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Murthy MHS, Jasbi P, Lowe W, Kumar L, Olaosebikan M, Roger L, Yang J, Lewinski N, Daniels N, Cowen L, Klein-Seetharaman J. Insulin signaling and pharmacology in humans and in corals. PeerJ 2024; 12:e16804. [PMID: 38313028 PMCID: PMC10838073 DOI: 10.7717/peerj.16804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 12/27/2023] [Indexed: 02/06/2024] Open
Abstract
Once thought to be a unique capability of the Langerhans islets in the pancreas of mammals, insulin (INS) signaling is now recognized as an evolutionarily ancient function going back to prokaryotes. INS is ubiquitously present not only in humans but also in unicellular eukaryotes, fungi, worms, and Drosophila. Remote homologue identification also supports the presence of INS and INS receptor in corals where the availability of glucose is largely dependent on the photosynthetic activity of the symbiotic algae. The cnidarian animal host of corals operates together with a 20,000-sized microbiome, in direct analogy to the human gut microbiome. In humans, aberrant INS signaling is the hallmark of metabolic disease, and is thought to play a major role in aging, and age-related diseases, such as Alzheimer's disease. We here would like to argue that a broader view of INS beyond its human homeostasis function may help us understand other organisms, and in turn, studying those non-model organisms may enable a novel view of the human INS signaling system. To this end, we here review INS signaling from a new angle, by drawing analogies between humans and corals at the molecular level.
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Affiliation(s)
| | - Paniz Jasbi
- School of Molecular Sciences, Arizona State University, Phoenix, AZ, USA
| | - Whitney Lowe
- Departments of Chemistry & Physics, Colorado School of Mines, Golden, CO, United States
| | - Lokender Kumar
- Departments of Chemistry & Physics, Colorado School of Mines, Golden, CO, United States
| | | | - Liza Roger
- School of Molecular Sciences, Arizona State University, Phoenix, AZ, USA
- School of Ocean Futures, Arizona State University, Tempe, AZ, United States of America
| | - Jinkyu Yang
- Department of Aeronautics & Astronautics, University of Washington, Seattle, WA, USA
| | - Nastassja Lewinski
- Department of Chemical and Life Science Engineering, Virginia Commonwealth University, Richmond, VA, USA
| | - Noah Daniels
- Department of Computer Science, University of Rhode Island, Kingston, RI, USA
| | - Lenore Cowen
- Department of Computer Science, Tufts University, Medford, MA, USA
| | - Judith Klein-Seetharaman
- School of Molecular Sciences, Arizona State University, Phoenix, AZ, USA
- Departments of Chemistry & Physics, Colorado School of Mines, Golden, CO, United States
- College of Health Solutions, Arizona State University, Phoenix, AZ, United States
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2
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Islam Z, Diane A, Khattab N, Dehbi M, Thornalley P, Kolatkar PR. DNAJB3 attenuates ER stress through direct interaction with AKT. PLoS One 2023; 18:e0290340. [PMID: 37594932 PMCID: PMC10437922 DOI: 10.1371/journal.pone.0290340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 08/03/2023] [Indexed: 08/20/2023] Open
Abstract
Metabolic stress involved in several dysregulation disorders such as type 2 diabetes mellitus (T2DM) results in down regulation of several heat shock proteins (HSPs) including DNAJB3. This down regulation of HSPs is associated with insulin resistance (IR) and interventions which induce the heat shock response (HSR) help to increase the insulin sensitivity. Metabolic stress leads to changes in signaling pathways through increased activation of both c-jun N-terminal kinase-1 (JNK1) and the inhibitor of κB inflammatory kinase (IKKβ) which in turn leads to inactivation of insulin receptor substrates 1 and 2 (IRS-1 and IRS-2). DNAJB3 interacts with both JNK1 and IKKβ kinases to mitigate metabolic stress. In addition DNAJB3 also activates the PI3K-PKB/AKT pathway through increased phosphorylation of AKT1 and its substrate AS160, a Rab GTPase-activating protein, which results in mobilization of GLUT4 transporter protein and improved glucose uptake. We show through pull down that AK T1 is an interacting partner of DNAJB3, further confirmed by isothermal titration calorimetry (ITC) which quantified the avidity of AKT1 for DNAJB3. The binding interface was identified by combining protein modelling with docking of the AKT1-DNAJB3 complex. DNAJB3 is localized in the cytoplasm and ER, where it interacts directly with AKT1 and mobilizes AS160 for glucose transport. Inhibition of AKT1 resulted in loss of GLUT4 translocation activity mediated by DNAJB3 and also abolished the protective effect of DNAJB3 on tunicamycin-induced ER stress. Taken together, our findings provide evidence for a direct protein-protein interaction between DNAJB3 and AKT1 upon which DNAJB3 alleviates ER stress and promotes GLUT4 translocation.
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Affiliation(s)
- Zeyaul Islam
- Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Abdoulaye Diane
- Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Namat Khattab
- Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Mohammed Dehbi
- Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Paul Thornalley
- Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
| | - Prasanna R. Kolatkar
- Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation, Doha, Qatar
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Zhang J, Zhang Z, Huang Z, Li M, Yang F, Wu Z, Guo Q, Mei X, Lu B, Wang C, Wang Z, Ji L. Isotoosendanin exerts inhibition on triple-negative breast cancer through abrogating TGF- β-induced epithelial-mesenchymal transition via directly targeting TGF βR1. Acta Pharm Sin B 2023; 13:2990-3007. [PMID: 37521871 PMCID: PMC10372922 DOI: 10.1016/j.apsb.2023.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 03/07/2023] [Accepted: 03/14/2023] [Indexed: 08/01/2023] Open
Abstract
As the most aggressive breast cancer, triple-negative breast cancer (TNBC) is still incurable and very prone to metastasis. The transform growth factor β (TGF-β)-induced epithelial-mesenchymal transition (EMT) is crucially involved in the growth and metastasis of TNBC. This study reported that a natural compound isotoosendanin (ITSN) reduced TNBC metastasis by inhibiting TGF-β-induced EMT and the formation of invadopodia. ITSN can directly interact with TGF-β receptor type-1 (TGFβR1) and abrogated the kinase activity of TGFβR1, thereby blocking the TGF-β-initiated downstream signaling pathway. Moreover, the ITSN-provided inhibition on metastasis obviously disappeared in TGFβR1-overexpressed TNBC cells in vitro as well as in mice bearing TNBC cells overexpressed TGFβR1. Furthermore, Lys232 and Asp351 residues in the kinase domain of TGFβR1 were found to be crucial for the interaction of ITSN with TGFβR1. Additionally, ITSN also improved the inhibitory efficacy of programmed cell death 1 ligand 1 (PD-L1) antibody for TNBC in vivo via inhibiting the TGF-β-mediated EMT in the tumor microenvironment. Our findings not only highlight the key role of TGFβR1 in TNBC metastasis, but also provide a leading compound targeting TGFβR1 for the treatment of TNBC metastasis. Moreover, this study also points out a potential strategy for TNBC treatment by using the combined application of anti-PD-L1 with a TGFβR1 inhibitor.
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Affiliation(s)
- Jingnan Zhang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Ze Zhang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhenlin Huang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Manlin Li
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Fan Yang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zeqi Wu
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Qian Guo
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Xiyu Mei
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Bin Lu
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Changhong Wang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zhengtao Wang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Lili Ji
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
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Bae H, Viennet T, Park E, Chu N, Salguero A, Eck MJ, Arthanari H, Cole PA. PH domain-mediated autoinhibition and oncogenic activation of Akt. eLife 2022; 11:80148. [PMID: 35968932 PMCID: PMC9417420 DOI: 10.7554/elife.80148] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
Akt is a Ser/Thr protein kinase that plays a central role in metabolism and cancer. Regulation of Akt’s activity involves an autoinhibitory intramolecular interaction between its pleckstrin homology (PH) domain and its kinase domain that can be relieved by C-tail phosphorylation. PH domain mutant E17K Akt is a well-established oncogene. Previously, we reported that the conformation of autoinhibited Akt may be shifted by small molecule allosteric inhibitors limiting the mechanistic insights from existing X-ray structures that have relied on such compounds (Chu et al., 2020). Here, we discover unexpectedly that a single mutation R86A Akt exhibits intensified autoinhibitory features with enhanced PH domain-kinase domain affinity. Structural and biochemical analysis uncovers the importance of a key interaction network involving Arg86, Glu17, and Tyr18 that controls Akt conformation and activity. Our studies also shed light on the molecular basis for E17K Akt activation as an oncogenic driver.
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Affiliation(s)
- Hwan Bae
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Thibault Viennet
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
| | - Eunyoung Park
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
| | - Nam Chu
- Department of Cancer Biology and Genetics, The Ohio State University, Columbus, United States
| | - Antonieta Salguero
- Department of Medicine, Brigham and Women's Hospital, Boston, United States
| | - Michael J Eck
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States
| | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Philip A Cole
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
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Ahmad Z, Somanath PR. AKT Isoforms in the Immune Response in Cancer. Curr Top Microbiol Immunol 2022; 436:349-366. [PMID: 36243852 DOI: 10.1007/978-3-031-06566-8_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
AKT is a protein kinase that exists in three isoforms: AKT1, AKT2, and AKT3. Though similar in structure, these isoforms display different effects. AKT is activated downstream of PI3K, and together, this signaling pathway helps regulate cellular processes including cell growth, proliferation, metabolism, survival, and apoptosis. Disruption in these pathways has been associated with disorders including cardiovascular diseases, developmental disorders, inflammatory responses, autoimmune diseases, neurologic disorders, type 2 diabetes, and several cancers. In cancer, deregulation in the PI3K/AKT pathway can be manifested as tumorigenesis, pathological angiogenesis, and metastasis. Increased activity has been correlated with tumor progression and resistance to cancer treatments. Recent studies have suggested that inhibition of the PI3K/AKT pathway plays a significant role in the development, expansion, and proliferation of cells of the immune system. Additionally, AKT has been found to play an important role in differentiating regulatory T cells, activating B cells, and augmenting tumor immunosurveillance. This emphasizes AKT as a potential target for inhibition in cancer therapy. This chapter reviews AKT structure and regulation, its different isoforms, its role in immune cells, and its modulation in oncotherapy.
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Affiliation(s)
- Zayd Ahmad
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA, 30912, USA
| | - Payaningal R Somanath
- Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and Charlie Norwood VA Medical Center, Augusta, GA, 30912, USA.
- Georgia Cancer Center, Vascular Biology Center and Department of Medicine, Augusta University, Augusta, GA, 30912, USA.
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6
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AKT Isoforms in Macrophage Activation, Polarization, and Survival. Curr Top Microbiol Immunol 2022; 436:165-196. [DOI: 10.1007/978-3-031-06566-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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7
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Li N, Yang F, Liu DY, Guo JT, Ge N, Sun SY. Scoparone inhibits pancreatic cancer through PI3K/Akt signaling pathway. World J Gastrointest Oncol 2021; 13:1164-1183. [PMID: 34616521 PMCID: PMC8465440 DOI: 10.4251/wjgo.v13.i9.1164] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/09/2021] [Accepted: 07/05/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Pancreatic cancer is a highly malignant tumor of the gastrointestinal system whose emerging resistance to chemotherapy has necessitated the development of novel antitumor treatments. Scoparone, a traditional Chinese medicine monomer with a wide range of pharmacological properties, has attracted considerable attention for its antitumor activity. AIM To explore the potential antitumor effect of scoparone on pancreatic cancer and the possible molecular mechanism of action. METHODS The target genes of scoparone were determined using both the bioinformatics and multiplatform analyses. The effect of scoparone on pancreatic cancer cell proliferation, migration, invasion, cell cycle, and apoptosis was detected in vitro. The expression of hub genes was tested using quantitative reverse transcription polymerase chain reaction (qRT-PCR), and the molecular mechanism was analyzed using Western blot. The in vivo effect of scoparone on pancreatic cancer cell proliferation was detected using a xenograft tumor model in nude mice as well as immunohistochemistry. RESULTS The hub genes involved in the suppression of pancreatic cancer by scoparone were obtained by network bioinformatics analyses using publicly available databases and platforms, including SwissTargetPrediction, STITCH, GeneCards, CTD, STRING, WebGestalt, Cytoscape, and Gepia; AKT1 was confirmed using qRT-PCR to be the hub gene. Cell Counting Kit-8 assay revealed that the viability of Capan-2 and SW1990 cells was significantly reduced by scoparone treatment exhibiting IC50 values of 225.2 μmol/L and 209.1 μmol/L, respectively. Wound healing and transwell assays showed that scoparone inhibited the migration and invasion of pancreatic cancer cells. Additionally, flow cytometry confirmed that scoparone caused cell cycle arrest and induced apoptosis. Scoparone also increased the expression levels of Bax and cleaved caspase-3, decreased the levels of MMP9 and Bcl-2, and suppressed the phosphorylation of Akt without affecting total PI3K and Akt. Moreover, compared with the control group, xenograft tumors, in the 200 μmol/L scoparone treatment group, were smaller in volume and lighter in weight, and the percentages of Ki65- and PCNA-positive cells were decreased. CONCLUSION Our findings indicate that scoparone inhibits pancreatic cancer cell proliferation in vitro and in vivo, inhibits migration and invasion, and induces cycle arrest and apoptosis in vitro through the PI3K/Akt signaling pathway.
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Affiliation(s)
- Na Li
- Department of Hospice Care, Shengjing Hospital of China Medical University, Shenyang 110022, Liaoning Province, China
| | - Fan Yang
- Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Dong-Yan Liu
- Medical Research Center, Shengjing Hospital of China Medical University, Benxi 111700, Liaoning Province, China
| | - Jin-Tao Guo
- Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Nan Ge
- Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
| | - Si-Yu Sun
- Department of Gastroenterology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
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Dwivedy A, Mariadasse R, Ahmad M, Chakraborty S, Kar D, Tiwari S, Bhattacharyya S, Sonar S, Mani S, Tailor P, Majumdar T, Jeyakanthan J, Biswal BK. Characterization of the NiRAN domain from RNA-dependent RNA polymerase provides insights into a potential therapeutic target against SARS-CoV-2. PLoS Comput Biol 2021; 17:e1009384. [PMID: 34516563 PMCID: PMC8478224 DOI: 10.1371/journal.pcbi.1009384] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 09/28/2021] [Accepted: 08/26/2021] [Indexed: 12/14/2022] Open
Abstract
Apart from the canonical fingers, palm and thumb domains, the RNA dependent RNA polymerases (RdRp) from the viral order Nidovirales possess two additional domains. Of these, the function of the Nidovirus RdRp associated nucleotidyl transferase domain (NiRAN) remains unanswered. The elucidation of the 3D structure of RdRp from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), provided the first ever insights into the domain organisation and possible functional characteristics of the NiRAN domain. Using in silico tools, we predict that the NiRAN domain assumes a kinase or phosphotransferase like fold and binds nucleoside triphosphates at its proposed active site. Additionally, using molecular docking we have predicted the binding of three widely used kinase inhibitors and five well characterized anti-microbial compounds at the NiRAN domain active site along with their drug-likeliness. For the first time ever, using basic biochemical tools, this study shows the presence of a kinase like activity exhibited by the SARS-CoV-2 RdRp. Interestingly, a well-known kinase inhibitor- Sorafenib showed a significant inhibition and dampened viral load in SARS-CoV-2 infected cells. In line with the current global COVID-19 pandemic urgency and the emergence of newer strains with significantly higher infectivity, this study provides a new anti-SARS-CoV-2 drug target and potential lead compounds for drug repurposing against SARS-CoV-2. The on-going coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is significantly affecting the world health. Unfortunately, over 180 million cases of COVID-19 resulting in nearly 4 million deaths have been reported till June, 2021. In this study, using a combination of bioinformatics, biochemical and mass spectrometry methods, we show that the Nidovirus RdRp associated Nucleotidyl transferase (NiRAN) domain of the RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2 exhibits a kinase like activity. Additionally, we also show that few broad spectrum anti-cancer and anti-microbial drugs dampen this kinase like activity. Of note, Sorafenib, an FDA approved anti-cancer kinase inhibiting drug significantly reduces the SARS-CoV-2 load in cell lines. Our study suggests that NiRAN domain of the SARS-CoV-2 RdRp is indispensible for the successful viral life cycle and shows that abolishing this enzymatic function of RdRp by small molecule inhibitors may open novel avenues for COVID-19 therapeutics.
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Affiliation(s)
| | | | | | | | | | | | | | - Sudipta Sonar
- Translational Health Science and Technology Institute, Faridabad, India
| | - Shailendra Mani
- Translational Health Science and Technology Institute, Faridabad, India
| | | | - Tanmay Majumdar
- National Institute of Immunology, New Delhi, India
- * E-mail: (TM); (JJ); (BKB)
| | - Jeyaraman Jeyakanthan
- Department of Bioinformatics, Alagappa University, Tamil Nadu, India
- * E-mail: (TM); (JJ); (BKB)
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9
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Dwivedy A, Mariadasse R, Ahmad M, Chakraborty S, Kar D, Tiwari S, Bhattacharyya S, Sonar S, Mani S, Tailor P, Majumdar T, Jeyakanthan J, Biswal BK. Characterization of the NiRAN domain from RNA-dependent RNA polymerase provides insights into a potential therapeutic target against SARS-CoV-2. PLoS Comput Biol 2021. [DOI: https://doi.org/10.1371/journal.pcbi.1009384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apart from the canonical fingers, palm and thumb domains, the RNA dependent RNA polymerases (RdRp) from the viral order Nidovirales possess two additional domains. Of these, the function of the Nidovirus RdRp associated nucleotidyl transferase domain (NiRAN) remains unanswered. The elucidation of the 3D structure of RdRp from the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), provided the first ever insights into the domain organisation and possible functional characteristics of the NiRAN domain. Using in silico tools, we predict that the NiRAN domain assumes a kinase or phosphotransferase like fold and binds nucleoside triphosphates at its proposed active site. Additionally, using molecular docking we have predicted the binding of three widely used kinase inhibitors and five well characterized anti-microbial compounds at the NiRAN domain active site along with their drug-likeliness. For the first time ever, using basic biochemical tools, this study shows the presence of a kinase like activity exhibited by the SARS-CoV-2 RdRp. Interestingly, a well-known kinase inhibitor- Sorafenib showed a significant inhibition and dampened viral load in SARS-CoV-2 infected cells. In line with the current global COVID-19 pandemic urgency and the emergence of newer strains with significantly higher infectivity, this study provides a new anti-SARS-CoV-2 drug target and potential lead compounds for drug repurposing against SARS-CoV-2.
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10
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Truebestein L, Hornegger H, Anrather D, Hartl M, Fleming KD, Stariha JTB, Pardon E, Steyaert J, Burke JE, Leonard TA. Structure of autoinhibited Akt1 reveals mechanism of PIP 3-mediated activation. Proc Natl Acad Sci U S A 2021; 118:e2101496118. [PMID: 34385319 PMCID: PMC8379990 DOI: 10.1073/pnas.2101496118] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The protein kinase Akt is one of the primary effectors of growth factor signaling in the cell. Akt responds specifically to the lipid second messengers phosphatidylinositol-3,4,5-trisphosphate [PI(3,4,5)P3] and phosphatidylinositol-3,4-bisphosphate [PI(3,4)P2] via its PH domain, leading to phosphorylation of its activation loop and the hydrophobic motif of its kinase domain, which are critical for activity. We have now determined the crystal structure of Akt1, revealing an autoinhibitory interface between the PH and kinase domains that is often mutated in cancer and overgrowth disorders. This interface persists even after stoichiometric phosphorylation, thereby restricting maximum Akt activity to PI(3,4,5)P3- or PI(3,4)P2-containing membranes. Our work helps to resolve the roles of lipids and phosphorylation in the activation of Akt and has wide implications for the spatiotemporal control of Akt and potentially lipid-activated kinase signaling in general.
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Affiliation(s)
- Linda Truebestein
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna BioCenter, 1030 Vienna, Austria
- Department of Medical Biochemistry, Medical University of Vienna, 1090 Vienna, Austria
| | - Harald Hornegger
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna BioCenter, 1030 Vienna, Austria
- Department of Medical Biochemistry, Medical University of Vienna, 1090 Vienna, Austria
| | - Dorothea Anrather
- Mass Spectrometry Core Facility, Max Perutz Labs, Vienna BioCenter, 1030 Vienna, Austria
| | - Markus Hartl
- Mass Spectrometry Core Facility, Max Perutz Labs, Vienna BioCenter, 1030 Vienna, Austria
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Jordan T B Stariha
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), 1050 Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium
- VIB-VUB Center for Structural Biology, Vlaams Instituut voor Biotechnologie (VIB), 1050 Brussels, Belgium
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Thomas A Leonard
- Department of Structural and Computational Biology, Max Perutz Labs, Vienna BioCenter, 1030 Vienna, Austria;
- Department of Medical Biochemistry, Medical University of Vienna, 1090 Vienna, Austria
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11
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Merckaert T, Zwaenepoel O, Gevaert K, Gettemans J. An AKT2-specific nanobody that targets the hydrophobic motif induces cell cycle arrest, autophagy and loss of focal adhesions in MDA-MB-231 cells. Biomed Pharmacother 2020; 133:111055. [PMID: 33378961 DOI: 10.1016/j.biopha.2020.111055] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 10/21/2020] [Accepted: 11/19/2020] [Indexed: 02/06/2023] Open
Abstract
The AKT kinase family is a high-profile target for cancer therapy. Despite their high degree of homology the three AKT isoforms (AKT1, AKT2 and AKT3) are non-redundant and can even have opposing functions. Small-molecule AKT inhibitors affect all three isoforms which severely limits their usefulness as research tool or therapeutic. Using AKT2-specific nanobodies we examined the function of endogenous AKT2 in breast cancer cells. Two AKT2 nanobodies (Nb8 and Nb9) modulate AKT2 and reduce MDA-MB-231 cell viability/proliferation. Nb8 binds the AKT2 hydrophobic motif and reduces IGF-1-induced phosphorylation of this site. This nanobody also affects the phosphorylation and/or expression levels of a wide range of proteins downstream of AKT, resulting in a G0/G1 cell cycle arrest, the induction of autophagy, a reduction in focal adhesion count and loss of stress fibers. While cell cycle progression is likely to be regulated by more than one isoform, our results indicate that both the effects on autophagy and the cytoskeleton are specific to AKT2. By using an isoform-specific nanobody we were able to map a part of the AKT2 pathway. Our results confirm AKT2 and the hydrophobic motif as targets for cancer therapy. Nb8 can be used as a research tool to study AKT2 signalling events and aid in the design of an AKT2-specific inhibitor.
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Affiliation(s)
- Tijs Merckaert
- Department of Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Tech Lane Ghent Science Park 75, 9052 Ghent, Belgium; VIB-UGent Center for Medical Biotechnology, Tech Lane Ghent Science Park 75, 9052 Ghent, Belgium.
| | - Olivier Zwaenepoel
- Department of Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Tech Lane Ghent Science Park 75, 9052 Ghent, Belgium.
| | - Kris Gevaert
- Department of Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Tech Lane Ghent Science Park 75, 9052 Ghent, Belgium; VIB-UGent Center for Medical Biotechnology, Tech Lane Ghent Science Park 75, 9052 Ghent, Belgium.
| | - Jan Gettemans
- Department of Biomolecular Medicine, Faculty of Medicine and Health Sciences, Ghent University, Tech Lane Ghent Science Park 75, 9052 Ghent, Belgium.
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12
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Bono B, Franco G, Riva V, Garbelli A, Maga G. Novel Insights into the Biochemical Mechanism of CK1ε and its Functional Interplay with DDX3X. Int J Mol Sci 2020; 21:ijms21176449. [PMID: 32899434 PMCID: PMC7503845 DOI: 10.3390/ijms21176449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/14/2020] [Accepted: 09/01/2020] [Indexed: 11/23/2022] Open
Abstract
Casein Kinase 1 epsilon (CK1ε) is a member of the serine (Ser)/threonine (Thr) CK1 family, known to have crucial roles in several biological scenarios and, ever more frequently, in pathological contexts, such as cancer. Recently, the human DEAD-box RNA helicase 3 X-linked (DDX3X), involved in cancer proliferation and viral infections, has been identified as one of CK1ε substrates and its positive regulator in the Wnt/β-catenin network. However, the way by which these two proteins influence each other has not been fully clarified. In order to further investigate their interplay, we defined the kinetic parameters of CK1ε towards its substrates: ATP, casein, Dvl2 and DDX3X. CK1ε affinity for ATP depends on the nature of the substrate: increasing of casein concentrations led to an increase of KmATP, while increasing DDX3X reduced it. In literature, DDX3X is described to act as an allosteric activator of CK1ε. However, when we performed kinase reactions combining DDX3X and casein, we did not find a positive effect of DDX3X on casein phosphorylation by CK1ε, while both substrates were phosphorylated in a competitive manner. Moreover, CK1ε positively stimulates DDX3X ATPase activity. Our data provide a more detailed kinetic characterization on the functional interplay of these two proteins.
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13
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Balasuriya N, Davey NE, Johnson JL, Liu H, Biggar KK, Cantley LC, Li SSC, O'Donoghue P. Phosphorylation-dependent substrate selectivity of protein kinase B (AKT1). J Biol Chem 2020; 295:8120-8134. [PMID: 32350110 DOI: 10.1074/jbc.ra119.012425] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/22/2020] [Indexed: 12/31/2022] Open
Abstract
Protein kinase B (AKT1) is a central node in a signaling pathway that regulates cell survival. The diverse pathways regulated by AKT1 are communicated in the cell via the phosphorylation of perhaps more than 100 cellular substrates. AKT1 is itself activated by phosphorylation at Thr-308 and Ser-473. Despite the fact that these phosphorylation sites are biomarkers for cancers and tumor biology, their individual roles in shaping AKT1 substrate selectivity are unknown. We recently developed a method to produce AKT1 with programmed phosphorylation at either or both of its key regulatory sites. Here, we used both defined and randomized peptide libraries to map the substrate selectivity of site-specific, singly and doubly phosphorylated AKT1 variants. To globally quantitate AKT1 substrate preferences, we synthesized three AKT1 substrate peptide libraries: one based on 84 "known" substrates and two independent and larger oriented peptide array libraries (OPALs) of ∼1011 peptides each. We found that each phospho-form of AKT1 has common and distinct substrate requirements. Compared with pAKT1T308, the addition of Ser-473 phosphorylation increased AKT1 activities on some, but not all of its substrates. This is the first report that Ser-473 phosphorylation can positively or negatively regulate kinase activity in a substrate-dependent fashion. Bioinformatics analysis indicated that the OPAL-activity data effectively discriminate known AKT1 substrates from closely related kinase substrates. Our results also enabled predictions of novel AKT1 substrates that suggest new and expanded roles for AKT1 signaling in regulating cellular processes.
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Affiliation(s)
- Nileeka Balasuriya
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Norman E Davey
- Division of Cancer Biology, The Institute of Cancer Research, London, United Kingdom
| | - Jared L Johnson
- Meyer Cancer Center, Department of Medicine, Weill Cornell Medical College, New York, New York, United States
| | - Huadong Liu
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada.,Center for Mitochondrial Biology and Medicine, Xi'an Jiaotong University, Xi'an, Shanxi, China
| | - Kyle K Biggar
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada.,Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Lewis C Cantley
- Meyer Cancer Center, Department of Medicine, Weill Cornell Medical College, New York, New York, United States
| | - Shawn Shun-Cheng Li
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada
| | - Patrick O'Donoghue
- Department of Biochemistry, The University of Western Ontario, London, Ontario, Canada .,Department of Chemistry, The University of Western Ontario, London, Ontario, Canada
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14
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Chen EP, Song RS, Chen X. Mathematical model of hypoxia and tumor signaling interplay reveals the importance of hypoxia and cell-to-cell variability in tumor growth inhibition. BMC Bioinformatics 2019; 20:507. [PMID: 31638911 PMCID: PMC6802183 DOI: 10.1186/s12859-019-3098-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 09/13/2019] [Indexed: 01/10/2023] Open
Abstract
Background Human tumor is a complex tissue with multiple heterogeneous hypoxic regions and significant cell-to-cell variability. Due to the complexity of the disease, the explanation of why anticancer therapies fail cannot be attributed to intrinsic or acquired drug resistance alone. Furthermore, there are inconsistent reports of hypoxia-induced kinase activities in different cancer cell-lines, where increase, decreases, or no change has been observed. Thus, we asked, why are there widely contrasting results in kinase activity under hypoxia in different cancer cell-lines and how does hypoxia play a role in anti-cancer drug sensitivity? Results We took a modeling approach to address these questions by analyzing the model simulation to explain why hypoxia driven signals can have dissimilar impact on tumor growth and alter the efficacy of anti-cancer drugs. Repeated simulations with varying concentrations of biomolecules followed by decision tree analysis reveal that the highly differential effects among heterogeneous subpopulation of tumor cells could be governed by varying concentrations of just a few key biomolecules. These biomolecules include activated serine/threonine-specific protein kinases (pRAF), mitogen-activated protein kinase kinase (pMEK), protein kinase B (pAkt), or phosphoinositide-4,5-bisphosphate 3-kinase (pPI3K). Additionally, the ratio of activated extracellular signal-regulated kinases (pERK) or pAkt to its respective total was a key factor in determining the sensitivity of pERK or pAkt to hypoxia. Conclusion This work offers a mechanistic insight into how hypoxia can affect the efficacy of anti-cancer drug that targets tumor signaling and provides a framework to identify the types of tumor cells that are either sensitive or resistant to anti-cancer therapy.
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Affiliation(s)
- Emile P Chen
- Computational Sciences, GlaxoSmithKline, Collegeville, PA, 19426, USA.
| | - Roy S Song
- Computational Sciences, GlaxoSmithKline, Collegeville, PA, 19426, USA
| | - Xueer Chen
- Department of Biomedical Informatics, University of Pittsburgh, Pittsburgh, PA, 15206-3701, USA
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15
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Alwhaibi A, Verma A, Adil MS, Somanath PR. The unconventional role of Akt1 in the advanced cancers and in diabetes-promoted carcinogenesis. Pharmacol Res 2019; 145:104270. [PMID: 31078742 PMCID: PMC6659399 DOI: 10.1016/j.phrs.2019.104270] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 04/03/2019] [Accepted: 05/08/2019] [Indexed: 12/15/2022]
Abstract
Decades of research have elucidated the critical role of Akt isoforms in cancer as pro-tumorigenic and metastatic regulators through their specific effects on the cancer cells, tumor endothelial cells and the stromal cells. The pro-cancerous role of Akt isoforms through enhanced cell proliferation and suppression of apoptosis in cancer cells and the cells in the tumor microenvironment is considered a dogma. Intriguingly, studies also indicate that the Akt pathway is essential to protect the endothelial-barrier and prevent aberrant vascular permeability, which is also integral to tumor perfusion and metastasis. To complicate this further, a flurry of recent reports strongly indicates the metastasis suppressive role of Akt, Akt1 in particular in various cancer types. These reports emanated from different laboratories have elegantly demonstrated the paradoxical effect of Akt1 on cancer cell epithelial-to-mesenchymal transition, invasion, tumor endothelial-barrier disruption, and cancer metastasis. Here, we emphasize on the specific role of Akt1 in mediating tumor cell-vasculature reciprocity during the advanced stages of cancers and discuss how Akt1 differentially regulates cancer metastasis through mechanisms distinct from its pro-tumorigenic effects. Since Akt is integral for insulin signaling, endothelial function, and metabolic regulation, we also attempt to shed some light on the specific effects of diabetes in modulating Akt pathway in the promotion of tumor growth and metastasis.
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Affiliation(s)
- Abdulrahman Alwhaibi
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and the Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Arti Verma
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and the Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Mir S Adil
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and the Charlie Norwood VA Medical Center, Augusta, GA, USA
| | - Payaningal R Somanath
- Program in Clinical and Experimental Therapeutics, College of Pharmacy, University of Georgia and the Charlie Norwood VA Medical Center, Augusta, GA, USA; Department of Medicine, Vascular Biology Center and Cancer Center, Augusta University, USA.
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16
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Wlodarchak N, Teachout N, Beczkiewicz J, Procknow R, Schaenzer AJ, Satyshur K, Pavelka M, Zuercher W, Drewry D, Sauer JD, Striker R. In Silico Screen and Structural Analysis Identifies Bacterial Kinase Inhibitors which Act with β-Lactams To Inhibit Mycobacterial Growth. Mol Pharm 2018; 15:5410-5426. [PMID: 30285456 PMCID: PMC6648700 DOI: 10.1021/acs.molpharmaceut.8b00905] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
New tools and concepts are needed to combat antimicrobial resistance. Actinomycetes and firmicutes share several eukaryotic-like Ser/Thr kinases (eSTK) that offer antibiotic development opportunities, including PknB, an essential mycobacterial eSTK. Despite successful development of potent biochemical PknB inhibitors by many groups, clinically useful microbiologic activity has been elusive. Additionally, PknB kinetics are not fully described, nor are structures with specific inhibitors available to inform inhibitor design. We used computational modeling with available structural information to identify human kinase inhibitors predicted to bind PknB, and we selected hits based on drug-like characteristics intended to increase the likelihood of cell entry. The computational model suggested a family of inhibitors, the imidazopyridine aminofurazans (IPAs), bind PknB with high affinity. We performed an in-depth characterization of PknB and found that these inhibitors biochemically inhibit PknB, with potency roughly following the predicted models. A novel X-ray structure confirmed that the inhibitors bound as predicted and made favorable protein contacts with the target. These inhibitors also have antimicrobial activity toward mycobacteria and nocardia. We demonstrated that the inhibitors are uniquely potentiated by β-lactams but not antibiotics traditionally used to treat mycobacteria, consistent with PknB's role in sensing cell wall stress. This is the first demonstration in the phylum actinobacteria that some β-lactam antibiotics could be more effective if paired with a PknB inhibitor. Collectively, our data show that in silico modeling can be used as a tool to discover promising drug leads, and the inhibitors we discovered can act with clinically relevant antibiotics to restore their efficacy against bacteria with limited treatment options.
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Affiliation(s)
- Nathan Wlodarchak
- Department of Medicine, University of Wisconsin-Madison, 3341 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706
| | - Nathan Teachout
- Department of Medicine, University of Wisconsin-Madison, 3341 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706
| | - Jeffrey Beczkiewicz
- Department of Medicine, University of Wisconsin-Madison, 3341 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706
| | - Rebecca Procknow
- Department of Medicine, University of Wisconsin-Madison, 3341 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706
| | - Adam J. Schaenzer
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 4203 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706
| | - Kenneth Satyshur
- Small Molecule Screening Facility, Carbone Cancer Center, University of Wisconsin-Madison, 1111Highland Ave., Madison, WI 53705
| | - Martin Pavelka
- School of Medicine and Dentistry, University of Rochester Medical Center, 601 Elmwood Ave., Rochester, NY 14620
| | - William Zuercher
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, SGC Center for Chemical Biology, 120 Mason Farm Rd., Chapel Hill, NC 27599
| | - David Drewry
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, SGC Center for Chemical Biology, 120 Mason Farm Rd., Chapel Hill, NC 27599
| | - John-Demian Sauer
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 4203 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706
| | - Rob Striker
- Department of Medicine, University of Wisconsin-Madison, 3341 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706,William S. Middleton Memorial Veterans Hospital, 2500 Overlook Terr., Madison, WI 53705,To whom correspondence should be addressed Rob Striker, Department of Medicine, University of Wisconsin-Madison, 3301 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706, 608-263-2994,
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17
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Phosphorylation-Dependent Inhibition of Akt1. Genes (Basel) 2018; 9:genes9090450. [PMID: 30205513 PMCID: PMC6162393 DOI: 10.3390/genes9090450] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/10/2018] [Accepted: 08/10/2018] [Indexed: 11/16/2022] Open
Abstract
Protein kinase B (Akt1) is a proto-oncogene that is overactive in most cancers. Akt1 activation requires phosphorylation at Thr308; phosphorylation at Ser473 further enhances catalytic activity. Akt1 activity is also regulated via interactions between the kinase domain and the N-terminal auto-inhibitory pleckstrin homology (PH) domain. As it was previously difficult to produce Akt1 in site-specific phosphorylated forms, the contribution of each activating phosphorylation site to auto-inhibition was unknown. Using a combination of genetic code expansion and in vivo enzymatic phosphorylation, we produced Akt1 variants containing programmed phosphorylation to probe the interplay between Akt1 phosphorylation status and the auto-inhibitory function of the PH domain. Deletion of the PH domain increased the enzyme activity for all three phosphorylated Akt1 variants. For the doubly phosphorylated enzyme, deletion of the PH domain relieved auto-inhibition by 295-fold. We next found that phosphorylation at Ser473 provided resistance to chemical inhibition by Akti-1/2 inhibitor VIII. The Akti-1/2 inhibitor was most effective against pAkt1T308 and showed four-fold decreased potency with Akt1 variants phosphorylated at Ser473. The data highlight the need to design more potent Akt1 inhibitors that are effective against the doubly phosphorylated and most pathogenic form of Akt1.
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18
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Chu N, Salguero AL, Liu AZ, Chen Z, Dempsey DR, Ficarro SB, Alexander WM, Marto JA, Li Y, Amzel LM, Gabelli SB, Cole PA. Akt Kinase Activation Mechanisms Revealed Using Protein Semisynthesis. Cell 2018; 174:897-907.e14. [PMID: 30078705 DOI: 10.1016/j.cell.2018.07.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/15/2018] [Accepted: 07/03/2018] [Indexed: 11/30/2022]
Abstract
Akt is a critical protein kinase that drives cancer proliferation, modulates metabolism, and is activated by C-terminal phosphorylation. The current structural model for Akt activation by C-terminal phosphorylation has centered on intramolecular interactions between the C-terminal tail and the N lobe of the kinase domain. Here, we employ expressed protein ligation to produce site-specifically phosphorylated forms of purified Akt1 that are well suited for mechanistic analysis. Using biochemical, crystallographic, and cellular approaches, we determine that pSer473-Akt activation is driven by an intramolecular interaction between the C-tail and the pleckstrin homology (PH)-kinase domain linker that relieves PH domain-mediated Akt1 autoinhibition. Moreover, dual phosphorylation at Ser477/Thr479 activates Akt1 through a different allosteric mechanism via an apparent activation loop interaction that reduces autoinhibition by the PH domain and weakens PIP3 affinity. These results provide a new framework for understanding how Akt is controlled in cell signaling and suggest distinct functions for differentially modified Akt forms.
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Affiliation(s)
- Nam Chu
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Antonieta L Salguero
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Albert Z Liu
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Zan Chen
- Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Daniel R Dempsey
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Scott B Ficarro
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology and Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - William M Alexander
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Biology and Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Jarrod A Marto
- Department of Cancer Biology and Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Department of Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Yana Li
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - L Mario Amzel
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Sandra B Gabelli
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
| | - Philip A Cole
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
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19
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Balasuriya N, Kunkel MT, Liu X, Biggar KK, Li SSC, Newton AC, O'Donoghue P. Genetic code expansion and live cell imaging reveal that Thr-308 phosphorylation is irreplaceable and sufficient for Akt1 activity. J Biol Chem 2018; 293:10744-10756. [PMID: 29773654 DOI: 10.1074/jbc.ra118.002357] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 05/08/2018] [Indexed: 01/05/2023] Open
Abstract
The proto-oncogene Akt/protein kinase B (PKB) is a pivotal signal transducer for growth and survival. Growth factor stimulation leads to Akt phosphorylation at two regulatory sites (Thr-308 and Ser-473), acutely activating Akt signaling. Delineating the exact role of each regulatory site is, however, technically challenging and has remained elusive. Here, we used genetic code expansion to produce site-specifically phosphorylated Akt1 to dissect the contribution of each regulatory site to Akt1 activity. We achieved recombinant production of full-length Akt1 containing site-specific pThr and pSer residues for the first time. Our analysis of Akt1 site-specifically phosphorylated at either or both sites revealed that phosphorylation at both sites increases the apparent catalytic rate 1500-fold relative to unphosphorylated Akt1, an increase attributable primarily to phosphorylation at Thr-308. Live imaging of COS-7 cells confirmed that phosphorylation of Thr-308, but not Ser-473, is required for cellular activation of Akt. We found in vitro and in the cell that pThr-308 function cannot be mimicked with acidic residues, nor could unphosphorylated Thr-308 be mimicked by an Ala mutation. An Akt1 variant with pSer-308 achieved only partial enzymatic and cellular signaling activity, revealing a critical interaction between the γ-methyl group of pThr-308 and Cys-310 in the Akt1 active site. Thus, pThr-308 is necessary and sufficient to stimulate Akt signaling in cells, and the common use of phosphomimetics is not appropriate for studying the biology of Akt signaling. Our data also indicate that pThr-308 should be regarded as the primary diagnostic marker of Akt activity.
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Affiliation(s)
| | - Maya T Kunkel
- the Department of Pharmacology, University of California, San Diego, La Jolla, California 92093
| | | | | | | | - Alexandra C Newton
- the Department of Pharmacology, University of California, San Diego, La Jolla, California 92093
| | - Patrick O'Donoghue
- From the Departments of Biochemistry and .,Chemistry, The University of Western Ontario, London, Ontario N6A 5C1, Canada and
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20
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Lu CL, Zheng Q, Shen Q, Song C, Zhang ZM. Uncovering the relationship and mechanisms of Tartary buckwheat ( Fagopyrum tataricum) and Type II diabetes, hypertension, and hyperlipidemia using a network pharmacology approach. PeerJ 2017; 5:e4042. [PMID: 29177114 PMCID: PMC5701543 DOI: 10.7717/peerj.4042] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 10/25/2017] [Indexed: 12/12/2022] Open
Abstract
Background Tartary buckwheat (TB), a crop rich in protein, dietary fiber, and flavonoids, has been reported to have an effect on Type II diabetes (T2D), hypertension (HT), and hyperlipidemia (HL). However, limited information is available about the relationship between Tartary buckwheat and these three diseases. The mechanisms of how TB impacts these diseases are still unclear. Methods In this study, network pharmacology was used to investigate the relationship between the herb as well as the diseases and the mechanisms of how TB might impact these diseases. Results A total of 97 putative targets of 20 compounds found in TB were obtained. Then, an interaction network of 97 putative targets for these compounds and known therapeutic targets for the treatment of the three diseases was constructed. Based on the constructed network, 28 major nodes were identified as the key targets of TB due to their importance in network topology. The targets of ATK2, IKBKB, RAF1, CHUK, TNF, JUN, and PRKCA were mainly involved in fluid shear stress and the atherosclerosis and PI3K-Akt signaling pathways. Finally, molecular docking simulation showed that 174 pairs of chemical components and the corresponding key targets had strong binding efficiencies. Conclusion For the first time, a comprehensive systemic approach integrating drug target prediction, network analysis, and molecular docking simulation was developed to reveal the relationships and mechanisms between the putative targets in TB and T2D, HT, and HL.
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Affiliation(s)
- Chao-Long Lu
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, China.,Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Qi Zheng
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, China
| | - Qi Shen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China.,Guizhou Rapeseed Institute, Guizhou Province of Academy of Agricultural Sciences, Guiyang, China
| | - Chi Song
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Zhi-Ming Zhang
- Key Laboratory of Biology and Genetic Improvement of Maize in Southwest Region, Ministry of Agriculture, Maize Research Institute, Sichuan Agricultural University, Wenjiang, China
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21
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Ebner M, Lučić I, Leonard TA, Yudushkin I. PI(3,4,5)P 3 Engagement Restricts Akt Activity to Cellular Membranes. Mol Cell 2017; 65:416-431.e6. [PMID: 28157504 DOI: 10.1016/j.molcel.2016.12.028] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 10/19/2016] [Accepted: 12/29/2016] [Indexed: 01/13/2023]
Abstract
Protein kinase B/Akt regulates cellular metabolism, survival, and proliferation in response to hormones and growth factors. Hyperactivation of Akt is frequently observed in cancer, while Akt inactivation is associated with severe diabetes. Here, we investigated the molecular and cellular mechanisms that maintain Akt activity proportional to the activating stimulus. We show that binding of phosphatidylinositol-3,4,5-trisphosphate (PIP3) or PI(3,4)P2 to the PH domain allosterically activates Akt by promoting high-affinity substrate binding. Conversely, dissociation from PIP3 was rate limiting for Akt dephosphorylation, dependent on the presence of the PH domain. In cells, active Akt associated primarily with cellular membranes. In contrast, a transforming mutation that uncouples kinase activation from PIP3 resulted in the accumulation of hyperphosphorylated, active Akt in the cytosol. Our results suggest that intramolecular allosteric and cellular mechanisms cooperate to restrict Akt activity to cellular membranes, thereby enhancing the fidelity of Akt signaling and the specificity of downstream substrate phosphorylation.
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Affiliation(s)
- Michael Ebner
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, Vienna Biocenter (VBC), Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Iva Lučić
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, Vienna Biocenter (VBC), Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Thomas A Leonard
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, Vienna Biocenter (VBC), Campus Vienna Biocenter 5, 1030 Vienna, Austria; Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, 1030 Vienna, Austria.
| | - Ivan Yudushkin
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, Vienna Biocenter (VBC), Campus Vienna Biocenter 5, 1030 Vienna, Austria; Department of Medical Biochemistry, Medical University of Vienna, Vienna Biocenter (VBC), Dr. Bohr-Gasse 9, 1030 Vienna, Austria.
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Xie J, Ye Q, Cui X, Madan N, Yi Q, Pierre SV, Xie Z. Expression of rat Na-K-ATPase α2 enables ion pumping but not ouabain-induced signaling in α1-deficient porcine renal epithelial cells. Am J Physiol Cell Physiol 2015; 309:C373-82. [PMID: 26108663 DOI: 10.1152/ajpcell.00103.2015] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 06/13/2015] [Indexed: 11/22/2022]
Abstract
Na-K-ATPase is a fundamental component of ion transport. Four α isoforms of the Na-K-ATPase catalytic α subunit are expressed in human cells. The ubiquitous Na-K-ATPase α1 was recently discovered to also mediate signal transduction through Src kinase. In contrast, α2 expression is limited to a few cell types including myocytes, where it is coupled to the Na(+)/Ca(2+) exchanger. To test whether rat Na-K-ATPase α2 is capable of cellular signaling like its α1 counterpart in a recipient mammalian system, we used an α1 knockdown pig renal epithelial cell (PY-17) to create an α2-expressing cell line with no detectable level of α1 expression. These cells exhibited normal ouabain-sensitive ATPase, but failed to effectively regulate Src. In contrast to α1-expressing cells, ouabain did not stimulate Src kinase or downstream effectors such as ERK and Akt in α2 cells, although their signaling apparatus was intact as evidenced by EGF-mediated signal transduction. Additionally, α2 cells were unable to rescue caveolin-1. Unlike the NaKtide sequence derived from Na-K-ATPase α1, which downregulates basal Src activity, the corresponding α2 NaKtide was unable to inhibit Src in vitro. Finally, coimmunoprecipitation of cellular Src was diminished in α2 cells. These findings indicate that Na-K-ATPase α2 does not regulate Src and, therefore, may not serve the same role in signal transduction as α1. This further implies that the signaling mechanism of Na-K-ATPase is isoform specific, thereby supporting a model where α1 and α2 isoforms play distinct roles in mediating contraction and signaling in myocytes.
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Affiliation(s)
- Joe Xie
- Department of Medicine, University of Colorado, Aurora, Colorado
| | - Qiqi Ye
- Department of Physiology and Pharmacology, University of Toledo, Toledo, Ohio
| | - Xiaoyu Cui
- Department of Physiology and Pharmacology, University of Toledo, Toledo, Ohio
| | - Namrata Madan
- Department of Physiology and Pharmacology, University of Toledo, Toledo, Ohio
| | - Qiying Yi
- Laboratory Animal Center, Chongqing Medical University, Chongqing, PR China; and
| | - Sandrine V Pierre
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, West Virginia
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, West Virginia
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23
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Hudson CS, Knegtel RM, Brown K, Charlton PA, Pollard JR. Kinetic and mechanistic characterisation of Choline Kinase-α. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:1107-16. [PMID: 23416529 DOI: 10.1016/j.bbapap.2013.02.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 02/01/2013] [Accepted: 02/05/2013] [Indexed: 10/27/2022]
Abstract
Choline Kinase is a key component of the Kennedy pathway that converts choline into a number of structural and signalling lipids that are essential for cell growth and survival. One member of the family, Choline Kinase-α (ChoKα) is frequently up-regulated in human cancers, and expression of ChoKα is sufficient to transform cells. Consequently ChoKα has been studied as a potential target for therapeutic agents in cancer research. Despite great interest in the enzyme, mechanistic studies have not been reported. In this study, a combination of initial velocity and product inhibition studies, together with the kinetic and structural characterisation of a novel ChoKα inhibitor is used to support a mechanism of action for human ChoKα. Substrate and inhibition kinetics are consistent with an iso double displacement mechanism, in which the γ-phosphate from ATP is transferred to choline in two distinct steps via a phospho-enzyme intermediate. Co-crystal structures, and existing site-specific mutation studies, support an important role for Asp306, in stabilising the phospho-enzyme intermediate. The kinetics also indicate a distinct kinetic (isomerisation) step associated with product release, which may be attributed to a conformational change in the protein to disrupt an interaction between Asp306 and the phosphocholine product, facilitating product release. This study describes a mechanism for ChoKα that is unusual amongst kinases, and highlights the availability of different enzyme states that can be exploited for drug discovery.
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24
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Leander R, Dai S, Schlesinger LS, Friedman A. A mathematical model of CR3/TLR2 crosstalk in the context of Francisella tularensis infection. PLoS Comput Biol 2012; 8:e1002757. [PMID: 23133361 PMCID: PMC3486853 DOI: 10.1371/journal.pcbi.1002757] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 09/05/2012] [Indexed: 02/04/2023] Open
Abstract
Complement Receptor 3 (CR3) and Toll-like Receptor 2 (TLR2) are pattern recognition receptors expressed on the surface of human macrophages. Although these receptors are essential components for recognition by the innate immune system, pathogen coordinated crosstalk between them can suppress the production of protective cytokines and promote infection. Recognition of the virulent Schu S4 strain of the intracellular pathogen Francisella tularensis by host macrophages involves CR3/TLR2 crosstalk. Although experimental data provide evidence that Lyn kinase and PI3K are essential components of the CR3 pathway that influences TLR2 activity, additional responsible upstream signaling components remain unknown. In this paper we construct a mathematical model of CR3 and TLR2 signaling in response to F. tularensis. After demonstrating that the model is consistent with experimental results we perform numerical simulations to evaluate the contributions that Akt and Ras-GAP make to ERK inhibition. The model confirms that phagocytosis-associated changes in the composition of the cell membrane can inhibit ERK activity and predicts that Akt and Ras-GAP synergize to inhibit ERK.
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Affiliation(s)
- Rachel Leander
- Mathematical Biosciences Institute, The Ohio State University, Columbus, Ohio, United States of America
| | - Shipan Dai
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
| | - Larry S. Schlesinger
- Center for Microbial Interface Biology, Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, United States of America
| | - Avner Friedman
- Mathematical Biosciences Institute, The Ohio State University, Columbus, Ohio, United States of America
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25
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Design and synthesis of novel amide AKT1 inhibitors with selectivity over CDK2. Bioorg Med Chem Lett 2011; 21:5191-6. [DOI: 10.1016/j.bmcl.2011.07.056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 07/11/2011] [Accepted: 07/13/2011] [Indexed: 11/19/2022]
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26
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Hibino K, Shibata T, Yanagida T, Sako Y. Activation kinetics of RAF protein in the ternary complex of RAF, RAS-GTP, and kinase on the plasma membrane of living cells: single-molecule imaging analysis. J Biol Chem 2011; 286:36460-8. [PMID: 21862573 DOI: 10.1074/jbc.m111.262675] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
RAS is an important cell signaling molecule, regulating the activities of various effector proteins, including the kinase c-RAF (RAF). Despite the critical function of RAS signaling, the activation kinetics have not been analyzed experimentally in living cells for any of the RAS effectors. Here, we analyzed the kinetics of RAF activation on the plasma membrane in living HeLa cells after stimulation with EGF to activate RAS. RAF is recruited by the active form of RAS (RAS-GTP) from the cytoplasm to the plasma membrane through two RAS-binding sites (the RAS-binding domain and the cysteine-rich domain (CRD)) and is activated by its phosphorylation by still undetermined kinases on the plasma membrane. Using single-molecule imaging, we measured the dissociation time courses of GFP-tagged molecules of wild type RAF and fragments or mutants of RAF containing one or two of the three functional domains (the RAS-binding domain, the CRD, and the catalytic domain) to determine their interaction with membrane components. Each molecule showed a unique dissociation time course, indicating that both its interaction with RAS-GTP and its phosphorylation by the kinases are rate-limiting steps in RAF activation. Based on our experimental results, we propose a kinetic model for the activation of RAF. The model suggests the importance of the interaction between RAS-GTP and CRD for the effective activation of RAF, which is triggered by rapid RAS-GTP-induced conformational changes in RAF and the subsequent presentation of RAF to the kinase. The model also suggests necessary properties of the kinases that activate RAF.
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Affiliation(s)
- Kayo Hibino
- Cellular Informatics Laboratory, RIKEN, Advanced Science Institute, 2-1 Hirosawa, Wako 351-0198, Japan
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27
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Schwartz PA, Murray BW. Protein kinase biochemistry and drug discovery. Bioorg Chem 2011; 39:192-210. [PMID: 21872901 DOI: 10.1016/j.bioorg.2011.07.004] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 07/22/2011] [Indexed: 12/19/2022]
Abstract
Protein kinases are fascinating biological catalysts with a rapidly expanding knowledge base, a growing appreciation in cell regulatory control, and an ascendant role in successful therapeutic intervention. To better understand protein kinases, the molecular underpinnings of phosphoryl group transfer, protein phosphorylation, and inhibitor interactions are examined. This analysis begins with a survey of phosphate group and phosphoprotein properties which provide context to the evolutionary selection of phosphorylation as a central mechanism for biological regulation of most cellular processes. Next, the kinetic and catalytic mechanisms of protein kinases are examined with respect to model aqueous systems to define the elements of catalysis. A brief structural biology overview further delves into the molecular basis of catalysis and regulation of catalytic activity. Concomitant with a prominent role in normal physiology, protein kinases have important roles in the disease state. To facilitate effective kinase drug discovery, classic and emerging approaches for characterizing kinase inhibitors are evaluated including biochemical assay design, inhibitor mechanism of action analysis, and proper kinetic treatment of irreversible inhibitors. As the resulting protein kinase inhibitors can modulate intended and unintended targets, profiling methods are discussed which can illuminate a more complete range of an inhibitor's biological activities to enable more meaningful cellular studies and more effective clinical studies. Taken as a whole, a wealth of protein kinase biochemistry knowledge is available, yet it is clear that a substantial extent of our understanding in this field remains to be discovered which should yield many new opportunities for therapeutic intervention.
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Affiliation(s)
- Phillip A Schwartz
- Pfizer Worldwide Research and Development, La Jolla, Pfizer Inc., San Diego, CA 92121, United States
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28
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Schneck JL, Briand J, Chen S, Lehr R, McDevitt P, Zhao B, Smallwood A, Concha N, Oza K, Kirkpatrick R, Yan K, Villa JP, Meek TD, Thrall SH. Kinetic mechanism and rate-limiting steps of focal adhesion kinase-1. Biochemistry 2010; 49:7151-63. [PMID: 20597513 DOI: 10.1021/bi100824v] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Steady-state kinetic analysis of focal adhesion kinase-1 (FAK1) was performed using radiometric measurement of phosphorylation of a synthetic peptide substrate (Ac-RRRRRRSETDDYAEIID-NH(2), FAK-tide) which corresponds to the sequence of an autophosphorylation site in FAK1. Initial velocity studies were consistent with a sequential kinetic mechanism, for which apparent kinetic values k(cat) (0.052 +/- 0.001 s(-1)), K(MgATP) (1.2 +/- 0.1 microM), K(iMgATP) (1.3 +/- 0.2 microM), K(FAK-tide) (5.6 +/- 0.4 microM), and K(iFAK-tide) (6.1 +/- 1.1 microM) were obtained. Product and dead-end inhibition data indicated that enzymatic phosphorylation of FAK-tide by FAK1 was best described by a random bi bi kinetic mechanism, for which both E-MgADP-FAK-tide and E-MgATP-P-FAK-tide dead-end complexes form. FAK1 catalyzed the betagamma-bridge:beta-nonbridge positional oxygen exchange of [gamma-(18)O(4)]ATP in the presence of 1 mM [gamma-(18)O(4)]ATP and 1.5 mM FAK-tide with a progressive time course which was commensurate with catalysis, resulting in a rate of exchange to catalysis of k(x)/k(cat) = 0.14 +/- 0.01. These results indicate that phosphoryl transfer is reversible and that a slow kinetic step follows formation of the E-MgADP-P-FAK-tide complex. Further kinetic studies performed in the presence of the microscopic viscosogen sucrose revealed that solvent viscosity had no effect on k(cat)/K(FAK-tide), while k(cat) and k(cat)/K(MgATP) were both decreased linearly at increasing solvent viscosity. Crystallographic characterization of inactive versus AMP-PNP-liganded structures of FAK1 showed that a large conformational motion of the activation loop upon ATP binding may be an essential step during catalysis and would explain the viscosity effect observed on k(cat)/K(m) for MgATP but not on k(cat)/K(m) for FAK-tide. From the positional isotope exchange, viscosity, and structural data it may be concluded that enzyme turnover (k(cat)) is rate-limited by both reversible phosphoryl group transfer (k(forward) approximately 0.2 s(-1) and k(reverse) approximately 0.04 s(-1)) and a slow step (k(conf) approximately 0.1 s(-1)) which is probably the opening of the activation loop after phosphoryl group transfer but preceding product release.
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Affiliation(s)
- Jessica L Schneck
- Department of Biological Reagents, GlaxoSmithKline Pharmaceuticals, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426-0989, USA
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29
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Zeng Q, Bourbeau MP, Wohlhieter GE, Yao G, Monenschein H, Rider JT, Lee MR, Zhang S, Lofgren J, Freeman D, Li C, Tominey E, Huang X, Hoffman D, Yamane H, Tasker AS, Dominguez C, Viswanadhan VN, Hungate R, Zhang X. 2-Aminothiadiazole inhibitors of AKT1 as potential cancer therapeutics. Bioorg Med Chem Lett 2010; 20:1652-6. [DOI: 10.1016/j.bmcl.2010.01.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2009] [Revised: 01/08/2010] [Accepted: 01/11/2010] [Indexed: 10/19/2022]
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30
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Oscillations of the p53-Akt network: implications on cell survival and death. PLoS One 2009; 4:e4407. [PMID: 19197384 PMCID: PMC2634840 DOI: 10.1371/journal.pone.0004407] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2008] [Accepted: 12/16/2008] [Indexed: 11/19/2022] Open
Abstract
Intracellular protein levels of p53 and MDM2 have been shown to oscillate in response to ionizing radiation (IR), but the physiological significance of these oscillations remains unclear. The p53-MDM2 negative feedback loop – the putative cause of the oscillations – is embedded in a network involving a mutual antagonism (or positive feedback loop) between p53 and AKT. We have shown earlier that this p53-AKT network predicts an all-or-none switching behavior between a pro-survival cellular state (low p53 and high AKT levels) and a pro-apoptotic state (high p53 and low AKT levels). Here, we show that upon exposure to IR, the p53-AKT network can also reproduce the experimentally observed p53 and MDM2 oscillations. The present work is based on the hypothesis that the physiological significance of the experimentally observed oscillations could be found in their role in regulating the switching behavior of the p53-AKT network between pro-survival and pro-apoptotic states. It is shown here that these oscillations are associated with a significant decrease in the threshold level of IR at which switching from a pro-survival to a pro-apoptotic state occurs. Moreover, oscillations in p53 protein levels induce higher levels of expression of p53-target genes compared to non-oscillatory p53, and thus influence cell-fate decisions between cell cycle arrest/DNA damage repair versus apoptosis.
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31
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Lavogina D, Lust M, Viil I, König N, Raidaru G, Rogozina J, Enkvist E, Uri A, Bossemeyer D. Structural Analysis of ARC-Type Inhibitor (ARC-1034) Binding to Protein Kinase A Catalytic Subunit and Rational Design of Bisubstrate Analogue Inhibitors of Basophilic Protein Kinases. J Med Chem 2008; 52:308-21. [DOI: 10.1021/jm800797n] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Darja Lavogina
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Marje Lust
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Indrek Viil
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Norbert König
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Gerda Raidaru
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Jevgenia Rogozina
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Erki Enkvist
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Asko Uri
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Dirk Bossemeyer
- Institute of Chemistry, 2 Jakobi Street, 51014 Tartu, Estonia, Group of Structural Biochemistry, German Cancer Research Centre, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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32
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Toral-Barza L, Zhang WG, Huang X, McDonald LA, Salaski EJ, Barbieri LR, Ding WD, Krishnamurthy G, Hu YB, Lucas J, Bernan VS, Cai P, Levin JI, Mansour TS, Gibbons JJ, Abraham RT, Yu K. Discovery of lactoquinomycin and related pyranonaphthoquinones as potent and allosteric inhibitors of AKT/PKB: mechanistic involvement of AKT catalytic activation loop cysteines. Mol Cancer Ther 2007; 6:3028-38. [PMID: 17989320 DOI: 10.1158/1535-7163.mct-07-0211] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The serine/threonine kinase AKT/PKB plays a critical role in cancer and represents a rational target for therapy. Although efforts in targeting AKT pathway have accelerated in recent years, relatively few small molecule inhibitors of AKT have been reported. The development of selective AKT inhibitors is further challenged by the extensive conservation of the ATP-binding sites of the AGC kinase family. In this report, we have conducted a high-throughput screen for inhibitors of activated AKT1. We have identified lactoquinomycin as a potent inhibitor of AKT kinases (AKT1 IC(50), 0.149 +/- 0.045 micromol/L). Biochemical studies implicated a novel irreversible interaction of the inhibitor and AKT involving a critical cysteine residue(s). To examine the role of conserved cysteines in the activation loop (T-loop), we studied mutant AKT1 harboring C296A, C310A, and C296A/C310A. Whereas the ATP-pocket inhibitor, staurosporine, indiscriminately targeted the wild-type and all three mutant-enzymes, the inhibition by lactoquinomycin was drastically diminished in the single mutants C296A and C310A, and completely abolished in the double mutant C296A/C310A. These data strongly implicate the binding of lactoquinomycin to the T-loop cysteines as critical for abrogation of catalysis, and define an unprecedented mechanism of AKT inhibition by a small molecule. Lactoquinomycin inhibited cellular AKT substrate phosphorylation induced by growth factor, loss of PTEN, and myristoylated AKT. The inhibition was substantially attenuated by coexpression of C296A/C310A. Moreover, lactoquinomycin reduced cellular mammalian target of rapamycin signaling and cap-dependent mRNA translation initiation. Our results highlight T-loop targeting as a new strategy for the generation of selective AKT inhibitors.
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33
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Martin T, Sharma R, Sippel C, Waegemann K, Soll J, Vothknecht UC. A protein kinase family in Arabidopsis phosphorylates chloroplast precursor proteins. J Biol Chem 2006; 281:40216-23. [PMID: 17090544 DOI: 10.1074/jbc.m606580200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A serine/threonine protein kinase that is able to phosphorylate chloroplast-destined precursor proteins was purified from leaf extract of Arabidopsis thaliana and was identified by mass spectrometry. The protein kinase, encoded by AT2G17700, belongs to a small protein family comprising in addition AT4G35780 and AT4G38470. All three proteins were expressed heterologously in Escherichia coli and characterized with regard to their properties in precursor protein phosphorylation. They were able to phosphorylate several chloroplast-destined precursor proteins within their cleavable presequences. In contrast, a mitochondria-destined precursor protein was not a substrate for these kinases. For all three enzymes, the phosphorylation reaction was specific for ATP with apparent K(m) values between 14 and 67 microM. They did not utilize other NTPs nor were those able to compete for ATP in the reaction. An excess of ADP was able to inhibit ATP-dependent phosphorylation. Furthermore, all three kinases exhibited autophosphorylation. The protein kinases described here could represent subunits of a regulatory network involved in the cytosolic events of chloroplast protein import.
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Affiliation(s)
- Torsten Martin
- Department Biology I, Botany, Ludwig-Maximilians-University Munich, Menzingerstrasse 67, D-80638 Munich, Germany
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