrate binding by blocking the LxxIxE-motif substrate binding pocket on B56α. Relevant to oncogenic activity of CIP2A across human cancers, the N-terminal head domain-mediated interaction with B56α stabilizes CIP2A protein. Functionally, CRISPR/Cas9-mediated single amino acid mutagenesis of the head domain blunted MYC expression and MEK phosphorylation, and abrogated triple-negative breast cancer in vivo tumour growth. Collectively, we discover a unique multi-step hijack and mute protein complex regulation mechanism resulting in tumour suppressor PP2A-B56α inhibition. Further, the results unfold a structural determinant for the oncogenic activity of CIP2A, potentially facilitating therapeutic modulation of CIP2A in cancer and other diseases.
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Affiliation(s)
- Karolina Pavic
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Nikhil Gupta
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Judit Domènech Omella
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Rita Derua
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
- SyBioMa, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Anna Aakula
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Riikka Huhtaniemi
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Juha A Määttä
- Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland and Fimlab Laboratories, 33520, Tampere, Finland
| | - Nico Höfflin
- Faculty of Biology, Institute of Biology III, University of Freiburg, 79104, Freiburg, Germany
| | - Juha Okkeri
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Zhizhi Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Otto Kauko
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Roosa Varjus
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Henrik Honkanen
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Maja Köhn
- Faculty of Biology, Institute of Biology III, University of Freiburg, 79104, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Vesa P Hytönen
- Faculty of Medicine and Health Technology, Tampere University, 33520 Tampere, Finland and Fimlab Laboratories, 33520, Tampere, Finland
| | - Wenqing Xu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Rebecca Page
- Department of Chemistry and Biochemistry University of Arizona, Tucson, AZ, USA
| | - Veerle Janssens
- Laboratory of Protein Phosphorylation & Proteomics, Department of Cellular & Molecular Medicine, University of Leuven (KU Leuven), B-3000, Leuven, Belgium
| | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, 8093, Zurich, Switzerland
| | - Jukka Westermarck
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520, Turku, Finland.
- Institute of Biomedicine, University of Turku, 20520, Turku, Finland.
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3
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Manoharan GB, Okutachi S, Abankwa D. Potential of phenothiazines to synergistically block calmodulin and reactivate PP2A in cancer cells. PLoS One 2022; 17:e0268635. [PMID: 35617282 PMCID: PMC9135253 DOI: 10.1371/journal.pone.0268635] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 05/04/2022] [Indexed: 11/19/2022] Open
Abstract
Phenothiazines (PTZ) were developed as inhibitors of monoamine neurotransmitter receptors, notably dopamine receptors. Because of this activity they have been used for decades as antipsychotic drugs. In addition, they possess significant anti-cancer properties and several attempts for their repurposing were made. However, their incompletely understood polypharmacology is challenging. Here we examined the potential of the PTZ fluphenazine (Flu) and its mustard derivative (Flu-M) to synergistically act on two cancer associated targets, calmodulin (CaM) and the tumor suppressor protein phosphatase 2A (PP2A). Both proteins are known to modulate the Ras- and MAPK-pathway, cell viability and features of cancer cell stemness. Consistently, we show that the combination of a CaM inhibitor and the PP2A activator DT-061 synergistically inhibited the 3D-spheroid formation of MDA-MB-231 (K-Ras-G13D), NCI-H358 (K-Ras-G12C) and A375 (B-raf-V600E) cancer cells, and increased apoptosis in MDA-MB-231. We reasoned that these activities remain combined in PTZ, which were the starting point for PP2A activator development, while several PTZ are known CaM inhibitors. We show that both Flu and Flu-M retained CaM inhibitory activity in vitro and in cells, with a higher potency of the mustard derivative in cells. In line with the CaM dependence of Ras plasma membrane organization, the mustard derivative potently reduced the functional membrane organization of oncogenic Ras, while DT-061 had a negligible effect. Like DT-061, both PTZ potently decreased c-MYC levels, a hallmark of PP2A activation. Benchmarking against the KRAS-G12C specific inhibitor AMG-510 in MIA PaCa-2 cells revealed a higher potency of Flu-M than combinations of DT-061 and a CaM inhibitor on MAPK-output and a strong effect on cell proliferation. While our study is limited, our results suggest that improved PTZ derivatives that retain both, their CaM inhibitory and PP2A activating properties, but have lost their neurological side-effects, may be interesting to pursue further as anti-cancer agents.
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Affiliation(s)
- Ganesh Babu Manoharan
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Sunday Okutachi
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
- * E-mail:
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4
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Pavic K, Chippalkatti R, Abankwa D. Drug targeting opportunities en route to Ras nanoclusters. Adv Cancer Res 2022; 153:63-99. [PMID: 35101236 DOI: 10.1016/bs.acr.2021.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Disruption of the native membrane organization of Ras by the farnesyltransferase inhibitor tipifarnib in the late 1990s constituted the first indirect approach to drug target Ras. Since then, our understanding of how dynamically Ras shuttles between subcellular locations has changed significantly. Ras proteins have to arrive at the plasma membrane for efficient MAPK-signal propagation. On the plasma membrane Ras proteins are organized into isoform specific proteo-lipid assemblies called nanocluster. Recent evidence suggests that Ras nanocluster have a specific lipid composition, which supports the recruitment of effectors such as Raf. Conversely, effectors possess lipid-recognition motifs, which appear to serve as co-incidence detectors for the lipid domain of a given Ras isoform. Evidence suggests that dimeric Raf proteins then co-assemble dimeric Ras in an immobile complex, thus forming the minimal unit of an active nanocluster. Here we review established and novel trafficking chaperones and trafficking factors of Ras, along with the set of lipid and protein modulators of Ras nanoclustering. We highlight drug targeting approaches and opportunities against these determinants of functional Ras membrane organization. Finally, we reflect on implications for Ras signaling in polarized cells, such as epithelia, which are a common origin of tumorigenesis.
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Affiliation(s)
- Karolina Pavic
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Rohan Chippalkatti
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
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5
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Rouzbahani Y, Chippalkatti R, Abankwa D, Carravilla P, Eggeling C. Advanced microscope studies of the cell polarization instructing activity of Ras proteins. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.1350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
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6
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Cipriani C, Pacheco MP, Kishk A, Wachich M, Abankwa D, Schaffner-Reckinger E, Sauter T. Bruceine D Identified as a Drug Candidate against Breast Cancer by a Novel Drug Selection Pipeline and Cell Viability Assay. Pharmaceuticals (Basel) 2022; 15:ph15020179. [PMID: 35215292 PMCID: PMC8875459 DOI: 10.3390/ph15020179] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/20/2022] [Accepted: 01/26/2022] [Indexed: 02/06/2023] Open
Abstract
The multi-target effects of natural products allow us to fight complex diseases like cancer on multiple fronts. Unlike docking techniques, network-based approaches such as genome-scale metabolic modelling can capture multi-target effects. However, the incompleteness of natural product target information reduces the prediction accuracy of in silico gene knockout strategies. Here, we present a drug selection workflow based on context-specific genome-scale metabolic models, built from the expression data of cancer cells treated with natural products, to predict cell viability. The workflow comprises four steps: first, in silico single-drug and drug combination predictions; second, the assessment of the effects of natural products on cancer metabolism via the computation of a dissimilarity score between the treated and control models; third, the identification of natural products with similar effects to the approved drugs; and fourth, the identification of drugs with the predicted effects in pathways of interest, such as the androgen and estrogen pathway. Out of the initial 101 natural products, nine candidates were tested in a 2D cell viability assay. Bruceine D, emodin, and scutellarein showed a dose-dependent inhibition of MCF-7 and Hs 578T cell proliferation with IC50 values between 0.7 to 65 μM, depending on the drug and cell line. Bruceine D, extracted from Brucea javanica seeds, showed the highest potency.
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Affiliation(s)
- Claudia Cipriani
- Systems Biology Group, Department of Life Sciences and Medicine, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg; (C.C.); (M.P.P.); (A.K.)
| | - Maria Pires Pacheco
- Systems Biology Group, Department of Life Sciences and Medicine, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg; (C.C.); (M.P.P.); (A.K.)
| | - Ali Kishk
- Systems Biology Group, Department of Life Sciences and Medicine, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg; (C.C.); (M.P.P.); (A.K.)
| | - Maryem Wachich
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg; (M.W.); (D.A.); (E.S.-R.)
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg; (M.W.); (D.A.); (E.S.-R.)
| | - Elisabeth Schaffner-Reckinger
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg; (M.W.); (D.A.); (E.S.-R.)
| | - Thomas Sauter
- Systems Biology Group, Department of Life Sciences and Medicine, University of Luxembourg, L-4365 Esch-sur-Alzette, Luxembourg; (C.C.); (M.P.P.); (A.K.)
- Correspondence:
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7
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Glaab E, Manoharan GB, Abankwa D. Pharmacophore Model for SARS-CoV-2 3CLpro Small-Molecule Inhibitors and in Vitro Experimental Validation of Computationally Screened Inhibitors. J Chem Inf Model 2021; 61:4082-4096. [PMID: 34348021 PMCID: PMC8353990 DOI: 10.1021/acs.jcim.1c00258] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Indexed: 01/18/2023]
Abstract
Among the biomedical efforts in response to the current coronavirus (COVID-19) pandemic, pharmacological strategies to reduce viral load in patients with severe forms of the disease are being studied intensively. One of the main drug target proteins proposed so far is the SARS-CoV-2 viral protease 3CLpro (also called Mpro), an essential component for viral replication. Ongoing ligand- and receptor-based computational screening efforts would be facilitated by an improved understanding of the electrostatic, hydrophobic, and steric features that characterize small-molecule inhibitors binding stably to 3CLpro and by an extended collection of known binders. Here, we present combined virtual screening, molecular dynamics (MD) simulation, machine learning, and in vitro experimental validation analyses, which have led to the identification of small-molecule inhibitors of 3CLpro with micromolar activity and to a pharmacophore model that describes functional chemical groups associated with the molecular recognition of ligands by the 3CLpro binding pocket. Experimentally validated inhibitors using a ligand activity assay include natural compounds with the available prior knowledge on safety and bioavailability properties, such as the natural compound rottlerin (IC50 = 37 μM) and synthetic compounds previously not characterized (e.g., compound CID 46897844, IC50 = 31 μM). In combination with the developed pharmacophore model, these and other confirmed 3CLpro inhibitors may provide a basis for further similarity-based screening in independent compound databases and structural design optimization efforts to identify 3CLpro ligands with improved potency and selectivity. Overall, this study suggests that the integration of virtual screening, MD simulations, and machine learning can facilitate 3CLpro-targeted small-molecule screening investigations. Different receptor-, ligand-, and machine learning-based screening strategies provided complementary information, helping to increase the number and diversity of the identified active compounds. Finally, the resulting pharmacophore model and experimentally validated small-molecule inhibitors for 3CLpro provide resources to support follow-up computational screening efforts for this drug target.
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Affiliation(s)
- Enrico Glaab
- Luxembourg Centre for Systems Biomedicine (LCSB),
University of Luxembourg, 7 Avenue des Hauts Fourneaux,
L-4362 Esch-sur-Alzette, Luxembourg
| | - Ganesh Babu Manoharan
- Department of Life Sciences and Medicine,
University of Luxembourg, 7 Avenue des Hauts Fourneaux,
L-4362 Esch-sur-Alzette, Luxembourg
| | - Daniel Abankwa
- Department of Life Sciences and Medicine,
University of Luxembourg, 7 Avenue des Hauts Fourneaux,
L-4362 Esch-sur-Alzette, Luxembourg
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Okutachi S, Manoharan GB, Kiriazis A, Laurini C, Catillon M, McCormick F, Yli-Kauhaluoma J, Abankwa D. A Covalent Calmodulin Inhibitor as a Tool to Study Cellular Mechanisms of K-Ras-Driven Stemness. Front Cell Dev Biol 2021; 9:665673. [PMID: 34307350 PMCID: PMC8296985 DOI: 10.3389/fcell.2021.665673] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 06/04/2021] [Indexed: 11/23/2022] Open
Abstract
Recently, the highly mutated oncoprotein K-Ras4B (hereafter K-Ras) was shown to drive cancer cell stemness in conjunction with calmodulin (CaM). We previously showed that the covalent CaM inhibitor ophiobolin A (OphA) can potently inhibit K-Ras stemness activity. However, OphA, a fungus-derived natural product, exhibits an unspecific, broad toxicity across all phyla. Here we identified a less toxic, functional analog of OphA that can efficiently inactivate CaM by covalent inhibition. We analyzed a small series of benzazulenones, which bear some structural similarity to OphA and can be synthesized in only six steps. We identified the formyl aminobenzazulenone 1, here named Calmirasone1, as a novel and potent covalent CaM inhibitor. Calmirasone1 has a 4-fold increased affinity for CaM as compared to OphA and was active against K-Ras in cells within minutes, as compared to hours required by OphA. Calmirasone1 displayed a 2.5–4.5-fold higher selectivity for KRAS over BRAF mutant 3D spheroid growth than OphA, suggesting improved relative on-target activity. Importantly, Calmirasone1 has a 40–260-fold lower unspecific toxic effect on HRAS mutant cells, while it reaches almost 50% of the activity of novel K-RasG12C specific inhibitors in 3D spheroid assays. Our results suggest that Calmirasone1 can serve as a new tool compound to further investigate the cancer cell biology of the K-Ras and CaM associated stemness activities.
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Affiliation(s)
- Sunday Okutachi
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Ganesh Babu Manoharan
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Alexandros Kiriazis
- Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Christina Laurini
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Marie Catillon
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Frank McCormick
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, United States.,Frederick National Laboratory for Cancer Research, Cancer Research Technology Program, Leidos Biomedical Research, Inc., National Cancer Institute RAS Initiative, Frederick, MD, United States
| | - Jari Yli-Kauhaluoma
- Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
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Abstract
On the plasma membrane, Ras is organized into laterally segregated proteo-lipid complexes called nanoclusters. The extent of Ras nanoclustering correlates with its signaling output, positioning nanocluster as dynamic signaling gain modulators. Recent evidence suggests that stacked dimers of Ras and Raf are elemental units at least of one type of Ras nanocluster. However, it is still incompletely understood, in which physiological contexts nanoclustering is regulated and which constituents are parts of nanocluster. Nonetheless, disruption of nanoclustering faithfully diminishes Ras activity in cells, suggesting Ras nanocluster as potential drug targets.While there are several methods available to study Ras nanocluster , fluorescence or Förster resonance energy transfer (FRET ) between fluorescently labeled, nanoclustered Ras proteins is a relatively simple readout. FRET measurements using fluorescence lifetime imaging microscopy (FLIM ) have proven to be robust and sensitive to determine Ras nanoclustering changes. Loss of FRET that emerges due to nanoclustering reports on all processes upstream of Ras nanoclustering, i.e., also on proper trafficking or lipid modification of Ras. Here we report our standard FLIM-FRET protocol to measure nanoclustering-dependent FRET of Ras in mammalian cells. Importantly, nanoclustering-dependent FRET is one of the few methods that can detect differences between the Ras isoforms.
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Affiliation(s)
- Hanna Parkkola
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Farid Ahmad Siddiqui
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | | | - Daniel Abankwa
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg.
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10
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Siddiqui FA, Parkkola H, Vukic V, Oetken-Lindholm C, Jaiswal A, Kiriazis A, Pavic K, Aittokallio T, Salminen TA, Abankwa D. Novel Small Molecule Hsp90/Cdc37 Interface Inhibitors Indirectly Target K-Ras-Signaling. Cancers (Basel) 2021; 13:927. [PMID: 33672199 PMCID: PMC7927014 DOI: 10.3390/cancers13040927] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/12/2021] [Accepted: 02/17/2021] [Indexed: 12/23/2022] Open
Abstract
The ATP-competitive inhibitors of Hsp90 have been tested predominantly in kinase addicted cancers; however, they have had limited success. A mechanistic connection between Hsp90 and oncogenic K-Ras is not known. Here, we show that K-Ras selectivity is enabled by the loss of the K-Ras membrane nanocluster modulator galectin-3 downstream of the Hsp90 client HIF-1α. This mechanism suggests a higher drug sensitivity in the context of KRAS mutant, HIF-1α-high and/or Gal3-high cancer cells, such as those found, in particular, in pancreatic adenocarcinoma. The low toxicity of conglobatin further indicates a beneficial on-target toxicity profile for Hsp90/Cdc37 interface inhibitors. We therefore computationally screened >7 M compounds, and identified four novel small molecules with activities of 4 μM-44 μM in vitro. All of the compounds were K-Ras selective, and potently decreased the Hsp90 client protein levels without inducing the heat shock response. Moreover, they all inhibited the 2D proliferation of breast, pancreatic, and lung cancer cell lines. The most active compounds from each scaffold, furthermore, significantly blocked 3D spheroids and the growth of K-Ras-dependent microtumors. We foresee new opportunities for improved Hsp90/Cdc37 interface inhibitors in cancer and other aging-associated diseases.
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Affiliation(s)
- Farid Ahmad Siddiqui
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland; (F.A.S.); (H.P.); (V.V.); (C.O.-L.); (A.K.)
| | - Hanna Parkkola
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland; (F.A.S.); (H.P.); (V.V.); (C.O.-L.); (A.K.)
| | - Vladimir Vukic
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland; (F.A.S.); (H.P.); (V.V.); (C.O.-L.); (A.K.)
- Faculty of Technology, University of Novi Sad, 21000 Novi Sad, Serbia
| | - Christina Oetken-Lindholm
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland; (F.A.S.); (H.P.); (V.V.); (C.O.-L.); (A.K.)
| | - Alok Jaiswal
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00014 Helsinki, Finland; (A.J.); (T.A.)
| | - Alexandros Kiriazis
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland; (F.A.S.); (H.P.); (V.V.); (C.O.-L.); (A.K.)
| | - Karolina Pavic
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg;
| | - Tero Aittokallio
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, 00014 Helsinki, Finland; (A.J.); (T.A.)
- Department of Cancer Genetics, Institute for Cancer Research, Oslo University Hospital, N-0310 Oslo, Norway
- Centre for Biostatistics and Epidemiology (OCBE), Faculty of Medicine, University of Oslo, N-0372 Oslo, Norway
| | - Tiina A. Salminen
- Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, 20520 Turku, Finland;
| | - Daniel Abankwa
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland; (F.A.S.); (H.P.); (V.V.); (C.O.-L.); (A.K.)
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg;
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11
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Ahearn IM, Court HR, Siddiqui F, Abankwa D, Philips MR. NRAS is unique among RAS proteins in requiring ICMT for trafficking to the plasma membrane. Life Sci Alliance 2021; 4:4/5/e202000972. [PMID: 33579760 PMCID: PMC7893820 DOI: 10.26508/lsa.202000972] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 12/17/2022] Open
Abstract
Among the RAS isoforms, NRAS uniquely requires carboxyl methylation by ICMT for delivery to the plasma membrane because of having only a single palmitoylation as a second targeting signal. Isoprenylcysteine carboxyl methyltransferase (ICMT) is the third of three enzymes that sequentially modify the C-terminus of CaaX proteins, including RAS. Although all four RAS proteins are substrates for ICMT, each traffics to membranes differently by virtue of their hypervariable regions that are differentially palmitoylated. We found that among RAS proteins, NRAS was unique in requiring ICMT for delivery to the PM, a consequence of having only a single palmitoylation site as its secondary affinity module. Although not absolutely required for palmitoylation, acylation was diminished in the absence of ICMT. Photoactivation and FRAP of GFP-NRAS revealed increase flux at the Golgi, independent of palmitoylation, in the absence of ICMT. Association of NRAS with the prenyl-protein chaperone PDE6δ also required ICMT and promoted anterograde trafficking from the Golgi. We conclude that carboxyl methylation of NRAS is required for efficient palmitoylation, PDE6δ binding, and homeostatic flux through the Golgi, processes that direct delivery to the plasma membrane.
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Affiliation(s)
- Ian M Ahearn
- The Ronald O Perelman Department of Dermatology, New York University Grossman School of Medicine, New York, NY, USA .,The Perlmutter Cancer Center, New York University Langone Medical Center, New York, NY, USA.,Veterans Affairs New York Harbor Healthcare System, Manhattan Campus, New York, NY, USA
| | - Helen R Court
- The Perlmutter Cancer Center, New York University Langone Medical Center, New York, NY, USA
| | - Farid Siddiqui
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Daniel Abankwa
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.,Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Mark R Philips
- The Perlmutter Cancer Center, New York University Langone Medical Center, New York, NY, USA
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12
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Rosenqvist P, Sabt A, Dyunyasheva V, Abankwa D, Virta P, Ora M. Stability of the Phosphotriester PDE6D Inhibitors. ChemistrySelect 2021. [DOI: 10.1002/slct.202004426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Petja Rosenqvist
- Department of Chemistry University of Turku FI- 20014 Turku Finland
| | - Ahmed Sabt
- Chemistry of Natural Compounds Department National Research Centre Dokki 12622 Giza Egypt
| | | | - Daniel Abankwa
- Department of Life Sciences and Medicine University of Luxembourg 4362 Esch-sur-Alzette Luxembourg
| | - Pasi Virta
- Department of Chemistry University of Turku FI- 20014 Turku Finland
| | - Mikko Ora
- Department of Chemistry University of Turku FI- 20014 Turku Finland
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13
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Abstract
Ras is the most frequently mutated oncogene and recent drug development efforts have spurred significant new research interest. Here we review progress toward understanding how Ras functions in nanoscale, proteo-lipid signaling complexes on the plasma membrane, called nanoclusters. We discuss how G-domain reorientation is plausibly linked to Ras-nanoclustering and -dimerization. We then look at how these mechanistic features could cooperate in the engagement and activation of RAF by Ras. Moreover, we show how this structural information can be integrated with microscopy data that provide nanoscale resolution in cell biological experiments. Synthesizing the available data, we propose to distinguish between two types of Ras nanoclusters, an active, immobile RAF-dependent type and an inactive/neutral membrane anchor-dependent. We conclude that it is possible that Ras reorientation enables dynamic Ras dimerization while the whole Ras/RAF complex transits into an active state. These transient di/oligomer interfaces of Ras may be amenable to pharmacological intervention. We close by highlighting a number of open questions including whether all effectors form active nanoclusters and whether there is an isoform specific composition of Ras nanocluster.
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Affiliation(s)
- Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Department of Life Sciences and Medicine, University of Luxembourg, Esch-sur-Alzette 4362, Luxembourg
| | - Alemayehu A. Gorfe
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin St., Houston, TX 77030, USA
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14
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Yurugi H, Zhuang Y, Siddiqui FA, Liang H, Rosigkeit S, Zeng Y, Abou-Hamdan H, Bockamp E, Zhou Y, Abankwa D, Zhao W, Désaubry L, Rajalingam K. A subset of flavaglines inhibits KRAS nanoclustering and activation. J Cell Sci 2020; 133:jcs244111. [PMID: 32501281 DOI: 10.1242/jcs.244111] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/30/2020] [Indexed: 08/31/2023] Open
Abstract
The RAS oncogenes are frequently mutated in human cancers and among the three isoforms (KRAS, HRAS and NRAS), KRAS is the most frequently mutated oncogene. Here, we demonstrate that a subset of flavaglines, a class of natural anti-tumour drugs and chemical ligands of prohibitins, inhibit RAS GTP loading and oncogene activation in cells at nanomolar concentrations. Treatment with rocaglamide, the first discovered flavagline, inhibited the nanoclustering of KRAS, but not HRAS and NRAS, at specific phospholipid-enriched plasma membrane domains. We further demonstrate that plasma membrane-associated prohibitins directly interact with KRAS, phosphatidylserine and phosphatidic acid, and these interactions are disrupted by rocaglamide but not by the structurally related flavagline FL1. Depletion of prohibitin-1 phenocopied the rocaglamide-mediated effects on KRAS activation and stability. We also demonstrate that flavaglines inhibit the oncogenic growth of KRAS-mutated cells and that treatment with rocaglamide reduces non-small-cell lung carcinoma (NSCLC) tumour nodules in autochthonous KRAS-driven mouse models without severe side effects. Our data suggest that it will be promising to further develop flavagline derivatives as specific KRAS inhibitors for clinical applications.
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Affiliation(s)
- Hajime Yurugi
- Cell Biology Unit, University Medical Center Mainz, Johannes Gutenberg University, D 55131 Mainz, Germany
| | - Yinyin Zhuang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637457 Singapore
| | - Farid A Siddiqui
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, Mcgovern Medical School, UT Health, 6431 Fannin St. MSE R382, Houston, TX 77030, USA
| | - Sebastian Rosigkeit
- Cell Biology Unit, University Medical Center Mainz, Johannes Gutenberg University, D 55131 Mainz, Germany
| | - Yongpeng Zeng
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637457 Singapore
| | - Hussein Abou-Hamdan
- Therapeutic Laboratory of Cardio-Oncology and Medicinal Chemistry (FRE 2033), CNRS, University of Strasbourg, 4 rue Blaise Pascal, CS 90032, 67081 Strasbourg, France
| | - Ernesto Bockamp
- Institute for Translational Immunology and Research Center for Immunotherapy, University Medical Center, Johannes Gutenberg University, D 55131 Mainz, Germany
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, Mcgovern Medical School, UT Health, 6431 Fannin St. MSE R382, Houston, TX 77030, USA
| | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
- Cancer Cell Biology and Drug Discovery Group, Life Sciences Research Unit University of Luxembourg, L 4362 Esch-sur-Alzette, Luxembourg
| | - Wenting Zhao
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637457 Singapore
| | - Laurent Désaubry
- Therapeutic Laboratory of Cardio-Oncology and Medicinal Chemistry (FRE 2033), CNRS, University of Strasbourg, 4 rue Blaise Pascal, CS 90032, 67081 Strasbourg, France
| | - Krishnaraj Rajalingam
- Cell Biology Unit, University Medical Center Mainz, Johannes Gutenberg University, D 55131 Mainz, Germany
- University Cancer Center Mainz, University Medical Center Mainz, D 55131 Mainz, Germany
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15
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Siddiqui F, Alam C, Rosenqvist P, Ora M, Sabt A, Manoharan GB, Bindu L, Okutachi S, Catillon M, Taylor T, Abdelhafez OM, Lönnberg H, Stephen AG, Papageorgiou AC, Virta P, Abankwa D. PDE6D Inhibitors with a New Design Principle Selectively Block K-Ras Activity. ACS Omega 2020; 5:832-842. [PMID: 31956834 PMCID: PMC6964506 DOI: 10.1021/acsomega.9b03639] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/09/2019] [Indexed: 05/12/2023]
Abstract
The trafficking chaperone PDE6D (also referred to as PDEδ) has been nominated as a surrogate target for K-Ras4B (hereafter K-Ras). Arl2-assisted unloading of K-Ras from PDE6D in the perinuclear area is significant for correct K-Ras localization and therefore activity. However, the unloading mechanism also leads to the undesired ejection of PDE6D inhibitors. To counteract ejection, others have recently optimized inhibitors for picomolar affinities; however, cell penetration generally seems to remain an issue. To increase resilience against ejection, we engineered a "chemical spring" into prenyl-binding pocket inhibitors of PDE6D. Furthermore, cell penetration was improved by attaching a cell-penetration group, allowing us to arrive at micromolar in cellulo potencies in the first generation. Our model compounds, Deltaflexin-1 and -2, selectively disrupt K-Ras, but not H-Ras membrane organization. This selectivity profile is reflected in the antiproliferative activity on colorectal and breast cancer cells, as well as the ability to block stemness traits of lung and breast cancer cells. While our current model compounds still have a low in vitro potency, we expect that our modular and simple inhibitor redesign could significantly advance the development of pharmacologically more potent compounds against PDE6D and related targets, such as UNC119 in the future.
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Affiliation(s)
- Farid
A. Siddiqui
- Turku
Bioscience Centre, University of Turku and
Åbo Akademi University, 20520 Turku, Finland
| | - Catharina Alam
- Turku
Bioscience Centre, University of Turku and
Åbo Akademi University, 20520 Turku, Finland
| | - Petja Rosenqvist
- Department
of Chemistry, University of Turku, 20014 Turku, Finland
| | - Mikko Ora
- Department
of Chemistry, University of Turku, 20014 Turku, Finland
| | - Ahmed Sabt
- Department
of Chemistry, University of Turku, 20014 Turku, Finland
- Chemistry
of Natural Compounds Department, National
Research Centre, Dokki, 12622 Giza, Egypt
| | - Ganesh babu Manoharan
- Cancer
Cell Biology and Drug Discovery Group, Life Sciences Research Unit, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg
| | - Lakshman Bindu
- NCI
RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, 21702 Frederick, Maryland, United States
| | - Sunday Okutachi
- Cancer
Cell Biology and Drug Discovery Group, Life Sciences Research Unit, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg
| | - Marie Catillon
- Cancer
Cell Biology and Drug Discovery Group, Life Sciences Research Unit, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg
| | - Troy Taylor
- NCI
RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, 21702 Frederick, Maryland, United States
| | - Omaima M. Abdelhafez
- Chemistry
of Natural Compounds Department, National
Research Centre, Dokki, 12622 Giza, Egypt
| | - Harri Lönnberg
- Department
of Chemistry, University of Turku, 20014 Turku, Finland
| | - Andrew G. Stephen
- NCI
RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, 21702 Frederick, Maryland, United States
| | | | - Pasi Virta
- Department
of Chemistry, University of Turku, 20014 Turku, Finland
| | - Daniel Abankwa
- Turku
Bioscience Centre, University of Turku and
Åbo Akademi University, 20520 Turku, Finland
- Cancer
Cell Biology and Drug Discovery Group, Life Sciences Research Unit, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg
- E-mail:
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16
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Siddiqui FA, Parkkola H, Manoharan GB, Abankwa D. Medium-Throughput Detection of Hsp90/Cdc37 Protein-Protein Interaction Inhibitors Using a Split Renilla Luciferase-Based Assay. SLAS Discov 2019; 25:195-206. [PMID: 31662027 DOI: 10.1177/2472555219884033] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The protein-folding chaperone Hsp90 enables the maturation and stability of various oncogenic signaling proteins and is thus pursued as a cancer drug target. Folding in particular of protein kinases is assisted by the co-chaperone Cdc37. Several inhibitors against the Hsp90 ATP-binding site have been developed. However, they displayed significant toxicity in clinical trials. By contrast, the natural product conglobatin A has an exceptionally low toxicity in mice. It targets the protein-protein interface (PPI) of Hsp90 and Cdc37, suggesting that interface inhibitors have an interesting drug development potential. In order to identify inhibitors of the Hsp90/Cdc37 PPI, we have established a mammalian cell lysate-based, medium-throughput amenable split Renilla luciferase assay. This assay employs N-terminal and C-terminal fragments of Renilla luciferase fused to full-length human Hsp90 and Cdc37, respectively. We expect that our assay will allow for the identification of novel Hsp90/Cdc37 interaction inhibitors. Such tool compounds will help to evaluate whether the toxicity profile of Hsp90/Cdc37 PPI inhibitors is in general more favorable than that of ATP-competitive Hsp90 inhibitors. Further development of such tool compounds may lead to new classes of Hsp90 inhibitors with applications in cancer and other diseases.
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Affiliation(s)
- Farid Ahmad Siddiqui
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Hanna Parkkola
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
| | - Ganesh Babu Manoharan
- Cancer Cell Biology and Drug Discovery Group, Life Sciences Research Unit, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Daniel Abankwa
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland.,Cancer Cell Biology and Drug Discovery Group, Life Sciences Research Unit, University of Luxembourg, Esch-sur-Alzette, Luxembourg
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17
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Manoharan GB, Kopra K, Eskonen V, Härmä H, Abankwa D. High-throughput amenable fluorescence-assays to screen for calmodulin-inhibitors. Anal Biochem 2019; 572:25-32. [PMID: 30825429 DOI: 10.1016/j.ab.2019.02.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/21/2019] [Accepted: 02/17/2019] [Indexed: 12/12/2022]
Abstract
The KRAS gene is highly mutated in human cancers and the focus of current Ras drug development efforts. Recently the interface between the C-terminus of K-Ras and calmodulin (CaM) was proposed as a target site to block K-Ras driven cancer cell stemness. We therefore aimed at developing a high-throughput amenable screening assay to identify novel CaM-inhibitors as potential K-Ras stemness-signaling disruptors. A modulated time-resolved Förster resonance energy transfer (mTR-FRET)-assay was developed and benchmarked against an identically designed fluorescence anisotropy (FA)-assay. In both assays, two CaM-binding peptides were labeled with Eu(III)-chelate or fluorescein and used as single-label reporter probes that were displaced from CaM upon competitor binding. Thus, peptidic and small molecule competitors with nanomolar to micromolar affinities to CaM could be detected, including a peptide that was derived from the C-terminus of K-Ras. In order to detect CaM-residue specific covalent inhibitors, a cell lysate-based Förster resonance energy transfer (FRET)-assay was furthermore established. This assay enabled us to measure the slow, residue-specific, covalent inhibition by ophiobolin A in the presence of other endogenous proteins. In conclusion, we have developed a panel of fluorescence-assays that allows identification of conventional and covalent CaM-inhibitors as potential disruptors of K-Ras driven cancer cell stemness.
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Affiliation(s)
- Ganesh Babu Manoharan
- Cancer Cell Biology and Drug Discovery Group, Life Sciences Research Unit, University of Luxembourg, 4362, Esch-sur-Alzette, Luxembourg; Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520, Turku, Finland
| | - Kari Kopra
- Materials Chemistry and Chemical Analysis, University of Turku, 20500, Turku, Finland
| | - Ville Eskonen
- Materials Chemistry and Chemical Analysis, University of Turku, 20500, Turku, Finland
| | - Harri Härmä
- Materials Chemistry and Chemical Analysis, University of Turku, 20500, Turku, Finland
| | - Daniel Abankwa
- Cancer Cell Biology and Drug Discovery Group, Life Sciences Research Unit, University of Luxembourg, 4362, Esch-sur-Alzette, Luxembourg; Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20520, Turku, Finland.
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18
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Buehler U, Schulenburg K, Yurugi H, Šolman M, Abankwa D, Ulges A, Tenzer S, Bopp T, Thiede B, Zipp F, Rajalingam K. Targeting prohibitins at the cell surface prevents Th17-mediated autoimmunity. EMBO J 2018; 37:embj.201899429. [PMID: 30049713 DOI: 10.15252/embj.201899429] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 05/31/2018] [Accepted: 06/21/2018] [Indexed: 12/25/2022] Open
Abstract
T helper (Th)17 cells represent a unique subset of CD4+ T cells and are vital for clearance of extracellular pathogens including bacteria and fungi. However, Th17 cells are also involved in orchestrating autoimmunity. By employing quantitative surface proteomics, we found that the evolutionarily conserved prohibitins (PHB1/2) are highly expressed on the surface of both murine and human Th17 cells. Increased expression of PHBs at the cell surface contributed to enhanced CRAF/MAPK activation in Th17 cells. Targeting surface-expressed PHBs on Th17 cells with ligands such as Vi polysaccharide (Typhim vaccine) inhibited CRAF-MAPK pathway, reduced interleukin (IL)-17 expression and ameliorated disease pathology with an increase in FOXP3+-expressing Tregs in an animal model for multiple sclerosis (MS). Interestingly, we detected a CD4+ T cell population with high PHB1 surface expression in blood samples from MS patients in comparison with age- and sex-matched healthy subjects. Our observations suggest a pivotal role for the PHB-CRAF-MAPK signalling axis in regulating the polarization and pathogenicity of Th17 cells and unveil druggable targets in autoimmune disorders such as MS.
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Affiliation(s)
- Ulrike Buehler
- Department of Neurology, Focus Program Translational Neurosciences (FTN) and Research Center for Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn²), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Katharina Schulenburg
- Cell Biology Unit, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Hajime Yurugi
- Cell Biology Unit, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Maja Šolman
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland.,Cancer Cell Biology and Drug Discovery Group, Life Sciences Research Unit University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | - Alexander Ulges
- Institute of Immunology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Tobias Bopp
- Institute of Immunology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Bernd Thiede
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Frauke Zipp
- Department of Neurology, Focus Program Translational Neurosciences (FTN) and Research Center for Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn²), University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Krishnaraj Rajalingam
- Cell Biology Unit, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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19
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Sahlgren C, Meinander A, Zhang H, Cheng F, Preis M, Xu C, Salminen TA, Toivola D, Abankwa D, Rosling A, Karaman DŞ, Salo-Ahen OMH, Österbacka R, Eriksson JE, Willför S, Petre I, Peltonen J, Leino R, Johnson M, Rosenholm J, Sandler N. Tailored Approaches in Drug Development and Diagnostics: From Molecular Design to Biological Model Systems. Adv Healthc Mater 2017; 6. [PMID: 28892296 DOI: 10.1002/adhm.201700258] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 05/04/2017] [Indexed: 12/13/2022]
Abstract
Approaches to increase the efficiency in developing drugs and diagnostics tools, including new drug delivery and diagnostic technologies, are needed for improved diagnosis and treatment of major diseases and health problems such as cancer, inflammatory diseases, chronic wounds, and antibiotic resistance. Development within several areas of research ranging from computational sciences, material sciences, bioengineering to biomedical sciences and bioimaging is needed to realize innovative drug development and diagnostic (DDD) approaches. Here, an overview of recent progresses within key areas that can provide customizable solutions to improve processes and the approaches taken within DDD is provided. Due to the broadness of the area, unfortunately all relevant aspects such as pharmacokinetics of bioactive molecules and delivery systems cannot be covered. Tailored approaches within (i) bioinformatics and computer-aided drug design, (ii) nanotechnology, (iii) novel materials and technologies for drug delivery and diagnostic systems, and (iv) disease models to predict safety and efficacy of medicines under development are focused on. Current developments and challenges ahead are discussed. The broad scope reflects the multidisciplinary nature of the field of DDD and aims to highlight the convergence of biological, pharmaceutical, and medical disciplines needed to meet the societal challenges of the 21st century.
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Affiliation(s)
- Cecilia Sahlgren
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
- Turku Centre for Biotechnology; Åbo Akademi University and University of Turku; FI-20520 Turku Finland
- Department of Biomedical Engineering; Technical University of Eindhoven; 5613 DR Eindhoven Netherlands
| | - Annika Meinander
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
| | - Hongbo Zhang
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Fang Cheng
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
| | - Maren Preis
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Chunlin Xu
- Faculty of Science and Engineering; Natural Materials Technology; Åbo Akademi University; FI-20500 Turku Finland
| | - Tiina A. Salminen
- Faculty of Science and Engineering; Structural Bioinformatics Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Diana Toivola
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
- Turku Center for Disease Modeling; University of Turku; FI-20520 Turku Finland
| | - Daniel Abankwa
- Department of Biomedical Engineering; Technical University of Eindhoven; 5613 DR Eindhoven Netherlands
| | - Ari Rosling
- Faculty of Science and Engineering; Polymer Technologies; Åbo Akademi University; FI-20500 Turku Finland
| | - Didem Şen Karaman
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Outi M. H. Salo-Ahen
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
- Faculty of Science and Engineering; Structural Bioinformatics Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Ronald Österbacka
- Faculty of Science and Engineering; Physics; Åbo Akademi University; FI-20500 Turku Finland
| | - John E. Eriksson
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
- Turku Centre for Biotechnology; Åbo Akademi University and University of Turku; FI-20520 Turku Finland
| | - Stefan Willför
- Faculty of Science and Engineering; Natural Materials Technology; Åbo Akademi University; FI-20500 Turku Finland
| | - Ion Petre
- Faculty of Science and Engineering; Computer Science; Åbo Akademi University; FI-20500 Turku Finland
| | - Jouko Peltonen
- Faculty of Science and Engineering; Physical Chemistry; Åbo Akademi University; FI-20500 Turku Finland
| | - Reko Leino
- Faculty of Science and Engineering; Organic Chemistry; Johan Gadolin Process Chemistry Centre; Åbo Akademi University; FI-20500 Turku Finland
| | - Mark Johnson
- Faculty of Science and Engineering; Structural Bioinformatics Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Jessica Rosenholm
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Niklas Sandler
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
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20
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Sahlgren C, Meinander A, Zhang H, Cheng F, Preis M, Xu C, Salminen TA, Toivola D, Abankwa D, Rosling A, Karaman DŞ, Salo-Ahen OMH, Österbacka R, Eriksson JE, Willför S, Petre I, Peltonen J, Leino R, Johnson M, Rosenholm J, Sandler N. Tailored Approaches in Drug Development and Diagnostics: From Molecular Design to Biological Model Systems. Adv Healthc Mater 2017. [DOI: 10.1002/adhm.201700258 10.1002/adhm.201700258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Affiliation(s)
- Cecilia Sahlgren
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
- Turku Centre for Biotechnology; Åbo Akademi University and University of Turku; FI-20520 Turku Finland
- Department of Biomedical Engineering; Technical University of Eindhoven; 5613 DR Eindhoven Netherlands
| | - Annika Meinander
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
| | - Hongbo Zhang
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Fang Cheng
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
| | - Maren Preis
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Chunlin Xu
- Faculty of Science and Engineering; Natural Materials Technology; Åbo Akademi University; FI-20500 Turku Finland
| | - Tiina A. Salminen
- Faculty of Science and Engineering; Structural Bioinformatics Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Diana Toivola
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
- Turku Center for Disease Modeling; University of Turku; FI-20520 Turku Finland
| | - Daniel Abankwa
- Department of Biomedical Engineering; Technical University of Eindhoven; 5613 DR Eindhoven Netherlands
| | - Ari Rosling
- Faculty of Science and Engineering; Polymer Technologies; Åbo Akademi University; FI-20500 Turku Finland
| | - Didem Şen Karaman
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Outi M. H. Salo-Ahen
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
- Faculty of Science and Engineering; Structural Bioinformatics Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Ronald Österbacka
- Faculty of Science and Engineering; Physics; Åbo Akademi University; FI-20500 Turku Finland
| | - John E. Eriksson
- Faculty of Science and Engineering; Cell Biology; Åbo Akademi University; FI-20520 Turku Finland
- Turku Centre for Biotechnology; Åbo Akademi University and University of Turku; FI-20520 Turku Finland
| | - Stefan Willför
- Faculty of Science and Engineering; Natural Materials Technology; Åbo Akademi University; FI-20500 Turku Finland
| | - Ion Petre
- Faculty of Science and Engineering; Computer Science; Åbo Akademi University; FI-20500 Turku Finland
| | - Jouko Peltonen
- Faculty of Science and Engineering; Physical Chemistry; Åbo Akademi University; FI-20500 Turku Finland
| | - Reko Leino
- Faculty of Science and Engineering; Organic Chemistry; Johan Gadolin Process Chemistry Centre; Åbo Akademi University; FI-20500 Turku Finland
| | - Mark Johnson
- Faculty of Science and Engineering; Structural Bioinformatics Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Jessica Rosenholm
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
| | - Niklas Sandler
- Faculty of Science and Engineering; Pharmaceutical Sciences Laboratory; Åbo Akademi University; FI-20520 Turku Finland
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Posada IMD, Lectez B, Siddiqui FA, Oetken-Lindholm C, Sharma M, Abankwa D. Opposite feedback from mTORC1 to H-ras and K-ras4B downstream of SREBP1. Sci Rep 2017; 7:8944. [PMID: 28827765 PMCID: PMC5567141 DOI: 10.1038/s41598-017-09387-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/26/2017] [Indexed: 01/12/2023] Open
Abstract
As a major growth factor transducer, Ras is an upstream activator of mTORC1, which further integrates nutrient and energy inputs. To ensure a contextual coupling of cell division via Ras/MAPK-signalling and growth via mTORC1-signalling, feedback loops from one pathway back to the other are required. Here we describe a novel feedback from mTORC1, which oppositely affects oncogenic H-ras- and K-ras-signalling output, and as a consequence stemness properties of tumourigenic cells. Amino acid stimulation of mTORC1 increases the processed form of SREBP1, a major lipidome regulator. We show that modulation of the SREBP1 levels downstream of S6K1 has opposite effects on oncogenic H-ras and K-ras nanoscale membrane organisation, ensuing signalling output and promotion of mammospheres expressing these oncogenes. Our data suggest that modulation of phosphatidic acid, a major target of SREBP1 controlled lipid metabolism, is sufficient to affect H-ras and K-ras oppositely in the membrane. Thus mTORC1 activation increases H-ras-, but decreases K-ras-signalling output in cells transformed with the respective oncogene. Given the different impact of these two Ras isoforms on stemness, our results could have implications for stem cell biology and inhibition of cancer stem cells.
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Affiliation(s)
- Itziar M D Posada
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
| | - Benoit Lectez
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
| | - Farid A Siddiqui
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
| | | | - Mukund Sharma
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
| | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland.
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Posada IM, Lectez B, Sharma M, Oetken-Lindholm C, Yetukuri L, Zhou Y, Aittokallio T, Abankwa D. Rapalogs can promote cancer cell stemness in vitro in a Galectin-1 and H-ras-dependent manner. Oncotarget 2017; 8:44550-44566. [PMID: 28562352 PMCID: PMC5546501 DOI: 10.18632/oncotarget.17819] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 04/22/2017] [Indexed: 01/05/2023] Open
Abstract
Currently several combination treatments of mTor- and Ras-pathway inhibitors are being tested in cancer therapy. While multiple feedback loops render these central signaling pathways robust, they complicate drug targeting.Here, we describe a novel H-ras specific feedback, which leads to an inadvertent rapalog induced activation of tumorigenicity in Ras transformed cells. We find that rapalogs specifically increase nanoscale clustering (nanoclustering) of oncogenic H-ras but not K-ras on the plasma membrane. This increases H-ras signaling output, promotes mammosphere numbers in a H-ras-dependent manner and tumor growth in ovo. Surprisingly, also other FKBP12 binders, but not mTor-inhibitors, robustly decrease FKBP12 levels after prolonged (>2 days) exposure. This leads to an upregulation of the nanocluster scaffold galectin-1 (Gal-1), which is responsible for the rapamycin-induced increase in H-ras nanoclustering and signaling output. We provide evidence that Gal-1 promotes stemness features in tumorigenic cells. Therefore, it may be necessary to block inadvertent induction of stemness traits in H-ras transformed cells by specific Gal-1 inhibitors that abrogate its effect on H-ras nanocluster. On a more general level, our findings may add an important mechanistic explanation to the pleiotropic physiological effects that are observed with rapalogs.
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Affiliation(s)
- Itziar M.D. Posada
- Turku Center for Biotechnology, Åbo Akademi University, Tykistökatu 6B, Turku, Finland
| | - Benoit Lectez
- Turku Center for Biotechnology, Åbo Akademi University, Tykistökatu 6B, Turku, Finland
| | - Mukund Sharma
- Turku Center for Biotechnology, Åbo Akademi University, Tykistökatu 6B, Turku, Finland
| | | | - Laxman Yetukuri
- Turku Center for Biotechnology, Åbo Akademi University, Tykistökatu 6B, Turku, Finland
- Institute for Molecular Medicine Finland, FIMM, University of Helsinki, Helsinki, Finland
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas, United States of America
| | - Tero Aittokallio
- Institute for Molecular Medicine Finland, FIMM, University of Helsinki, Helsinki, Finland
- Department of Mathematics and Statistics, University of Turku, Turku, Finland
| | - Daniel Abankwa
- Turku Center for Biotechnology, Åbo Akademi University, Tykistökatu 6B, Turku, Finland
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23
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Najumudeen AK, Jaiswal A, Lectez B, Oetken-Lindholm C, Guzmán C, Siljamäki E, Posada IMD, Lacey E, Aittokallio T, Abankwa D. Cancer stem cell drugs target K-ras signaling in a stemness context. Oncogene 2016; 35:5248-5262. [PMID: 26973241 PMCID: PMC5057041 DOI: 10.1038/onc.2016.59] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 01/02/2023]
Abstract
Cancer stem cells (CSCs) are considered to be responsible for treatment relapse and have therefore become a major target in cancer research. Salinomycin is the most established CSC inhibitor. However, its primary mechanistic target is still unclear, impeding the discovery of compounds with similar anti-CSC activity. Here, we show that salinomycin very specifically interferes with the activity of K-ras4B, but not H-ras, by disrupting its nanoscale membrane organization. We found that caveolae negatively regulate the sensitivity to this drug. On the basis of this novel mechanistic insight, we defined a K-ras-associated and stem cell-derived gene expression signature that predicts the drug response of cancer cells to salinomycin. Consistent with therapy resistance of CSC, 8% of tumor samples in the TCGA-database displayed our signature and were associated with a significantly higher mortality. Using our K-ras-specific screening platform, we identified several new candidate CSC drugs. Two of these, ophiobolin A and conglobatin A, possessed a similar or higher potency than salinomycin. Finally, we established that the most potent compound, ophiobolin A, exerts its K-ras4B-specific activity through inactivation of calmodulin. Our data suggest that specific interference with the K-ras4B/calmodulin interaction selectively inhibits CSC.
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Affiliation(s)
- A K Najumudeen
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - A Jaiswal
- Institute for Molecular Medicine Finland, FIMM, University of Helsinki, Helsinki, Finland
| | - B Lectez
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - C Oetken-Lindholm
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - C Guzmán
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - E Siljamäki
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - I M D Posada
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - E Lacey
- Microbial Screening Technologies Pty. Ltd., Building C, Smithfield, New South Wales, Australia
| | - T Aittokallio
- Institute for Molecular Medicine Finland, FIMM, University of Helsinki, Helsinki, Finland
| | - D Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
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Abstract
Ras-induced senescence mediated through ASPP2 represents a barrier to tumour formation. It is initiated by ASPP2’s interaction with Ras at the plasma membrane, which stimulates the Raf/MEK/ERK signaling cascade. Ras to Raf signalling requires Ras to be organized in nanoscale signalling complexes, called nanocluster. We therefore wanted to investigate whether ASPP2 affects Ras nanoclustering. Here we show that ASPP2 increases the nanoscale clustering of all oncogenic Ras isoforms, H-ras, K-ras and N-ras. Structure-function analysis with ASPP2 truncation mutants suggests that the nanocluster scaffolding activity of ASPP2 converges on its α-helical domain. While ASPP2 increased effector recruitment and stimulated ERK and AKT phosphorylation, it did not increase colony formation of RasG12V transformed NIH/3T3 cells. By contrast, ASPP2 was able to suppress the transformation enhancing ability of the nanocluster scaffold Gal-1, by competing with the specific effect of Gal-1 on H-rasG12V- and K-rasG12V-nanoclustering, thus imposing ASPP2’s ERK and AKT signalling signature. Similarly, ASPP2 robustly induced senescence and strongly abrogated mammosphere formation irrespective of whether it was expressed alone or together with Gal-1, which by itself showed the opposite effect in Ras wt or H-ras mutant breast cancer cells. Our results suggest that Gal-1 and ASPP2 functionally compete in nanocluster for active Ras on the plasma membrane. ASPP2 dominates the biological outcome, thus switching from a Gal-1 supported growth-promoting setting to a senescence inducing and stemness suppressive program in cancer cells. Our results support Ras nanocluster as major integrators of tumour fate decision events.
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Affiliation(s)
- Itziar M. D. Posada
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
| | - Marc Serulla
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
| | - Yong Zhou
- University of Texas Health Science Center at Houston, Medical School, Houston, Texas, United States of America
| | | | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
- * E-mail:
| | - Benoît Lectez
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
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Posada IMD, Lectez B, Oetken-Lindholm C, Abankwa D. Abstract 1877: A new H-ras specific feedback loop from the TOR-pathway impacts on tumorigenicity. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-1877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction:
The lack of direct Ras inhibitors, has led to the development of inhibitors of downstream components of the Ras pathway albeit with mixed success. Unexpected mechanistic complexity, feedback loops and tumor specific synthetically lethal requirements continue to be major obstacles. In the past we investigated the mechanisms of the Ras membrane signaling system on the nanoscale (nanoclustering). Ras nanoclustering on the plasma membrane is critical for its signaling activity and we and others recently showed how it is exploited in a number of physiological and pathophysiological conditions, including cancer. Importantly, Ras isoform specificity seems to emerge at the level of laterally segregated nanocluster. This is supported by isoform specific nanocluster scaffolds, such as galectin-1 (Gal-1), which specifically augments GTP-H-ras nanocluster.
Methods:
The effect of compounds and siRNAs targeting the TOR pathway and associated proteins on H- vs. K-ras4B (hereafter K-ras)-nanoclustering was evaluated using FRET-measurements in BHK and HEK cells, or point pattern analysis of electron micrographs from BHK cell plasma membrane sheets. Ras specific effects of treatments were furthermore assessed in PC12 differentiation assays, driven by oncogenic H- or K-ras. Changes in downstream signaling were evaluated using Western Blotting of treated BHK and HEK cells. The effect of treatments (compounds or siRNAs) on mammosphere formation was assessed in MDA-MB-231 cells.
Results:
Here we describe a new feedback mechanism from the TOR-pathway specifically to H-ras, but not K-ras. Inhibition of FKBP12 inhibitors cycloheximide (CHX), Rapamycin (Rapa) and FK506, as well as knockdown of FKBP12 specifically increased H-ras nanoclustering. While all compounds could also specifically increase differentiation of H- but not K-rasG12V transfected PC12 cells, their effect on cellular signaling pathways differed in BHK cells. Both, CHX and Rapa increased Erk phosphorylation, but only Rapa blocked S6K and S6 phosphorylation, while CHX did the opposite. Surprisingly, siRNA-mediated ablation of FKBP12 upregulated Gal-1 protein levels, suggesting that the observed increase in H-ras nanoclustering is due to this response. This was however not observed for FKBP12 inhibitors. On the other hand overexpression of Gal-1 also increased FKBP12 levels. Intriguingly, only FKBP12 ablation (with concomitant Gal-1 upregulation) was sufficient to increase the mammosphere forming ability, but not Gal-1 overexpression alone. This effect could be mimicked by FKBP12 inhibition with CHX or Rapa, but not FK506.
Conclusions:
Our data indicate a H-ras specific feedback from inhibition of the TOR pathway, which can lead to increased mammosphere formation. These data suggest a tumor promoting effect by TOR pathway inhibitors via H-ras probably in a specific cellular and genetic context.
Citation Format: Itziar M. D. Posada, Benoit Lectez, Christina Oetken-Lindholm, Daniel Abankwa. A new H-ras specific feedback loop from the TOR-pathway impacts on tumorigenicity. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1877.
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Blaževitš O, Mideksa YG, Šolman M, Ligabue A, Ariotti N, Nakhaeizadeh H, Fansa EK, Papageorgiou AC, Wittinghofer A, Ahmadian MR, Abankwa D. Galectin-1 dimers can scaffold Raf-effectors to increase H-ras nanoclustering. Sci Rep 2016; 6:24165. [PMID: 27087647 PMCID: PMC4834570 DOI: 10.1038/srep24165] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 03/22/2016] [Indexed: 12/12/2022] Open
Abstract
Galectin-1 (Gal-1) dimers crosslink carbohydrates on cell surface receptors. Carbohydrate-derived inhibitors have been developed for cancer treatment. Intracellularly, Gal-1 was suggested to interact with the farnesylated C-terminus of Ras thus specifically stabilizing GTP-H-ras nanoscale signalling hubs in the membrane, termed nanoclusters. The latter activity may present an alternative mechanism for how overexpressed Gal-1 stimulates tumourigenesis. Here we revise the current model for the interaction of Gal-1 with H-ras. We show that it indirectly forms a complex with GTP-H-ras via a high-affinity interaction with the Ras binding domain (RBD) of Ras effectors. A computationally generated model of the Gal-1/C-Raf-RBD complex is validated by mutational analysis. Both cellular FRET as well as proximity ligation assay experiments confirm interaction of Gal-1 with Raf proteins in mammalian cells. Consistently, interference with H-rasG12V-effector interactions basically abolishes H-ras nanoclustering. In addition, an intact dimer interface of Gal-1 is required for it to positively regulate H-rasG12V nanoclustering, but negatively K-rasG12V nanoclustering. Our findings suggest stacked dimers of H-ras, Raf and Gal-1 as building blocks of GTP-H-ras-nanocluster at high Gal-1 levels. Based on our results the Gal-1/effector interface represents a potential drug target site in diseases with aberrant Ras signalling.
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Affiliation(s)
- Olga Blaževitš
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
| | - Yonatan G Mideksa
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
| | - Maja Šolman
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
| | - Alessio Ligabue
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
| | - Nicholas Ariotti
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Hossein Nakhaeizadeh
- Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Eyad K Fansa
- Max Planck Institute for Molecular Physiology, 44227 Dortmund, Germany
| | | | | | - Mohammad R Ahmadian
- Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
| | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
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27
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Brooks AJ, O’Mara ML, Dai W, Abankwa D, Chhabra Y, Tunny KA, Parker MW, Sierecki E, Gambin Y, Gomez GA, Haxholm GW, Nikolajsen LF, Doxastakis M, Mark AE, Waters MJ. Mechanism of JAK2 Activation by the Archetype Class I Cytokine Receptor, the Growth Hormone Receptor. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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28
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Najumudeen AK, Posada IMD, Lectez B, Zhou Y, Landor SKJ, Fallarero A, Vuorela P, Hancock J, Abankwa D. Phenotypic Screening Identifies Protein Synthesis Inhibitors as H-Ras-Nanocluster-Increasing Tumor Growth Inducers. Biochemistry 2015; 54:7212-21. [PMID: 26568031 DOI: 10.1021/acs.biochem.5b00724] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Ras isoforms H-, N-, and K-ras are each mutated in specific cancer types at varying frequencies and have different activities in cell fate control. On the plasma membrane, Ras proteins are laterally segregated into isoform-specific nanoscale signaling hubs, termed nanoclusters. As Ras nanoclusters are required for Ras signaling, chemical modulators of nanoclusters represent ideal candidates for the specific modulation of Ras activity in cancer drug development. We therefore conducted a chemical screen with commercial and in-house natural product libraries using a cell-based H-ras-nanoclustering FRET assay. Next to established Ras inhibitors, such as a statin and farnesyl-transferase inhibitor, we surprisingly identified five protein synthesis inhibitors as positive regulators. Using commonly employed cycloheximide as a representative compound, we show that protein synthesis inhibition increased nanoclustering and effector recruitment specifically of active H-ras but not of K-ras. Consistent with these data, cycloheximide treatment activated both Erk and Akt kinases and specifically promoted H-rasG12V-induced, but not K-rasG12V-induced, PC12 cell differentiation. Intriguingly, cycloheximide increased the number of mammospheres, which are enriched for cancer stem cells. Depletion of H-ras in combination with cycloheximide significantly reduced mammosphere formation, suggesting an exquisite synthetic lethality. The potential of cycloheximide to promote tumor cell growth was also reflected in its ability to increase breast cancer cell tumors grown in ovo. These results illustrate the possibility of identifying Ras-isoform-specific modulators using nanocluster-directed screening. They also suggest an unexpected feedback from protein synthesis inhibition to Ras signaling, which might present a vulnerability in certain tumor cell types.
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Affiliation(s)
- Arafath K Najumudeen
- Turku Centre for Biotechnology, Åbo Akademi University , Tykistökatu 6B, 20520 Turku, Finland
| | - Itziar M D Posada
- Turku Centre for Biotechnology, Åbo Akademi University , Tykistökatu 6B, 20520 Turku, Finland
| | - Benoit Lectez
- Turku Centre for Biotechnology, Åbo Akademi University , Tykistökatu 6B, 20520 Turku, Finland
| | - Yong Zhou
- University of Texas Health Science Center at Houston , Medical School, Houston, Texas 77030, United States
| | - Sebastian K-J Landor
- Turku Centre for Biotechnology, Åbo Akademi University , Tykistökatu 6B, 20520 Turku, Finland.,Department of Cell and Molecular Biology (CMB), Karolinska Institutet , SE-171 77 Stockholm, Sweden
| | - Adyary Fallarero
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki , FI-00014 Helsinki, Finland
| | - Pia Vuorela
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki , FI-00014 Helsinki, Finland
| | - John Hancock
- University of Texas Health Science Center at Houston , Medical School, Houston, Texas 77030, United States
| | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University , Tykistökatu 6B, 20520 Turku, Finland
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Guzmán C, Oetken-Lindholm C, Abankwa D. Automated High-Throughput Fluorescence Lifetime Imaging Microscopy to Detect Protein-Protein Interactions. ACTA ACUST UNITED AC 2015; 21:238-45. [PMID: 26384400 DOI: 10.1177/2211068215606048] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Indexed: 11/16/2022]
Abstract
Fluorescence resonance energy transfer (FRET) is widely used to study conformational changes of macromolecules and protein-protein, protein-nucleic acid, and protein-small molecule interactions. FRET biosensors can serve as valuable secondary assays in drug discovery and for target validation in mammalian cells. Fluorescence lifetime imaging microscopy (FLIM) allows precise quantification of the FRET efficiency in intact cells, as FLIM is independent of fluorophore concentration, detection efficiency, and fluorescence intensity. We have developed an automated FLIM system using a commercial frequency domain FLIM attachment (Lambert Instruments) for wide-field imaging. Our automated FLIM system is capable of imaging and analyzing up to 50 different positions of a slide in less than 4 min, or the inner 60 wells of a 96-well plate in less than 20 min. Automation is achieved using a motorized stage and controller (Prior Scientific) coupled with a Zeiss Axio Observer body and full integration into the Lambert Instruments FLIM acquisition software. As an application example, we analyze the interaction of the oncoprotein Ras and its effector Raf after drug treatment. In conclusion, our automated FLIM imaging system requires only commercial components and may therefore allow for a broader use of this technique in chemogenomics projects.
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Affiliation(s)
- Camilo Guzmán
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | | | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
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30
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Šolman M, Ligabue A, Blaževitš O, Jaiswal A, Zhou Y, Liang H, Lectez B, Kopra K, Guzmán C, Härmä H, Hancock JF, Aittokallio T, Abankwa D. Specific cancer-associated mutations in the switch III region of Ras increase tumorigenicity by nanocluster augmentation. eLife 2015; 4:e08905. [PMID: 26274561 PMCID: PMC4563131 DOI: 10.7554/elife.08905] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 08/13/2015] [Indexed: 01/09/2023] Open
Abstract
Hotspot mutations of Ras drive cell transformation and tumorigenesis. Less frequent mutations in Ras are poorly characterized for their oncogenic potential. Yet insight into their mechanism of action may point to novel opportunities to target Ras. Here, we show that several cancer-associated mutations in the switch III region moderately increase Ras activity in all isoforms. Mutants are biochemically inconspicuous, while their clustering into nanoscale signaling complexes on the plasma membrane, termed nanocluster, is augmented. Nanoclustering dictates downstream effector recruitment, MAPK-activity, and tumorigenic cell proliferation. Our results describe an unprecedented mechanism of signaling protein activation in cancer. DOI:http://dx.doi.org/10.7554/eLife.08905.001 Cancer is a disease that develops when cells within the body acquire genetic mutations that allow them to grow and divide rapidly. Many human cancers have mutations in a gene that encodes a protein called Ras, which promotes cell growth and division by controlling the activities of other proteins. Ras congregates at the membrane that surrounds the cell and can assemble into clusters (called nanoclusters) that each contain six to eight Ras proteins. The tight packing of the proteins in these nanoclusters increases the amount of Ras in the membrane locally, which allows Ras to interact with other proteins more efficiently to promote growth and cell division. In normal cells, other proteins control when Ras is active. However, in many cancer cells, Ras is active all the time due to mutations that occur in three ‘hotspots’ within its gene. Other mutations in the gene that encodes Ras are also found in cancer cells, but these are less common and it is not clear how they alter the activity of the protein. Here, Solman et al. used microscopy and biochemical techniques to study the effects of some of the less common mutations on Ras activity in human cells. The experiments show that several mutations that alter a region of Ras called the ‘switch III region’ moderately increase the activity of Ras. The mutations probably alter the way that Ras sits in the membrane, which in turn changes the way it interacts with other proteins and the membrane so that more Ras nanoclusters form. Solman et al.'s findings reveal a new way that Ras can be activated in cancer cells. The next challenge is to develop drugs that block the formation of Ras nanoclusters and to find out if they have the potential to be used to treat cancer. DOI:http://dx.doi.org/10.7554/eLife.08905.002
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Affiliation(s)
- Maja Šolman
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Alessio Ligabue
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Olga Blaževitš
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Alok Jaiswal
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, United States
| | - Hong Liang
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, United States
| | - Benoit Lectez
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Kari Kopra
- Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Camilo Guzmán
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Harri Härmä
- Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Turku, Finland
| | - John F Hancock
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, United States
| | - Tero Aittokallio
- Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland
| | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
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31
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Kopra K, Rozwandowicz-Jansen A, Syrjänpää M, Blaževitš O, Ligabue A, Veltel S, Lamminmäki U, Abankwa D, Härmä H. GTP-specific fab fragment-based GTPase activity assay. Anal Chem 2015; 87:3527-34. [PMID: 25707436 DOI: 10.1021/acs.analchem.5b00117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
GTPases are central cellular signaling proteins, which cycle between a GDP-bound inactive and a GTP-bound active conformation in a controlled manner. Ras GTPases are frequently mutated in cancer and so far only few experimental inhibitors exist. The most common methods for monitoring GTP hydrolysis rely on luminescent GDP- or GTP-analogs. In this study, the first GTP-specific Fab fragment and its application are described. We selected Fab fragments using the phage display technology. Six Fab fragments were found against 2'/3'-GTP-biotin and 8-GTP-biotin. Selected antibody fragments allowed specific detection of endogenous, free GTP. The most potent Fab fragment (2A4(GTP)) showed over 100-fold GTP-specificity over GDP, ATP, or CTP and was used to develop a heterogeneous time-resolved luminescence based assay for the monitoring of GTP concentration. The method allows studying the GEF dependent H-Ras activation (GTP binding) and GAP-catalyzed H-Ras deactivation (GTP hydrolysis) at nanomolar protein concentrations.
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Affiliation(s)
- Kari Kopra
- †Institute of Biomedicine, Department of Cell Biology and Anatomy, University of Turku, Kiinamyllynkatu 10, Third Floor, FI-20520 Turku, Finland
| | | | | | - Olga Blaževitš
- ∥Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Alessio Ligabue
- ∥Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Stefan Veltel
- ⊥University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | | | - Daniel Abankwa
- ∥Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Harri Härmä
- †Institute of Biomedicine, Department of Cell Biology and Anatomy, University of Turku, Kiinamyllynkatu 10, Third Floor, FI-20520 Turku, Finland
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32
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Najumudeen AK, Guzmán C, Posada IMD, Abankwa D. Rab-NANOPS: FRET biosensors for Rab membrane nanoclustering and prenylation detection in mammalian cells. Methods Mol Biol 2015; 1298:29-45. [PMID: 25800830 DOI: 10.1007/978-1-4939-2569-8_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Rab proteins constitute the largest subfamily of Ras-like small GTPases. They are central to vesicular transport and organelle definition in eukaryotic cells. Unlike their Ras counterparts, they are not a hallmark of cancer. However, a number of diseases, including cancer, show a misregulation of Rab protein activity. As for all membrane-anchored signaling proteins, correct membrane organization is critical for Rabs to operate. In this chapter, we provide a detailed protocol for the use of a flow cytometry-based Fluorescence Resonance Energy Transfer (FRET)-biosensors assay, which allows to detect changes in membrane anchorage, subcellular distribution, and of the nanoscale organization of Rab-GTPases in mammalian cell lines. This assay is high-throughput amenable and can therefore be utilized in chemical-genomic and drug discovery efforts.
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Affiliation(s)
- Arafath Kaja Najumudeen
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520, Turku, Finland
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33
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Abstract
Fluorescence Recovery After Photobleaching (FRAP) and Raster Image Correlation Spectroscopy (RICS) are two powerful techniques to study the diffusion dynamics of fluorescently labeled proteins. FRAP and RICS can be easily applied on any commercial confocal microscope. In this chapter, we describe the principles of these methods and provide the reader with a detailed guide on how to apply these methods in the study of Ras nanoclustering and diffusion in the plasma membrane of live cells.
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Affiliation(s)
- Camilo Guzmán
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
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34
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Tnimov Z, Abankwa D, Alexandrov K. RhoGDI facilitates geranylgeranyltransferase-I-mediated RhoA prenylation. Biochem Biophys Res Commun 2014; 452:967-73. [PMID: 25223799 DOI: 10.1016/j.bbrc.2014.09.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 09/07/2014] [Indexed: 11/28/2022]
Abstract
Protein prenylation is a post-translational modification where farnesyl or geranylgeranyl groups are enzymatically attached to a C-terminal cysteine residue. This modification is essential for the activity of small cellular GTPases, as it allows them to associate with intracellular membranes. Dissociated from membranes, prenylated proteins need to be transported through the aqueous cytoplasm by protein carriers that shield the hydrophobic anchor from the solvent. One such carrier is Rho GDP dissociation inhibitor (RhoGDI). Recently, it was shown that prenylated Rho proteins that are not associated with RhoGDI are subjected to proteolysis in the cell. We hypothesized that the role of RhoGDI might be not only to associate with prenylated proteins but also to regulate the prenylation process in the cell. This idea is supported by the fact that RhoGDI binds both unprenylated and prenylated Rho proteins with high affinity in vitro, and hence, these interactions may affect the kinetics of prenylation. We addressed this question experimentally and found that RhoGDI increased the catalytic efficiency of geranylgeranyl transferase-I in RhoA prenylation. Nevertheless, we did not observe formation of a ternary RhoGDI∗RhoA∗GGTase-I complex, indicating sequential operation of geranylgeranyltransferase-I and RhoGDI. Our results suggest that RhoGDI accelerates Rho prenylation by kinetically trapping the reaction product, thereby increasing the rate of product release.
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Affiliation(s)
- Zakir Tnimov
- Department of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, QLD 4072, Australia
| | - Daniel Abankwa
- Department of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, QLD 4072, Australia
| | - Kirill Alexandrov
- Department of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, QLD 4072, Australia.
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35
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Coxon FP, Joachimiak L, Najumudeen AK, Breen G, Gmach J, Oetken-Lindholm C, Way R, Dunford JE, Abankwa D, Błażewska KM. Synthesis and characterization of novel phosphonocarboxylate inhibitors of RGGT. Eur J Med Chem 2014; 84:77-89. [PMID: 25016230 DOI: 10.1016/j.ejmech.2014.06.062] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 06/14/2014] [Accepted: 06/27/2014] [Indexed: 12/31/2022]
Abstract
Phosphonocarboxylate (PC) analogs of the anti-osteoporotic drugs, bisphosphonates, represent the first class of selective inhibitors of Rab geranylgeranyl transferase (RabGGTase, RGGT), an enzyme implicated in several diseases including ovarian, breast and skin cancer. Here we present the synthesis and biological characterization of an extended set of this class of compounds, including lipophilic derivatives of the known RGGT inhibitors. From this new panel of PCs, we have identified an inhibitor of RGGT that is of similar potency as the most active published phosphonocarboxylate, but of higher selectivity towards this enzyme compared to prenyl pyrophosphate synthases. New insights into structural requirements are also presented, showing that only PC analogs of the most potent 3rd generation bisphosphonates inhibit RGGT. In addition, the first phosphonocarboxylate-derived GGPPS inhibitor is reported.
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Affiliation(s)
- Fraser P Coxon
- Musculoskeletal Programme, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB252ZD, UK
| | - Lukasz Joachimiak
- Institute of Organic Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Łódź, Poland
| | - Arafath Kaja Najumudeen
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
| | - George Breen
- Musculoskeletal Programme, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB252ZD, UK
| | - Joanna Gmach
- Institute of Organic Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Łódź, Poland
| | | | - Rebecca Way
- Musculoskeletal Programme, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB252ZD, UK
| | - James E Dunford
- University of Oxford, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, The Botnar Research Center, UK
| | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
| | - Katarzyna M Błażewska
- Institute of Organic Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Łódź, Poland.
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36
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Brooks AJ, Dai W, O'Mara ML, Abankwa D, Chhabra Y, Pelekanos RA, Gardon O, Tunny KA, Blucher KM, Morton CJ, Parker MW, Sierecki E, Gambin Y, Gomez GA, Alexandrov K, Wilson IA, Doxastakis M, Mark AE, Waters MJ. Mechanism of activation of protein kinase JAK2 by the growth hormone receptor. Science 2014; 344:1249783. [PMID: 24833397 DOI: 10.1126/science.1249783] [Citation(s) in RCA: 280] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Signaling from JAK (Janus kinase) protein kinases to STAT (signal transducers and activators of transcription) transcription factors is key to many aspects of biology and medicine, yet the mechanism by which cytokine receptors initiate signaling is enigmatic. We present a complete mechanistic model for activation of receptor-bound JAK2, based on an archetypal cytokine receptor, the growth hormone receptor. For this, we used fluorescence resonance energy transfer to monitor positioning of the JAK2 binding motif in the receptor dimer, substitution of the receptor extracellular domains with Jun zippers to control the position of its transmembrane (TM) helices, atomistic modeling of TM helix movements, and docking of the crystal structures of the JAK2 kinase and its inhibitory pseudokinase domain with an opposing kinase-pseudokinase domain pair. Activation of the receptor dimer induced a separation of its JAK2 binding motifs, driven by a ligand-induced transition from a parallel TM helix pair to a left-handed crossover arrangement. This separation leads to removal of the pseudokinase domain from the kinase domain of the partner JAK2 and pairing of the two kinase domains, facilitating trans-activation. This model may well generalize to other class I cytokine receptors.
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Affiliation(s)
- Andrew J Brooks
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia.
| | - Wei Dai
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA
| | - Megan L O'Mara
- The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
| | - Daniel Abankwa
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Yash Chhabra
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Rebecca A Pelekanos
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Olivier Gardon
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kathryn A Tunny
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kristopher M Blucher
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Craig J Morton
- Biota Structural Biology Laboratory and Australian Cancer Research Foundation (ACRF) Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia
| | - Michael W Parker
- Biota Structural Biology Laboratory and Australian Cancer Research Foundation (ACRF) Rational Drug Discovery Centre, St Vincent's Institute of Medical Research, Fitzroy, Victoria 3065, Australia. Department of Biochemistry and Molecular Biology and Bio21 Institute, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Emma Sierecki
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Yann Gambin
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Guillermo A Gomez
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Kirill Alexandrov
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia
| | - Ian A Wilson
- Scripps Research Institute, La Jolla, CA 92037, USA
| | - Manolis Doxastakis
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA
| | - Alan E Mark
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia. The University of Queensland, School of Chemistry and Molecular Biosciences, St Lucia, Queensland 4072, Australia
| | - Michael J Waters
- The University of Queensland, Institute for Molecular Bioscience (IMB), St Lucia, Queensland 4072, Australia.
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37
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Guzmán C, Bagga M, Kaur A, Westermarck J, Abankwa D. ColonyArea: an ImageJ plugin to automatically quantify colony formation in clonogenic assays. PLoS One 2014; 9:e92444. [PMID: 24647355 PMCID: PMC3960247 DOI: 10.1371/journal.pone.0092444] [Citation(s) in RCA: 426] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 02/21/2014] [Indexed: 11/18/2022] Open
Abstract
The clonogenic or colony formation assay is a widely used method to study the number and size of cancer cell colonies that remain after irradiation or cytotoxic agent administration and serves as a measure for the anti-proliferative effect of these treatments. Alternatively, this assay is used to quantitate the transforming potential of cancer associated genes and chemical agents. Therefore, there is a need for a simplified and standardized analysis of colony formation assays for both routine laboratory use and for parallelized automated analysis. Here we describe the freely available ImageJ-plugin "ColonyArea", which is optimized for rapid and quantitative analysis of focus formation assays conducted in 6- to 24-well dishes. ColonyArea processes image data of multi-well dishes, by separating, concentrically cropping and background correcting well images individually, before colony formation is quantitated. Instead of counting the number of colonies, ColonyArea determines the percentage of area covered by crystal violet stained cell colonies, also taking the intensity of the staining and therefore cell density into account. We demonstrate that these parameters alone or in combination allow for robust quantification of IC50 values of the cytotoxic effect of two staurosporines, UCN-01 and staurosporine (STS) on human glioblastoma cells (T98G). The relation between the potencies of the two compounds compared very well with that obtained from an absorbance based method to quantify colony growth and to published data. The ColonyArea ImageJ plugin provides a simple and efficient analysis routine to quantitate assay data of one of the most commonly used cellular assays. The bundle is freely available for download as supporting information. We expect that ColonyArea will be of broad utility for cancer biologists, as well as clinical radiation scientists.
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Affiliation(s)
- Camilo Guzmán
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Manish Bagga
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
| | - Amanpreet Kaur
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- Department of Pathology, University of Turku, Turku, Finland
- Turku Doctoral Program of Biomedical Sciences, University of Turku and Åbo Akademi University, Turku, Finland
| | - Jukka Westermarck
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- Department of Pathology, University of Turku, Turku, Finland
| | - Daniel Abankwa
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, Turku, Finland
- * E-mail:
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38
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Köhnke M, Schmitt S, Ariotti N, Piggott AM, Parton RG, Lacey E, Capon RJ, Alexandrov K, Abankwa D. Design and application of in vivo FRET biosensors to identify protein prenylation and nanoclustering inhibitors. ACTA ACUST UNITED AC 2014; 19:866-74. [PMID: 22840774 DOI: 10.1016/j.chembiol.2012.05.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 05/25/2012] [Accepted: 05/30/2012] [Indexed: 12/24/2022]
Abstract
Protein prenylation is required for membrane anchorage of small GTPases. Correct membrane targeting is essential for their biological activity. Signal output of the prenylated proto-oncogene Ras in addition critically depends on its organization into nanoscale proteolipid assemblies of the plasma membrane, so called nanoclusters. While protein prenylation is an established drug target, only a handful of nanoclustering inhibitors are known, partially due to the lack of appropriate assays to screen for such compounds. Here, we describe three cell-based high-throughput screening amenable Förster resonance energy transfer NANOclustering and Prenylation Sensors (NANOPS) that are specific for Ras, Rho, and Rab proteins. Rab-NANOPS provides the first evidence for nanoclustering of Rab proteins. Using NANOPS in a cell-based chemical screen, we now identify macrotetrolides, known ionophoric antibiotics, as submicromolar disruptors of Ras nanoclustering and MAPK signaling.
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Affiliation(s)
- Monika Köhnke
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, QLD 4072, Australia
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39
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Guzmán C, Šolman M, Ligabue A, Blaževitš O, Andrade DM, Reymond L, Eggeling C, Abankwa D. The efficacy of Raf kinase recruitment to the GTPase H-ras depends on H-ras membrane conformer-specific nanoclustering. J Biol Chem 2014; 289:9519-33. [PMID: 24569991 DOI: 10.1074/jbc.m113.537001] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Solution structures and biochemical data have provided a wealth of mechanistic insight into Ras GTPases. However, information on how much the membrane organization of these lipid-modified proteins impacts on their signaling is still scarce. Ras proteins are organized into membrane nanoclusters, which are necessary for Ras-MAPK signaling. Using quantitative conventional and super-resolution fluorescence methods, as well as mathematical modeling, we investigated nanoclustering of H-ras helix α4 and hypervariable region mutants that have different bona fide conformations on the membrane. By following the emergence of conformer-specific nanoclusters in the plasma membrane of mammalian cells, we found that conformers impart distinct nanoclustering responses depending on the cytoplasmic levels of the nanocluster scaffold galectin-1. Computational modeling revealed that complexes containing H-ras conformers and galectin-1 affect both the number and lifetime of nanoclusters and thus determine the specific Raf effector recruitment. Our results show that mutations in Ras can affect its nanoclustering response and thus allosterically effector recruitment and downstream signaling. We postulate that cancer- and developmental disease-linked mutations that are associated with the Ras membrane conformation may exhibit so far unrecognized Ras nanoclustering and therefore signaling alterations.
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Affiliation(s)
- Camilo Guzmán
- From the Turku Centre for Biotechnology, Åbo Akademi University, Tykistökatu 6B, 20520 Turku, Finland
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40
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Gulin-Sarfraz T, Sarfraz J, Didem Şen Karaman DŞK, Zhang J, Oetken-Lindholm C, Duchanoy A, Rosenholm JM, Abankwa D. FRET-reporter nanoparticles to monitor redox-induced intracellular delivery of active compounds. RSC Adv 2014. [DOI: 10.1039/c4ra00270a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
FRET-reporter particles for redox-induced release of active compounds in cells were developed. This particle system allowed following the intracellular cleavage of delivered compounds after particle internalization.
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Affiliation(s)
- Tina Gulin-Sarfraz
- Center for Functional Materials
- Laboratory for Physical Chemistry
- Åbo Akademi University
- 20500 Turku, Finland
| | - Jawad Sarfraz
- Center for Functional Materials
- Laboratory for Physical Chemistry
- Åbo Akademi University
- 20500 Turku, Finland
| | | | - Jixi Zhang
- Center for Functional Materials
- Laboratory for Physical Chemistry
- Åbo Akademi University
- 20500 Turku, Finland
| | | | - Alain Duchanoy
- Center for Functional Materials
- Laboratory for Physical Chemistry
- Åbo Akademi University
- 20500 Turku, Finland
| | - Jessica M. Rosenholm
- Center for Functional Materials
- Laboratory for Physical Chemistry
- Åbo Akademi University
- 20500 Turku, Finland
| | - Daniel Abankwa
- Turku Centre for Biotechnology
- Åbo Akademi University
- 20520 Turku, Finland
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41
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Najumudeen AK, Köhnke M, Šolman M, Alexandrov K, Abankwa D. Cellular FRET-Biosensors to Detect Membrane Targeting Inhibitors of N-Myristoylated Proteins. PLoS One 2013; 8:e66425. [PMID: 23824448 PMCID: PMC3688908 DOI: 10.1371/journal.pone.0066425] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 05/08/2013] [Indexed: 11/18/2022] Open
Abstract
Hundreds of eukaryotic signaling proteins require myristoylation to functionally associate with intracellular membranes. N-myristoyl transferases (NMT) responsible for this modification are established drug targets in cancer and infectious diseases. Here we describe NANOMS (NANOclustering and Myristoylation Sensors), biosensors that exploit the FRET resulting from plasma membrane nanoclustering of myristoylated membrane targeting sequences of Gαi2, Yes- or Src-kinases fused to fluorescent proteins. When expressed in mammalian cells, NANOMS report on loss of membrane anchorage due to chemical or genetic inhibition of myristoylation e.g. by blocking NMT and methionine-aminopeptidase (Met-AP). We used Yes-NANOMS to assess inhibitors of NMT and a cherry-picked compound library of putative Met-AP inhibitors. Thus we successfully confirmed the activity of DDD85646 and fumagillin in our cellular assay. The developed assay is unique in its ability to identify modulators of signaling protein nanoclustering, and is amenable to high throughput screening for chemical or genetic inhibitors of functional membrane anchorage of myristoylated proteins in mammalian cells.
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Affiliation(s)
| | - Monika Köhnke
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, Australia
| | - Maja Šolman
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
| | - Kirill Alexandrov
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, Australia
- * E-mail: (DA); (KA)
| | - Daniel Abankwa
- Turku Centre for Biotechnology, Åbo Akademi University, Turku, Finland
- The University of Queensland, Institute for Molecular Bioscience, Brisbane, Queensland, Australia
- * E-mail: (DA); (KA)
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42
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Abankwa D, Millard SM, Martel N, Choong CS, Yang M, Butler LM, Buchanan G, Tilley WD, Ueki N, Hayman MJ, Leong GM. Ski-interacting protein (SKIP) interacts with androgen receptor in the nucleus and modulates androgen-dependent transcription. BMC Biochem 2013; 14:10. [PMID: 23566155 PMCID: PMC3668167 DOI: 10.1186/1471-2091-14-10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 03/25/2013] [Indexed: 11/10/2022]
Abstract
Background The androgen receptor (AR) is a member of the nuclear receptor (NR) superfamily of ligand-inducible DNA transcription factors, and is the major mediator of male sexual development, prostate growth and the pathogenesis of prostate cancer. Cell and gene specific regulation by the AR is determined by availability of and interaction with sets of key accessory cofactors. Ski-interacting protein (SKIP; SNW1, NCOA62) is a cofactor shown to interact with several NRs and a diverse range of other transcription factors. Interestingly, SKIP as part of the spliceosome is thought to link mRNA splicing with transcription. SKIP has not been previously shown to interact with the AR. Results The aim of this study was to investigate whether SKIP interacts with the AR and modulates AR-dependent transcription. Here, we show by co-immunoprecipitation experiments that SKIP is in a complex with the AR. Moreover, SKIP increased 5α-dihydrotestosterone (DHT) induced N-terminal/C-terminal AR interaction from 12-fold to almost 300-fold in a two-hybrid assay, and enhanced AR ligand-independent AF-1 transactivation. SKIP augmented ligand- and AR-dependent transactivation in PC3 prostate cancer cells. Live-cell imaging revealed a fast (half-time=129 s) translocation of AR from the cytoplasm to the nucleus upon DHT-stimulation. Förster resonance energy transfer (FRET) experiments suggest a direct AR-SKIP interaction in the nucleus upon translocation. Conclusions Our results suggest that SKIP interacts with AR in the nucleus and enhances AR-dependent transactivation and N/C-interaction supporting a role for SKIP as an AR co-factor.
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Affiliation(s)
- Daniel Abankwa
- University of Queensland, Obesity Research Centre, Institute for Molecular Bioscience, St,Lucia, Queensland, 4072, Australia
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43
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Šolman M, Guzmán C, Abankwa D. H-Ras Membrane Orientation Affects Galectin-1 Dependent Nanoclustering. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Larsen J, Jensen MB, Bhatia VK, Pedersen SL, Bjørnholm T, Jensen KJ, Kohnke M, Abankwa D, Alexandrov K, Hatzakis NS, Stamou D. Lipid-Anchored Ras is Sorted by Membrane Curvature Both In Vitro and in Living Cells. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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45
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Sykes AM, Palstra N, Abankwa D, Hill JM, Skeldal S, Matusica D, Venkatraman P, Hancock JF, Coulson EJ. The effects of transmembrane sequence and dimerization on cleavage of the p75 neurotrophin receptor by γ-secretase. J Biol Chem 2012; 287:43810-24. [PMID: 23105112 DOI: 10.1074/jbc.m112.382903] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Cleavage of transmembrane receptors by γ-secretase is the final step in the process of regulated intramembrane proteolysis (RIP) and has a significant impact on receptor function. Although relatively little is known about the molecular mechanism of γ-secretase enzymatic activity, it is becoming clear that substrate dimerization and/or the α-helical structure of the substrate can regulate the site and rate of γ-secretase activity. Here we show that the transmembrane domain of the pan-neurotrophin receptor p75(NTR), best known for regulating neuronal death, is sufficient for its homodimerization. Although the p75(NTR) ligands NGF and pro-NGF do not induce homerdimerization or RIP, homodimers of p75(NTR) are γ-secretase substrates. However, dimerization is not a requirement for p75(NTR) cleavage, suggesting that γ-secretase has the ability to recognize and cleave each receptor molecule independently. The transmembrane cysteine 257, which mediates covalent p75(NTR) interactions, is not crucial for homodimerization, but this residue is required for normal rates of γ-secretase cleavage. Similarly, mutation of the residues alanine 262 and glycine 266 of an AXXXG dimerization motif flanking the γ-secretase cleavage site within the p75(NTR) transmembrane domain alters the orientation of the domain and inhibits γ-secretase cleavage of p75(NTR). Nonetheless, heteromer interactions of p75(NTR) with TrkA increase full-length p75(NTR) homodimerization, which in turn potentiates the rate of γ-cleavage following TrkA activation independently of rates of α-cleavage. These results provide support for the idea that the helical structure of the p75(NTR) transmembrane domain, which may be affected by co-receptor interactions, is a key element in γ-secretase-catalyzed cleavage.
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Affiliation(s)
- Alex M Sykes
- Queensland Brain Institute, University of Queensland, Brisbane, Queensland 4072, Australia
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Tnimov Z, Guo Z, Gambin Y, Nguyen UTT, Wu YW, Abankwa D, Stigter A, Collins BM, Waldmann H, Goody RS, Alexandrov K. Quantitative analysis of prenylated RhoA interaction with its chaperone, RhoGDI. J Biol Chem 2012; 287:26549-62. [PMID: 22628549 DOI: 10.1074/jbc.m112.371294] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Small GTPases of the Rho family regulate cytoskeleton remodeling, cell polarity, and transcription, as well as the cell cycle, in eukaryotic cells. Membrane delivery and recycling of the Rho GTPases is mediated by Rho GDP dissociation inhibitor (RhoGDI), which forms a stable complex with prenylated Rho GTPases. We analyzed the interaction of RhoGDI with the active and inactive forms of prenylated and unprenylated RhoA. We demonstrate that RhoGDI binds the prenylated form of RhoA·GDP with unexpectedly high affinity (K(d) = 5 pm). The very long half-life of the complex is reduced 25-fold on RhoA activation, with a concomitant reduction in affinity (K(d) = 3 nm). The 2.8-Å structure of the RhoA·guanosine 5'-[β,γ-imido] triphosphate (GMPPNP)·RhoGDI complex demonstrated that complex formation forces the activated RhoA into a GDP-bound conformation in the absence of nucleotide hydrolysis. We demonstrate that membrane extraction of Rho GTPase by RhoGDI is a thermodynamically favored passive process that operates through a series of progressively tighter intermediates, much like the one that is mediated by RabGDI.
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Affiliation(s)
- Zakir Tnimov
- Department of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, 306 Carmody Road, St. Lucia, Queensland 4072, Australia
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Das D, Tnimov Z, Nguyen UTT, Thimmaiah G, Lo H, Abankwa D, Wu Y, Goody RS, Waldmann H, Alexandrov K. Flexible and general synthesis of functionalized phosphoisoprenoids for the study of prenylation in vivo and in vitro. Chembiochem 2012; 13:674-83. [PMID: 22351497 DOI: 10.1002/cbic.201100733] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Indexed: 11/06/2022]
Abstract
Protein modification with isoprenoid lipids affects hundreds of signaling proteins in eukaryotic cells. Modification of isoprenoids with reporter groups is the main approach for the creation of probes for the analysis of protein prenylation in vitro and in vivo. Here, we describe a new strategy for the synthesis of functionalized phosphoisoprenoids that uses an aminederivatized isoprenoid scaffold as a starting point for the synthesis of functionalized phosphoisoprenoid libraries. This overcomes a long-standing problem in the field, where multistep synthesis had to be carried out for each individual isoprenoid analogue. The described approach enabled us to synthesize a range of new compounds, including two novel fluorescent isoprenoids that previously could not be generated by conventional means. The fluorescent probes that were developed using the described approach possess significant spectroscopic advantages to all previously generated fluorescent isoprenoid analogue. Using these analogues for flow cytometry and cell imaging, we analyzed the uptake of isoprenoids by mammalian cells and zebrafish embryos. Furthermore, we demonstrate that derivatization of the scaffold can be coupled in a one-pot reaction to enzymatic incorporation of the resulting isoprenoid group into proteins. This enables rapid evaluation of functional groups for compatibility with individual prenyltransferases and identification of the prenyltransferase specific substrates.
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Affiliation(s)
- Debapratim Das
- Department of Chemical Biology, Max-Planck Institute of Molecular Physiology, Otto Hahn Strasse 11, 44227 Dortmund, Germany
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Sinha B, Köster D, Ruez R, Gonnord P, Bastiani M, Abankwa D, Stan RV, Butler-Browne G, Vedie B, Johannes L, Morone N, Parton RG, Raposo G, Sens P, Lamaze C, Nassoy P. Cells respond to mechanical stress by rapid disassembly of caveolae. Cell 2011; 144:402-13. [PMID: 21295700 DOI: 10.1016/j.cell.2010.12.031] [Citation(s) in RCA: 634] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 10/27/2010] [Accepted: 12/23/2010] [Indexed: 12/15/2022]
Abstract
The functions of caveolae, the characteristic plasma membrane invaginations, remain debated. Their abundance in cells experiencing mechanical stress led us to investigate their role in membrane-mediated mechanical response. Acute mechanical stress induced by osmotic swelling or by uniaxial stretching results in a rapid disappearance of caveolae, in a reduced caveolin/Cavin1 interaction, and in an increase of free caveolins at the plasma membrane. Tether-pulling force measurements in cells and in plasma membrane spheres demonstrate that caveola flattening and disassembly is the primary actin- and ATP-independent cell response that buffers membrane tension surges during mechanical stress. Conversely, stress release leads to complete caveola reassembly in an actin- and ATP-dependent process. The absence of a functional caveola reservoir in myotubes from muscular dystrophic patients enhanced membrane fragility under mechanical stress. Our findings support a new role for caveolae as a physiological membrane reservoir that quickly accommodates sudden and acute mechanical stresses.
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Crouthamel M, Abankwa D, Zhang L, DiLizio C, Manning DR, Hancock JF, Wedegaertner PB. An N-terminal polybasic motif of Gαq is required for signaling and influences membrane nanodomain distribution. Mol Pharmacol 2010; 78:767-77. [PMID: 20664004 DOI: 10.1124/mol.110.066340] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Regions of basic amino acids in proteins can promote membrane localization through electrostatic interactions with negatively charged membrane lipid head groups. Previous work showed that the heterotrimeric G protein subunit α(q) contains a polybasic region in its N terminus that contributes to plasma membrane localization. Here, the role of the N-terminal polybasic region of α(q) in signaling was addressed. For α(q) mutants, loss of plasma membrane localization correlated with loss of signaling function, as measured by the ability to couple activated G protein-coupled receptors (GPCRs) to stimulation of inositol phosphate production. However, recovery of plasma membrane localization of α(q) polybasic mutants by introduction of a site for myristoylation or by coexpression of βγ failed to recover signaling, suggesting a role for N-terminal basic amino acids of α(q) beyond simple plasma membrane localization. It is noteworthy that an α(q)4Q mutant, containing glutamine substitutions at arginines 27, 30, 31, and 34, was identified that failed to mediate signaling yet retained plasma membrane localization. Although α(q)4Q failed to couple activated receptors to inositol phosphate production, it was able to bind βγ, bind RGS4 in an activation-dependent manner, stimulate inositol phosphate production in a receptor-independent manner, and productively interact with a GPCR in isolated membranes. It is noteworthy that α(q)4Q showed a differing localization to plasma membrane nanodomains compared with wild-type α(q). Thus, basic amino acids in the N terminus of α(q) can affect its lateral segregation on plasma membranes, and changes in such lateral segregation may be responsible for the observed signaling defects of α(q)4Q.
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Affiliation(s)
- Marykate Crouthamel
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233 S. 10th Street, 839 BLSB, Philadelphia, PA 19107, USA
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Bastiani M, Liu L, Hill MM, Jedrychowski MP, Nixon SJ, Lo HP, Abankwa D, Luetterforst R, Fernandez-Rojo M, Breen MR, Gygi SP, Vinten J, Walser PJ, North KN, Hancock JF, Pilch PF, Parton RG. MURC/Cavin-4 and cavin family members form tissue-specific caveolar complexes. ACTA ACUST UNITED AC 2009; 185:1259-73. [PMID: 19546242 PMCID: PMC2712963 DOI: 10.1083/jcb.200903053] [Citation(s) in RCA: 207] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Polymerase I and transcript release factor (PTRF)/Cavin is a cytoplasmic protein whose expression is obligatory for caveola formation. Using biochemistry and fluorescence resonance energy transfer–based approaches, we now show that a family of related proteins, PTRF/Cavin-1, serum deprivation response (SDR)/Cavin-2, SDR-related gene product that binds to C kinase (SRBC)/Cavin-3, and muscle-restricted coiled-coil protein (MURC)/Cavin-4, forms a multiprotein complex that associates with caveolae. This complex can constitutively assemble in the cytosol and associate with caveolin at plasma membrane caveolae. Cavin-1, but not other cavins, can induce caveola formation in a heterologous system and is required for the recruitment of the cavin complex to caveolae. The tissue-restricted expression of cavins suggests that caveolae may perform tissue-specific functions regulated by the composition of the cavin complex. Cavin-4 is expressed predominantly in muscle, and its distribution is perturbed in human muscle disease associated with Caveolin-3 dysfunction, identifying Cavin-4 as a novel muscle disease candidate caveolar protein.
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Affiliation(s)
- Michele Bastiani
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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