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Levental I, Levental KR, Heberle FA. Lipid Rafts: Controversies Resolved, Mysteries Remain. Trends Cell Biol 2020; 30:341-353. [PMID: 32302547 DOI: 10.1016/j.tcb.2020.01.009] [Citation(s) in RCA: 308] [Impact Index Per Article: 77.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/23/2020] [Accepted: 01/24/2020] [Indexed: 01/08/2023]
Abstract
The lipid raft hypothesis postulates that lipid-lipid interactions can laterally organize biological membranes into domains of distinct structures, compositions, and functions. This proposal has in equal measure exhilarated and frustrated membrane research for decades. While the physicochemical principles underlying lipid-driven domains has been explored and is well understood, the existence and relevance of such domains in cells remains elusive, despite decades of research. Here, we review the conceptual underpinnings of the raft hypothesis and critically discuss the supporting and contradicting evidence in cells, focusing on why controversies about the composition, properties, and even the very existence of lipid rafts remain unresolved. Finally, we highlight several recent breakthroughs that may resolve existing controversies and suggest general approaches for moving beyond questions of the existence of rafts and towards understanding their physiological significance.
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Affiliation(s)
- Ilya Levental
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 70030, USA.
| | - Kandice R Levental
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 70030, USA
| | - Frederick A Heberle
- Department of Chemistry, University of Tennessee, Knoxville, TN 37996, USA; Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN 33830, USA
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Lee TL, Wang SG, Chan WL, Lee CH, Wu TS, Lin ML, Chen SS. Impairment of Membrane Lipid Homeostasis by Bichalcone Analog TSWU-BR4 Attenuates Function of GRP78 in Regulation of the Oxidative Balance and Invasion of Cancer Cells. Cells 2020; 9:cells9020371. [PMID: 32033487 PMCID: PMC7072528 DOI: 10.3390/cells9020371] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 01/14/2020] [Accepted: 01/30/2020] [Indexed: 12/22/2022] Open
Abstract
The specialized cholesterol/sphingolipid-rich membrane domains termed lipid rafts are highly dynamic in the cancer cells, which rapidly assemble effector molecules to form a sorting platform essential for oncogenic signaling transduction in response to extra- or intracellular stimuli. Density-based membrane flotation, subcellular fractionation, cell surface biotinylation, and co-immunoprecipitation analyses of bichalcone analog ((E)-1-(4-Hydroxy-3-((4-(4-((E)-3-(pyridin-3-yl)acryloyl)phenyl)piperazin-1-yl)methyl)phenyl)-3-(pyridin-3-yl)prop-2-en-1-one (TSWU-BR4)-treated cancer cells showed dissociation between GRP78 and p85α conferring the recruitment of PTEN to lipid raft membranes associated with p85α. Ectopic expression of GRP78 could overcome induction of lipid raft membrane-associated p85α–unphosphorylated PTEN complex formation and suppression of GRP78−PI3K−Akt−GTP-Rac1-mediated and GRP78-regulated PERK−Nrf2 antioxidant pathway and cancer cell invasion by TSWU-BR4. Using specific inducer, inhibitor, or short hairpin RNA for ASM demonstrated that induction of the lipid raft membrane localization and activation of ASM by TSWU-BR4 is responsible for perturbing homeostasis of cholesterol and ceramide levels in the lipid raft and ER membranes, leading to alteration of GRP78 membrane trafficking and subsequently inducing p85α–unphosphorylated PTEN complex formation, causing disruption of GRP78−PI3K−Akt−GTP-Rac1-mediated signal and ER membrane-associated GRP78-regulated oxidative stress balance, thus inhibiting cancer cell invasion. The involvement of the enrichment of ceramide to lipid raft membranes in inhibition of NF-κB-mediated MMP-2 expression was confirmed through attenuation of NF-κB activation using C2-ceramide, NF-κB specific inhibitors, ectopic expression of NF-κB p65, MMP-2 promoter-driven luciferase, and NF-κB-dependent reporter genes. In conclusion, localization of ASM in the lipid raft membranes by TSWU-BR4 is a key event for initiating formation of ceramide-enriched lipid raft membrane platforms, which causes delocalization of GRP78 from the lipid raft and ER membranes to the cytosol and formation of p85α–unphosphorylated PTEN complexes to attenuate the GRP78-regulated oxidative stress balance and GRP78−p85α−Akt−GTP-Rac1−NF-κB−MMP-2-mediated cancer cell invasion.
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Affiliation(s)
- Tsung-Lin Lee
- Department of Family Medicine, Chang Bing Show Chwan Memorial Hospital, Changhua 50544, Taiwan;
| | - Shyang-Guang Wang
- Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 40601, Taiwan;
| | - Wen-Ling Chan
- Department of Bioinformatics and Medical Enginerring, Asia University, Taichung, Taiwan;
| | - Ching-Hsiao Lee
- Department of Medical Technology, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli 356, Taiwan;
| | - Tian-Shung Wu
- Department of Chemistry, National Cheng Kung University, Tainan 70101, Taiwan;
| | - Meng-Liang Lin
- Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung 40402, Taiwan
- Correspondence: (M.-L.L.); (S.-S.C.); Tel.: +886-4-22053366 (ext. 7211) (M.-L.L.); +886-4-22391647 (ext. 7057) (S.-S.C.)
| | - Shih-Shun Chen
- Department of Medical Laboratory Science and Biotechnology, Central Taiwan University of Science and Technology, Taichung 40601, Taiwan;
- Correspondence: (M.-L.L.); (S.-S.C.); Tel.: +886-4-22053366 (ext. 7211) (M.-L.L.); +886-4-22391647 (ext. 7057) (S.-S.C.)
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Pan Z, Zhou Z, Zhang H, Zhao H, Song P, Wang D, Yin J, Zhao W, Xie Z, Wang F, Li Y, Guo C, Zhu F, Zhang L, Wang Q. CD90 serves as differential modulator of subcutaneous and visceral adipose-derived stem cells by regulating AKT activation that influences adipose tissue and metabolic homeostasis. Stem Cell Res Ther 2019; 10:355. [PMID: 31779686 PMCID: PMC6883612 DOI: 10.1186/s13287-019-1459-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 10/11/2019] [Accepted: 10/16/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND White adipose tissue includes subcutaneous and visceral adipose tissue (SAT and VAT) with different metabolic features. SAT protects from metabolic disorders, while VAT promotes them. The proliferative and adipogenic potentials of adipose-derived stem cells (ADSCs) are critical for maintaining adipose tissue homeostasis through driving adipocyte hyperplasia and inhibiting pathological hypertrophy. However, it remains to be elucidated the critical molecules that regulate different potentials of subcutaneous and visceral ADSCs (S-ADSCs, V-ADSCs) and mediate distinct metabolic properties of SAT and VAT. CD90 is a glycosylphosphatidylinositol-anchored protein on various cells, which is also expressed on ADSCs. However, its expression patterns and differential regulation on S-ADSCs and V-ADSCs remain unclear. METHODS S-ADSCs and V-ADSCs were detected for CD90 expression. Proliferation, colony formation, cell cycle, mitotic clonal expansion, and adipogenic differentiation were assayed in S-ADSCs, V-ADSCs, or CD90-silenced S-ADSCs. Glucose tolerance test and adipocyte hypertrophy were examined in mice after silencing of CD90 in SAT. CD90 expression and its association with CyclinD1 and Leptin were analyzed in adipose tissue from mice and humans. Regulation of AKT by CD90 was detected using a co-transfection system. RESULTS Compared with V-ADSCs, S-ADSCs expressed high level of CD90 and showed increases in proliferation, mitotic clonal expansion, and adipogenic differentiation, together with AKT activation and G1-S phase transition. CD90 silencing inhibited AKT activation and S phase entry, thereby curbing proliferation and mitotic clonal expansion of S-ADSCs. In vivo CD90 silencing in SAT inhibited S-ADSC proliferation, which caused adipocyte hypertrophy and glucose intolerance in mice. Furthermore, CD90 was highly expressed in SAT rather than in VAT in human and mouse, which had positive correlation with CyclinD1 but negative correlation with Leptin. CD90 promoted AKT activation through recruiting its pleckstrin homology domain to plasma membrane. CONCLUSIONS CD90 is differentially expressed on S-ADSCs and V-ADSCs, and plays critical roles in ADSC proliferation, mitotic clonal expansion, and hemostasis of adipose tissue and metabolism. These findings identify CD90 as a crucial modulator of S-ADSCs and V-ADSCs to mediate distinct metabolic features of SAT and VAT, thus proposing CD90 as a valuable biomarker or target for evaluating ADSC potentials, monitoring or treating obesity-associated metabolic disorders.
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Affiliation(s)
- Zhenzhen Pan
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Zixin Zhou
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Huiying Zhang
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Hui Zhao
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China.,Department of Clinical Laboratory, The Second Hospital of Shandong University, Jinan, 250033, Shandong, People's Republic of China
| | - Peixuan Song
- School of Mathematics and Statistics, Shandong University, Weihai, 264209, Shandong, People's Republic of China
| | - Di Wang
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Jilong Yin
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Wanyi Zhao
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Zhaoxiang Xie
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Fuwu Wang
- Key Laboratory of the Ministry of Education for Experimental Teratology, Department of Histology and Embryology, School of Basic Medical Science, Shandong University, Jinan, 250012, Shandong, People's Republic of China
| | - Yan Li
- Department of Pathogen Biology, School of Basic Medical Science, Shandong University, Jinan, 250012, Shandong, People's Republic of China
| | - Chun Guo
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Faliang Zhu
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Lining Zhang
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China
| | - Qun Wang
- Key Laboratory of Infection and Immunity of Shandong Province, Department of Immunology, School of Basic Medical Sciences, Shandong University, 44 Wenhua Xi Road, Jinan, 250012, Shandong, People's Republic of China.
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Zhou Y, Dobritsa AA. Formation of aperture sites on the pollen surface as a model for development of distinct cellular domains. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 288:110222. [PMID: 31521218 DOI: 10.1016/j.plantsci.2019.110222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/14/2019] [Accepted: 08/16/2019] [Indexed: 06/10/2023]
Abstract
Pollen grains are covered by the complex extracellular structure, called exine, which in most species is deposited on the pollen surface non-uniformly. Certain surface areas receive fewer exine deposits and develop into regions whose structure and morphology differ significantly from the rest of pollen wall. These regions are known as pollen apertures. Across species, pollen apertures can vary in their numbers, positions, and morphology, generating highly diverse patterns. The process of aperture formation involves establishment of cell polarity, formation of distinct plasma membrane domains, and deposition of extracellular materials at precise positions. Thus, pollen apertures present an excellent model for studying the development of cellular domains and formation of patterns at the single-cell level. Until very recently, the molecular mechanisms underlying the specification and formation of aperture sites were completely unknown. Here, we review recent advances in understanding of the molecular processes involved in pollen aperture formation, focusing on the molecular players identified through genetic approaches in the model plant Arabidopsis. We discuss a potential working model that describes the process of aperture formation, including specification of domains, creation of their defining features, and protection of these regions from exine deposition.
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Affiliation(s)
- Yuan Zhou
- Department of Molecular Genetics and Center for Applied Plant Sciences, Ohio State University, Columbus, OH, 43210, United States
| | - Anna A Dobritsa
- Department of Molecular Genetics and Center for Applied Plant Sciences, Ohio State University, Columbus, OH, 43210, United States.
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55
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Pasello M, Giudice AM, Scotlandi K. The ABC subfamily A transporters: Multifaceted players with incipient potentialities in cancer. Semin Cancer Biol 2019; 60:57-71. [PMID: 31605751 DOI: 10.1016/j.semcancer.2019.10.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/30/2019] [Accepted: 10/04/2019] [Indexed: 12/12/2022]
Abstract
Overexpression of ATP-binding cassette (ABC) transporters is a cause of drug resistance in a plethora of tumors. More recent evidence indicates additional contribution of these transporters to other processes, such as tumor cell dissemination and metastasis, thereby extending their possible roles in tumor progression. While the role of some ABC transporters, such as ABCB1, ABCC1 and ABCG2, in multidrug resistance is well documented, the mechanisms by which ABC transporters affect the proliferation, differentiation, migration and invasion of cancer cells are still poorly defined and are frequently controversial. This review, summarizes recent advances that highlight the role of subfamily A members in cancer. Emerging evidence highlights the potential value of ABCA members as biomarkers of risk and response in different tumors, but information is disperse and very little is known about their possible mechanisms of action. The only clear evidence is that ABCA members are involved in lipid metabolism and homeostasis. In particular, the relationship between ABCA1 and cholesterol is becoming evident in different fields of biology, including cancer. In parallel, emerging findings indicate that cholesterol, the main component of cell membranes, can influence many physiological and pathological processes, including cell migration, cancer progression and metastasis. This review aims to link the dispersed knowledge regarding the relationship of ABCA members with lipid metabolism and cancer in an effort to stimulate and guide readers to areas that the writers consider to have significant impact and relevant potentialities.
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Affiliation(s)
- Michela Pasello
- CRS Development of Biomolecular Therapies, Experimental Oncology Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, 40136, Italy.
| | - Anna Maria Giudice
- CRS Development of Biomolecular Therapies, Experimental Oncology Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, 40136, Italy; Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, 40126, Italy
| | - Katia Scotlandi
- CRS Development of Biomolecular Therapies, Experimental Oncology Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, 40136, Italy.
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56
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Zhai XH, Xiao J, Yu JK, Sun H, Zheng S. Novel sphingomyelin biomarkers for brain glioma and associated regulation research on the PI3K/Akt signaling pathway. Oncol Lett 2019; 18:6207-6213. [PMID: 31788096 DOI: 10.3892/ol.2019.10946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 07/09/2019] [Indexed: 11/06/2022] Open
Abstract
Glioma is one of the most common malignant tumor types of the central nervous system. It is necessary to identify biomarkers and novel therapeutic targets for glioma. The purpose of the present study was to distinguish lipid biomarkers with differential expression patterns in glioma tissues and normal brain tissues by matrix assisted laser desorption/ionization (MALDI)-imaging and MALDI-time of flight (TOF)-mass spectrometry (MS). Additionally, identification of lipid biomarkers was performed to describe novel therapeutic targets for glioma treatment. A total of six tissues from three patients with glioma and three control patients with traumatic brain injury were analyzed using UltrafleXtreme MALDI-TOF/TOF. The expression levels of 15 lipid peaks were higher in the TBT samples compared with in the GBT samples. The expression levels of another 16 lipid peaks were higher in the GBT samples compared with in the TBT samples. 14 peaks were identified as sphingomyelins using MS/MS. Additional results were also obtained from experiments using the glioma cell line U373-MG. These results indicated that treatment with the drug desipramine (Desi) inhibited the accumulation of ceramide on the cell membranes of glioma U373-MG cells. Treatment with Desi inhibited the activation of insulin-like growth factor-1 receptor and inhibited the activation of proteins in the PI3K/Akt signaling pathway.
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Affiliation(s)
- Xiao-Hui Zhai
- Department of Medical Oncology, The Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510655, P.R. China.,Cancer Institute, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Jian Xiao
- Department of Medical Oncology, The Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510655, P.R. China
| | - Jie-Kai Yu
- Cancer Institute, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
| | - Hong Sun
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, NV 89135, USA
| | - Shu Zheng
- Cancer Institute, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310009, P.R. China
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Begicevic RR, Arfuso F, Falasca M. Bioactive lipids in cancer stem cells. World J Stem Cells 2019; 11:693-704. [PMID: 31616544 PMCID: PMC6789187 DOI: 10.4252/wjsc.v11.i9.693] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/08/2019] [Accepted: 08/20/2019] [Indexed: 02/06/2023] Open
Abstract
Tumours are known to be a heterogeneous group of cells, which is why they are difficult to eradicate. One possible cause for this is the existence of slow-cycling cancer stem cells (CSCs) endowed with stem cell-like properties of self-renewal, which are responsible for resistance to chemotherapy and radiotherapy. In recent years, the role of lipid metabolism has garnered increasing attention in cancer. Specifically, the key roles of enzymes such as stearoyl-CoA desaturase-1 and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase in CSCs, have gained particular interest. However, despite accumulating evidence on the role of proteins in controlling lipid metabolism, very little is known about the specific role played by lipid products in CSCs. This review highlights recent findings on the role of lipid metabolism in CSCs, focusing on the specific mechanism by which bioactive lipids regulate the fate of CSCs and their involvement in signal transduction pathways.
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Affiliation(s)
- Romana-Rea Begicevic
- Metabolic Signalling Group, School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6102, Australia
| | - Frank Arfuso
- Stem Cell and Cancer Biology Laboratory, School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6102, Australia
| | - Marco Falasca
- Metabolic Signalling Group, School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, WA 6102, Australia.
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Mühlhäuser WWD, Weber W, Radziwill G. OpEn-Tag-A Customizable Optogenetic Toolbox To Dissect Subcellular Signaling. ACS Synth Biol 2019; 8:1679-1684. [PMID: 31185174 DOI: 10.1021/acssynbio.9b00059] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Subcellular localization of signal molecules is a hallmark in organizing the signaling network. OpEn-Tag is a modular optogenetic endomembrane targeting toolbox that allows alteration of the localization and therefore the activity of signaling processes with the spatiotemporal resolution of optogenetics. OpEn-Tag is a two-component system employing (1) a variety of targeting peptides fused to and thereby dictating the localization of mCherry-labeled cryptochrome 2 binding protein CIBN toward distinct endomembranes and (2) the cytosolic, fluorescence-labeled blue light photoreceptor cryptochrome 2 as a customizable building block that can be fused to proteins of interest. The combination of OpEn-Tag with growth factor stimulation or the use of two membrane anchor sequences allows investigation of multilayered signal transduction processes as demonstrated here for the protein kinase AKT.
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Affiliation(s)
- Wignand W. D. Mühlhäuser
- Faculty of Biology and Signalling research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, 79104, Germany
| | - Wilfried Weber
- Faculty of Biology and Signalling research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, 79104, Germany
| | - Gerald Radziwill
- Faculty of Biology and Signalling research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, 79104, Germany
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59
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Graber ZT, Thomas J, Johnson E, Gericke A, Kooijman EE. Effect of H-Bond Donor Lipids on Phosphatidylinositol-3,4,5-Trisphosphate Ionization and Clustering. Biophys J 2019; 114:126-136. [PMID: 29320679 DOI: 10.1016/j.bpj.2017.10.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/10/2017] [Accepted: 10/13/2017] [Indexed: 12/29/2022] Open
Abstract
The phosphoinositide, phosphatidylinositol-3,4,5-trisphosphate (PI(3,4,5)P3), is a key signaling lipid in the inner leaflet of the cell plasma membrane, regulating diverse signaling pathways including cell growth and migration. In this study we investigate the impact of the hydrogen-bond donor lipids phosphatidylethanolamine (PE) and phosphatidylinositol (PI) on the charge and phase behavior of PI(3,4,5)P3. PE and PI can interact with PI(3,4,5)P3 through hydrogen-bond formation, leading to altered ionization behavior and charge distribution within the PI(3,4,5)P3 headgroup. We quantify the altered PI(3,4,5)P3 ionization behavior using a multistate ionization model to obtain micro-pKa values for the ionization of each phosphate group. The presence of PE leads to a decrease in the pKa values for the initial deprotonation of PI(3,4,5)P3, which describes the removal of the first proton of the three protons remaining at the phosphomonoester groups at pH 4.0. The decrease in these micro-pKa values thus leads to a higher charge at low pH. Additionally, the charge distribution changes lead to increased charge on the 3- and 5-phosphates. In the presence of PI, the final deprotonation of PI(3,4,5)P3 is delayed, leading to a lower charge at high pH. This is due to a combination of hydrogen-bond formation between PI and PI(3,4,5)P3, and increased surface charge due to the addition of the negatively charged PI. The interaction between PI and PI(3,4,5)P3 leads to the formation of PI and PI(3,4,5)P3-enriched domains within the membrane. These domains may have a critical impact on PI(3,4,5)P3-signaling. We also reevaluate results for all phosphatidylinositol bisphosphates as well as for PI(4,5)P2 in complex lipid mixtures with the multistate ionization model.
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Affiliation(s)
| | - Joseph Thomas
- Department of Biological Sciences, Kent State University, Kent, Ohio
| | - Emily Johnson
- Department of Biological Sciences, Kent State University, Kent, Ohio
| | - Arne Gericke
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts.
| | - Edgar E Kooijman
- Department of Biological Sciences, Kent State University, Kent, Ohio
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Kucheryavykh LY, Ortiz-Rivera J, Kucheryavykh YV, Zayas-Santiago A, Diaz-Garcia A, Inyushin MY. Accumulation of Innate Amyloid Beta Peptide in Glioblastoma Tumors. Int J Mol Sci 2019; 20:ijms20102482. [PMID: 31137462 PMCID: PMC6567111 DOI: 10.3390/ijms20102482] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 04/23/2019] [Accepted: 05/15/2019] [Indexed: 12/12/2022] Open
Abstract
Immunostaining with specific antibodies has shown that innate amyloid beta (Aβ) is accumulated naturally in glioma tumors and nearby blood vessels in a mouse model of glioma. In immunofluorescence images, Aβ peptide coincides with glioma cells, and enzyme-linked immunosorbent assay (ELISA) have shown that Aβ peptide is enriched in the membrane protein fraction of tumor cells. ELISAs have also confirmed that the Aβ(1–40) peptide is enriched in glioma tumor areas relative to healthy brain areas. Thioflavin staining revealed that at least some amyloid is present in glioma tumors in aggregated forms. We may suggest that the presence of aggregated amyloid in glioma tumors together with the presence of Aβ immunofluorescence coinciding with glioma cells and the nearby vasculature imply that the source of Aβ peptides in glioma can be systemic Aβ from blood vessels, but this question remains unresolved and needs additional studies.
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Affiliation(s)
- Lilia Y Kucheryavykh
- Department of Biochemistry, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Jescelica Ortiz-Rivera
- Department of Biochemistry, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Yuriy V Kucheryavykh
- Department of Biochemistry, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Astrid Zayas-Santiago
- Department of Physiology, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Amanda Diaz-Garcia
- Department of Physiology, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
| | - Mikhail Y Inyushin
- Department of Physiology, School of Medicine, Universidad Central del Caribe, PO Box 60327, Bayamon, PR 00960-6032, USA.
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Sugiyama MG, Fairn GD, Antonescu CN. Akt-ing Up Just About Everywhere: Compartment-Specific Akt Activation and Function in Receptor Tyrosine Kinase Signaling. Front Cell Dev Biol 2019; 7:70. [PMID: 31131274 PMCID: PMC6509475 DOI: 10.3389/fcell.2019.00070] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/09/2019] [Indexed: 12/12/2022] Open
Abstract
The serine/threonine kinase Akt is a master regulator of many diverse cellular functions, including survival, growth, metabolism, migration, and differentiation. Receptor tyrosine kinases are critical regulators of Akt, as a result of activation of phosphatidylinositol-3-kinase (PI3K) signaling leading to Akt activation upon receptor stimulation. The signaling axis formed by receptor tyrosine kinases, PI3K and Akt, as well as the vast range of downstream substrates is thus central to control of cell physiology in many different contexts and tissues. This axis must be tightly regulated, as disruption of PI3K-Akt signaling underlies the pathology of many diseases such as cancer and diabetes. This sophisticated regulation of PI3K-Akt signaling is due in part to the spatial and temporal compartmentalization of Akt activation and function, including in specific nanoscale domains of the plasma membrane as well as in specific intracellular membrane compartments. Here, we review the evidence for localized activation of PI3K-Akt signaling by receptor tyrosine kinases in various specific cellular compartments, as well as that of compartment-specific functions of Akt leading to control of several fundamental cellular processes. This spatial and temporal control of Akt activation and function occurs by a large number of parallel molecular mechanisms that are central to regulation of cell physiology.
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Affiliation(s)
- Michael G. Sugiyama
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, ON, Canada
| | - Gregory D. Fairn
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, ON, Canada
- Department of Surgery, University of Toronto, Toronto, ON, Canada
| | - Costin N. Antonescu
- Department of Chemistry and Biology, Ryerson University, Toronto, ON, Canada
- Keenan Research Centre for Biomedical Science, St. Michael’s Hospital, Toronto, ON, Canada
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62
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Yan Y, An J, Yang Y, Wu D, Bai Y, Cao W, Ma L, Chen J, Yu Z, He Y, Jin X, Pan Y, Ma T, Wang S, Hou X, Weroha SJ, Karnes RJ, Zhang J, Westendorf JJ, Wang L, Chen Y, Xu W, Zhu R, Wang D, Huang H. Dual inhibition of AKT-mTOR and AR signaling by targeting HDAC3 in PTEN- or SPOP-mutated prostate cancer. EMBO Mol Med 2019. [PMID: 29523594 PMCID: PMC5887910 DOI: 10.15252/emmm.201708478] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
AKT‐mTOR and androgen receptor (AR) signaling pathways are aberrantly activated in prostate cancer due to frequent PTEN deletions or SPOP mutations. A clinical barrier is that targeting one of them often activates the other. Here, we demonstrate that HDAC3 augments AKT phosphorylation in prostate cancer cells and its overexpression correlates with AKT phosphorylation in patient samples. HDAC3 facilitates lysine‐63‐chain polyubiquitination and phosphorylation of AKT, and this effect is mediated by AKT deacetylation at lysine 14 and 20 residues and HDAC3 interaction with the scaffold protein APPL1. Conditional homozygous deletion of Hdac3 suppresses prostate tumorigenesis and progression by concomitant blockade of AKT and AR signaling in the Pten knockout mouse model. Pharmacological inhibition of HDAC3 using a selective HDAC3 inhibitor RGFP966 inhibits growth of both PTEN‐deficient and SPOP‐mutated prostate cancer cells in culture, patient‐derived organoids and xenografts in mice. Our study identifies HDAC3 as a common upstream activator of AKT and AR signaling and reveals that dual inhibition of AKT and AR pathways is achievable by single‐agent targeting of HDAC3 in prostate cancer.
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Affiliation(s)
- Yuqian Yan
- Department of Gastroenterology, Jiangxi Institute of Gastroenterology and Hepatology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.,Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Jian An
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Yinhui Yang
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA.,Department of Urology, The Fourth Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Di Wu
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Yang Bai
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA.,Department of Urology, The Fourth Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - William Cao
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Linlin Ma
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA.,Center for Cell Therapy, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Junhui Chen
- Department of Minimally Invasive Intervention, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Zhendong Yu
- Central Laboratory, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Yundong He
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Xin Jin
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Yunqian Pan
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Tao Ma
- Department of Biomedical Statistics and Informatics, Mayo Clinic Cancer Center, Rochester, MN, USA
| | - Shangqian Wang
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Xiaonan Hou
- Department of Oncology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | | | - R Jeffrey Karnes
- Department of Urology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Jun Zhang
- Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Jennifer J Westendorf
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Liguo Wang
- Department of Biomedical Statistics and Informatics, Mayo Clinic Cancer Center, Rochester, MN, USA
| | - Yu Chen
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Wanhai Xu
- Department of Urology, The Fourth Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Runzhi Zhu
- Center for Cell Therapy, The Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Dejie Wang
- Department of Gastroenterology, Jiangxi Institute of Gastroenterology and Hepatology, First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China .,Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Haojie Huang
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA .,Department of Urology, Mayo Clinic College of Medicine, Rochester, MN, USA.,Mayo Clinic Cancer Center, Mayo Clinic College of Medicine, Rochester, MN, USA
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63
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Affiliation(s)
- Xiaolin Cheng
- Division of Medicinal Chemistry and Pharmacognosy, Biophysics Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jeremy C. Smith
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
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64
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Greenwald EC, Mehta S, Zhang J. Genetically Encoded Fluorescent Biosensors Illuminate the Spatiotemporal Regulation of Signaling Networks. Chem Rev 2018; 118:11707-11794. [PMID: 30550275 DOI: 10.1021/acs.chemrev.8b00333] [Citation(s) in RCA: 299] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cellular signaling networks are the foundation which determines the fate and function of cells as they respond to various cues and stimuli. The discovery of fluorescent proteins over 25 years ago enabled the development of a diverse array of genetically encodable fluorescent biosensors that are capable of measuring the spatiotemporal dynamics of signal transduction pathways in live cells. In an effort to encapsulate the breadth over which fluorescent biosensors have expanded, we endeavored to assemble a comprehensive list of published engineered biosensors, and we discuss many of the molecular designs utilized in their development. Then, we review how the high temporal and spatial resolution afforded by fluorescent biosensors has aided our understanding of the spatiotemporal regulation of signaling networks at the cellular and subcellular level. Finally, we highlight some emerging areas of research in both biosensor design and applications that are on the forefront of biosensor development.
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Affiliation(s)
- Eric C Greenwald
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Sohum Mehta
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
| | - Jin Zhang
- University of California , San Diego, 9500 Gilman Drive, BRFII , La Jolla , CA 92093-0702 , United States
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65
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Wang D, Ba H, Li C, Zhao Q, Li C. Proteomic Analysis of Plasma Membrane Proteins of Antler Stem Cells Using Label-Free LC⁻MS/MS. Int J Mol Sci 2018; 19:E3477. [PMID: 30400663 PMCID: PMC6275008 DOI: 10.3390/ijms19113477] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 10/31/2018] [Accepted: 11/03/2018] [Indexed: 12/16/2022] Open
Abstract
Deer antlers are unusual mammalian organs that can fully regenerate after annual shedding. Stem cells resident in the pedicle periosteum (PPCs) provide the main cell source for antler regeneration. Central to various cellular processes are plasma membrane proteins, but the expression of these proteins has not been well documented in antler regeneration. In the present study, plasma membrane proteins of PPCs and facial periosteal cells (FPCs) were analyzed using label-free liquid chromatography⁻mass spetrometry (LC⁻MS/MS). A total of 1739 proteins were identified. Of these proteins, 53 were found solely in the PPCs, 100 solely in the FPCs, and 1576 co-existed in both PPCs and FPCs; and 39 were significantly up-regulated in PPCs and 49 up-regulated in FPCs. In total, 226 gene ontology (GO) terms were significantly enriched from the differentially expressed proteins (DEPs). Five clusters of biological processes from these GO terms comprised responses to external stimuli, signal transduction, membrane transport, regulation of tissue regeneration, and protein modification processes. Further studies are required to demonstrate the relevancy of these DEPs in antler stem cell biology and antler regeneration.
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Affiliation(s)
- Datao Wang
- Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun 130112, China.
| | - Hengxing Ba
- Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun 130112, China.
| | - Chenguang Li
- Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun 130112, China.
- College of Life Sciences, Jilin Agricultural University, Changchun 130118, China.
| | - Quanmin Zhao
- College of Life Sciences, Jilin Agricultural University, Changchun 130118, China.
| | - Chunyi Li
- Institute of Special Wild Economic Animals and Plants, Chinese Academy of Agricultural Sciences, Changchun 130112, China.
- Department of Biology, Changchun Sci-Tech University, Changchun 130600, China.
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66
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Weighing In on mTOR Complex 2 Signaling: The Expanding Role in Cell Metabolism. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:7838647. [PMID: 30510625 PMCID: PMC6232796 DOI: 10.1155/2018/7838647] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 08/29/2018] [Accepted: 09/18/2018] [Indexed: 12/21/2022]
Abstract
In all eukaryotes, the mechanistic target of rapamycin (mTOR) signaling emerges as a master regulator of homeostasis, which integrates environmental inputs, including nutrients, energy, and growth factors, to regulate many fundamental cellular processes such as cell growth and metabolism. mTOR signaling functions through two structurally and functionally distinct complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), which correspond to two major branches of signal output. While mTORC1 is well characterized for its structure, regulation, and function in the last decade, information of mTORC2 signaling is only rapidly expanding in recent years, from structural biology, signaling network, to functional impact. Here we review the recent advances in many aspects of the mTORC2 signaling, with particular focus on its involvement in the control of cell metabolism and its physiological implications in metabolic diseases and aging.
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67
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A selective inhibitor of ceramide synthase 1 reveals a novel role in fat metabolism. Nat Commun 2018; 9:3165. [PMID: 30131496 PMCID: PMC6104039 DOI: 10.1038/s41467-018-05613-7] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 07/17/2018] [Indexed: 02/06/2023] Open
Abstract
Specific forms of the lipid ceramide, synthesized by the ceramide synthase enzyme family, are believed to regulate metabolic physiology. Genetic mouse models have established C16 ceramide as a driver of insulin resistance in liver and adipose tissue. C18 ceramide, synthesized by ceramide synthase 1 (CerS1), is abundant in skeletal muscle and suggested to promote insulin resistance in humans. We herein describe the first isoform-specific ceramide synthase inhibitor, P053, which inhibits CerS1 with nanomolar potency. Lipidomic profiling shows that P053 is highly selective for CerS1. Daily P053 administration to mice fed a high-fat diet (HFD) increases fatty acid oxidation in skeletal muscle and impedes increases in muscle triglycerides and adiposity, but does not protect against HFD-induced insulin resistance. Our inhibitor therefore allowed us to define a role for CerS1 as an endogenous inhibitor of mitochondrial fatty acid oxidation in muscle and regulator of whole-body adiposity. Ceramides are signalling molecules that regulate several physiological functions including insulin sensitivity. Here the authors report a selective ceramide synthase 1 inhibitor that counteracts lipid accumulation within the muscle and adiposity by increasing fatty acid oxidation but without affecting insulin sensitivity in mice fed with an obesogenic diet.
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68
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Metcalfe LK, Smith GC, Turner N. Defining lipid mediators of insulin resistance - controversies and challenges. J Mol Endocrinol 2018; 62:JME-18-0023. [PMID: 30068522 DOI: 10.1530/jme-18-0023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 07/04/2018] [Accepted: 07/31/2018] [Indexed: 12/31/2022]
Abstract
Essential elements of all cells, lipids play important roles in energy production, signalling and as structural components. Despite these critical functions, excessive availability and intracellular accumulation of lipid is now recognised as a major factor contributing to many human diseases, including obesity and diabetes. In the context of these metabolic disorders, ectopic deposition of lipid has been proposed to have deleterious effects of insulin action. While this relationship has been recognised for some time now, there is currently no unifying mechanism to explain how lipids precipitate the development of insulin resistance. This review summarises the evidence linking specific lipid molecules to the induction of insulin resistance, describing some of the current controversies and challenges for future studies in this field.
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Affiliation(s)
- Louise K Metcalfe
- L Metcalfe, Department of Pharmacology, School of Medical Sciences, UNSW Australia, Kensington, Australia
| | - Greg C Smith
- G Smith, Department of Pharmacology, School of Medical Sciences, UNSW Australia, Kensington, Australia
| | - Nigel Turner
- N Turner, Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
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69
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Liu C, Zhang Y, She X, Fan L, Li P, Feng J, Fu H, Liu Q, Liu Q, Zhao C, Sun Y, Wu M. A cytoplasmic long noncoding RNA LINC00470 as a new AKT activator to mediate glioblastoma cell autophagy. J Hematol Oncol 2018; 11:77. [PMID: 29866190 PMCID: PMC5987392 DOI: 10.1186/s13045-018-0619-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 05/14/2018] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Despite the overwhelming number of investigations on AKT, little is known about lncRNA on AKT regulation, especially in GBM cells. METHODS RNA-binding protein immunoprecipitation assay (RIP) and RNA pulldown were used to confirm the binding of LINC00470 and fused in sarcoma (FUS). Confocal imaging, co-immunoprecipitation (Co-IP) and GST pulldown assays were used to detect the interaction between FUS and AKT. EdU assay, CCK-8 assay, and intracranial xenograft assays were performed to demonstrate the effect of LINC00470 on the malignant phenotype of GBM cells. RT-qPCR and Western blotting were performed to test the effect of LINC00470 on AKT and pAKT. RESULTS In this study, we demonstrated that LINC00470 was a positive regulator for AKT activation in GBM. LINC00470 bound to FUS and AKT to form a ternary complex, anchoring FUS in the cytoplasm to increase AKT activity. Higher pAKT activated by LINC00470 inhibited ubiquitination of HK1, which affected glycolysis, and inhibited cell autophagy. Furthermore, higher LINC00470 expression was associated with GBM tumorigenesis and poor patient prognosis. CONCLUSIONS Our findings revealed a noncanonical AKT activation signaling pathway, i.e., LINC00470 directly interacts with FUS, serving as an AKT activator to promote GBM progression. LINC00470 has an important referential significance to evaluate the prognosis of patients.
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Affiliation(s)
- Changhong Liu
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, 410006, Hunan, China
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, 410078, Hunan, China
| | - Yan Zhang
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, 410006, Hunan, China
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, 410078, Hunan, China
| | - Xiaoling She
- Second Xiangya Hospital, Central South University, Changsha, 410011, Hunan, China
| | - Li Fan
- Department of Biochemistry, University of California, Riverside, CA, 92521, USA
| | - Peiyao Li
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, 410006, Hunan, China
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, 410078, Hunan, China
| | - Jianbo Feng
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, 410006, Hunan, China
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, 410078, Hunan, China
| | - Haijuan Fu
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, 410006, Hunan, China
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, 410078, Hunan, China
| | - Qing Liu
- Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Qiang Liu
- Third Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China
| | - Chunhua Zhao
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, 410006, Hunan, China
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, 410078, Hunan, China
| | - Yingnan Sun
- Hunan Provincial Tumor Hospital and the Affiliated Tumor Hospital of Xiangya Medical School, Central South University, Changsha, 410006, Hunan, China
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, 410078, Hunan, China
- Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, 410078, Hunan, China
| | - Minghua Wu
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, 410078, Hunan, China.
- Key Laboratory of Carcinogenesis and Cancer Invasion, Ministry of Education, Changsha, 410078, Hunan, China.
- Key Laboratory of Carcinogenesis, Ministry of Health, Changsha, 410078, Hunan, China.
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Nussinov R, Zhang M, Tsai CJ, Jang H. Calmodulin and IQGAP1 activation of PI3Kα and Akt in KRAS, HRAS and NRAS-driven cancers. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2304-2314. [DOI: 10.1016/j.bbadis.2017.10.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/24/2017] [Accepted: 10/27/2017] [Indexed: 02/06/2023]
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71
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Agarwal SR, Gratwohl J, Cozad M, Yang PC, Clancy CE, Harvey RD. Compartmentalized cAMP Signaling Associated With Lipid Raft and Non-raft Membrane Domains in Adult Ventricular Myocytes. Front Pharmacol 2018; 9:332. [PMID: 29740315 PMCID: PMC5925456 DOI: 10.3389/fphar.2018.00332] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 03/21/2018] [Indexed: 11/23/2022] Open
Abstract
Aim: Confining cAMP production to discrete subcellular locations makes it possible for this ubiquitous second messenger to elicit unique functional responses. Yet, factors that determine how and where the production of this diffusible signaling molecule occurs are incompletely understood. The fluid mosaic model originally proposed that signal transduction occurs through random interactions between proteins diffusing freely throughout the plasma membrane. However, it is now known that the movement of membrane proteins is restricted, suggesting that the plasma membrane is segregated into distinct microdomains where different signaling proteins can be concentrated. In this study, we examined what role lipid raft and non-raft membrane domains play in compartmentation of cAMP signaling in adult ventricular myocytes. Methods and Results: The freely diffusible fluorescence resonance energy transfer-based biosensor Epac2-camps was used to measure global cytosolic cAMP responses, while versions of the probe targeted to lipid raft (Epac2-MyrPalm) and non-raft (Epac2-CAAX) domains were used to monitor local cAMP production near the plasma membrane. We found that β-adrenergic receptors, which are expressed in lipid raft and non-raft domains, produce cAMP responses near the plasma membrane that are distinctly different from those produced by E-type prostaglandin receptors, which are expressed exclusively in non-raft domains. We also found that there are differences in basal cAMP levels associated with lipid raft and non-raft domains, and that this can be explained by differences in basal adenylyl cyclase activity associated with each of these membrane environments. In addition, we found evidence that phosphodiesterases 2, 3, and 4 work together in regulating cAMP activity associated with both lipid raft and non-raft domains, while phosphodiesterase 3 plays a more prominent role in the bulk cytoplasmic compartment. Conclusion: These results suggest that different membrane domains contribute to the formation of distinct pools of cAMP under basal conditions as well as following receptor stimulation in adult ventricular myocytes.
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Affiliation(s)
- Shailesh R Agarwal
- Department of Pharmacology, University of Nevada, Reno, Reno, NV, United States
| | - Jackson Gratwohl
- Department of Pharmacology, University of Nevada, Reno, Reno, NV, United States
| | - Mia Cozad
- Department of Pharmacology, University of Nevada, Reno, Reno, NV, United States
| | - Pei-Chi Yang
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Colleen E Clancy
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
| | - Robert D Harvey
- Department of Pharmacology, University of Nevada, Reno, Reno, NV, United States
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72
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Weddell JC, Imoukhuede PI. Integrative meta-modeling identifies endocytic vesicles, late endosome and the nucleus as the cellular compartments primarily directing RTK signaling. Integr Biol (Camb) 2018; 9:464-484. [PMID: 28436498 DOI: 10.1039/c7ib00011a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recently, intracellular receptor signaling has been identified as a key component mediating cell responses for various receptor tyrosine kinases (RTKs). However, the extent each endocytic compartment (endocytic vesicle, early endosome, recycling endosome, late endosome, lysosome and nucleus) contributes to receptor signaling has not been quantified. Furthermore, our understanding of endocytosis and receptor signaling is complicated by cell- or receptor-specific endocytosis mechanisms. Therefore, towards understanding the differential endocytic compartment signaling roles, and identifying how to achieve signal transduction control for RTKs, we delineate how endocytosis regulates RTK signaling. We achieve this via a meta-analysis across eight RTKs, integrating computational modeling with experimentally derived cell (compartment volume, trafficking kinetics and pH) and ligand-receptor (ligand/receptor concentration and interaction kinetics) physiology. Our simulations predict the abundance of signaling from eight RTKs, identifying the following hierarchy in RTK signaling: PDGFRβ > IGFR1 > EGFR > PDGFRα > VEGFR1 > VEGFR2 > Tie2 > FGFR1. We find that endocytic vesicles are the primary cell signaling compartment; over 43% of total receptor signaling occurs within the endocytic vesicle compartment for these eight RTKs. Mechanistically, we found that high RTK signaling within endocytic vesicles may be attributed to their low volume (5.3 × 10-19 L) which facilitates an enriched ligand concentration (3.2 μM per ligand molecule within the endocytic vesicle). Under the analyzed physiological conditions, we identified extracellular ligand concentration as the most sensitive parameter to change; hence the most significant one to modify when regulating absolute compartment signaling. We also found that the late endosome and nucleus compartments are important contributors to receptor signaling, where 26% and 18%, respectively, of average receptor signaling occurs across the eight RTKs. Conversely, we found very low membrane-based receptor signaling, exhibiting <1% of the total receptor signaling for these eight RTKs. Moreover, we found that nuclear translocation, mechanistically, requires late endosomal transport; when we blocked receptor trafficking from late endosomes to the nucleus we found a 57% reduction in nuclear translocation. In summary, our research has elucidated the significance of endocytic vesicles, late endosomes and the nucleus in RTK signal propagation.
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Affiliation(s)
- Jared C Weddell
- Department of Bioengineering, University of Illinois at Urbana-Champaign, 1304 W Springfield Ave., 3233 Digital Computer Laboratory, Urbana, IL 61801, USA.
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von Erlach TC, Bertazzo S, Wozniak MA, Horejs CM, Maynard SA, Attwood S, Robinson BK, Autefage H, Kallepitis C, Del Río Hernández A, Chen CS, Goldoni S, Stevens MM. Cell-geometry-dependent changes in plasma membrane order direct stem cell signalling and fate. NATURE MATERIALS 2018; 17:237-242. [PMID: 29434303 PMCID: PMC5901718 DOI: 10.1038/s41563-017-0014-0] [Citation(s) in RCA: 121] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 12/18/2017] [Indexed: 05/04/2023]
Abstract
Cell size and shape affect cellular processes such as cell survival, growth and differentiation1-4, thus establishing cell geometry as a fundamental regulator of cell physiology. The contributions of the cytoskeleton, specifically actomyosin tension, to these effects have been described, but the exact biophysical mechanisms that translate changes in cell geometry to changes in cell behaviour remain mostly unresolved. Using a variety of innovative materials techniques, we demonstrate that the nanostructure and lipid assembly within the cell plasma membrane are regulated by cell geometry in a ligand-independent manner. These biophysical changes trigger signalling events involving the serine/threonine kinase Akt/protein kinase B (PKB) that direct cell-geometry-dependent mesenchymal stem cell differentiation. Our study defines a central regulatory role by plasma membrane ordered lipid raft microdomains in modulating stem cell differentiation with potential translational applications.
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Affiliation(s)
- Thomas C von Erlach
- Department of Materials, Imperial College London, London, UK
- Department of Bioengineering, Imperial College London, London, UK
- Institute of Biomedical Engineering, Imperial College London, London, UK
| | - Sergio Bertazzo
- Department of Materials, Imperial College London, London, UK
- Department of Medical Physics & Biomedical Engineering, University College London, London, UK
| | - Michele A Wozniak
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Christine-Maria Horejs
- Department of Materials, Imperial College London, London, UK
- Department of Bioengineering, Imperial College London, London, UK
- Institute of Biomedical Engineering, Imperial College London, London, UK
| | - Stephanie A Maynard
- Department of Materials, Imperial College London, London, UK
- Department of Bioengineering, Imperial College London, London, UK
- Institute of Biomedical Engineering, Imperial College London, London, UK
| | - Simon Attwood
- Department of Bioengineering, Imperial College London, London, UK
| | | | - Hélène Autefage
- Department of Materials, Imperial College London, London, UK
- Department of Bioengineering, Imperial College London, London, UK
- Institute of Biomedical Engineering, Imperial College London, London, UK
| | - Charalambos Kallepitis
- Department of Materials, Imperial College London, London, UK
- Department of Bioengineering, Imperial College London, London, UK
- Institute of Biomedical Engineering, Imperial College London, London, UK
| | | | - Christopher S Chen
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering and the Biological Design Center, Boston University, Boston, MA, USA
- The Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA
| | - Silvia Goldoni
- Department of Materials, Imperial College London, London, UK.
- Department of Bioengineering, Imperial College London, London, UK.
- Institute of Biomedical Engineering, Imperial College London, London, UK.
| | - Molly M Stevens
- Department of Materials, Imperial College London, London, UK.
- Department of Bioengineering, Imperial College London, London, UK.
- Institute of Biomedical Engineering, Imperial College London, London, UK.
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74
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Chimento A, Casaburi I, Avena P, Trotta F, De Luca A, Rago V, Pezzi V, Sirianni R. Cholesterol and Its Metabolites in Tumor Growth: Therapeutic Potential of Statins in Cancer Treatment. Front Endocrinol (Lausanne) 2018; 9:807. [PMID: 30719023 PMCID: PMC6348274 DOI: 10.3389/fendo.2018.00807] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 12/21/2018] [Indexed: 12/13/2022] Open
Abstract
Cholesterol is essential for cell function and viability. It is a component of the plasma membrane and lipid rafts and is a precursor for bile acids, steroid hormones, and Vitamin D. As a ligand for estrogen-related receptor alpha (ESRRA), cholesterol becomes a signaling molecule. Furthermore, cholesterol-derived oxysterols activate liver X receptors (LXRs) or estrogen receptors (ERs). Several studies performed in cancer cells reveal that cholesterol synthesis is enhanced compared to normal cells. Additionally, high serum cholesterol levels are associated with increased risk for many cancers, but thus far, clinical trials with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) have had mixed results. Statins inhibit cholesterol synthesis within cells through the inhibition of HMG-CoA reductase, the rate-limiting enzyme in the mevalonate and cholesterol synthetic pathway. Many downstream products of mevalonate have a role in cell proliferation, since they are required for maintenance of membrane integrity; signaling, as some proteins to be active must undergo prenylation; protein synthesis, as isopentenyladenine is an essential substrate for the modification of certain tRNAs; and cell-cycle progression. In this review starting from recent acquired findings on the role that cholesterol and its metabolites fulfill in the contest of cancer cells, we discuss the results of studies focused to investigate the use of statins in order to prevent cancer growth and metastasis.
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75
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Dobritsa AA, Kirkpatrick AB, Reeder SH, Li P, Owen HA. Pollen Aperture Factor INP1 Acts Late in Aperture Formation by Excluding Specific Membrane Domains from Exine Deposition. PLANT PHYSIOLOGY 2018; 176:326-339. [PMID: 28899962 PMCID: PMC5761771 DOI: 10.1104/pp.17.00720] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/07/2017] [Indexed: 05/07/2023]
Abstract
Accurate placement of extracellular materials is a critical part of cellular development. To study how cells achieve this accuracy, we use formation of pollen apertures as a model. In Arabidopsis (Arabidopsis thaliana), three regions on the pollen surface lack deposition of pollen wall exine and develop into apertures. In developing pollen, Arabidopsis INAPERTURATE POLLEN1 (INP1) protein acts as a marker for the preaperture domains, assembling there into three punctate lines. To understand the mechanism of aperture formation, we studied the dynamics of INP1 expression and localization and its relationship with the membrane domains at which it assembles. We found that INP1 assembly occurs after meiotic cytokinesis at the interface between the plasma membrane and the overlying callose wall, and requires the normal callose wall formation. Sites of INP1 localization coincide with positions of protruding membrane ridges in proximity to the callose wall. Our data suggest that INP1 is a late-acting factor involved in keeping specific membrane domains next to the callose wall to prevent formation of exine at these sites.
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Affiliation(s)
- Anna A Dobritsa
- Department of Molecular Genetics and Center for Applied Plant Science, The Ohio State University, Columbus, Ohio 43210
| | - Andrew B Kirkpatrick
- Department of Molecular Genetics and Center for Applied Plant Science, The Ohio State University, Columbus, Ohio 43210
| | - Sarah H Reeder
- Department of Molecular Genetics and Center for Applied Plant Science, The Ohio State University, Columbus, Ohio 43210
| | - Peng Li
- Department of Molecular Genetics and Center for Applied Plant Science, The Ohio State University, Columbus, Ohio 43210
| | - Heather A Owen
- Department of Biological Sciences, University of Wisconsin, Milwaukee, Wisconsin 53211
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76
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Hage-Sleiman R, Hamze AB, El-Hed AF, Attieh R, Kozhaya L, Kabbani S, Dbaibo G. Ceramide inhibits PKCθ by regulating its phosphorylation and translocation to lipid rafts in Jurkat cells. Immunol Res 2017; 64:869-86. [PMID: 26798039 DOI: 10.1007/s12026-016-8787-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Protein kinase C theta (PKCθ) is a novel, calcium-independent member of the PKC family of kinases that was identified as a central player in T cell signaling and proliferation. Upon T cell activation by antigen-presenting cells, PKCθ gets phosphorylated and activated prior to its translocation to the immunological synapse where it couples with downstream effectors. PKCθ may be regulated by ceramide, a crucial sphingolipid that is known to promote differentiation, growth arrest, and apoptosis. To further investigate the mechanism, we stimulated human Jurkat T cells with either PMA or anti-CD3/anti-CD28 antibodies following induction of ceramide accumulation by adding exogenous ceramide, bacterial sphingomyelinase, or Fas ligation. Our results suggest that ceramide regulates the PKCθ pathway through preventing its critical threonine 538 (Thr538) phosphorylation and subsequent activation, thereby inhibiting the kinase's translocation to lipid rafts. Moreover, this inhibition is not likely to be a generic effect of ceramide on membrane reorganization. Other lipids, namely dihydroceramide, palmitate, and sphingosine, did not produce similar effects on PKCθ. Addition of the phosphatase inhibitors okadaic acid and calyculin A reversed the inhibition exerted by ceramide, and this suggests involvement of a ceramide-activated protein phosphatase. Such previously undescribed mechanism of regulation of PKCθ raises the possibility that ceramide, or one of its derivatives, and may prove valuable in novel therapeutic approaches for disorders involving autoimmunity or excessive inflammation-where PKCθ plays a critical role.
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Affiliation(s)
- Rouba Hage-Sleiman
- Department of Biology, Faculty of Sciences, Lebanese University, Hadath, Lebanon
| | - Asmaa B Hamze
- Department of Biomedical Science, Faculty of Health Sciences, Global University, Batrakiyye, Beirut, Lebanon
| | - Aimée F El-Hed
- Department of Pediatrics and Adolescent Medicine, Center for Infectious Diseases Research, Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, PO Box 11-0236 Riad El Solh, Beirut, Lebanon
| | - Randa Attieh
- Department of Pediatrics and Adolescent Medicine, Center for Infectious Diseases Research, Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, PO Box 11-0236 Riad El Solh, Beirut, Lebanon
| | - Lina Kozhaya
- Department of Pediatrics and Adolescent Medicine, Center for Infectious Diseases Research, Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, PO Box 11-0236 Riad El Solh, Beirut, Lebanon
| | - Sarah Kabbani
- Department of Pediatrics and Adolescent Medicine, Center for Infectious Diseases Research, Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, PO Box 11-0236 Riad El Solh, Beirut, Lebanon
| | - Ghassan Dbaibo
- Department of Pediatrics and Adolescent Medicine, Center for Infectious Diseases Research, Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, PO Box 11-0236 Riad El Solh, Beirut, Lebanon.
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77
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Levental KR, Surma MA, Skinkle AD, Lorent JH, Zhou Y, Klose C, Chang JT, Hancock JF, Levental I. ω-3 polyunsaturated fatty acids direct differentiation of the membrane phenotype in mesenchymal stem cells to potentiate osteogenesis. SCIENCE ADVANCES 2017; 3:eaao1193. [PMID: 29134198 PMCID: PMC5677358 DOI: 10.1126/sciadv.aao1193] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 10/16/2017] [Indexed: 05/19/2023]
Abstract
Mammalian cells produce hundreds of dynamically regulated lipid species that are actively turned over and trafficked to produce functional membranes. These lipid repertoires are susceptible to perturbations from dietary sources, with potentially profound physiological consequences. However, neither the lipid repertoires of various cellular membranes, their modulation by dietary fats, nor their effects on cellular phenotypes have been widely explored. We report that differentiation of human mesenchymal stem cells (MSCs) into osteoblasts or adipocytes results in extensive remodeling of the plasma membrane (PM), producing cell-specific membrane compositions and biophysical properties. The distinct features of osteoblast PMs enabled rational engineering of membrane phenotypes to modulate differentiation in MSCs. Specifically, supplementation with docosahexaenoic acid (DHA), a lipid component characteristic of osteoblast membranes, induced broad lipidomic remodeling in MSCs that reproduced compositional and structural aspects of the osteoblastic PM phenotype. The PM changes induced by DHA supplementation potentiated osteogenic differentiation of MSCs concurrent with enhanced Akt activation at the PM. These observations prompt a model wherein the DHA-induced lipidome leads to more stable membrane microdomains, which serve to increase Akt activity and thereby enhance osteogenic differentiation. More broadly, our investigations suggest a general mechanism by which dietary fats affect cellular physiology through remodeling of membrane lipidomes, biophysical properties, and signaling.
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Affiliation(s)
- Kandice R. Levental
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | | | | | - Joseph H. Lorent
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yong Zhou
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | | | - Jeffrey T. Chang
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - John F. Hancock
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ilya Levental
- McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
- Corresponding author.
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78
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Gulyás G, Radvánszki G, Matuska R, Balla A, Hunyady L, Balla T, Várnai P. Plasma membrane phosphatidylinositol 4-phosphate and 4,5-bisphosphate determine the distribution and function of K-Ras4B but not H-Ras proteins. J Biol Chem 2017; 292:18862-18877. [PMID: 28939768 DOI: 10.1074/jbc.m117.806679] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/11/2017] [Indexed: 11/06/2022] Open
Abstract
Plasma membrane (PM) localization of Ras proteins is crucial for transmitting signals upon mitogen stimulation. Post-translational lipid modification of Ras proteins plays an important role in their recruitment to the PM. Electrostatic interactions between negatively charged PM phospholipids and basic amino acids found in K-Ras4B (K-Ras) but not in H-Ras are important for permanent K-Ras localization to the PM. Here, we investigated how acute depletion of negatively charged PM polyphosphoinositides (PPIns) from the PM alters the intracellular distribution and activity of K- and H-Ras proteins. PPIns depletion from the PM was achieved either by agonist-induced activation of phospholipase C β or with a rapamycin-inducible system in which various phosphatidylinositol phosphatases were recruited to the PM. Redistribution of the two Ras proteins was monitored with confocal microscopy or with a recently developed bioluminescence resonance energy transfer-based approach involving fusion of the Ras C-terminal targeting sequences or the entire Ras proteins to Venus fluorescent protein. We found that PM PPIns depletion caused rapid translocation of K-Ras but not H-Ras from the PM to the Golgi. PM depletion of either phosphatidylinositol 4-phosphate (PtdIns4P) or PtdIns(4,5)P2 but not PtdIns(3,4,5)P3 was sufficient to evoke K-Ras translocation. This effect was diminished by deltarasin, an inhibitor of the Ras-phosphodiesterase interaction, or by simultaneous depletion of the Golgi PtdIns4P. The PPIns depletion decreased incorporation of [3H]leucine in K-Ras-expressing cells, suggesting that Golgi-localized K-Ras is not as signaling-competent as its PM-bound form. We conclude that PPIns in the PM are important regulators of K-Ras-mediated signals.
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Affiliation(s)
- Gergő Gulyás
- From the Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest 1094, Hungary
| | - Glória Radvánszki
- From the Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest 1094, Hungary
| | - Rita Matuska
- From the Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest 1094, Hungary
| | - András Balla
- From the Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest 1094, Hungary.,MTA-SE Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest 1094, Hungary, and
| | - László Hunyady
- From the Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest 1094, Hungary.,MTA-SE Laboratory of Molecular Physiology, Hungarian Academy of Sciences and Semmelweis University, Budapest 1094, Hungary, and
| | - Tamas Balla
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver NICHD, National Institutes of Health, Bethesda, Maryland 20892
| | - Péter Várnai
- From the Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest 1094, Hungary,
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79
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Modelling compartmentalization towards elucidation and engineering of spatial organization in biochemical pathways. Sci Rep 2017; 7:12057. [PMID: 28935941 PMCID: PMC5608717 DOI: 10.1038/s41598-017-11081-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 08/08/2017] [Indexed: 01/21/2023] Open
Abstract
Compartmentalization is a fundamental ingredient, central to the functioning of biological systems at multiple levels. At the cellular level, compartmentalization is a key aspect of the functioning of biochemical pathways and an important element used in evolution. It is also being exploited in multiple contexts in synthetic biology. Accurate understanding of the role of compartments and designing compartmentalized systems needs reliable modelling/systems frameworks. We examine a series of building blocks of signalling and metabolic pathways with compartmental organization. We systematically analyze when compartmental ODE models can be used in these contexts, by comparing these models with detailed reaction-transport models, and establishing a correspondence between the two. We build on this to examine additional complexities associated with these pathways, and also examine sample problems in the engineering of these pathways. Our results indicate under which conditions compartmental models can and cannot be used, why this is the case, and what augmentations are needed to make them reliable and predictive. We also uncover other hidden consequences of employing compartmental models in these contexts. Or results contribute a number of insights relevant to the modelling, elucidation, and engineering of biochemical pathways with compartmentalization, at the core of systems and synthetic biology.
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80
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Secretory phospholipase A 2 modified HDL rapidly and potently suppresses platelet activation. Sci Rep 2017; 7:8030. [PMID: 28808297 PMCID: PMC5556053 DOI: 10.1038/s41598-017-08136-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 07/05/2017] [Indexed: 12/16/2022] Open
Abstract
Levels of secretory phospholipases A2 (sPLA2) highly increase under acute and chronic inflammatory conditions. sPLA2 is mainly associated with high-density lipoproteins (HDL) and generates bioactive lysophospholipids implicated in acute and chronic inflammatory processes. Unexpectedly, pharmacological inhibition of sPLA2 in patients with acute coronary syndrome was associated with an increased risk of myocardial infarction and stroke. Given that platelets are key players in thrombosis and inflammation, we hypothesized that sPLA2-induced hydrolysis of HDL-associated phospholipids (sPLA2-HDL) generates modified HDL particles that affect platelet function. We observed that sPLA2-HDL potently and rapidly inhibited platelet aggregation induced by several agonists, P-selectin expression, GPIIb/IIIa activation and superoxide production, whereas native HDL showed little effects. sPLA2-HDL suppressed the agonist-induced rise of intracellular Ca2+ levels and phosphorylation of Akt and ERK1/2, which trigger key steps in promoting platelet activation. Importantly, sPLA2 in the absence of HDL showed no effects, whereas enrichment of HDL with lysophosphatidylcholines containing saturated fatty acids (the main sPLA2 products) mimicked sPLA2-HDL activities. Our findings suggest that sPLA2 generates lysophosphatidylcholine-enriched HDL particles that modulate platelet function under inflammatory conditions.
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81
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System Biology Approach to Identify Potential Receptor for Targeting Cancer and Biomolecular Interaction Studies of Indole[2,1-a]Isoquinoline Derivative as Anticancerous Drug Candidate Against it. Interdiscip Sci 2017; 11:125-134. [PMID: 28748401 DOI: 10.1007/s12539-017-0249-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 04/28/2017] [Accepted: 07/01/2017] [Indexed: 02/06/2023]
Abstract
Cancer is a public health concern which is spreading throughout the world. Different approaches have been employed to combat this disease. System biology approach has been used to understand the molecular mechanisms of drugs targeting cancer cell's receptor which have opened-up a window to develop effective drugs for it. We have demonstrated biomolecular interaction studies using the rational drug design of indole[2,1-a]isoquinoline derivative as a potent inhibitor against identified cancerous protein PIK3CA -a catalytic sub-unit of PI3K family protein-and compared its affinity with FDA approved drugs for receptors such as dactolisib, idelalisib, and several others such afatinib, avastin, ceritinib and crizotinib, etc.; by docking against potential receptor to set a cutoff value for our screening. Isoquinolines are small alkaloids with a vast variety of substitution depending upon their biogenetic pattern. Isoquinoline derivatives have been reported for their antimalarial, antibacterial, antifungal and anticancerous activities. The results obtained from the present studies conclude that membrane protein is an efficient drug that can be used to target cancer. Moreover, comparative study with ADMET prediction concludes that isoquinoline can be a potent drug for cancer treatment.
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82
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Seong J, Huang M, Sim KM, Kim H, Wang Y. FRET-based Visualization of PDGF Receptor Activation at Membrane Microdomains. Sci Rep 2017; 7:1593. [PMID: 28487538 PMCID: PMC5431615 DOI: 10.1038/s41598-017-01789-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 03/31/2017] [Indexed: 11/09/2022] Open
Abstract
Platelet-derived growth factor receptor (PDGFR) senses extracellular growth factors and transfer the signals inside the cells regulating cell proliferation, migration and survival. It has been controversial at which membrane microdomains PDGFRs reside and how they control such diverse intracellular signaling pathways. Here, we developed a novel PDGFR biosensor based on fluorescence resonance energy transfer (FRET), which can detect the real-time PDGFR activity in live cells with high spatiotemporal resolutions. To study subcellular PDGFR activity at membrane microdomains, this PDGFR biosensor was further targeted in or outside lipid rafts via different lipid modification signals. The results suggest that, in response to PDGF stimulation, PDGFR activity is evenly distributed at different membrane microdomains, while integrin-mediated signaling events have inhibitory effects on the activation of PDGFR specifically located in lipid rafts but not outside rafts, implying the role of lipid microdomains as segregated signaling platforms.
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Affiliation(s)
- Jihye Seong
- Neuroscience Program, University of Illinois, Urbana-Champaign, Urbana, IL, 61801, USA. .,Convergence Research Center for Diagnosis Treatment Care of Dementia, Korea Institute of Science and Technology (KIST), Seoul, 02792, South Korea. .,Biological Chemistry Program, Korea University of Science and Technology (UST), Daejeon, 34113, South Korea. .,Department of Converging Science and Technology, Kyung Hee University, Seoul, 02447, South Korea.
| | - Min Huang
- Department of Bioengineering, University of Illinois, Urbana-Champaign, Urbana, IL, 61801, USA
| | - Kyoung Mi Sim
- Convergence Research Center for Diagnosis Treatment Care of Dementia, Korea Institute of Science and Technology (KIST), Seoul, 02792, South Korea
| | - Hyunbin Kim
- Convergence Research Center for Diagnosis Treatment Care of Dementia, Korea Institute of Science and Technology (KIST), Seoul, 02792, South Korea.,Department of Converging Science and Technology, Kyung Hee University, Seoul, 02447, South Korea
| | - Yingxiao Wang
- Neuroscience Program, University of Illinois, Urbana-Champaign, Urbana, IL, 61801, USA. .,Department of Bioengineering, University of Illinois, Urbana-Champaign, Urbana, IL, 61801, USA. .,Department of Bioengineering, University of California, San Diego, CA, 92093, USA.
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83
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Roux A, Loranger A, Lavoie JN, Marceau N. Keratin 8/18 regulation of insulin receptor signaling and trafficking in hepatocytes through a concerted phosphoinositide-dependent Akt and Rab5 modulation. FASEB J 2017; 31:3555-3573. [PMID: 28442548 DOI: 10.1096/fj.201700036r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 04/11/2017] [Indexed: 01/30/2023]
Abstract
Keratins (Ks) are epithelial cell intermediate filament (IF) proteins that are expressed as pairs in a differentiation-regulated manner. Hepatocyte IFs are made only of K8/K18 pairs, which means that a K8 loss in K8-null mice leads to degradation of K18. Functionally, there is accumulating evidence that IFs contribute to signaling platforms. Here, we investigate the role of K8/K18 IFs in the regulation of insulin receptor (IR) signaling and trafficking in hepatocytes. We find that the IR substrate 1 (IRS1)/PI3K/Akt signaling cascade-downstream of IR-displays prolonged activation in K8-null compared with wild-type hepatocytes. Assessment of the Akt/mammalian target of rapamycin complex 1-mediated feedback loop to IRS1/PI3K, in the absence or presence of drug inhibitors, further supports a preferential K8/K18 IF intervention at the surface membrane. In K8-null hepatocytes, IR trafficking vesicles that are labeled by Rab5/EEA1/phosphatidylinositol 3-phosphate accumulate at a juxtanuclear region via a microtubule-dependent process. Moreover, interference with phosphatidylinositol 4,5-biphosphate signaling aggravates IR/Rab5 accumulation. Overall, results uncover K8/K18 IF regulation of IR signaling via a concerted modulation of phosphatidylinositol 4,5-biphosphate-dependent IRS1/PI3K/Akt signaling and Rab5/phosphatidylinositol 3-phosphate/microtubule trafficking in hepatocytes.-Roux, A., Loranger, A., Lavoie, J. N., Marceau, N. Keratin 8/18 regulation of insulin receptor signaling and trafficking in hepatocytes through a concerted phosphoinositide-dependent Akt and Rab5 modulation.
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Affiliation(s)
- Alexandra Roux
- Centre de Recherche Sur le Cancer de l'Université Laval, Québec City, Quebec, Canada.,Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, L'Hôtel-Dieu de Québec, Québec City, Quebec, Canada
| | - Anne Loranger
- Centre de Recherche Sur le Cancer de l'Université Laval, Québec City, Quebec, Canada.,Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, L'Hôtel-Dieu de Québec, Québec City, Quebec, Canada
| | - Josée N Lavoie
- Centre de Recherche Sur le Cancer de l'Université Laval, Québec City, Quebec, Canada.,Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, L'Hôtel-Dieu de Québec, Québec City, Quebec, Canada
| | - Normand Marceau
- Centre de Recherche Sur le Cancer de l'Université Laval, Québec City, Quebec, Canada; .,Centre de Recherche du Centre Hospitalier Universitaire de Québec-Université Laval, L'Hôtel-Dieu de Québec, Québec City, Quebec, Canada
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84
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Rodriguez-Cuenca S, Pellegrinelli V, Campbell M, Oresic M, Vidal-Puig A. Sphingolipids and glycerophospholipids - The "ying and yang" of lipotoxicity in metabolic diseases. Prog Lipid Res 2017; 66:14-29. [PMID: 28104532 DOI: 10.1016/j.plipres.2017.01.002] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 11/30/2016] [Accepted: 01/05/2017] [Indexed: 12/14/2022]
Abstract
Sphingolipids in general and ceramides in particular, contribute to pathophysiological mechanisms by modifying signalling and metabolic pathways. Here, we present the available evidence for a bidirectional homeostatic crosstalk between sphingolipids and glycerophospholipids, whose dysregulation contributes to lipotoxicity induced metabolic stress. The initial evidence for this crosstalk originates from simulated models designed to investigate the biophysical properties of sphingolipids in plasma membrane representations. In this review, we reinterpret some of the original findings and conceptualise them as a sort of "ying/yang" interaction model of opposed/complementary forces, which is consistent with the current knowledge of lipid homeostasis and pathophysiology. We also propose that the dysregulation of the balance between sphingolipids and glycerophospholipids results in a lipotoxic insult relevant in the pathophysiology of common metabolic diseases, typically characterised by their increased ceramide/sphingosine pools.
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Affiliation(s)
- S Rodriguez-Cuenca
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge. Cambridge, UK.
| | - V Pellegrinelli
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge. Cambridge, UK
| | - M Campbell
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge. Cambridge, UK
| | - M Oresic
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, FI -20520 Turku, Finland
| | - A Vidal-Puig
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge. Cambridge, UK; Wellcome Trust Sanger Institute, Hinxton, UK.
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85
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SDF-1α/CXCR4 Signaling in Lipid Rafts Induces Platelet Aggregation via PI3 Kinase-Dependent Akt Phosphorylation. PLoS One 2017; 12:e0169609. [PMID: 28072855 PMCID: PMC5224795 DOI: 10.1371/journal.pone.0169609] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 12/18/2016] [Indexed: 01/05/2023] Open
Abstract
Stromal cell-derived factor-1α (SDF-1α)-induced platelet aggregation is mediated through its G protein-coupled receptor CXCR4 and phosphatidylinositol 3 kinase (PI3K). Here, we demonstrate that SDF-1α induces phosphorylation of Akt at Thr308 and Ser473 in human platelets. SDF-1α-induced platelet aggregation and Akt phosphorylation are inhibited by pretreatment with the CXCR4 antagonist AMD3100 or the PI3K inhibitor LY294002. SDF-1α also induces the phosphorylation of PDK1 at Ser241 (an upstream activator of Akt), GSK3β at Ser9 (a downstream substrate of Akt), and myosin light chain at Ser19 (a downstream element of the Akt signaling pathway). SDF-1α-induced platelet aggregation is inhibited by pretreatment with the Akt inhibitor MK-2206 in a dose-dependent manner. Furthermore, SDF-1α-induced platelet aggregation and Akt phosphorylation are inhibited by pretreatment with the raft-disrupting agent methyl-β-cyclodextrin. Sucrose density gradient analysis shows that 35% of CXCR4, 93% of the heterotrimeric G proteins Gαi-1, 91% of Gαi-2, 50% of Gβ and 4.0% of PI3Kβ, and 4.5% of Akt2 are localized in the detergent-resistant membrane raft fraction. These findings suggest that SDF-1α/CXCR4 signaling in lipid rafts induces platelet aggregation via PI3K-dependent Akt phosphorylation.
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86
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Soluble klotho binds monosialoganglioside to regulate membrane microdomains and growth factor signaling. Proc Natl Acad Sci U S A 2017; 114:752-757. [PMID: 28069944 DOI: 10.1073/pnas.1620301114] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Soluble klotho, the shed ectodomain of the antiaging membrane protein α-klotho, is a pleiotropic endocrine/paracrine factor with no known receptors and poorly understood mechanism of action. Soluble klotho down-regulates growth factor-driven PI3K signaling, contributing to extension of lifespan, cardioprotection, and tumor inhibition. Here we show that soluble klotho binds membrane lipid rafts. Klotho binding to rafts alters lipid organization, decreases membrane's propensity to form large ordered domains for endocytosis, and down-regulates raft-dependent PI3K/Akt signaling. We identify α2-3-sialyllactose present in the glycan of monosialogangliosides as targets of soluble klotho. α2-3-Sialyllactose is a common motif of glycans. To explain why klotho preferentially targets lipid rafts we show that clustering of gangliosides in lipid rafts is important. In vivo, raft-dependent PI3K signaling is up-regulated in klotho-deficient mouse hearts vs. wild-type hearts. Our results identify ganglioside-enriched lipid rafts to be receptors that mediate soluble klotho regulation of PI3K signaling. Targeting sialic acids may be a general mechanism for pleiotropic actions of soluble klotho.
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87
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Edwards BS, Isom WJ, Navratil AM. Gonadotropin releasing hormone activation of the mTORC2/Rictor complex regulates actin remodeling and ERK activity in LβT2 cells. Mol Cell Endocrinol 2017; 439:346-353. [PMID: 27663077 PMCID: PMC5123956 DOI: 10.1016/j.mce.2016.09.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 08/26/2016] [Accepted: 09/19/2016] [Indexed: 12/16/2022]
Abstract
The mammalian target of rapamycin (mTOR) assembles into two different multi-protein complexes, mTORC1 and mTORC2. The mTORC2 complex is distinct due to the unique expression of the specific core regulatory protein Rictor (rapamycin-insensitive companion of mTOR). mTORC2 has been implicated in regulating actin cytoskeletal reorganization but its role in gonadotrope function is unknown. Using the gonadotrope-derived LβT2 cell line, we find that the GnRH agonist buserelin (GnRHa) phosphorylates both mTOR and Rictor. Interestingly, inhibition of mTORC2 blunts GnRHa-induced cyto-architectural rearrangements. Coincident with blunting of actin reorganization, inhibition of mTORC2 also attenuates GnRHa-mediated activation of both protein kinase C (PKC) and extracellular signal regulated kinase (ERK). Collectively, our data suggests that GnRHa-mediated mTORC2 activation is important in facilitating actin reorganization events critical for initiating PKC activity and subsequent ERK phosphorylation in the gonadotrope-derived LβT2 cell line.
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Affiliation(s)
- Brian S Edwards
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA.
| | - William J Isom
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA.
| | - Amy M Navratil
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA.
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88
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A Transformation-Defective Polyomavirus Middle T Antigen with a Novel Defect in PI3 Kinase Signaling. J Virol 2017; 91:JVI.01774-16. [PMID: 27852846 DOI: 10.1128/jvi.01774-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/29/2016] [Indexed: 02/06/2023] Open
Abstract
Middle T antigen (MT), the principal oncoprotein of murine polyomavirus, transforms by association with cellular proteins. Protein phosphatase 2A (PP2A), YAP, Src family tyrosine kinases, Shc, phosphatidylinositol 3-kinase (PI3K), and phospholipase C-γ1 (PLCγ1) have all been implicated in MT transformation. Mutant dl1015, with deletion of residues 338 to 347 in the C-terminal region, has been an enigma, because the basis for its transformation defect has not been apparent. This work probes the dl1015 region of MT. Because the region is proline rich, the hypothesis that it targets Src homology domain 3 (SH3) domains was tested, but mutation of the putative SH3 binding motif did not affect transformation. During this work, two point mutants, W348R and E349K, were identified as transformation defective. Extensive analysis of the E349K mutant is described here. Similar to wild-type MT, the E349K mutant associates with PP2A, YAP, tyrosine kinases, Shc, PI3 kinase, and PLCγ1. The E349K mutant was examined to determine the mechanism for its transformation defect. Assays of cell localization and membrane targeting showed no obvious difference in localization. Src association was normal as assayed by in vitro kinase and MT phosphopeptide mapping. Shc activation was confirmed by its tyrosine phosphorylation. Association of type 1 PI3K with MT was demonstrated by coimmunoprecipitation, showing both PI3K subunits and in vitro activity. Nonetheless, expression of the mutants failed to lead to the activation of two known downstream targets of PI3K, Akt and Rac-1. Strikingly, despite normal association of the E349K mutant with PI3K, cells expressing the mutant failed to elevate phosphatidylinositol (3,4,5)-trisphosphate (PIP3) in mutant-expressing cells. These results indicate a novel unsuspected aspect to PI3K control. IMPORTANCE The gene coding for middle T antigen (MT) is the murine polyomavirus oncogene most responsible for tumor formation. Its study has a history of uncovering novel aspects of mammalian cell regulation. The importance of PI3K activity and tyrosine phosphorylation are two examples of insights coming from MT. This study describes new mutants unable to transform like the wild type that point to novel regulation of PI3K signaling. Previous mutants were defective in PI3K because they failed to bind the enzyme and bring the activity to the membrane. These mutants recruit PI3K activity like the wild type, but fail to elevate the cellular level of PIP3, the product used to signal downstream of PI3K. As a result, they fail to activate either Akt or Rac1, explaining the transformation defect.
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89
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Davey RA, Shtanko O, Anantpadma M, Sakurai Y, Chandran K, Maury W. Mechanisms of Filovirus Entry. Curr Top Microbiol Immunol 2017; 411:323-352. [PMID: 28601947 DOI: 10.1007/82_2017_14] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Filovirus entry into cells is complex, perhaps as complex as any viral entry mechanism identified to date. However, over the past 10 years, the important events required for filoviruses to enter into the endosomal compartment and fuse with vesicular membranes have been elucidated (Fig. 1). Here, we highlight the important steps that are required for productive entry of filoviruses into mammalian cells.
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Affiliation(s)
- R A Davey
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - O Shtanko
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - M Anantpadma
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Y Sakurai
- Department of Virology and Immunology, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - K Chandran
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - W Maury
- Department of Microbiology, The University of Iowa, Iowa City, IA, USA.
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90
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Gajate C, Mollinedo F. Isolation of Lipid Rafts Through Discontinuous Sucrose Gradient Centrifugation and Fas/CD95 Death Receptor Localization in Raft Fractions. Methods Mol Biol 2017; 1557:125-138. [PMID: 28078589 DOI: 10.1007/978-1-4939-6780-3_13] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Lipid raft domains, enriched in sphingolipids and cholesterol, serve as sorting platforms and hubs for signal transduction proteins, and show resistance to detergent solubilization. Despite rafts have been involved in survival processes, these membrane domains have also been shown to play a major role in the modulation of death receptor signaling. Here, we describe a detailed protocol for isolating lipid rafts from whole cells by taking advantage of the lipid raft resistance to Triton X-100 solubilization at 4 °C, followed by sucrose gradient centrifugation, with subsequent analysis of Fas/CD95 death receptor localization in the raft fractions by immunoblotting. This method is also useful to localize additional proteins in membrane rafts.
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Affiliation(s)
- Consuelo Gajate
- Laboratory of Cell Death and Cancer Therapy, Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), C/ Ramiro de Maeztu 9, 28040, Madrid, Spain.
| | - Faustino Mollinedo
- Laboratory of Cell Death and Cancer Therapy, Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), C/ Ramiro de Maeztu 9, 28040, Madrid, Spain.
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91
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Abstract
Physiological stimuli activate protein kinases for finite periods of time, which is critical for specific biological outcomes. Mimicking this transient biological activity of kinases is challenging due to the limitations of existing methods. Here, we report a strategy enabling transient kinase activation in living cells. Using two protein-engineering approaches, we achieve independent control of kinase activation and inactivation. We show successful regulation of tyrosine kinase c-Src (Src) and Ser/Thr kinase p38α (p38), demonstrating broad applicability of the method. By activating Src for finite periods of time, we reveal how the duration of kinase activation affects secondary morphological changes that follow transient Src activation. This approach highlights distinct roles for sequential Src-Rac1- and Src-PI3K-signaling pathways at different stages during transient Src activation. Finally, we demonstrate that this method enables transient activation of Src and p38 in a specific signaling complex, providing a tool for targeted regulation of individual signaling pathways.
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92
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Nishiga M, Horie T, Kuwabara Y, Nagao K, Baba O, Nakao T, Nishino T, Hakuno D, Nakashima Y, Nishi H, Nakazeki F, Ide Y, Koyama S, Kimura M, Hanada R, Nakamura T, Inada T, Hasegawa K, Conway SJ, Kita T, Kimura T, Ono K. MicroRNA-33 Controls Adaptive Fibrotic Response in the Remodeling Heart by Preserving Lipid Raft Cholesterol. Circ Res 2016; 120:835-847. [PMID: 27920122 DOI: 10.1161/circresaha.116.309528] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/27/2016] [Accepted: 12/05/2016] [Indexed: 12/13/2022]
Abstract
RATIONALE Heart failure and atherosclerosis share the underlying mechanisms of chronic inflammation followed by fibrosis. A highly conserved microRNA (miR), miR-33, is considered as a potential therapeutic target for atherosclerosis because it regulates lipid metabolism and inflammation. However, the role of miR-33 in heart failure remains to be elucidated. OBJECTIVE To clarify the role of miR-33 involved in heart failure. METHODS AND RESULTS We first investigated the expression levels of miR-33a/b in human cardiac tissue samples with dilated cardiomyopathy. Increased expression of miR-33a was associated with improving hemodynamic parameters. To clarify the role of miR-33 in remodeling hearts, we investigated the responses to pressure overload by transverse aortic constriction in miR-33-deficient (knockout [KO]) mice. When mice were subjected to transverse aortic constriction, miR-33 expression levels were significantly upregulated in wild-type left ventricles. There was no difference in hypertrophic responses between wild-type and miR-33KO hearts, whereas cardiac fibrosis was ameliorated in miR-33KO hearts compared with wild-type hearts. Despite the ameliorated cardiac fibrosis, miR-33KO mice showed impaired systolic function after transverse aortic constriction. We also found that cardiac fibroblasts were mainly responsible for miR-33 expression in the heart. Deficiency of miR-33 impaired cardiac fibroblast proliferation, which was considered to be caused by altered lipid raft cholesterol content. Moreover, cardiac fibroblast-specific miR-33-deficient mice also showed decreased cardiac fibrosis induced by transverse aortic constriction as systemic miR-33KO mice. CONCLUSION Our results demonstrate that miR-33 is involved in cardiac remodeling, and it preserves lipid raft cholesterol content in fibroblasts and maintains adaptive fibrotic responses in the remodeling heart.
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Affiliation(s)
- Masataka Nishiga
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Takahiro Horie
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Yasuhide Kuwabara
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Kazuya Nagao
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Osamu Baba
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Tetsushi Nakao
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Tomohiro Nishino
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Daihiko Hakuno
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Yasuhiro Nakashima
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Hitoo Nishi
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Fumiko Nakazeki
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Yuya Ide
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Satoshi Koyama
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Masahiro Kimura
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Ritsuko Hanada
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Tomoyuki Nakamura
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Tsukasa Inada
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Koji Hasegawa
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Simon J Conway
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Toru Kita
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Takeshi Kimura
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita)
| | - Koh Ono
- From the Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Japan (M.N., T.H., Y.K., O.B., T.Nakao, T.Nishino, D.H., Y.N., H.N., F.N., Y.I., S.K., M.K., R.H., T.Kimura, K.O.); Department of Cardiovascular Center, Osaka Red Cross Hospital, Japan (K.N., T.I.); Department of Pharmacology, Kansai Medical University, Hirakata, Osaka, Japan (T.Nakamura); Division of Translational Research, Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Japan (K.H.); Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University of Medicine, Indianapolis (S.J.C.); and Kobe City Medical Center General Hospital, Japan (T.Kita).
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93
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Bolbat A, Schultz C. Recent developments of genetically encoded optical sensors for cell biology. Biol Cell 2016; 109:1-23. [PMID: 27628952 DOI: 10.1111/boc.201600040] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/06/2016] [Accepted: 09/09/2016] [Indexed: 12/14/2022]
Abstract
Optical sensors are powerful tools for live cell research as they permit to follow the location, concentration changes or activities of key cellular players such as lipids, ions and enzymes. Most of the current sensor probes are based on fluorescence which provides great spatial and temporal precision provided that high-end microscopy is used and that the timescale of the event of interest fits the response time of the sensor. Many of the sensors developed in the past 20 years are genetically encoded. There is a diversity of designs leading to simple or sometimes complicated applications for the use in live cells. Genetically encoded sensors began to emerge after the discovery of fluorescent proteins, engineering of their improved optical properties and the manipulation of their structure through application of circular permutation. In this review, we will describe a variety of genetically encoded biosensor concepts, including those for intensiometric and ratiometric sensors based on single fluorescent proteins, Forster resonance energy transfer-based sensors, sensors utilising bioluminescence, sensors using self-labelling SNAP- and CLIP-tags, and finally tetracysteine-based sensors. We focus on the newer developments and discuss the current approaches and techniques for design and application. This will demonstrate the power of using optical sensors in cell biology and will help opening the field to more systematic applications in the future.
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Affiliation(s)
- Andrey Bolbat
- European Molecular Biology Laboratory (EMBL), Cell Biology & Biophysics Unit, Heidelberg, 69117, Germany
| | - Carsten Schultz
- European Molecular Biology Laboratory (EMBL), Cell Biology & Biophysics Unit, Heidelberg, 69117, Germany
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94
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Cizmecioglu O, Ni J, Xie S, Zhao JJ, Roberts TM. Rac1-mediated membrane raft localization of PI3K/p110β is required for its activation by GPCRs or PTEN loss. eLife 2016; 5. [PMID: 27700986 PMCID: PMC5050018 DOI: 10.7554/elife.17635] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 09/22/2016] [Indexed: 11/26/2022] Open
Abstract
We aimed to understand how spatial compartmentalization in the plasma membrane might contribute to the functions of the ubiquitous class IA phosphoinositide 3-kinase (PI3K) isoforms, p110α and p110β. We found that p110β localizes to membrane rafts in a Rac1-dependent manner. This localization potentiates Akt activation by G-protein-coupled receptors (GPCRs). Thus genetic targeting of a Rac1 binding-deficient allele of p110β to rafts alleviated the requirement for p110β-Rac1 association for GPCR signaling, cell growth and migration. In contrast, p110α, which does not play a physiological role in GPCR signaling, is found to reside in nonraft regions of the plasma membrane. Raft targeting of p110α allowed its EGFR-mediated activation by GPCRs. Notably, p110β dependent, PTEN null tumor cells critically rely upon raft-associated PI3K activity. Collectively, our findings provide a mechanistic account of how membrane raft localization regulates differential activation of distinct PI3K isoforms and offer insight into why PTEN-deficient cancers depend on p110β. DOI:http://dx.doi.org/10.7554/eLife.17635.001
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Affiliation(s)
- Onur Cizmecioglu
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Jing Ni
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Shaozhen Xie
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Jean J Zhao
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
| | - Thomas M Roberts
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, United States.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, United States
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95
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Igal RA. Stearoyl CoA desaturase-1: New insights into a central regulator of cancer metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1865-1880. [PMID: 27639967 DOI: 10.1016/j.bbalip.2016.09.009] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 08/22/2016] [Accepted: 09/11/2016] [Indexed: 12/24/2022]
Abstract
The processes of cell proliferation, cell death and differentiation involve an intricate array of biochemical and morphological changes that require a finely tuned modulation of metabolic pathways, chiefly among them is fatty acid metabolism. The critical participation of stearoyl CoA desaturase-1 (SCD1), the fatty acyl Δ9-desaturing enzyme that converts saturated fatty acids (SFA) into monounsaturated fatty acids (MUFA), in the mechanisms of replication and survival of mammalian cells, as well as their implication in the biological alterations of cancer have been actively investigated in recent years. This review examines the growing body of evidence that argues for a role of SCD1 as a central regulator of the complex synchronization of metabolic and signaling events that control cellular metabolism, cell cycle progression, survival, differentiation and transformation to cancer.
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Affiliation(s)
- R Ariel Igal
- Institute of Human Nutrition and Department of Pediatrics, Columbia University Medical Center, New York City, NY, United States.
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96
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Boesze-Battaglia K, Alexander D, Dlakić M, Shenker BJ. A Journey of Cytolethal Distending Toxins through Cell Membranes. Front Cell Infect Microbiol 2016; 6:81. [PMID: 27559534 PMCID: PMC4978709 DOI: 10.3389/fcimb.2016.00081] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 07/26/2016] [Indexed: 02/06/2023] Open
Abstract
The multifunctional role of lipids as structural components of membranes, signaling molecules, and metabolic substrates makes them an ideal partner for pathogens to hijack host cell processes for their own survival. The properties and composition of unique membrane micro-domains such as membrane rafts make these regions a natural target for pathogens as it affords them an opportunity to hijack cell signaling and intracellular trafficking pathways. Cytolethal distending toxins (Cdts), members of the AB2 family of toxins are comprised of three subunits, the active, CdtB unit, and the binding, CdtA-CdtC unit. Cdts are cyclomodulins leading to cell cycle arrest and apoptosis in a wide variety of cell types. Cdts from several species share a requirement for membrane rafts, and often cholesterol specifically for cell binding and CdtB mediated cytotoxicity. In this review we focus on how host–cell membrane bilayer organization contributes to the cell surface association, internalization, and action of bacteria derived cytolethal distending toxins (Cdts), with an emphasis on Aggregatibacter actinomycetemcomitans Cdt.
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Affiliation(s)
| | - Desiree Alexander
- Department of Biochemistry, SDM, University of Pennsylvania Philadelphia, PA, USA
| | - Mensur Dlakić
- Department of Microbiology and Immunology, Montana State University Bozeman, MT, USA
| | - Bruce J Shenker
- Department of Pathology, SDM, University of Pennsylvania Philadelphia, PA, USA
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97
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Boothe T, Lim GE, Cen H, Skovsø S, Piske M, Li SN, Nabi IR, Gilon P, Johnson JD. Inter-domain tagging implicates caveolin-1 in insulin receptor trafficking and Erk signaling bias in pancreatic beta-cells. Mol Metab 2016; 5:366-378. [PMID: 27110488 PMCID: PMC4837300 DOI: 10.1016/j.molmet.2016.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Revised: 01/18/2016] [Accepted: 01/25/2016] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVE The role and mechanisms of insulin receptor internalization remain incompletely understood. Previous trafficking studies of insulin receptors involved fluorescent protein tagging at their termini, manipulations that may be expected to result in dysfunctional receptors. Our objective was to determine the trafficking route and molecular mechanisms of functional tagged insulin receptors and endogenous insulin receptors in pancreatic beta-cells. METHODS We generated functional insulin receptors tagged with pH-resistant fluorescent proteins between domains. Confocal, TIRF and STED imaging revealed a trafficking pattern of inter-domain tagged insulin receptors and endogenous insulin receptors detected with antibodies. RESULTS Surprisingly, interdomain-tagged and endogenous insulin receptors in beta-cells bypassed classical Rab5a- or Rab7-mediated endocytic routes. Instead, we found that removal of insulin receptors from the plasma membrane involved tyrosine-phosphorylated caveolin-1, prior to trafficking within flotillin-1-positive structures to lysosomes. Multiple methods of inhibiting caveolin-1 significantly reduced Erk activation in vitro or in vivo, while leaving Akt signaling mostly intact. CONCLUSIONS We conclude that phosphorylated caveolin-1 plays a role in insulin receptor internalization towards lysosomes through flotillin-1-positive structures and that caveolin-1 helps bias physiological beta-cell insulin signaling towards Erk activation.
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Affiliation(s)
- Tobias Boothe
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Gareth E Lim
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Haoning Cen
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Søs Skovsø
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Micah Piske
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Shu Nan Li
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Ivan R Nabi
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Patrick Gilon
- Pôle d'endocrinologie, diabète et nutrition, Institut de recherche expérimentale et clinique, Université catholique de Louvain, Brussels, Belgium
| | - James D Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, BC, Canada.
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98
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Srinivasan P. Multifunctional-layered materials for creating membrane-restricted nanodomains and nanoscale imaging. APPLIED PHYSICS LETTERS 2016; 108:033702. [PMID: 26869725 PMCID: PMC4723406 DOI: 10.1063/1.4940388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 01/11/2016] [Indexed: 06/05/2023]
Abstract
Experimental platform that allows precise spatial positioning of biomolecules with an exquisite control at nanometer length scales is a valuable tool to study the molecular mechanisms of membrane bound signaling. Using micromachined thin film gold (Au) in layered architecture, it is possible to add both optical and biochemical functionalities in in vitro. Towards this goal, here, I show that docking of complementary DNA tethered giant phospholiposomes on Au surface can create membrane-restricted nanodomains. These nanodomains are critical features to dissect molecular choreography of membrane signaling complexes. The excited surface plasmon resonance modes of Au allow label-free imaging at diffraction-limited resolution of stably docked DNA tethered phospholiposomes, and lipid-detergent bicelle structures. Such multifunctional building block enables realizing rigorously controlled in vitro set-up to model membrane anchored biological signaling, besides serving as an optical tool for nanoscale imaging.
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Affiliation(s)
- P Srinivasan
- Department of Electrical and Computer Engineering, University of California , Santa Barbara, California 93106, USA and Neuroscience Research Institute, University of California , Santa Barbara, California 93106, USA
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99
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FRET biosensors reveal AKAP-mediated shaping of subcellular PKA activity and a novel mode of Ca(2+)/PKA crosstalk. Cell Signal 2016; 28:294-306. [PMID: 26772752 DOI: 10.1016/j.cellsig.2016.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 12/18/2015] [Accepted: 01/04/2016] [Indexed: 02/01/2023]
Abstract
Scaffold proteins play a critical role in cellular homeostasis by anchoring signaling enzymes in close proximity to downstream effectors. In addition to anchoring static enzyme complexes, some scaffold proteins also form dynamic signalosomes that can traffic to different subcellular compartments upon stimulation. Gravin (AKAP12), a multivalent scaffold, anchors PKA and other enzymes to the plasma membrane under basal conditions, but upon [Ca(2+)]i elevation, is rapidly redistributed to the cytosol. Because gravin redistribution also impacts PKA localization, we postulate that gravin acts as a calcium "switch" that modulates PKA-substrate interactions at the plasma membrane, thus facilitating a novel crosstalk mechanism between Ca(2+) and PKA-dependent pathways. To assess this, we measured the impact of gravin-V5/His expression on compartmentalized PKA activity using the FRET biosensor AKAR3 in cultured cells. Upon treatment with forskolin or isoproterenol, cells expressing gravin-V5/His showed elevated levels of plasma membrane PKA activity, but cytosolic PKA activity levels were reduced compared with control cells lacking gravin. This effect required both gravin interaction with PKA and localization at the plasma membrane. Pretreatment with calcium-elevating agents thapsigargin or ATP caused gravin redistribution away from the plasma membrane and prevented gravin from elevating PKA activity levels at the membrane. Importantly, this mode of Ca(2+)/PKA crosstalk was not observed in cells expressing a gravin mutant that resisted calcium-mediated redistribution from the cell periphery. These results reveal that gravin impacts subcellular PKA activity levels through the spatial targeting of PKA, and that calcium elevation modulates downstream β-adrenergic/PKA signaling through gravin redistribution, thus supporting the hypothesis that gravin mediates crosstalk between Ca(2+) and PKA-dependent signaling pathways. Based on these results, AKAP localization dynamics may represent an important paradigm for the regulation of cellular signaling networks.
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100
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Kohnhorst CL, Schmitt DL, Sundaram A, An S. Subcellular functions of proteins under fluorescence single-cell microscopy. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1864:77-84. [PMID: 26025769 PMCID: PMC5679394 DOI: 10.1016/j.bbapap.2015.05.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 05/08/2015] [Accepted: 05/18/2015] [Indexed: 11/25/2022]
Abstract
A cell is a highly organized, dynamic, and intricate biological entity orchestrated by a myriad of proteins and their self-assemblies. Because a protein's actions depend on its coordination in both space and time, our curiosity about protein functions has extended from the test tube into the intracellular space of the cell. Accordingly, modern technological developments and advances in enzymology have been geared towards analyzing protein functions within intact single cells. We discuss here how fluorescence single-cell microscopy has been employed to identify subcellular locations of proteins, detect reversible protein-protein interactions, and measure protein activity and kinetics in living cells. Considering that fluorescence single-cell microscopy has been only recently recognized as a primary technique in enzymology, its potentials and outcomes in studying intracellular protein functions are projected to be immensely useful and enlightening. We anticipate that this review would inspire many investigators to study their proteins of interest beyond the conventional boundary of specific disciplines. This article is part of a Special Issue entitled: Physiological Enzymology and Protein Functions.
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Affiliation(s)
- Casey L Kohnhorst
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Danielle L Schmitt
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Anand Sundaram
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Songon An
- Department of Chemistry and Biochemistry, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA.
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