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Mbonye U, Karn J. The cell biology of HIV-1 latency and rebound. Retrovirology 2024; 21:6. [PMID: 38580979 PMCID: PMC10996279 DOI: 10.1186/s12977-024-00639-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024] Open
Abstract
Transcriptionally latent forms of replication-competent proviruses, present primarily in a small subset of memory CD4+ T cells, pose the primary barrier to a cure for HIV-1 infection because they are the source of the viral rebound that almost inevitably follows the interruption of antiretroviral therapy. Over the last 30 years, many of the factors essential for initiating HIV-1 transcription have been identified in studies performed using transformed cell lines, such as the Jurkat T-cell model. However, as highlighted in this review, several poorly understood mechanisms still need to be elucidated, including the molecular basis for promoter-proximal pausing of the transcribing complex and the detailed mechanism of the delivery of P-TEFb from 7SK snRNP. Furthermore, the central paradox of HIV-1 transcription remains unsolved: how are the initial rounds of transcription achieved in the absence of Tat? A critical limitation of the transformed cell models is that they do not recapitulate the transitions between active effector cells and quiescent memory T cells. Therefore, investigation of the molecular mechanisms of HIV-1 latency reversal and LRA efficacy in a proper physiological context requires the utilization of primary cell models. Recent mechanistic studies of HIV-1 transcription using latently infected cells recovered from donors and ex vivo cellular models of viral latency have demonstrated that the primary blocks to HIV-1 transcription in memory CD4+ T cells are restrictive epigenetic features at the proviral promoter, the cytoplasmic sequestration of key transcription initiation factors such as NFAT and NF-κB, and the vanishingly low expression of the cellular transcription elongation factor P-TEFb. One of the foremost schemes to eliminate the residual reservoir is to deliberately reactivate latent HIV-1 proviruses to enable clearance of persisting latently infected cells-the "Shock and Kill" strategy. For "Shock and Kill" to become efficient, effective, non-toxic latency-reversing agents (LRAs) must be discovered. Since multiple restrictions limit viral reactivation in primary cells, understanding the T-cell signaling mechanisms that are essential for stimulating P-TEFb biogenesis, initiation factor activation, and reversing the proviral epigenetic restrictions have become a prerequisite for the development of more effective LRAs.
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Affiliation(s)
- Uri Mbonye
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA.
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2
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Das J, You Y, Mathukumalli K, Ann J, Lee J, Marquez VE. Activation of Munc13-1 by Diacylglycerol (DAG)-Lactones. Biochemistry 2023; 62:2717-2726. [PMID: 37651159 DOI: 10.1021/acs.biochem.3c00375] [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] [Indexed: 09/01/2023]
Abstract
Munc13-1 is a key protein necessary for vesicle fusion and neurotransmitter release in the brain. Diacylglycerol (DAG)/phorbol ester binds to its C1 domain in the plasma membrane and activates it. The C1 domain of Munc13-1 and protein kinase C (PKC) are homologous in terms of sequence and structure. In order to identify small-molecule modulators of Munc13-1 targeting the C1 domain, we studied the effect of three DAG-lactones, (R,Z)-(2-(hydroxymethyl)-4-(3-isobutyl-5-methylhexylidene)-5-oxotetrahydrofuran-2-yl)methyl pivalate (JH-131e-153), (E)-(2-(hydroxymethyl)-4-(3-isobutyl-5-methylhexylidene)-5-oxotetrahydrofuran-2-yl)methyl pivalate (AJH-836), and (E)-(2-(hydroxymethyl)-4-(4-nitrobenzylidene)-5-oxotetrahydrofuran-2-yl)methyl 4-(dimethylamino)benzoate (130C037), on Munc13-1 activation using the ligand-induced membrane translocation assay. JH-131e-153 showed higher activation than AJH-836, and 130C037 was not able to activate Munc13-1. To understand the role of the ligand-binding site residues in the activation process, three alanine mutants were generated. For AJH-836, the order of activation was wild-type (WT) Munc13-1 > R592A > W588A > I590A. For JH-131e-153, the order of activation was WT > I590 ≈ R592A ≈ W588A. Overall, the Z isomer of DAG-lactones showed higher potency than the E isomer and Trp-588, Ile-590, and Arg-592 were important for its binding. When comparing the activation of Munc13-1 and PKC, the order of activation for JH-131e-153 was PKCα > Munc13-1 > PKCε and for AJH-836, the order of activation was PKCε > PKCα > Munc13-1. Molecular docking supported higher binding of JH-131e-153 than AJH-836 with the Munc13-1 C1 domain. Our results suggest that DAG-lactones have the potential to modulate neuronal processes via Munc13-1 and can be further developed for therapeutic intervention for neurodegenerative diseases.
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Affiliation(s)
- Joydip Das
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas 77204, United States
| | - Youngki You
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas 77204, United States
| | - Kavya Mathukumalli
- Department of Pharmacological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, Texas 77204, United States
| | - Jihyae Ann
- College of Pharmacy, Seoul National University, Building 143, Room 507, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - Jeewoo Lee
- College of Pharmacy, Seoul National University, Building 143, Room 507, 1 Gwanak-Ro, Gwanak-Gu, Seoul 08826, Korea
| | - Victor E Marquez
- Center for Cancer Research, Chemical Biology Laboratory, NCI-Frederick, 376 Boyles Street, Frederick, Maryland 21702, United States
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3
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Chi Y, He HW, Chen CY, Zhao SY, Zhou H, Xu D, Liu X, Xu G. Furofuran Lignans for Plant Protection: Discovery of Sesamolin and Its Derivatives as Novel Anti-Tobacco Mosaic Virus and Antibacterial Agents. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37418668 DOI: 10.1021/acs.jafc.3c03257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2023]
Abstract
Natural products have been a valuable source of efficient and low-risk pesticides. In this work, a series of novel sesamolin derivatives A0-A31 and B0-B4 were designed and synthesized via structural simplification of furofuran lignan phrymarolin II, and their antiviral and antibacterial activities were systematically evaluated. The bioassay results showed that compound A24 displayed remarkable inactivation activity against tobacco mosaic virus (TMV) with an EC50 value of 130.4 μg/mL, which was superior to that of commercial ningnanmycin (EC50 = 202.0 μg/mL). The antiviral mode of action assays suggested that compound A24 may obstruct self-assembly by binding to TMV coat protein (CP), thus resisting the TMV infection. In addition, compound A25 possessed prominent antibacterial activities, especially against Ralstonia solanacearum with an EC50 value of 43.8 μg/mL, which is better than those of commercial bismerthiazol and thiodiazole copper. This research lays a solid foundation for the utilization of furofuran lignans in crop protection.
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Affiliation(s)
- Yuan Chi
- College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi 712100, China
| | - Hong-Wei He
- College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi 712100, China
| | - Cai-Yun Chen
- College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi 712100, China
| | - Si-Ying Zhao
- College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi 712100, China
| | - Huan Zhou
- College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi 712100, China
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, Shaanxi 712100, China
| | - Dan Xu
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, Shaanxi 712100, China
- Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China
| | - Xili Liu
- College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi 712100, China
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, Shaanxi 712100, China
| | - Gong Xu
- College of Plant Protection, Northwest A&F University, 3 Taicheng Road, Yangling, Shaanxi 712100, China
- Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling, Shaanxi 712100, China
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4
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Xiong YS, Zhang C, Rujian Y, Hai-Yan H, Pei W, Fu WY, Cheng JX. Silver-Mediated Radical Oxytrifluoromethylation of Unstaurated Carboxylic Acids for the Synthesis of γ-Trifluoromethylthio Lactones. Org Biomol Chem 2022; 20:2109-2114. [DOI: 10.1039/d2ob00018k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient silver-mediated oxidative trifluoromethylthiolation of unsaturated carboxylic acids to constructed trifluoromethylthiole-containing lactones has been disclosed. This protocol without added other metal-catalyst, preliminary mechanism investigations suggested that a free-radical pathway...
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5
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Elhalem E, Bellomo A, Cooke M, Scravaglieri A, Pearce LV, Peach ML, Gandolfi Donadío L, Kazanietz MG, Comin MJ. Design, Synthesis, and Characterization of Novel sn-1 Heterocyclic DAG-Lactones as PKC Activators. J Med Chem 2021; 64:11418-11431. [PMID: 34279947 DOI: 10.1021/acs.jmedchem.1c00739] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
DAG-lactones represent useful templates for the design of potent and selective C1 domain ligands for PKC isozymes. The ester moiety at the sn-1 position, a common feature in this template, is relevant for C1 domain interactions, but it represents a labile group susceptible to endogenous esterases. An interesting challenge involves replacing the ester group of these ligands while still maintaining biological activity. Here, we present the synthesis and functional characterization of novel diacylglycerol-lactones containing heterocyclic ring substituents at the sn-1 position. Our results showed that the new compound 10B12, a DAG-lactone with an isoxazole ring, binds PKCα and PKCε with nanomolar affinity. Remarkably, 10B12 displays preferential selectivity for PKCε translocation in cells and induces a PKCε-dependent reorganization of the actin cytoskeleton into peripheral ruffles in lung cancer cells. We conclude that introducing a stable isoxazole ring as an ester surrogate in DAG-lactones emerges as a novel structural approach to achieve PKC isozyme selectivity.
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Affiliation(s)
- Eleonora Elhalem
- Departamento de Ingredientes Activos y Biorrefinerías, Instituto Nacional de Tecnología Industrial, Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina
| | - Ana Bellomo
- Departamento de Ingredientes Activos y Biorrefinerías, Instituto Nacional de Tecnología Industrial, Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina
| | - Mariana Cooke
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.,Department of Medicine, Einstein Medical Center Philadelphia, Philadelphia, Pennsylvania 19141, United States
| | - Antonella Scravaglieri
- Departamento de Ingredientes Activos y Biorrefinerías, Instituto Nacional de Tecnología Industrial, Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina
| | - Larry V Pearce
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland 20892-4255, United States
| | - Megan L Peach
- Basic Science Program, Chemical Biology Laboratory, Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, Maryland 21702, United States
| | - Lucía Gandolfi Donadío
- Departamento de Ingredientes Activos y Biorrefinerías, Instituto Nacional de Tecnología Industrial, Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina
| | - Marcelo G Kazanietz
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - María J Comin
- Departamento de Ingredientes Activos y Biorrefinerías, Instituto Nacional de Tecnología Industrial, Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. General Paz 5445, San Martín, Buenos Aires B1650WAB, Argentina
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6
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Cheng F, Wang LL, Mao YH, Dong YX, Liu B, Zhu GF, Yang YY, Guo B, Tang L, Zhang JQ. Iron-Catalyzed Radical Annulation of Unsaturated Carboxylic Acids with Disulfides for the Synthesis of γ-Lactones. J Org Chem 2021; 86:8620-8629. [PMID: 34097828 DOI: 10.1021/acs.joc.1c00284] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
An efficient aerobic iron-catalyzed annulation of unsaturated carboxylic acids with disulfides has been developed. This procedure proceeds using FeCl3 as the catalyst and KI as an iodine source under an air atmosphere, which provides practical access to a wide range of substituted γ-lactone derivatives. The disclosed method is quite simple, highly atom-economic, environmentally friendly, and tolerates a broad substrate scope.
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Affiliation(s)
- Fei Cheng
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
| | - Li-Li Wang
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
| | - Yuan-Hu Mao
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
| | - Yong-Xi Dong
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
| | - Bin Liu
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
| | - Gao-Feng Zhu
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
| | - Yuan-Yong Yang
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
| | - Bing Guo
- Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang 550025, China
| | - Lei Tang
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
| | - Ji-Quan Zhang
- State Key Laboratory of Functions and Applications of Medicinal Plants and College of Pharmacy, Guizhou Provincial Engineering Technology Research Center for Chemical Drug R&D, Guizhou Medical University, Guiyang 550025, China
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7
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Ann J, Czikora A, Saini AS, Zhou X, Mitchell GA, Lewin NE, Peach ML, Blumberg PM, Lee J. α-Arylidene Diacylglycerol-Lactones (DAG-Lactones) as Selective Ras Guanine-Releasing Protein 3 (RasGRP3) Ligands. J Med Chem 2018; 61:6261-6276. [PMID: 29860841 DOI: 10.1021/acs.jmedchem.8b00661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Diacylglycerol-lactones have proven to be a powerful template for the design of potent ligands targeting C1 domains, the recognition motif for the cellular second messenger diacylglycerol. A major objective has been to better understand the structure activity relations distinguishing the seven families of signaling proteins that contain such domains, of which the protein kinase C (PKC) and RasGRP families are of particular interest. Here, we synthesize a series of aryl- and alkyl-substituted diacylglycerol-lactones and probe their relative selectivities for RasGRP3 versus PKC. Compound 96 showed 73-fold selectivity relative to PKCα and 45-fold selectivity relative to PKCε for in vitro binding activity. Likewise, in intact cells, compound 96 induced Ras activation, a downstream response to RasGRP stimulation, with 8-29 fold selectivity relative to PKCδ S299 phosphorylation, a measure of PKCδ stimulation.
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Affiliation(s)
- Jihyae Ann
- Laboratory of Medicinal Chemistry, College of Pharmacy , Seoul National University , Seoul 08826 , Republic of Korea
| | - Agnes Czikora
- Laboratory of Cancer Biology and Genetics , Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Amandeep S Saini
- Laboratory of Cancer Biology and Genetics , Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Xiaoling Zhou
- Laboratory of Cancer Biology and Genetics , Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Gary A Mitchell
- Laboratory of Cancer Biology and Genetics , Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics , Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Megan L Peach
- Basic Science Program, Leidos Biomedical Research Inc., Chemical Biology Laboratory , Frederick National Laboratory for Cancer Research, National Institutes of Health , Frederick , Maryland 21702 , United States
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics , Center for Cancer Research, National Cancer Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Jeewoo Lee
- Laboratory of Medicinal Chemistry, College of Pharmacy , Seoul National University , Seoul 08826 , Republic of Korea
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8
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Czikora A, Kedei N, Kalish H, Blumberg PM. Importance of the REM (Ras exchange) domain for membrane interactions by RasGRP3. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2017; 1859:2350-2360. [PMID: 28912101 PMCID: PMC5659902 DOI: 10.1016/j.bbamem.2017.09.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 11/18/2022]
Abstract
RasGRP comprises a family of guanine nucleotide exchange factors, regulating the dissociation of GDP from Ras GTPases to enhance the formation of the active GTP-bound form. RasGRP1 possesses REM (Ras exchange), GEF (catalytic), EF-hand, C1, SuPT (suppressor of PT), and PT (plasma membrane-targeting) domains, among which the C1 domain drives membrane localization in response to diacylglycerol or phorbol ester and the PT domain recognizes phosphoinositides. The homologous family member RasGRP3 shows less plasma membrane localization. The objective of this study was to explore the role of the different domains of RasGRP3 in membrane translocation in response to phorbol esters. The full-length RasGRP3 shows limited translocation to the plasma membrane in response to PMA, even when the basic hydrophobic cluster in the PT domain, reported to be critical for RasGRP1 translocation to endogenous activators, is mutated to resemble that of RasGRP1. Moreover, exchange of the C-termini (SuPT-PT domain) of the two proteins had little effect on their plasma membrane translocation. On the other hand, while the C1 domain of RasGRP3 alone showed partial plasma membrane translocation, truncated RasGRP3 constructs, which contain the PT domain and are missing the REM, showed stronger translocation, indicating that the REM of RasGRP3 was a suppressor of its membrane interaction. The REM of RasGRP1 failed to show comparable suppression of RasGRP3 translocation. The marked differences between RasGRP3 and RasGRP1 in membrane interaction necessarily will contribute to their different behavior in cells and are relevant to the design of selective ligands as potential therapeutic agents.
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Affiliation(s)
- Agnes Czikora
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, United States
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, United States
| | - Heather Kalish
- Trans-NIH Shared Resource on Biomedical Engineering and Physical Science (BEPS), National Institute of Biomedical Imaging and Bioengineering (NIBIB) National Institutes of Health, United States
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, United States.
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9
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Elhalem E, Donadío LG, Zhou X, Lewin NE, Garcia LC, Lai CC, Kelley JA, Peach ML, Blumberg PM, Comin MJ. Exploring the influence of indololactone structure on selectivity for binding to the C1 domains of PKCα, PKCε, and RasGRP. Bioorg Med Chem 2017; 25:2971-2980. [PMID: 28392275 PMCID: PMC5493039 DOI: 10.1016/j.bmc.2017.03.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 11/23/2022]
Abstract
C1 domain-containing proteins, such as protein kinase C (PKC), have a central role in cellular signal transduction. Their involvement in many diseases, including cancer, cardiovascular disease, and immunological and neurological disorders has been extensively demonstrated and has prompted a search for small molecules to modulate their activity. By employing a diacylglycerol (DAG)-lactone template, we have been able to develop ultra potent analogs of diacylglycerol with nanomolar binding affinities approaching those of complex natural products such as phorbol esters and bryostatins. One current challenge is the development of selective ligands capable of discriminating between different protein family members. Recently, structure-activity relationship studies have shown that the introduction of an indole ring as a DAG-lactone substituent yielded selective Ras guanine nucleotide-releasing protein (RasGRP1) activators when compared to PKCα and PKCε. In the present work, we examine the effects of ligand selectivity relative to the orientation of the indole ring and the nature of the DAG-lactone template itself. Our results show that the indole ring must be attached to the lactone moiety through the sn-2 position in order to achieve RasGRP1 selectivity.
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Affiliation(s)
- Eleonora Elhalem
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Lucía Gandolfi Donadío
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Xiaoling Zhou
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Lia C Garcia
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Christopher C Lai
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - James A Kelley
- Chemical Biology Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Megan L Peach
- Basic Science Program, Leidos Biomedical Research Inc., Chemical Biology Laboratory, Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, MD 21702, USA
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - María J Comin
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina.
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10
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PKC in Regenerative Therapy: New Insights for Old Targets. Pharmaceuticals (Basel) 2017; 10:ph10020046. [PMID: 28524095 PMCID: PMC5490403 DOI: 10.3390/ph10020046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 05/12/2017] [Accepted: 05/16/2017] [Indexed: 01/22/2023] Open
Abstract
Effective therapies for chronic or non-healing wounds are still lacking. These tissue insults often result in severe clinical complications (i.e., infections and/or amputation) and sometimes lead to patient death. Accordingly, several research groups have focused their efforts in finding innovative and powerful therapeutic strategies to overcome these issues. On the basis of these considerations, the comprehension of the molecular cascades behind these pathological conditions could allow the identification of molecules against chronic wounds. In this context, the regulation of the Protein Kinase C (PKC) cascade has gained relevance in the prevention and/or reparation of tissue damages. This class of phosphorylating enzymes has already been considered for different physiological and pathological pathways and modulation of such enzymes may be useful in reparative processes. Herein, the recent developments in this field will be disclosed, highlighting the pivotal role of PKC α and δ in regenerative medicine. Moreover, an overview of well-established PKC ligands, acting via the modulation of these isoenzymes, will be deeply investigated. This study is aimed at re-evaluating widely known PKC modulators, currently utilized for treating other diseases, as fruitful molecules in wound-healing.
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Affiliation(s)
- Joydip Das
- Department of Pharmacological
and Pharmaceutical Sciences, College of Pharmacy, University of Houston, 521 Science and Research Building 2, Houston, Texas 77204, United States
| | - Ghazi M. Rahman
- Department of Pharmacological
and Pharmaceutical Sciences, College of Pharmacy, University of Houston, 521 Science and Research Building 2, Houston, Texas 77204, United States
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12
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Ohashi N, Nomura W, Minato N, Tamamura H. Screening for protein kinase C ligands using fluorescence resonance energy transfer. Chem Pharm Bull (Tokyo) 2014; 62:1019-25. [PMID: 25109829 DOI: 10.1248/cpb.c14-00419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Protein kinase C (PKC) is correlated with cell signaling pathways and also receives attention as a therapeutic target for cancer and Alzheimer-type dementia. The application of Förster/fluorescence resonance energy transfer (FRET) phenomena to detect binding between proteins and small molecules, for example, PKC and its ligands, underlies a fluorescence-based assay method suitable for high-throughput screening. To accelerate studies on PKC functions in processing signals using small molecules and the development of drugs that target PKC, novel methods for the assessment of the PKC binding affinity of compounds are necessary. We previously developed solvatochromic fluorophore-based methods for that assessment. In this study, a novel method for a FRET-based PKC binding assay was developed and is expected to overcome the limitations of solvatochromic fluorophores.
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Affiliation(s)
- Nami Ohashi
- Department of Medicinal Chemistry, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University
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Talukdar D, Panda S, Borah R, Manna D. Membrane Interaction and Protein Kinase C-C1 Domain Binding Properties of 4-Hydroxy-3-(hydroxymethyl) Phenyl Ester Analogues. J Phys Chem B 2014; 118:7541-7553. [PMID: 24936745 DOI: 10.1021/jp5044305] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein kinase C (PKC)-C1 domain targeted regulator development is considered as a potential therapeutic strategy for the treatment of cancer and immunological and other diseases. Efforts are underway to synthesize small molecules to achieve higher specificity for the C1-domain than the natural activator, diacylglycerols (DAGs). In this regard, we conveniently synthesized 4-hydroxy-3-(hydroxymethyl) phenyl ester analogues and measured in vitro C1-domain binding properties. We also investigated different physicochemical properties of the synthesized molecules, including aggregation behavior in aqueous solution and interaction with lipid bilayers, and others with an aim for better understanding of their C1-domain binding properties. The results showed that the membrane-active compounds aggregate in aqueous solution at a reasonably lower concentration and strongly interact with the lipid bilayer. The hydrophilic part of the compounds localize at the bilayer/water interface and accessible for C1-domain binding. Biophysical studies revealed that the hydroxyl, hydroxymethyl, and carbonyl groups and acyl chain length are important for their interaction with the C1-domain. The potent compound showed more than 10-fold stronger binding affinity for the C1-domains than DAG under similar experimental conditions. Therefore, our findings reveal that these ester analogues represent an attractive group of C1-domain ligands that can be further structurally modified to improve their binding and activity.
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Affiliation(s)
- Dipjyoti Talukdar
- Department of Chemistry, Indian Institute of Technology , Guwahati, Assam 781039, India
| | - Subhankar Panda
- Department of Chemistry, Indian Institute of Technology , Guwahati, Assam 781039, India
| | - Rituparna Borah
- Department of Chemistry, Indian Institute of Technology , Guwahati, Assam 781039, India
| | - Debasis Manna
- Department of Chemistry, Indian Institute of Technology , Guwahati, Assam 781039, India
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14
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Garcia LC, Donadío LG, Mann E, Kolusheva S, Kedei N, Lewin NE, Hill CS, Kelsey JS, Yang J, Esch TE, Santos M, Peach ML, Kelley JA, Blumberg PM, Jelinek R, Marquez VE, Comin MJ. Synthesis, biological, and biophysical studies of DAG-indololactones designed as selective activators of RasGRP. Bioorg Med Chem 2014; 22:3123-40. [PMID: 24794745 PMCID: PMC4104769 DOI: 10.1016/j.bmc.2014.04.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/05/2014] [Accepted: 04/14/2014] [Indexed: 01/21/2023]
Abstract
The development of selective agents capable of discriminating between protein kinase C (PKC) isoforms and other diacylglycerol (DAG)-responsive C1 domain-containing proteins represents an important challenge. Recent studies have highlighted the role that Ras guanine nucleotide-releasing protein (RasGRP) isoforms play both in immune responses as well as in the development of prostate cancer and melanoma, suggesting that the discovery of selective ligands could have potential therapeutic value. Thus far, the N-methyl-substituted indololactone 1 is the agonist with the highest reported potency and selectivity for RasGRP relative to PKC. Here we present the synthesis, binding studies, cellular assays and biophysical analysis of interactions with model membranes of a family of regioisomers of 1 (compounds 2-5) that differ in the position of the linkage between the indole ring and the lactone moiety. These structural variations were studied to explore the interaction of the active complex (C1 domain-ligand) with cellular membranes, which is believed to be an important factor for selectivity in the activation of DAG-responsive C1 domain containing signaling proteins. All compounds were potent and selective activators of RasGRP when compared to PKCα with selectivities ranging from 6 to 65 fold. However, the parent compound 1 was appreciably more selective than any of the other isomers. In intact cells, modest differences in the patterns of translocation of the C1 domain targets were observed. Biophysical studies using giant vesicles as model membranes did show substantial differences in terms of molecular interactions impacting lipid organization, dynamics and membrane insertion. However, these differences did not yield correspondingly large changes in patterns of biological response, at least for the parameters examined.
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Affiliation(s)
- Lia C Garcia
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Lucia Gandolfi Donadío
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Ella Mann
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Sofiya Kolusheva
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Nancy E Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Colin S Hill
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Jessica S Kelsey
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Jing Yang
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Timothy E Esch
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Marina Santos
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina
| | - Megan L Peach
- Basic Science Program, Leidos Biomedical, Inc., Chemical Biology Laboratory, Frederick National Laboratory for Cancer Research, National Institutes of Health, Frederick, MD 21702, USA
| | - James A Kelley
- Chemical Biology Laboratory, Molecular Discovery Program, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Peter M Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA
| | - Raz Jelinek
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Victor E Marquez
- Chemical Biology Laboratory, Molecular Discovery Program, Center for Cancer Research, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD 21702, USA
| | - Maria J Comin
- Laboratory of Organic Synthesis, Center of Research and Development in Chemistry, National Institute of Industrial Technology, Buenos Aires, Argentina.
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15
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Wang W, Wang J, Zhou S, Sun Q, Ge Z, Wang X, Li R. An efficient organocatalytic enantioselective Michael addition of aryl methyl ketones with 2-furanones: highly functionalized chiral 3,4-substituted lactones. Chem Commun (Camb) 2013; 49:1333-5. [DOI: 10.1039/c2cc35488h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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Geczy T, Peach ML, El Kazzouli S, Sigano DM, Kang JH, Valle CJ, Selezneva J, Woo W, Kedei N, Lewin NE, Garfield SH, Lim L, Mannan P, Marquez VE, Blumberg PM. Molecular basis for failure of "atypical" C1 domain of Vav1 to bind diacylglycerol/phorbol ester. J Biol Chem 2012; 287:13137-58. [PMID: 22351766 DOI: 10.1074/jbc.m111.320010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
C1 domains, the recognition motif of the second messenger diacylglycerol and of the phorbol esters, are classified as typical (ligand-responsive) or atypical (not ligand-responsive). The C1 domain of Vav1, a guanine nucleotide exchange factor, plays a critical role in regulation of Vav activity through stabilization of the Dbl homology domain, which is responsible for exchange activity of Vav. Although the C1 domain of Vav1 is classified as atypical, it retains a binding pocket geometry homologous to that of the typical C1 domains of PKCs. This study clarifies the basis for its failure to bind ligands. Substituting Vav1-specific residues into the C1b domain of PKCδ, we identified five crucial residues (Glu(9), Glu(10), Thr(11), Thr(24), and Tyr(26)) along the rim of the binding cleft that weaken binding potency in a cumulative fashion. Reciprocally, replacing these incompatible residues in the Vav1 C1 domain with the corresponding residues from PKCδ C1b (δC1b) conferred high potency for phorbol ester binding. Computer modeling predicts that these unique residues in Vav1 increase the hydrophilicity of the rim of the binding pocket, impairing membrane association and thereby preventing formation of the ternary C1-ligand-membrane binding complex. The initial design of diacylglycerol-lactones to exploit these Vav1 unique residues showed enhanced selectivity for C1 domains incorporating these residues, suggesting a strategy for the development of ligands targeting Vav1.
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Affiliation(s)
- Tamas Geczy
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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17
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Mamidi N, Gorai S, Mukherjee R, Manna D. Development of diacyltetrol lipids as activators for the C1 domain of protein kinase C. MOLECULAR BIOSYSTEMS 2012; 8:1275-85. [PMID: 22301880 DOI: 10.1039/c2mb05452c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The protein kinase C (PKC) family of serine/threonine kinases is an attractive drug target for the treatment of cancer and other diseases. Diacylglycerol (DAG), phorbol esters and others act as ligands for the C1 domain of PKC isoforms. Inspection of the crystal structure of the PKCδ C1b subdomain in complex with phorbol-13-O-acetate shows that one carbonyl group and two hydroxyl groups play pivotal roles in recognition of the C1 domain. To understand the importance of two hydroxyl groups of phorbol esters in PKC binding and to develop effective PKC activators, we synthesized DAG like diacyltetrols (DATs) and studied binding affinities with C1b subdomains of PKCδ and PKCθ. DATs, with the stereochemistry of natural DAGs at the sn-2 position, were synthesized from (+)-diethyl L-tartrate in four to seven steps as single isomers. The calculated EC(50) values for the short and long chain DATs varied in the range of 3-6 μM. Furthermore, the fluorescence anisotropy values of the proteins were increased in the presence of DATs in a similar manner to that of DAGs. Molecular docking of DATs (1b-4b) with PKCδ C1b showed that the DATs form hydrogen bonds with the polar residues and backbone of the protein, at the same binding site, as that of DAG and phorbol esters. Our findings reveal that DATs represent an attractive group of C1 domain ligands that can be used as research tools or further structurally modified for potential drug development.
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Affiliation(s)
- Narsimha Mamidi
- Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India
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18
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Gal N, Kolusheva S, Kedei N, Telek A, Naeem TA, Lewin NE, Lim L, Mannan P, Garfield SH, El Kazzouli S, Sigano DM, Marquez VE, Blumberg PM, Jelinek R. N-Methyl-Substituted Fluorescent DAG-Indololactone Isomers Exhibit Dramatic Differences in Membrane Interactions and Biological Activity. Chembiochem 2011; 12:2331-40. [DOI: 10.1002/cbic.201100246] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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19
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Kedei N, Lubart E, Lewin NE, Telek A, Lim L, Mannan P, Garfield SH, Kraft MB, Keck GE, Kolusheva S, Jelinek R, Blumberg PM. Some phorbol esters might partially resemble bryostatin 1 in their actions on LNCaP prostate cancer cells and U937 leukemia cells. Chembiochem 2011; 12:1242-51. [PMID: 21542090 PMCID: PMC3313843 DOI: 10.1002/cbic.201100064] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Indexed: 11/11/2022]
Abstract
Phorbol 12-myristate 13-acetate (PMA) and bryostatin 1 are both potent protein kinase C (PKC) activators. In LNCaP human prostate cancer cells, PMA induces tumor necrosis factor alpha (TNFα) secretion and inhibits proliferation; bryostatin 1 does not, and indeed blocks the response to PMA. This difference has been attributed to bryostatin 1 not localizing PKCδ to the plasma membrane. Since phorbol ester lipophilicity influences PKCδ localization, we have examined in LNCaP cells a series of phorbol esters and related derivatives spanning some eight logs in lipophilicity (logP) to see if any behave like bryostatin 1. The compounds showed marked differences in their effects on proliferation and TNFα secretion. For example, maximal responses for TNFα secretion relative to PMA ranged from 97 % for octyl-indolactam V to 24 % for phorbol 12,13-dibenzoate. Dose-response curves ranged from monophasic for indolactam V to markedly biphasic for sapintoxin D. The divergent patterns of response, however, correlated neither to lipophilicity, to plasma membrane translocation of PKCδ, nor to the ability to interact with model membranes. In U937 human leukemia cells, a second system in which PMA and bryostatin 1 have divergent effects, viz. PMA but not bryostatin 1 inhibits proliferation and induces attachment, all the compounds acted like PMA for proliferation, but several induced a reduced level or a biphasic dose-response curve for attachment. We conclude that active phorbol esters are not all equivalent. Depending on the system, some might partially resemble bryostatin 1 in their behavior; this encourages the concept that bryostatin-like behavior may be obtained from other structural templates.
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Affiliation(s)
- Noemi Kedei
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, U.S.A
| | - Emanuel Lubart
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, U.S.A
| | - Nancy E. Lewin
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, U.S.A
| | - Andrea Telek
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, U.S.A
| | - Langston Lim
- Laboratory of Experimental Carcinogenesis, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, U.S.A
| | - Poonam Mannan
- Laboratory of Experimental Carcinogenesis, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, U.S.A
| | - Susan H. Garfield
- Laboratory of Experimental Carcinogenesis, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, U.S.A
| | - Matthew B. Kraft
- Department of Chemistry, University of Utah, Salt Lake City, UT 84112, U.S.A
| | - Gary E. Keck
- Department of Chemistry, University of Utah, Salt Lake City, UT 84112, U.S.A
| | - Sofiya Kolusheva
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Raz Jelinek
- Department of Chemistry, Ben Gurion University, Beer Sheva 84105, Israel
| | - Peter M. Blumberg
- Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, U.S.A
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20
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Raifman O, Kolusheva S, Comin MJ, Kedei N, Lewin NE, Blumberg PM, Marquez VE, Jelinek R. Membrane anchoring of diacylglycerol lactones substituted with rigid hydrophobic acyl domains correlates with biological activities. FEBS J 2009; 277:233-43. [PMID: 19961537 DOI: 10.1111/j.1742-4658.2009.07477.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Synthetic diacylglycerol lactones (DAG lactones) are effective modulators of critical cellular signaling pathways downstream of the lipophilic second messenger diacylglycerol that activate a host of protein kinase C (PKC) isozymes as well as other non-kinase proteins that share with PKC similar C1 membrane-targeting domains. A fundamental determinant of the biological activity of these amphiphilic molecules is the nature of their interactions with cellular membranes. This study characterizes the membrane interactions and bilayer anchoring of a series of DAG lactones in which the hydrophobic moiety is a 'molecular rod', namely a rigid 4-[2-(R-phenyl)ethynyl]benzoate moiety in the acyl position. Use of assays employing chromatic biomimetic vesicles and biophysical techniques revealed that the mode of membrane anchoring of the DAG lactone derivatives was markedly affected by the presence of the hydrophobic diphenyl rod and by the size of the functional unit at the terminus of the rod. Two primary mechanisms of interaction were observed: surface binding of the DAG lactones at the lipid/water interface and deep insertion of the ligands into the alkyl core of the lipid bilayer. These membrane-insertion properties could explain the different patterns of the PKC translocation from the cytosol to membranes that is induced by the molecular-rod DAG lactones. This investigation emphasizes that the side residues of DAG lactones, rather than simply conferring hydrophobicity, profoundly influence membrane interactions, and thus may further contribute to the diversity of biological actions of these synthetic biomimetic ligands.
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Affiliation(s)
- Or Raifman
- Department of Chemistry, Ben Gurion University, Beer Sheva, Israel
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21
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Hirai G, Ogoshi Y, Ohkubo M, Tamura Y, Watanabe T, Shimizu T, Sodeoka M. Asymmetric synthesis of isobenzofuranone derivatives and their unique character as protein kinase Cα (PKCα) activators. Tetrahedron Lett 2009. [DOI: 10.1016/j.tetlet.2009.03.069] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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