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Zhou S, Xu J, Zhu Y. Phospholipid scramblase 1 acts through the IL-6/JAK/STAT3 pathway to promote the malignant progression of glioma. Arch Biochem Biophys 2024; 756:110002. [PMID: 38636689 DOI: 10.1016/j.abb.2024.110002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/20/2024] [Accepted: 04/15/2024] [Indexed: 04/20/2024]
Abstract
BACKGROUND Phospholipid scramblase 1 (PLSCR1) is a calcium-dependent endofacial plasma-membrane protein that plays an essential role in multiple human cancers. However, little is known about its role in glioma. This study aimed to investigate PLSCR1 function in glioma, and elucidate its underlying molecular mechanisms. METHODS PLSCR1 expression in human glioma cell lines (U87MG, U251, LN229, A172 and T98G) and human astrocytes was detected by western blot and qRT-PCR. PLSCR1 was silenced using si-PLSCR1-1 and si-PLSCR1-2 in LN229 and U251 cells. PLSCR1 was overexpressed using the pcDNA-PLSCR1 plasmid in T98G cells. Colony formation, 5-ethynyl-2'-deoxyuridine, flow cytometry and transwell assays were employed for measuring cell proliferation, apoptosis and mobility after PLSCR1 knockdown or overexpression. PLSCR1 function in glycolysis in glioma cells was determined through measuring the extracellular acidification rate, oxygen consumption rate, glucose consumption and lactate production. Besides, immunohistochemistry, western blot and qRT-PCR were utilized to assess mRNA and protein expression. Besides, the effect of PLSCR1 silencing on subcutaneous tumor was also monitored. RESULTS PLSCR1 expression was upregulated in glioma. The downregulation of PLSCR1 repressed the proliferation, mobility, epithelial-to-mesenchymal transition (EMT) and glycolysis; however, it facilitated apoptosis in glioma cells. Whereas, PLSCR1 upregulation had the opposite effect. Moreover, PLSCR1 promoted the activation of the IL-6/JAK/STAT3 pathway in glioma cells. Besides, IL-6 treatment significantly reversed the function of PLSCR1 silencing on cell proliferation, mobility, EMT, apoptosis and glycolysis. In a nude mouse tumor model, silencing PLSCR1 suppressed tumor growth via inactivating IL-6/JAK/STAT3 signaling. CONCLUSION Our results indicated that PLSCR1 could facilitate proliferation, mobility, EMT and glycolysis, but repress apoptosis through activating IL-6/JAK/STAT3 signaling in glioma. Therefore, PLSCR1 may function as a potential therapeutic target for glioma.
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Affiliation(s)
- ShiZhen Zhou
- Department of Neurosurgery, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, 250117, China
| | - Jun Xu
- Department of Neurosurgery, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, 250117, China
| | - YuFang Zhu
- Department of Neurosurgery, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, 250117, China.
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2
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Li Y, Wu Y, Yang Z, Shi R, Zhang L, Feng Z, Wei G, Chou M. The Rpf107 gene, a homolog of LOR, is required for the symbiotic nodulation of Robinia pseudoacacia. PLANTA 2023; 259:6. [PMID: 38001306 DOI: 10.1007/s00425-023-04280-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 11/03/2023] [Indexed: 11/26/2023]
Abstract
MAIN CONCLUSION Rpf107 is involved in the infection process of rhizobia and the maintenance of symbiotic nitrogen fixation in black locust root nodules. The LURP-one related (LOR) protein family plays a pivotal role in mediating plant defense responses against both biotic and abiotic stresses. However, our understanding of its function in the symbiotic interaction between legumes and rhizobia remains limited. Here, Rpf107, a homolog of LOR, was identified in Robinia pseudoacacia (black locust). The subcellular localization of Rpf107 was analyzed, and its function was investigated using RNA interference (RNAi) and overexpression techniques. The subcellular localization assay revealed that Rpf107 was mainly distributed in the plasma membrane and nucleus. Rpf107 silencing prevented rhizobial infection and hampered plant growth. The number of infected cells in the nitrogen fixation zone of the Rpf107-RNAi nodules was also noticeably lower than that in the control nodules. Notably, Rpf107 silencing resulted in bacteroid degradation and the premature aging of nodules. In contrast, the overexpression of Rpf107 delayed the senescence of nodules and prolonged the nitrogen-fixing ability of nodules. These results demonstrate that Rpf107 was involved in the infection of rhizobia and the maintenance of symbiotic nitrogen fixation in black locust root nodules. The findings reveal that a member of the LOR protein family plays a role in leguminous root nodule symbiosis, which is helpful to clarify the functions of plant LOR protein family and fully understand the molecular mechanisms underlying legume-rhizobium symbiosis.
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Affiliation(s)
- Yuanli Li
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
| | - Yuanyuan Wu
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
- Xiangyang Public Inspection and Testing Center, No.69, Taiziwan Road, Xiangyang, 441000, Hubei Province, People's Republic of China
| | - Ziyi Yang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
| | - Rui Shi
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
| | - Lu Zhang
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
| | - Zhao Feng
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
| | - Gehong Wei
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China
| | - Minxia Chou
- State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, College of Life Sciences, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, People's Republic of China.
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Cusick JK, Alcaide J, Shi Y. The RELT Family of Proteins: An Increasing Awareness of Their Importance for Cancer, the Immune System, and Development. Biomedicines 2023; 11:2695. [PMID: 37893069 PMCID: PMC10603948 DOI: 10.3390/biomedicines11102695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/22/2023] [Accepted: 09/25/2023] [Indexed: 10/29/2023] Open
Abstract
This review highlights Receptor Expressed in Lymphoid Tissues (RELT), a Tumor Necrosis Factor Superfamily member, and its two paralogs, RELL1 and RELL2. Collectively, these three proteins are referred to as RELTfms and have gained much interest in recent years due to their association with cancer and other human diseases. A thorough knowledge of their physiological functions, including the ligand for RELT, is lacking, yet emerging evidence implicates RELTfms in a variety of processes including cytokine signaling and pathways that either promote cell death or survival. T cells from mice lacking RELT exhibit increased responses against tumors and increased inflammatory cytokine production, and multiple lines of evidence indicate that RELT may promote an immunosuppressive environment for tumors. The relationship of individual RELTfms in different cancers is not universal however, as evidence indicates that individual RELTfms may be risk factors in certain cancers yet appear to be protective in other cancers. RELTfms are important for a variety of additional processes related to human health including microbial pathogenesis, inflammation, behavior, reproduction, and development. All three proteins have been strongly conserved in all vertebrates, and this review aims to provide a clearer understanding of the current knowledge regarding these interesting proteins.
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Affiliation(s)
- John K. Cusick
- College of Medicine, California Northstate University, Elk Grove, CA 95757, USA
| | - Jessa Alcaide
- College of Medicine, California Northstate University, Elk Grove, CA 95757, USA
| | - Yihui Shi
- College of Medicine, California Northstate University, Elk Grove, CA 95757, USA
- California Pacific Medical Center Research Institute, Sutter Bay Hospitals, San Francisco, CA 94107, USA
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4
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Rayala S, Sivagnanam U, Gummadi SN. Biophysical characterization of the DNA binding motif of human phospholipid scramblase 1. EUROPEAN BIOPHYSICS JOURNAL 2022; 51:579-593. [DOI: 10.1007/s00249-022-01621-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 10/04/2022] [Accepted: 10/06/2022] [Indexed: 11/05/2022]
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5
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Dal Col J, Lamberti MJ, Nigro A, Casolaro V, Fratta E, Steffan A, Montico B. Phospholipid scramblase 1: a protein with multiple functions via multiple molecular interactors. Cell Commun Signal 2022; 20:78. [PMID: 35650588 PMCID: PMC9158361 DOI: 10.1186/s12964-022-00895-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/30/2022] [Indexed: 01/18/2023] Open
Abstract
Phospholipid scramblase 1 (PLSCR1) is the most studied protein of the scramblase family. Originally, it was identified as a membrane protein involved in maintaining plasma membrane asymmetry. However, studies conducted over the past few years have shown the involvement of PLSCR1 in several other cellular pathways. Indeed, PLSCR1 is not only embedded in the plasma membrane but is also expressed in several intracellular compartments where it interacts with a diverse repertoire of effectors, mediators, and regulators contributing to distinct cellular processes. Although most PLSCR1 interactors are thought to be cell-type specific, PLSCR1 often exerts its regulatory functions through shared mechanisms, including the trafficking of different molecules within intracellular vesicles such as endosomes, liposomes, and phagosomes. Intriguingly, besides endogenous proteins, PLSCR1 was also reported to interact with exogenous viral proteins, thereby regulating viral uptake and spread. This review aims to summarize the current knowledge about the multiple roles of PLSCR1 in distinct cellular pathways. Video Abstract
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Affiliation(s)
- Jessica Dal Col
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy.
| | - Marìa Julia Lamberti
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy.,INBIAS, CONICET-UNRC, Río Cuarto, Córdoba, Argentina
| | - Annunziata Nigro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Vincenzo Casolaro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Baronissi, Italy
| | - Elisabetta Fratta
- Division of Immunopathology and Cancer Biomarkers, Centro Di Riferimento Oncologico di Aviano (CRO), IRCCS, Aviano, Italy
| | - Agostino Steffan
- Division of Immunopathology and Cancer Biomarkers, Centro Di Riferimento Oncologico di Aviano (CRO), IRCCS, Aviano, Italy
| | - Barbara Montico
- Division of Immunopathology and Cancer Biomarkers, Centro Di Riferimento Oncologico di Aviano (CRO), IRCCS, Aviano, Italy.
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6
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Luo J, Lian Q, Zhu D, Zhao M, Mei T, Shang B, Yang Z, Liu C, Xu W, Zhou L, Wu K, Liu X, Lai Y, Mao F, Li W, Zuo C, Zhang K, Lin M, Zhuo Y, Liu Y, Lu L, Zhao L. PLSCR1 Promotes Apoptosis and Clearance of Retinal Ganglion Cells in Glaucoma Pathogenesis. Genes Dis 2022. [DOI: 10.1016/j.gendis.2022.05.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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7
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Interaction of human phospholipid scramblase 1 with cholesterol via CRAC motif is essential for functional regulation and subcellular localization. Int J Biol Macromol 2022; 209:850-857. [PMID: 35439477 DOI: 10.1016/j.ijbiomac.2022.04.087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 04/06/2022] [Accepted: 04/11/2022] [Indexed: 11/21/2022]
Abstract
Human phospholipid scramblase 1 (hPLSCR1) possesses a putative cholesterol binding CRAC (cholesterol interaction/recognition amino acid consensus) motif at the C-terminal. The CRAC motif of hPLSCR1 interacts with cholesterol with an energy of interaction -64.39 KJ mol-1. Since palmitoylated hPLSCR1 localizes to the cholesterol-rich lipid rafts, the interaction between hPLSCR1 and raft cholesterol is highly likely. The present study investigated the hPLSCR1-cholesterol interaction in plasma membrane via putative CRAC motif. hPLSCR1 remains at cholesterol-rich lipid rafts as long as they interact. This interaction is inhibited by mutations in the CRAC motif or cholesterol depletion. Thus, CRAC mutants I300D hPLSCR1 and ΔCRAC hPLSCR1 diffused to the cytoplasm and nucleus. Cholesterol depletion by methyl-β-cyclodextrin (MβCD) dose-dependently reduced cell viability in A549 cells. However, cholesterol depletion released 1.74 ± 0.12 times Ca2+ to the cytosol in A549 cells. Similarly, cholesterol depletion increased intracellular Ca2+ release by 1.81 ± 0.13 and 4.11 ± 0.19 times in RAJI cells expressing hPLSCR1 and ΔCRAC hPLSCR1, respectively. Moreover, the expression of hPLSCR1 and ΔCRAC hPLSCR1 increased apoptosis in RAJI cells by 21 ± 1.5% and 53.50 ± 4.40%, respectively. It was further increased to 43 ± 2.5% and 71.4 ± 1.4% upon cholesterol depletion. The current work links hPLSCR1 expression with cholesterol depletion, intracellular Ca2+ release, and induction of apoptosis.
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Behuria HG, Dash S, Sahu SK. Phospholipid Scramblases: Role in Cancer Progression and Anticancer Therapeutics. Front Genet 2022; 13:875894. [PMID: 35422844 PMCID: PMC9002267 DOI: 10.3389/fgene.2022.875894] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/11/2022] [Indexed: 11/13/2022] Open
Abstract
Phospholipid scramblases (PLSCRs) that catalyze rapid mixing of plasma membrane lipids result in surface exposure of phosphatidyl serine (PS), a lipid normally residing to the inner plasma membrane leaflet. PS exposure provides a chemotactic eat-me signal for phagocytes resulting in non-inflammatory clearance of apoptotic cells by efferocytosis. However, metastatic tumor cells escape efferocytosis through alteration of tumor microenvironment and apoptotic signaling. Tumor cells exhibit altered membrane features, high constitutive PS exposure, low drug permeability and increased multidrug resistance through clonal evolution. PLSCRs are transcriptionally up-regulated in tumor cells leading to plasma membrane remodeling and aberrant PS exposure on cell surface. In addition, PLSCRs interact with multiple cellular components to modulate cancer progression and survival. While PLSCRs and PS exposed on tumor cells are novel drug targets, many exogenous molecules that catalyze lipid scrambling on tumor plasma membrane are potent anticancer therapeutic molecules. In this review, we provide a comprehensive analysis of scramblase mediated signaling events, membrane alteration specific to tumor development and possible therapeutic implications of scramblases and PS exposure.
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Affiliation(s)
- Himadri Gourav Behuria
- Laboratory of Molecular Membrane Biology, Department of Biotechnology, Maharaja Sriram Chandra Bhanjadeo University, Baripada, India
| | - Sabyasachi Dash
- Department of Pathology and Laboratory Medicine, Weill Cornell Medicine, New York, NY, United States
| | - Santosh Kumar Sahu
- Laboratory of Molecular Membrane Biology, Department of Biotechnology, Maharaja Sriram Chandra Bhanjadeo University, Baripada, India
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9
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Liao WC, Lin TJ, Liu YC, Wei YS, Chen GY, Feng HP, Chang YF, Chang HT, Wang CL, Chi HC, Wang CI, Lin KH, Ou Yang WT, Yu CJ. Nuclear accumulation of KPNA2 impacts radioresistance through positive regulation of the PLSCR1-STAT1 loop in lung adenocarcinoma. Cancer Sci 2021; 113:205-220. [PMID: 34773335 PMCID: PMC8748229 DOI: 10.1111/cas.15197] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 11/01/2021] [Accepted: 11/03/2021] [Indexed: 12/13/2022] Open
Abstract
Lung adenocarcinoma (ADC) is the predominant histological type of lung cancer, and radiotherapy is one of the current therapeutic strategies for lung cancer treatment. Unfortunately, biological complexity and cancer heterogeneity contribute to radioresistance development. Karyopherin α2 (KPNA2) is a member of the importin α family that mediates the nucleocytoplasmic transport of cargo proteins. KPNA2 overexpression is observed across cancer tissues of diverse origins. However, the role of KPNA2 in lung cancer radioresistance is unclear. Herein, we demonstrated that high expression of KPNA2 is positively correlated with radioresistance and cancer stem cell (CSC) properties in lung ADC cells. Radioresistant cells exhibited nuclear accumulation of KPNA2 and its cargos (OCT4 and c‐MYC). Additionally, KPNA2 knockdown regulated CSC‐related gene expression in radioresistant cells. Next‐generation sequencing and bioinformatic analysis revealed that STAT1 activation and nuclear phospholipid scramblase 1 (PLSCR1) are involved in KPNA2‐mediated radioresistance. Endogenous PLSCR1 interacting with KPNA2 and PLSCR1 knockdown suppressed the radioresistance induced by KPNA2 expression. Both STAT1 and PLSCR1 were found to be positively correlated with dysregulated KPNA2 in radioresistant cells and ADC tissues. We further demonstrated a potential positive feedback loop between PLSCR1 and STAT1 in radioresistant cells, and this PLSCR1‐STAT1 loop modulates CSC characteristics. In addition, AKT1 knockdown attenuated the nuclear accumulation of KPNA2 in radioresistant lung cancer cells. Our results collectively support a mechanistic understanding of a novel role for KPNA2 in promoting radioresistance in lung ADC cells.
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Affiliation(s)
- Wei-Chao Liao
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.,Department of Nephrology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Tsung-Jen Lin
- Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Chin Liu
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.,Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Shan Wei
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Guan-Ying Chen
- Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Hsiang-Pu Feng
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Feng Chang
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.,Department of Neurosurgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Hsin-Tzu Chang
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.,Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chih-Liang Wang
- School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Hsinag-Cheng Chi
- Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan.,Chinese Medicine Research Center, China Medical University, Taichung, Taiwan
| | - Chun-I Wang
- Radiation Biology Research Center, Institute for Radiological Research, Chang Gung University/Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Kwang-Huei Lin
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Biochemistry, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Liver Research Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan.,Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan, Taiwan
| | - Wei-Ting Ou Yang
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan
| | - Chia-Jung Yu
- Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan.,Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
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10
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Berger CS, Laroche J, Maaroufi H, Martin H, Moon KM, Landry CR, Foster LJ, Aubin-Horth N. The parasite Schistocephalus solidus secretes proteins with putative host manipulation functions. Parasit Vectors 2021; 14:436. [PMID: 34454597 PMCID: PMC8400842 DOI: 10.1186/s13071-021-04933-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 08/06/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Manipulative parasites are thought to liberate molecules in their external environment, acting as manipulation factors with biological functions implicated in their host's physiological and behavioural alterations. These manipulation factors are part of a complex mixture called the secretome. While the secretomes of various parasites have been described, there is very little data for a putative manipulative parasite. It is necessary to study the molecular interaction between a manipulative parasite and its host to better understand how such alterations evolve. METHODS Here, we used proteomics to characterize the secretome of a model cestode with a complex life cycle based on trophic transmission. We studied Schistocephalus solidus during the life stage in which behavioural changes take place in its obligatory intermediate fish host, the threespine stickleback (Gasterosteus aculeatus). We produced a novel genome sequence and assembly of S. solidus to improve protein coding gene prediction and annotation for this parasite. We then described the whole worm's proteome and its secretome during fish host infection using LC-MS/MS. RESULTS A total of 2290 proteins were detected in the proteome of S. solidus, and 30 additional proteins were detected specifically in the secretome. We found that the secretome contains proteases, proteins with neural and immune functions, as well as proteins involved in cell communication. We detected receptor-type tyrosine-protein phosphatases, which were reported in other parasitic systems to be manipulation factors. We also detected 12 S. solidus-specific proteins in the secretome that may play important roles in host-parasite interactions. CONCLUSIONS Our results suggest that S. solidus liberates molecules with putative host manipulation functions in the host and that many of them are species-specific.
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Affiliation(s)
- Chloé Suzanne Berger
- Département de Biologie, Université Laval, Quebec, QC Canada
- Institut de Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Quebec, QC Canada
- Ressources Aquatiques Québec (RAQ), Institut Des Sciences de La Mer de Rimouski, Quebec, Canada
| | - Jérôme Laroche
- Institut de Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Quebec, QC Canada
| | - Halim Maaroufi
- Institut de Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Quebec, QC Canada
| | - Hélène Martin
- Département de Biologie, Université Laval, Quebec, QC Canada
- Institut de Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Quebec, QC Canada
- Département de Biochimie, Microbiologie Et Bioinformatique, Université Laval, Quebec, QC Canada
| | - Kyung-Mee Moon
- Department of Biochemistry & Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, V6T 1Z4 Canada
| | - Christian R. Landry
- Département de Biologie, Université Laval, Quebec, QC Canada
- Institut de Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Quebec, QC Canada
- Département de Biochimie, Microbiologie Et Bioinformatique, Université Laval, Quebec, QC Canada
- PROTEO, Le Réseau Québécois de Recherche Sur La Fonction, la structure et l’ingénierie des protéines, Université Laval, Quebec, Canada
- Centre de Recherche en Données Massives (CRDM), Université Laval, Quebec, Canada
| | - Leonard J. Foster
- Department of Biochemistry & Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, V6T 1Z4 Canada
| | - Nadia Aubin-Horth
- Département de Biologie, Université Laval, Quebec, QC Canada
- Institut de Biologie Intégrative Et Des Systèmes (IBIS), Université Laval, Quebec, QC Canada
- Ressources Aquatiques Québec (RAQ), Institut Des Sciences de La Mer de Rimouski, Quebec, Canada
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11
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Haase S, Condron M, Miller D, Cherkaoui D, Jordan S, Gulbis JM, Baum J. Identification and characterisation of a phospholipid scramblase in the malaria parasite Plasmodium falciparum. Mol Biochem Parasitol 2021; 243:111374. [PMID: 33974939 PMCID: PMC8202325 DOI: 10.1016/j.molbiopara.2021.111374] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/27/2021] [Accepted: 05/06/2021] [Indexed: 02/07/2023]
Abstract
Recent studies highlight the emerging role of lipids as important messengers in malaria parasite biology. In an attempt to identify interacting proteins and regulators of these dynamic and versatile molecules, we hypothesised the involvement of phospholipid translocases and their substrates in the infection of the host erythrocyte by the malaria parasite Plasmodium spp. Here, using a data base searching approach of the Plasmodium Genomics Resources (www.plasmodb.org), we have identified a putative phospholipid (PL) scramblase in P. falciparum (PfPLSCR) that is conserved across the genus and in closely related unicellular algae. By reconstituting recombinant PfPLSCR into liposomes, we demonstrate metal ion dependent PL translocase activity and substrate preference, confirming PfPLSCR as a bona fide scramblase. We show that PfPLSCR is expressed during asexual and sexual parasite development, localising to different membranous compartments of the parasite throughout the intra-erythrocytic life cycle. Two different gene knockout approaches, however, suggest that PfPLSCR is not essential for erythrocyte invasion and asexual parasite development, pointing towards a possible role in other stages of the parasite life cycle.
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Affiliation(s)
- Silvia Haase
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK.
| | - Melanie Condron
- Division of Infection and Immunity, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - David Miller
- Division of Structural Biology, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
| | - Dounia Cherkaoui
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Sarah Jordan
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK
| | - Jacqueline M Gulbis
- Division of Structural Biology, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria, Australia
| | - Jake Baum
- Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, South Kensington, London, UK.
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12
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Gui L, Zhu YW, Xu Q, Huang JJ, Hua P, Wu GJ, Lu J, Ni JB, Tang H, Zhang LL. RNA interference-mediated downregulation of phospholipid scramblase 1 expression in primary liver cancer in vitro. Oncol Lett 2020; 20:361. [PMID: 33133261 PMCID: PMC7590428 DOI: 10.3892/ol.2020.12225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 08/05/2020] [Indexed: 01/12/2023] Open
Abstract
Phospholipid scramblase 1 (PLSCR1) serves a function in the pathogenesis and progression of various types of cancer. However, the role of PLSCR1 in human primary liver cancer remains unknown. The aim of the present study was to evaluate the expression of PLSCR1 in primary liver cancer and analyse the clinical significance. In addition, the present study detected and compared the biological behaviours of HepG2 cells with different levels of activated PLSCR1 or silenced PLSCR1. PLSCR1 expression in primary liver cancer tissue samples was examined using immunohistochemistry. Cultured HepG2 cells were infected with lentiviruses to suppress or activate PLSCR1 expression. Reverse transcription-quantitative PCR and western blotting were performed to analyse the effects of silencing or activating PLSCR1 in cell lines at the mRNA and protein levels, respectively. The effects of PLSCR1 expression on cell proliferation, adhesion, migration and invasion were subsequently determined using Cell Counting Kit 8, adhesion, and Transwell migration and invasion assays. PLSCR1 expression in primary liver cancer tissue samples was higher compared with that in adjacent non-cancerous liver tissue samples and normal tissue samples, and positively correlated with the clinical stage. PLSCR1 was effectively downregulated or overexpressed in HepG2 cells using small interfering RNA and lentivirus techniques, respectively. PLSCR1 upregulation promoted cell proliferation, invasion and migration, while PLSCR1 downregulation inhibited these effects. PLSCR1 is highly expressed in primary liver cancer and associated with the clinical stage. Downregulating the expression of PLSCR1 significantly inhibited the proliferation, adhesion, migration and invasion of cancer cells, suggesting that PLSCR1 may be a potential therapeutic target for preventing the progression of primary liver cancer.
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Affiliation(s)
- Liang Gui
- Department of Vascular Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Science, Beijing 100730, P.R. China
| | - Ying-Wei Zhu
- Department of Gastroenterology, The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214002, P.R. China
| | - Qiang Xu
- Department of Intervention, Wujin Hospital Affiliated to Jiangsu University, Changzhou, Jiangsu 213002, P.R. China
| | - Ju-Ju Huang
- Department of Gastroenterology, The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214002, P.R. China
| | - Ping Hua
- Department of Gastroenterology, The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214002, P.R. China
| | - Gao-Jue Wu
- Department of Gastroenterology, The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214002, P.R. China
| | - Jian Lu
- Department of Gastroenterology, The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214002, P.R. China
| | - Jing-Bin Ni
- Department of Gastroenterology, The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214002, P.R. China
| | - Hong Tang
- Department of Pathology, The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214002, P.R. China
| | - Li-Li Zhang
- Department of Gastroenterology, The Affiliated Wuxi No. 2 People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214002, P.R. China
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13
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Phylogenetic Analysis and In Vitro Bifunctional Nuclease Assay of Arabidopsis BBD1 and BBD2. Molecules 2020; 25:molecules25092169. [PMID: 32384799 PMCID: PMC7249048 DOI: 10.3390/molecules25092169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 01/08/2023] Open
Abstract
Nucleases are a very diverse group of enzymes that play important roles in many crucial physiological processes in plants. We previously reported that the highly conserved region (HCR), domain of unknown function 151 (DUF151) and UV responsive (UVR) domain-containing OmBBD is a novel nuclease that does not share homology with other well-studied plant nucleases. Here, we report that DUF151 domain-containing proteins are present in bacteria, archaea and only Viridiplantae kingdom of eukarya, but not in any other eukaryotes. Two Arabidopsis homologs of OmBBD, AtBBD1 and AtBBD2, shared 43.69% and 44.38% sequence identity and contained all three distinct domains of OmBBD. We confirmed that the recombinant MBP-AtBBD1 and MBP-AtBBD2 exhibited non-substrate-specific DNase and RNase activity, like OmBBD. We also found that a metal cofactor is not necessarily required for DNase activity of AtBBD1 and AtBBD2, but their activities were much enhanced in the presence of Mg2+ or Mn2+. Using a yeast two-hybrid assay, we found that AtBBD1 and AtBBD2 each form a homodimer but not a heterodimer and that the HCR domain is possibly crucial for dimerization.
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14
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Xu Y, Zhang Z, Zhang L, Zhang C. Novel module and hub genes of distinctive breast cancer associated fibroblasts identified by weighted gene co-expression network analysis. Breast Cancer 2020; 27:1017-1028. [PMID: 32383139 DOI: 10.1007/s12282-020-01101-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 04/22/2020] [Indexed: 01/07/2023]
Abstract
BACKGROUND As abundant and heterogeneous stromal cells in tumor microenvironment, carcinoma-associated fibroblasts (CAFs) are critically involved in cancer progression. METHODS To identify co-expression module and hub genes of distinctive breast CAFs, weighted gene co-expression network analysis (WGCNA) was conducted based on the expression array results of CAFs from seven chemo-sensitive breast cancer (BC) patients and seven chemo-resistant ones before neo-adjuvant chemotherapy. RESULTS A total of 4916 genes were included in WGCNA, and 12 modules were determined. Module-trait assay showed that the blue module (cor = 0.97, P < 0.001) was associated with CAF-related chemo-resistance, which was enriched mainly as "inflammatory response", "interferon-gamma-mediated signaling" and "NIK/NF-kappaB signaling" pathways. Moreover, CXCL8, CXCL10, CXCL11, PLSCR1, RIPK2 and USP18 were found to be potentially associated with chemo-resistance related to CAFs and prognosis of BC. CONCLUSIONS Our current data offered valuable insights into the molecular mechanisms of distinctive breast CAFs, which was beneficial for revealing how chemo-resistance of BC was initiated.
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Affiliation(s)
- Yangguang Xu
- Department of Pediatrics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
| | - Zhen Zhang
- Institute of Basic Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Luoyan Zhang
- Key Lab of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan, 250014, Shandong, China
| | - Chi Zhang
- Department of Breast and Thyroid Surgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China.
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15
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Huang P, Liao R, Chen X, Wu X, Li X, Wang Y, Cao Q, Dong C. Nuclear translocation of PLSCR1 activates STAT1 signaling in basal-like breast cancer. Theranostics 2020; 10:4644-4658. [PMID: 32292520 PMCID: PMC7150476 DOI: 10.7150/thno.43150] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/05/2020] [Indexed: 12/22/2022] Open
Abstract
Rationale: Basal-like breast cancer (BLBC) is associated with high grade, distant metastasis, and poor prognosis; however, the mechanism underlying aggressiveness of BLBC is still unclear. Emerging evidence has suggested that phospholipid scramblase 1 (PLSCR1) is involved in tumor progression. Here, we aimed to study the possible involvement and molecular mechanisms of PLSCR1 contributing to the aggressive behavior of BLBC. Methods: The potential functions of PLSCR1 in breast cancer cells were assessed by Western blotting, colony formation, migration and invasion, Cell Counting Kit-8 assay, mammosphere formation and flow cytometry. The relationship between nuclear translocation of PLSCR1 and transactivation of STAT1 was examined by immunostaining, co-IP, ChIP, and quantitative reverse transcription PCR. The effect of PLSCR1 expression on BLBC cells was determined by in vitro and in vivo tumorigenesis and a lung metastasis mouse model. Results: Compared to other subtypes, PLSCR1 was considerably increased in BLBC. Phosphorylation of PLSCR1 at Tyr 69/74 contributed to the nuclear translocation of this protein. PLSCR1 was enriched in the promoter region of STAT1 and enhanced STAT3 binding to the STAT1 promoter, resulting in transactivation of STAT1; STAT1 then enhanced cancer stem cell (CSC)-like properties that promoted BLBC progression. The knockdown of PLSCR1 led to significant inhibitory effects on proliferation, migration, invasion, tumor growth and lung metastasis of BLBC cells. Clinically, high PLSCR1 expression was strongly correlated with large tumor size, high grade, metastasis, chemotherapy resistance, and poor survival, indicating poor prognosis in breast cancer patients. Conclusions: Our data show that overexpression and nuclear translocation of PLSCR1 provide tumorigenic and metastatic advantages by activating STAT1 signaling in BLBC. This study not only reveals a critical mechanism of how PLSCR1 contributes to BLBC progression, but also suggests potential prognostic indicators and therapeutic targets for this challenging disease.
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16
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Hagemann PM, Nsiah-Dosu S, Hundt JE, Hartmann K, Orinska Z. Modulation of Mast Cell Reactivity by Lipids: The Neglected Side of Allergic Diseases. Front Immunol 2019; 10:1174. [PMID: 31191542 PMCID: PMC6549522 DOI: 10.3389/fimmu.2019.01174] [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: 09/22/2018] [Accepted: 05/08/2019] [Indexed: 12/20/2022] Open
Abstract
Mast cells (MCs) have long been mainly regarded as effector cells in IgE-associated allergic disorders with potential immunoregulatory roles. Located close to the allergen entry sites in the skin and mucosa, MCs can capture foreign substances such as allergens, toxins, or noxious substances and are exposed to the danger signals produced by epithelial cells. MC reactivity shaped by tissue-specific factors is crucial for allergic responses ranging from local skin reactions to anaphylactic shock. Development of Th2 response leading to allergen-specific IgE production is a prerequisite for MC sensitization and induction of FcεRI-mediated MC degranulation. Up to now, IgE production has been mainly associated with proteins, whereas lipids present in plant pollen grains, mite fecal particles, insect venoms, or food have been largely overlooked regarding their immunostimulatory and immunomodulatory properties. Recent studies, however, have now demonstrated that lipids affect the sensitization process by modulating innate immune responses of epithelial cells, dendritic cells, and NK-T cells and thus crucially contribute to the outcome of sensitization. Whether and how lipids affect also MC effector functions in allergic reactions has not yet been fully clarified. Here, we discuss how lipids can affect MC responses in the context of allergic inflammation. Direct effects of immunomodulatory lipids on MC degranulation, changes in local lipid composition induced by allergens themselves and changes in lipid transport affecting MC reactivity are possible mechanisms by which the function of MC might be modulated.
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Affiliation(s)
- Philipp M Hagemann
- Division of Experimental Pneumology, Research Center Borstel, Leibniz Lungenzentrum, Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany
| | | | | | - Karin Hartmann
- Department of Dermatology, University of Luebeck, Luebeck, Germany.,Division of Allergy, Department of Dermatology, University of Basel, Basel, Switzerland
| | - Zane Orinska
- Division of Experimental Pneumology, Research Center Borstel, Leibniz Lungenzentrum, Airway Research Center North, German Center for Lung Research (DZL), Borstel, Germany
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17
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Palanirajan SK, Sivagnanam U, Murugan S, Gummadi SN. In vitro reconstitution and biochemical characterization of human phospholipid scramblase 3: phospholipid specificity and metal ion binding studies. Biol Chem 2018; 399:361-374. [DOI: 10.1515/hsz-2017-0309] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 12/14/2017] [Indexed: 01/11/2023]
Abstract
AbstractHuman phospholipid scramblase 3 (hPLSCR3) is a single pass transmembrane protein that plays a vital role in fat metabolism, mitochondrial function, structure, maintenance and apoptosis. The mechanism of action of scramblases remains still unknown, and the role of scramblases in phospholipid translocation is heavily debated. hPLSCR3 is the only member of scramblase family localized to mitochondria and is involved in cardiolipin translocation at the mitochondrial membrane. Direct biochemical evidence of phospholipid translocation by hPLSCR3 is yet to be reported. Functional assay in synthetic proteoliposomes upon Ca2+and Mg2+revealed that, apart from cardiolipin, recombinant hPLSCR3 translocates aminophospholipids such as NBD-PE and NBD-PS but not neutral phospholipids. Point mutation in hPLSCR3 (F258V) resulted in decreased Ca2+binding affinity. Functional assay with F258V-hPLSCR3 led to ~50% loss in scramblase activity in the presence of Ca2+and Mg2+. Metal ion-induced conformational changes were monitored by intrinsic tryptophan fluorescence, circular dichroism, surface hydrophobicity changes and aggregation studies. Our results revealed that Ca2+and Mg2+bind to hPLSCR3 and trigger conformational changes mediated by aggregation. In summary, we suggest that the metal ion-induced conformational change and the aggregation of the protein are essential for the phospholipid translocation by hPLSCR3.
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18
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Li H, Yu X, Liu X, Hu P, Shen L, Zhou Y, Zhu Y, Li Z, Hui H, Guo Q, Xu J. Wogonoside induces depalmitoylation and translocation of PLSCR1 and N-RAS in primary acute myeloid leukaemia cells. J Cell Mol Med 2018; 22:2117-2130. [PMID: 29377576 PMCID: PMC5867108 DOI: 10.1111/jcmm.13481] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/24/2017] [Indexed: 11/30/2022] Open
Abstract
Acute myeloid leukaemia (AML) comprises a range of disparate genetic subtypes, involving complex gene mutations and specific molecular alterations. Post‐translational modifications of specific proteins influence their translocation, stability, aggregation and even leading disease progression. Therapies that target to post‐translational modification of specific proteins in cancer cells represent a novel treatment strategy. Non‐homogenous subcellular distribution of PLSCR1 is involved in the primary AML cell differentiation. However, the nuclear translocation mechanism of PLSCR1 remains poorly understood. Here, we leveraged the observation that nuclear translocation of PLSCR1 could be induced during wogonoside treatment in some primary AML cells, despite their genetic heterogeneity that contributed to the depalmitoylation of PLSCR1 via acyl protein thioesterase 1 (APT‐1), an enzyme catalysing protein depalmitoylation. Besides, we found a similar phenomenon on another AML‐related protein, N‐RAS. Wogonoside inhibited the palmitoylation of small GTPase N‐RAS and enhanced its trafficking into Golgi complex, leading to the inactivation of N‐RAS/RAF1 pathway in some primary AML cells. Taken together, our findings provide new insight into the mechanism of wogonoside‐induced nuclear translocation of PLSCR1 and illuminate the influence of N‐RAS depalmitoylation on its Golgi trafficking and RAF1 signalling inactivation in AML.
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Affiliation(s)
- Hui Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Xiaoxuan Yu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Xiao Liu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Po Hu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Le Shen
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Yuxin Zhou
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Yu Zhu
- Department of Hematology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Zhiyu Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Hui Hui
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Qinglong Guo
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, China
| | - Jingyan Xu
- Department of Hematology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
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19
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Luo W, Zhang J, Liang L, Wang G, Li Q, Zhu P, Zhou Y, Li J, Zhao Y, Sun N, Huang S, Zhou C, Chang Y, Cui P, Chen P, Jiang Y, Deng G, Bu Z, Li C, Jiang L, Chen H. Phospholipid scramblase 1 interacts with influenza A virus NP, impairing its nuclear import and thereby suppressing virus replication. PLoS Pathog 2018; 14:e1006851. [PMID: 29352288 PMCID: PMC5792031 DOI: 10.1371/journal.ppat.1006851] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/31/2018] [Accepted: 01/03/2018] [Indexed: 12/21/2022] Open
Abstract
Transcription and replication of the influenza A virus (IAV) genome occur in the nucleus of infected cells and are carried out by the viral ribonucleoprotein complex (vRNP). As a major component of the vRNP complex, the viral nucleoprotein (NP) mediates the nuclear import of the vRNP complex via its nuclear localization signals (NLSs). Clearly, an effective way for the host to antagonize IAV infection would be by targeting vRNP nuclear import. Here, we identified phospholipid scramblase 1 (PLSCR1) as a binding partner of NP by using a yeast two-hybrid (Y2H) screen. The interaction between NP and PLSCR1 in mammalian cells was demonstrated by using co-immunoprecipitation and pull-down assays. We found that the stable overexpression of PLSCR1 suppressed the nuclear import of NP, hindered the virus life cycle, and significantly inhibited the replication of various influenza subtypes. In contrast, siRNA knockdown or CRISPR/Cas9 knockout of PLSCR1 increased virus propagation. Further analysis indicated that the inhibitory effect of PLSCR1 on the nuclear import of NP was not caused by affecting the phosphorylation status of NP or by stimulating the interferon (IFN) pathways. Instead, PLSCR1 was found to form a trimeric complex with NP and members of the importin α family, which inhibited the incorporation of importin β, a key mediator of the classical nuclear import pathway, into the complex, thus impairing the nuclear import of NP and suppressing virus replication. Our results demonstrate that PLSCR1 negatively regulates virus replication by interacting with NP in the cytoplasm and preventing its nuclear import.
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Affiliation(s)
- Weiyu Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jie Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Libin Liang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Guangwen Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Qibing Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Pengyang Zhu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yuan Zhou
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Junping Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yuhui Zhao
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Nan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Shanyu Huang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Chenchen Zhou
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yu Chang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Pengfei Cui
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Pucheng Chen
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yongping Jiang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Guohua Deng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhigao Bu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Chengjun Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Li Jiang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Hualan Chen
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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20
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Sivagnanam U, Palanirajan SK, Gummadi SN. The role of human phospholipid scramblases in apoptosis: An overview. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:2261-2271. [PMID: 28844836 DOI: 10.1016/j.bbamcr.2017.08.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 08/03/2017] [Accepted: 08/10/2017] [Indexed: 02/08/2023]
Abstract
Human phospholipid scramblases (hPLSCRs) are a family of four homologous single pass transmembrane proteins (hPLSCR1-4) initially identified as the proteins responsible for Ca2+ mediated bidirectional phospholipid translocation in plasma membrane. Though in-vitro assays had provided evidence, the role of hPLSCRs in phospholipid translocation is still debated. Recent reports revealed a new class of proteins, TMEM16 and Xkr8 to exhibit scramblase activity challenging the function of hPLSCRs. Apart from phospholipid scrambling, numerous reports have emphasized the multifunctional roles of hPLSCRs in key cellular processes including tumorigenesis, antiviral defense, protein and DNA interactions, transcriptional regulation and apoptosis. In this review, the role of hPLSCRs in mediating cell death through phosphatidylserine exposure, interaction with death receptors, cardiolipin exposure, heavy metal and radiation induced apoptosis and pathological apoptosis followed by their involvement in cancer cells are discussed. This review aims to connect the multifunctional characteristics of hPLSCRs to their decisive involvement in apoptotic pathways.
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Affiliation(s)
- Ulaganathan Sivagnanam
- Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Santosh Kumar Palanirajan
- Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Sathyanarayana N Gummadi
- Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600 036, India.
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21
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Chai J, Xiong Q, Wang D, Wan X, Niu H, Xiang H, Li H, Wang H, Zheng R, Peng J, Jiang S. Identification of novel regulatory GRE-binding elements in the porcine IP3R1 gene promoter and their transcriptional activation under glucocorticoid stimulation. Gen Comp Endocrinol 2017; 249:71-81. [PMID: 28495269 DOI: 10.1016/j.ygcen.2017.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 05/02/2017] [Accepted: 05/06/2017] [Indexed: 01/24/2023]
Abstract
Inositol 1,4,5-trisphosphate receptor 1 (IP3R1) is a type of ligand-gated calcium channel that is expressed predominantly in mammalian skeletal muscle, where it acts as a key regulator of calcium homeostasis. In meat, calcium disequilibrium is accompanied by the deterioration of meat quality. Here we show that serum cortisol concentration was higher and the IP3R1 gene expression level increased markedly in pigs exposed to high stress. In porcine primary muscle cells, dexamethasone (DEX, a synthetic glucocorticoid) increased the protein levels of porcine IP3R1 and GRα, and cell apoptosis, and the specific GRα inhibitor RU486 attenuated these effects. DEX also increased the expression of IP3R1 at both the gene and protein levels, and this expression was attenuated by RU486, siRNA against GRα, and the transcriptional inhibitor actinomycin D. DEX significantly reduced cell viability and increased the intracellular calcium concentration, and these effects were attenuated by siRNA against GRα. Bioinformatics analyses predicted a potential glucocorticoid response element (GRE) located in the region -326 to -309 upstream of the IP3R1 promoter and highly conserved in pigs and other mammalian species. Promoter analysis showed that this region containing the GRE was critical for transcriptional activity of porcine IP3R1 under DEX stimulation. This was confirmed by deletion and site-mutation methods. EMSA and ChIP assays showed that this potential GRE bound specifically to GRα and this complex activated the transcription of the IP3R1 gene. Taken together, these data suggest that DEX-mediated induction of IP3R1 influences porcine muscle cells through the transcriptional activation of a mechanism involving interactions between GRα and a GRE present in the proximal IP3R1 promoter. This process can lead to an imbalance in intracellular calcium concentration, which may subsequently activate the apoptosis signal and decrease cell activity, and cause deterioration of meat quality.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Base Sequence
- Calcium/metabolism
- Cell Survival/drug effects
- Chromatin Immunoprecipitation
- Cloning, Molecular
- Dexamethasone/pharmacology
- Gene Expression Regulation/drug effects
- Glucocorticoids/pharmacology
- Hydrocortisone/blood
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Male
- Muscles/drug effects
- Muscles/metabolism
- Protein Binding/drug effects
- Receptors, Glucocorticoid/metabolism
- Response Elements/genetics
- Sequence Analysis, DNA
- Stress, Physiological/drug effects
- Stress, Physiological/genetics
- Sus scrofa/blood
- Sus scrofa/genetics
- Transcription, Genetic/drug effects
- Transcriptional Activation/drug effects
- Transcriptional Activation/genetics
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Affiliation(s)
- Jin Chai
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Qi Xiong
- Hubei Key Laboratory of Animal Embryo Engineering and Molecular Breeding, Institute of Animal Husbandry and Veterinary, Hubei Academy of Agricultural Science, Wuhan, China
| | - Dan Wang
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Xuebing Wan
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Hongdan Niu
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Hong Xiang
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Huanan Li
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Hongshuai Wang
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Rong Zheng
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Jian Peng
- Department of Animal Nutrition, Huazhong Agricultural University, Wuhan, China.
| | - Siwen Jiang
- Agricultural Ministry Key Laboratory of Swine Breeding and Genetics & Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China.
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Interactions stabilizing the C-terminal helix of human phospholipid scramblase 1 in lipid bilayers: A computational study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1200-1210. [DOI: 10.1016/j.bbamem.2017.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/09/2017] [Accepted: 03/29/2017] [Indexed: 12/19/2022]
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Li H, Xu J, Zhou Y, Liu X, Shen LE, Zhu YU, Li Z, Wang X, Guo Q, Hui H. PLSCR1/IP3R1/Ca 2+ axis contributes to differentiation of primary AML cells induced by wogonoside. Cell Death Dis 2017; 8:e2768. [PMID: 28492556 PMCID: PMC5520700 DOI: 10.1038/cddis.2017.175] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/09/2017] [Accepted: 03/17/2017] [Indexed: 01/25/2023]
Abstract
Multiple lines of evidence have demonstrated that increased expression of phospholipid scramblase 1 (PLSCR1) is involved in the differentiation of acute myeloid leukemia (AML) cells by several differentiation-inducing agents including ATRA and phorbol 12-myristate 13-acetate. However, none of these agents can achieve nonhomogenous subcellular distribution of PLSCR1. We have demonstrated that wogonoside possesses differentiation and anti-leukemic effects in AML cell lines by promoting PLSCR1 trafficking into nucleus. Here we report that wogonoside promotes the expression of PLSCR1 and enhances its nuclear translocation and binding to the 1, 4, 5-trisphosphate receptor 1 (IP3R1) promoter in AML patient-derived primary cells. Wogonoside activates IP3R1, in turn, promotes release of Ca2+ from endoplasmic reticulum, and eventually leads to cell differentiation. Our in vivo study further confirms that wogonoside can promote PLSCR1 and IP3R1 expression in primary AML cells and reduce the AML cell counts in engrafted nonobese diabetic/severe combined immunodeficient mice. Taken together, our findings provide new insight into the mechanism of wogonoside-induced differentiation and anti-leukemic effect on primary AML cells, suggesting the therapeutic potential of wogonoside for AML, especially for non-APL AML.
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Affiliation(s)
- Hui Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Jingyan Xu
- Department of Hematology, The Affiliated DrumTower Hospital of Nanjing University Medical School, Nanjing, People's Republic of China
| | - Yuxin Zhou
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Xiao Liu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, People's Republic of China
| | - L E Shen
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Y U Zhu
- Department of Hematology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, People's Republic of China
| | - Zhiyu Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Xiaotang Wang
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA
| | - Qinglong Guo
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Hui Hui
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, China Pharmaceutical University, Nanjing, People's Republic of China
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24
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Andraka N, Sánchez-Magraner L, García-Pacios M, Goñi FM, Arrondo JLR. The conformation of human phospholipid scramblase 1, as studied by infrared spectroscopy. Effects of calcium and detergent. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1019-1028. [PMID: 28238818 DOI: 10.1016/j.bbamem.2017.02.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 02/18/2017] [Accepted: 02/22/2017] [Indexed: 12/18/2022]
Abstract
Human phospholipid scramblase 1 (SCR) is a membrane protein that catalyzes the transmembrane (flip-flop) motion of phospholipids. It can also exist in a non membrane-bound form in the nucleus, where it modulates several aspects of gene expression. Catalysis of phospholipid flip-flop requires the presence of millimolar Ca2+, and occurs in the absence of ATP. Membrane-bound SCR contains a C-terminal α-helical domain embedded in the membrane bilayer. The latter domain can be removed giving rise to a stable truncated mutant SCRΔ that is devoid of scramblase activity. In order to improve our understanding of SCR structure infrared spectra have been recorded of both the native and truncated forms, and the effects of adding Ca2+, or removing detergent, or thermally denaturing the protein have been observed. Under all conditions the main structural component of SCR/SCRΔ is a β-sheet. Removing the C-terminal 28 aa residues, which anchor SCR to the membrane, leads to a change in tertiary structure and an increased structural flexibility. The main effect of Ca2+ is an increase in the α/β ratio of secondary structure components, with a concomitant increase in the proportion of non-periodic structures. At least in SCRΔ, detergent (Zwittergent 3-12) decreases the structural flexibility, an effect somewhat opposite to that of increasing temperature. Thermal denaturation is affected by Ca2+, detergent, and by the presence or absence of the C-terminal domain, each of them influencing in different ways the denaturation pattern.
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Affiliation(s)
- Nagore Andraka
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | - Lissete Sánchez-Magraner
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | - Marcos García-Pacios
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | - Félix M Goñi
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain
| | - José L R Arrondo
- Unidad de Biofísica (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, P.O. Box 644, 48080 Bilbao, Spain.
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25
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Han Y, Li A, Gao L, Wu W, Deng H, Hu W, Li N, Sun S, Zhang X, Zhao B, Liu B, Pang Q. Identification and characterization of a phospholipid scramblase encoded by planarian Dugesia japonica. Gene 2017; 602:43-49. [DOI: 10.1016/j.gene.2016.11.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/27/2016] [Accepted: 11/15/2016] [Indexed: 01/02/2023]
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26
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Tufail Y, Cook D, Fourgeaud L, Powers CJ, Merten K, Clark CL, Hoffman E, Ngo A, Sekiguchi KJ, O'Shea CC, Lemke G, Nimmerjahn A. Phosphatidylserine Exposure Controls Viral Innate Immune Responses by Microglia. Neuron 2017; 93:574-586.e8. [PMID: 28111081 DOI: 10.1016/j.neuron.2016.12.021] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/17/2016] [Accepted: 12/15/2016] [Indexed: 01/09/2023]
Abstract
Microglia are the intrinsic immune sentinels of the central nervous system. Their activation restricts tissue injury and pathogen spread, but in some settings, including viral infection, this response can contribute to cell death and disease. Identifying mechanisms that control microglial responses is therefore an important objective. Using replication-incompetent adenovirus 5 (Ad5)-based vectors as a model, we investigated the mechanisms through which microglia recognize and respond to viral uptake. Transgenic, immunohistochemical, molecular-genetic, and fluorescence imaging approaches revealed that phosphatidylserine (PtdSer) exposure on the outer leaflet of transduced cells triggers their engulfment by microglia through TAM receptor-dependent mechanisms. We show that inhibition of phospholipid scramblase 1 (PLSCR1) activity reduces intracellular calcium dysregulation, prevents PtdSer externalization, and enables months-long protection of vector-transduced, transgene-expressing cells from microglial phagocytosis. Our study identifies PLSCR1 as a potent target through which the innate immune response to viral vectors, and potentially other stimuli, may be controlled.
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Affiliation(s)
- Yusuf Tufail
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Daniela Cook
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Lawrence Fourgeaud
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Colin J Powers
- Molecular and Cell Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Katharina Merten
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Charles L Clark
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Elizabeth Hoffman
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Alexander Ngo
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Kohei J Sekiguchi
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Clodagh C O'Shea
- Molecular and Cell Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Greg Lemke
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA; Immunobiology and Microbial Pathogenesis Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Axel Nimmerjahn
- Waitt Advanced Biophotonics Center, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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27
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Vinnakota JM, Gummadi SN. Snail represses the expression of human phospholipid scramblase 4 gene. Gene 2016; 591:433-41. [PMID: 27363667 DOI: 10.1016/j.gene.2016.06.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/09/2016] [Accepted: 06/24/2016] [Indexed: 11/18/2022]
Abstract
Human phospholipid scramblases (hPLSCRs) are a group of transmembrane ATP independent lipid transporters mediating bi-directional transport of phospholipids. There are four homologues hPLSCR1-hPLSCR4 and hPLSCR1 is the extensively studied homologue among them. hPLSCR4 shares 48% homology with hPLSCR1 and mediates scrambling of PLs similar to hPLSCR1 in Ca(2+) dependent manner. Transcriptional regulation helps in better understanding of the function and the expression of a protein. Till date there are no reports suggesting the transcriptional regulation of hPLSCR4. In this study, we identified Snail to be a potent regulator of hPLSCR4. ConSite tool predicted the presence of a putative Snail binding site with a consensus sequence of (-1521)CAGGTG(-1516) on hPLSCR4 promoter. Luciferase assays depicted a dose dependent decrease in hPLSCR4 promoter activity with an increase in amount of Snail. Deletion analysis revealed that the region from -1380 to -2100 to be the regulatory region of hPLSCR4. Knock down studies further confirmed Snail mediated downregulation of hPLSCR4, as the mRNA and the protein levels of hPLSCR4 considerably increased under knock down conditions. The in vivo interaction of Snail with hPLSCR4 promoter was further confirmed by ChIP assay. This is the first report on the transcriptional regulation of hPLSCR4, where Snail was shown to downregulate the expression of hPLSCR4.
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Affiliation(s)
- Janaki Manoja Vinnakota
- Applied and Industrial Microbiology Lab, Bhupat and Jyoti Mehta School of Biosciences, Department of Biotechnology, IIT Madras, Chennai 600036, India.
| | - Sathyanarayana N Gummadi
- Applied and Industrial Microbiology Lab, Bhupat and Jyoti Mehta School of Biosciences, Department of Biotechnology, IIT Madras, Chennai 600036, India.
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28
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Sivagnanam U, Narayana Murthy S, Gummadi SN. Identification and characterization of the novel nuclease activity of human phospholipid scramblase 1. BMC BIOCHEMISTRY 2016; 17:10. [PMID: 27206388 PMCID: PMC4875679 DOI: 10.1186/s12858-016-0067-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 05/17/2016] [Indexed: 01/05/2023]
Abstract
Background Human phospholipid scramblase 1 (hPLSCR1) was initially identified as a Ca2+ dependent phospholipid translocator involved in disrupting membrane asymmetry. Recent reports revealed that hPLSCR1 acts as a multifunctional signaling molecule rather than functioning as scramblase. hPLSCR1 is overexpressed in a variety of tumor cells and is known to interact with a number of protein molecules implying diverse functions. Results In this study, the nuclease activity of recombinant hPLSCR1 and its biochemical properties have been determined. Point mutations were generated to identify the critical region responsible for the nuclease activity. Recombinant hPLSCR1 exhibits Mg2+ dependent nuclease activity with an optimum pH and temperature of 8.5 and 37 °C respectively. Experiments with amino acid modifying reagents revealed that histidine, cysteine and arginine residues were crucial for its function. hPLSCR1 has five histidine residues and point mutations of histidine residues to alanine in hPLSCR1 resulted in 60 % loss in nuclease activity. Thus histidine residues could play a critical role in the nuclease activity of hPLSCR1. Conclusions This is the first report on the novel nuclease activity of the multi-functional hPLSCR1. hPLSCR1 shows a metal dependent nuclease activity which could play a role in key cellular processes that needs to be further investigated.
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Affiliation(s)
- Ulaganathan Sivagnanam
- From the Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600 036, India
| | - Shweta Narayana Murthy
- From the Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600 036, India
| | - Sathyanarayana N Gummadi
- From the Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, 600 036, India.
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29
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Tubby-like protein superfamily member PLSCR3 functions as a negative regulator of adipogenesis in mouse 3T3-L1 preadipocytes by suppressing induction of late differentiation stage transcription factors. Biosci Rep 2015; 36:e00287. [PMID: 26677203 PMCID: PMC4725246 DOI: 10.1042/bsr20150215] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/15/2015] [Indexed: 02/08/2023] Open
Abstract
Decrease in intracellular amount of phospholipid scramblase 3 (PLSCR3) is accompanied by enhanced unconventional secretion during differentiation of mouse preadipocytic 3T3-L1 cells. Forced overexpression of PLSCR3 in 3T3-L1 cells inhibited adipogenesis by suppressing induction of late stage pro-adipogenic transcription factors. PLSCR3 (phospholipid scramblase 3, Scr3) belongs to the superfamily of membrane-associated transcription regulators named Tubby-like proteins (TULPs). Physiological phospholipid scrambling activities of PLSCRs in vivo have been skeptically argued, and knowledge of the biological functions of Scr3 is limited. We investigated the expression of Scr3 during differentiation of mouse 3T3-L1 preadipocytes by Western blotting (WB) and by reverse-transcription and real-time quantitative PCR (RT-qPCR). The Scr3 protein decreased during 3T3-L1 differentiation accompanied by a reduction in the mRNA level, and there was a significant increase in the amount of Scr3 protein secreted into the culture medium in the form of extracellular microvesicles (exosomes). On the other hand, Scr3 expression did not significantly decrease, and the secretion of Scr3 in 3T3 Swiss-albino fibroblasts (a parental cell-line of 3T3-L1) was not increased by differentiation treatment. Overexpression of human Scr3 during 3T3-L1 differentiation suppressed triacylglycerol accumulation and inhibited induction of the mRNAs of late stage pro-adipogenic transcription factors [CCAAT/enhancer-binding protein α (C/EBPα) and peroxisome proliferator-activated receptor γ (PPARγ)] and X-box-binding protein 1 (XBP1). Expression of early stage pro-adipogenic transcription factors (C/EBPβ and C/EBPδ) was not significantly affected. These results suggest that Scr3 functions as a negative regulator of adipogenesis in 3T3-L1 cells at a specific differentiation stage and that decrease in the intracellular amount of Scr3 protein caused by reduction in Scr3 mRNA expression and enhanced secretion of Scr3 protein appears to be important for appropriate adipocyte differentiation.
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Two c-Myc binding sites are crucial in upregulating the expression of human phospholipid scramblase 1 gene. Biochem Biophys Res Commun 2015; 469:412-7. [PMID: 26679604 DOI: 10.1016/j.bbrc.2015.11.131] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 11/29/2015] [Indexed: 11/21/2022]
Abstract
Human phospholipid scramblase 1 (hPLSCR1) is a type II endofacial membrane protein which mediates bi-directional transport of phospholipids across the plasma membrane. hPLSCR1, a multifunctional protein with variety of roles in apoptosis, tumor progression, cell signaling and anti-viral defense. The expression of such a multifunctional protein should be under tight regulation. Apart from a single report showing snail mediated down regulation of hPLSCR1, the molecular mechanisms regulating the expression of scramblases are not well elucidated. In this study we identified c-Myc as a transcriptional regulator of hPLSCR1. Transcription factor prediction tool ConSite predicted three binding sites for c-Myc. Reporter gene assays and western blot analysis revealed c-Myc mediated up regulation of hPLSCR1 expression. Deletion construct -790 lacking one c-Myc binding site showed a 27% decrease in promoter activity while deletion construct -469 lacking two c-Myc binding sites showed a 62% decrease in promoter activity. Site directed mutagenesis revealed the importance of c-Myc binding sites from -751 to -756 and -548 to -553 on the promoter of hPLSCR1in transcriptionally regulating the expression of hPLSCR1. The results were further confirmed by shRNA mediated knock down of endogenous c-Myc and in vivo interactions by ChIP assay.
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31
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Natural products against hematological malignancies and identification of their targets. SCIENCE CHINA-LIFE SCIENCES 2015; 58:1191-201. [DOI: 10.1007/s11427-015-4922-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 08/16/2015] [Indexed: 01/14/2023]
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32
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Rysavy NM, Shimoda LMN, Dixon AM, Speck M, Stokes AJ, Turner H, Umemoto EY. Beyond apoptosis: the mechanism and function of phosphatidylserine asymmetry in the membrane of activating mast cells. BIOARCHITECTURE 2015; 4:127-37. [PMID: 25759911 DOI: 10.1080/19490992.2014.995516] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Loss of plasma membrane asymmetry is a hallmark of apoptosis, but lipid bilayer asymmetry and loss of asymmetry can contribute to numerous cellular functions and responses that are independent of programmed cell death. Exofacial exposure of phosphatidylserine occurs in lymphocytes and mast cells after antigenic stimulation and in the absence of apoptosis, suggesting that there is a functional requirement for phosphatidylserine exposure in immunocytes. In this review we examine current ideas as to the nature of this functional role in mast cell activation. Mechanistically, there is controversy as to the candidate proteins responsible for phosphatidylserine translocation from the internal to external leaflet, and here we review the candidacies of mast cell PLSCR1 and TMEM16F. Finally we examine the potential relationship between functionally important mast cell membrane perturbations and phosphatidylserine exposure during activation.
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Key Words
- ABCA, ABC binding cassette family A
- CRAC, calcium release activated channel
- GPMV, giant plasma membrane vesicle
- ITIM, immunoreceptor tyrosine based inhibitory motif
- PLA2, phospholipase A2
- PLSCR, phospholipid scramblase
- PMA, phorbol 12,13-myristate acetate
- RBL, rat basophilic leukemia
- RFU, relative fluorescence units
- ROI, region of interest
- TMEM, transmembrane protein
- TMEM16F
- WGA, wheat germ agglutinin
- mast cells
- membrane lipids
- phosphatidylserine
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Affiliation(s)
- Noel M Rysavy
- a Laboratory of Immunology and Signal Transduction ; Department of Biology; Chaminade University ; Honolulu , Hawai'i USA
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Posada IMD, Fantini J, Contreras FX, Barrantes F, Alonso A, Goñi FM. A cholesterol recognition motif in human phospholipid scramblase 1. Biophys J 2015; 107:1383-92. [PMID: 25229146 DOI: 10.1016/j.bpj.2014.07.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 06/28/2014] [Accepted: 07/22/2014] [Indexed: 11/26/2022] Open
Abstract
Human phospholipid scramblase 1 (SCR) catalyzes phospholipid transmembrane (flip-flop) motion. This protein is assumed to bind the membrane hydrophobic core through a transmembrane domain (TMD) as well as via covalently bound palmitoyl residues. Here, we explore the possible interaction of the SCR TMD with cholesterol by using a variety of experimental and computational biophysical approaches. Our findings indicate that SCR contains an amino acid segment at the C-terminal region that shows a remarkable affinity for cholesterol, although it lacks the CRAC sequence. Other 3-OH sterols, but not steroids lacking the 3-OH group, also bind this region of the protein. The newly identified cholesterol-binding region is located partly at the C-terminal portion of the TMD and partly in the first amino acid residues in the SCR C-terminal extracellular coil. This finding could be related to the previously described affinity of SCR for cholesterol-rich domains in membranes.
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Affiliation(s)
- Itziar M D Posada
- Unidad de Biofísica (CSIC, UPV/EHU), Departamento de Bioquímica y Biología Molecular, Bilbao, Spain
| | - Jacques Fantini
- Interactions Moléculaires et Systèmes Membranaires, EA-4674, Aix-Marseille Université, Marseille, France
| | - F Xabier Contreras
- Unidad de Biofísica (CSIC, UPV/EHU), Departamento de Bioquímica y Biología Molecular, Bilbao, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Francisco Barrantes
- Laboratory of Molecular Neurobiology, Faculty of Medical Sciences, Biomedical Research Institute (BIOMED) UCA-CONICET, Catholic University of Argentina, Buenos Aires, Argentina
| | - Alicia Alonso
- Unidad de Biofísica (CSIC, UPV/EHU), Departamento de Bioquímica y Biología Molecular, Bilbao, Spain
| | - Félix M Goñi
- Unidad de Biofísica (CSIC, UPV/EHU), Departamento de Bioquímica y Biología Molecular, Bilbao, Spain.
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Kodigepalli KM, Nanjundan M. Induction of PLSCR1 in a STING/IRF3-dependent manner upon vector transfection in ovarian epithelial cells. PLoS One 2015; 10:e0117464. [PMID: 25658875 PMCID: PMC4320088 DOI: 10.1371/journal.pone.0117464] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 12/23/2014] [Indexed: 12/14/2022] Open
Abstract
Toll-like receptors (TLRs) are the primary sensors of the innate immune system that recognize pathogenic nucleic acids including double-stranded plasmid DNA (dsDNA). TLR signaling activates multiple pathways including IRF3 which is involved in transcriptional induction of inflammatory cytokines (i.e. interferons (IFNs)). Phospholipid scramblase 1, PLSCR1, is a highly inducible IFN-regulated gene mediating anti-viral properties of IFNs. Herein, we report a novel finding that dsDNA transfection in T80 immortalized normal ovarian surface epithelial cell line leads to a marked increase in PLSCR1 mRNA and protein. We also noted a comparable response in primary mammary epithelial cells (HMECs). Similar to IFN-2α treated cells, de novo synthesized PLSCR1 was localized predominantly to the plasma membrane. dsDNA transfection, in T80 and HMEC cells, led to activation of MAPK and IRF3. Although inhibition of MAPK (using U0126) did not modulate PLSCR1 mRNA and protein, IRF3 knockdown (using siRNA) significantly ablated the PLSCR1 induction. In prior studies, the activation of IRF3 was shown to be mediated by cGAS-STING pathway. To investigate the contribution of STING to PLSCR1 induction, we utilized siRNA to reduce STING expression and observed that PLSCR1 protein was markedly reduced. In contrast to normal T80/HMECs, the phosphorylation of IRF3 as well as induction of STING and PLSCR1 were absent in ovarian cancer cells (serous, clear cell, and endometrioid) suggesting that the STING/IRF3 pathway may be dysregulated in these cancer cells. However, we also noted induction of different TLR and IFN mRNAs between the T80 and HEY (serous epithelial ovarian carcinoma) cell lines upon dsDNA transfection. Collectively, these results indicate that the STING/IRF3 pathway, activated following dsDNA transfection, contributes to upregulation of PLSCR1 in ovarian epithelial cells.
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Affiliation(s)
- Karthik M. Kodigepalli
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, 33620, United States of America
| | - Meera Nanjundan
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, 33620, United States of America
- * E-mail:
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Choi HJ, Lui A, Ogony J, Jan R, Sims PJ, Lewis-Wambi J. Targeting interferon response genes sensitizes aromatase inhibitor resistant breast cancer cells to estrogen-induced cell death. Breast Cancer Res 2015; 17:6. [PMID: 25588716 PMCID: PMC4336497 DOI: 10.1186/s13058-014-0506-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 12/15/2014] [Indexed: 01/21/2023] Open
Abstract
Introduction Estrogen deprivation using aromatase inhibitors (AIs) is currently the standard of care for postmenopausal women with hormone receptor-positive breast cancer. Unfortunately, the majority of patients treated with AIs eventually develop resistance, inevitably resulting in patient relapse and, ultimately, death. The mechanism by which resistance occurs is still not completely known, however, recent studies suggest that impaired/defective interferon signaling might play a role. In the present study, we assessed the functional role of IFITM1 and PLSCR1; two well-known interferon response genes in AI resistance. Methods Real-time PCR and Western blot analyses were used to assess mRNA and protein levels of IFITM1, PLSCR1, STAT1, STAT2, and IRF-7 in AI-resistant MCF-7:5C breast cancer cells and AI-sensitive MCF-7 and T47D cells. Immunohistochemistry (IHC) staining was performed on tissue microarrays consisting of normal breast tissues, primary breast tumors, and AI-resistant recurrence tumors. Enzyme-linked immunosorbent assay was used to quantitate intracellular IFNα level. Neutralizing antibody was used to block type 1 interferon receptor IFNAR1 signaling. Small interference RNA (siRNA) was used to knockdown IFITM1, PLSCR1, STAT1, STAT2, IRF-7, and IFNα expression. Results We found that IFITM1 and PLSCR1 were constitutively overexpressed in AI-resistant MCF-7:5C breast cancer cells and AI-resistant tumors and that siRNA knockdown of IFITM1 significantly inhibited the ability of the resistant cells to proliferate, migrate, and invade. Interestingly, suppression of IFITM1 significantly enhanced estradiol-induced cell death in AI-resistant MCF-7:5C cells and markedly increased expression of p21, Bax, and Noxa in these cells. Significantly elevated level of IFNα was detected in AI-resistant MCF-7:5C cells compared to parental MCF-7 cells and suppression of IFNα dramatically reduced IFITM1, PLSCR1, p-STAT1, and p-STAT2 expression in the resistant cells. Lastly, neutralizing antibody against IFNAR1/2 and knockdown of STAT1/STAT2 completely suppressed IFITM1, PLSCR1, p-STAT1, and p-STAT2 expression in the resistant cells, thus confirming the involvement of the canonical IFNα signaling pathway in driving the overexpression of IFITM1 and other interferon-stimulated genes (ISGs) in the resistant cells. Conclusion Overall, these results demonstrate that constitutive overexpression of ISGs enhances the progression of AI-resistant breast cancer and that suppression of IFITM1 and other ISGs sensitizes AI-resistant cells to estrogen-induced cell death. Electronic supplementary material The online version of this article (doi:10.1186/s13058-014-0506-7) contains supplementary material, which is available to authorized users.
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Kodigepalli KM, Bowers K, Sharp A, Nanjundan M. Roles and regulation of phospholipid scramblases. FEBS Lett 2014; 589:3-14. [PMID: 25479087 DOI: 10.1016/j.febslet.2014.11.036] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Revised: 11/22/2014] [Accepted: 11/24/2014] [Indexed: 02/06/2023]
Abstract
Phospholipid scramblase activity is involved in the collapse of phospholipid (PL) asymmetry at the plasma membrane leading to externalization of phosphatidylserine. This activity is crucial for initiation of the blood coagulation cascade and for recognition/elimination of apoptotic cells by macrophages. Efforts to identify gene products associated with this activity led to the characterization of PL scramblase (PLSCR) and XKR family members which contribute to phosphatidylserine exposure in response to apoptotic stimuli. Meanwhile, TMEM16 family members were identified to externalize phosphatidylserine in response to elevated calcium in Scott syndrome platelets, which is critical for activation of the coagulation cascade. Herein, we report their mechanisms of gene regulation, molecular functions independent of their scrambling activity, and their potential roles in pathogenic conditions.
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Affiliation(s)
- Karthik M Kodigepalli
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Kiah Bowers
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Arielle Sharp
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States
| | - Meera Nanjundan
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, United States.
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Yuan Y, Tian C, Gong Q, Shang L, Zhang Y, Jin C, He F, Wang J. Interactome map reveals phospholipid scramblase 1 as a novel regulator of hepatitis B virus x protein. J Proteome Res 2014; 14:154-63. [PMID: 25365352 DOI: 10.1021/pr500943x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
HBV X protein plays crucial roles during viral infection and hepatocellular carcinoma (HCC) development through interaction with various host factors. Here, we mapped the interactome of HBx using a yeast two-hybrid screen. Nine human proteins were identified as novel interacting partners of HBx, one of which is phospholipid scramblase 1 (PLSCR1). PLSCR1 is an interferon-inducible protein that mediates antiviral activity against DNA and RNA viruses. However, the molecular mechanisms of PLSCR1 activity against HBV remain unclear. Here, we reported that PLSCR1 promotes HBx degradation by a proteasome- and ubiquitin-dependent mechanism. Furthermore, we found that PLSCR1 inhibits HBx-mediated cell proliferation. After HBV infection, the protein level of PLSCR1 in plasma is elevated, and chronic hepatitis B patients with low plasma levels of PLSCR1 have a high risk of developing HCC. These results suggest that the nuclear trafficking of PLSCR1 mediates the antiviral activity and anticarcinogenesis against HBV by regulating HBx stability.
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Affiliation(s)
- Yanzhi Yuan
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine , Beijing 102206, China
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Kassas A, Moura IC, Yamashita Y, Scheffel J, Guérin-Marchand C, Blank U, Sims PJ, Wiedmer T, Monteiro RC, Rivera J, Charles N, Benhamou M. Regulation of the tyrosine phosphorylation of Phospholipid Scramblase 1 in mast cells that are stimulated through the high-affinity IgE receptor. PLoS One 2014; 9:e109800. [PMID: 25289695 PMCID: PMC4188579 DOI: 10.1371/journal.pone.0109800] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 09/14/2014] [Indexed: 01/05/2023] Open
Abstract
Engagement of high-affinity immunoglobulin E receptors (FcεRI) activates two signaling pathways in mast cells. The Lyn pathway leads to recruitment of Syk and to calcium mobilization whereas the Fyn pathway leads to phosphatidylinositol 3-kinase recruitment. Mapping the connections between both pathways remains an important task to be completed. We previously reported that Phospholipid Scramblase 1 (PLSCR1) is phosphorylated on tyrosine after cross-linking FcεRI on RBL-2H3 rat mast cells, amplifies mast cell degranulation, and is associated with both Lyn and Syk tyrosine kinases. Here, analysis of the pathway leading to PLSCR1 tyrosine phosphorylation reveals that it depends on the FcRγ chain. FcεRI aggregation in Fyn-deficient mouse bone marrow-derived mast cells (BMMC) induced a more robust increase in FcεRI-dependent tyrosine phosphorylation of PLSCR1 compared to wild-type cells, whereas PLSCR1 phosphorylation was abolished in Lyn-deficient BMMC. Lyn association with PLSCR1 was not altered in Fyn-deficient BMMC. PLSCR1 phosphorylation was also dependent on the kinase Syk and significantly, but partially, dependent on detectable calcium mobilization. Thus, the Lyn/Syk/calcium axis promotes PLSCR1 phosphorylation in multiple ways. Conversely, the Fyn-dependent pathway negatively regulates it. This study reveals a complex regulation for PLSCR1 tyrosine phosphorylation in FcεRI-activated mast cells and that PLSCR1 sits at a crossroads between Lyn and Fyn pathways.
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Affiliation(s)
- Asma Kassas
- INSERM U1149, Faculté de Médecine Xavier Bichat, Paris, France
- University Paris-Diderot, Sorbonne Paris Cité, Laboratoire d’excellence INFLAMEX, DHU FIRE, Paris, France
| | - Ivan C. Moura
- INSERM U1149, Faculté de Médecine Xavier Bichat, Paris, France
- University Paris-Diderot, Sorbonne Paris Cité, Laboratoire d’excellence INFLAMEX, DHU FIRE, Paris, France
| | - Yumi Yamashita
- Laboratory of Molecular Immunogenetics, Molecular Immunology and Inflammation Branch, NIAMSD, NIH, Bethesda, Maryland, United States of America
| | - Jorg Scheffel
- Laboratory of Molecular Immunogenetics, Molecular Immunology and Inflammation Branch, NIAMSD, NIH, Bethesda, Maryland, United States of America
| | - Claudine Guérin-Marchand
- INSERM U1149, Faculté de Médecine Xavier Bichat, Paris, France
- University Paris-Diderot, Sorbonne Paris Cité, Laboratoire d’excellence INFLAMEX, DHU FIRE, Paris, France
| | - Ulrich Blank
- INSERM U1149, Faculté de Médecine Xavier Bichat, Paris, France
- University Paris-Diderot, Sorbonne Paris Cité, Laboratoire d’excellence INFLAMEX, DHU FIRE, Paris, France
| | - Peter J. Sims
- Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Therese Wiedmer
- Department of Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York, United States of America
| | - Renato C. Monteiro
- INSERM U1149, Faculté de Médecine Xavier Bichat, Paris, France
- University Paris-Diderot, Sorbonne Paris Cité, Laboratoire d’excellence INFLAMEX, DHU FIRE, Paris, France
| | - Juan Rivera
- Laboratory of Molecular Immunogenetics, Molecular Immunology and Inflammation Branch, NIAMSD, NIH, Bethesda, Maryland, United States of America
| | - Nicolas Charles
- INSERM U1149, Faculté de Médecine Xavier Bichat, Paris, France
- University Paris-Diderot, Sorbonne Paris Cité, Laboratoire d’excellence INFLAMEX, DHU FIRE, Paris, France
- * E-mail: (NC); (MB)
| | - Marc Benhamou
- INSERM U1149, Faculté de Médecine Xavier Bichat, Paris, France
- University Paris-Diderot, Sorbonne Paris Cité, Laboratoire d’excellence INFLAMEX, DHU FIRE, Paris, France
- * E-mail: (NC); (MB)
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Francis VG, Padmanabhan P, Gummadi SN. Snail interacts with hPLSCR1 promoter and down regulates its expression in IMR-32. Biochem Biophys Res Commun 2014; 450:172-7. [PMID: 24878522 DOI: 10.1016/j.bbrc.2014.05.094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 05/20/2014] [Indexed: 10/25/2022]
Abstract
Human phospholipid scramblase 1 (hPLSCR1) is a proapoptotic protein whose expression is deregulated in a variety of cancers cells. However till date the transcription regulation of hPLSCR1 is unknown. Transcriptional regulation of hPLSCR1 was studied by cloning the 5'-flanking region of hPLSCR1. Luciferase assays revealed that -1525 to -1244 region of hPLSCR1 was found to regulate its promoter activity. A putative Snail transcription factor (TF) binding site was found within the regulatory region of the promoter. Snail binding was found to down regulate the expression of hPLSCR1 both at the transcriptional and translational levels. Snail knock down using Snail-shRNA confirmed that down regulation of hPLSCR1 by Snail was specific. Point mutation studies confirm that the predicted Snail TF binds to -1123 to -1117 site. ChIP assay further confirms the physical interaction of Snail with hPLSCR1 promoter. This is the first report showing the transcriptional regulation of hPLSCR1 expression by Snail TF and its possible implications in cancer progression.
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Affiliation(s)
- Vincent Gerard Francis
- Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Purnima Padmanabhan
- Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600 036, India
| | - Sathyanarayana N Gummadi
- Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600 036, India.
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Membrane binding of human phospholipid scramblase 1 cytoplasmic domain. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1785-92. [PMID: 24680654 DOI: 10.1016/j.bbamem.2014.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 03/12/2014] [Accepted: 03/18/2014] [Indexed: 02/08/2023]
Abstract
Human phospholipid scramblase 1 (SCR) consists of a large cytoplasmic domain and a small presumed transmembrane domain near the C-terminal end of the protein. Previous studies with the SCRΔ mutant lacking the C-terminal portion (last 28 aa) revealed the importance of this C-terminal moiety for protein function and calcium-binding affinity. The present contribution is intended to elucidate the effect of the transmembrane domain suppression on SCRΔ binding to model membranes (lipid monolayers and bilayers) and on SCRΔ reconstitution in proteoliposomes. In all cases the protein cytoplasmic domain showed a great affinity for lipid membranes, and behaved in most aspects as an intrinsic membrane protein. Assays have been performed in the presence of phosphatidylserine, presumably important for the SCR cytoplasmic domain to be electrostatically anchored to the plasma membrane inner surface. The fusion protein maltose binding protein-SCR has also been studied as an intermediate case of a molecule that can insert into the bilayer hydrophobic core, yet it is stable in detergent-free buffers. Although the intracellular location of SCR has been the object of debate, the present data support the view of SCR as an integral membrane protein, in which not only the transmembrane domain but also the cytoplasmic moiety play a role in membrane docking of the protein.
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Rayala S, Francis VG, Sivagnanam U, Gummadi SN. N-terminal proline-rich domain is required for scrambling activity of human phospholipid scramblases. J Biol Chem 2014; 289:13206-18. [PMID: 24648509 DOI: 10.1074/jbc.m113.522953] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Human phospholipid scramblase 1 (hPLSCR1), a type II integral class membrane protein, is known to mediate bidirectional scrambling of phospholipids in a Ca(2+)-dependent manner. hPLSCR2, a homolog of hPLSCR1 that lacks N-terminal proline-rich domain (PRD), did not show scramblase activity. We attribute this absence of scramblase activity of hPLSCR2 to the lack of N-terminal PRD. Hence to investigate the above hypothesis, we added the PRD of hPLSCR1 to hPLSCR2 (PRD-hPLSCR2) and checked whether scramblase activity was restored. Functional assays showed that the addition of PRD to hPLSCR2 restored scrambling activity, and deletion of PRD in hPLSCR1 (ΔPRD-hPLSCR1) resulted in a lack of activity. These results suggest that PRD is crucial for the function of the protein. The effects of the PRD deletion in hPLSCR1 and the addition of PRD to hPLSCR2 were characterized using various spectroscopic techniques. Our results clearly showed that hPLSCR1 and PRD-hPLSCR2 showed Ca(2+)-dependent aggregation and scrambling activity, whereas hPLSCR2 and ΔPRD-hPLSCR1 did not show aggregation and activity. Thus we conclude that scramblases exhibit Ca(2+)-dependent scrambling activity by aggregation of protein. Our results provide a possible mechanism for phospholipid scrambling mediated by PLSCRs and the importance of PRD in its function and cellular localization.
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Affiliation(s)
- Sarika Rayala
- From the Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600 036, India
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Schlattner U, Tokarska-Schlattner M, Rousseau D, Boissan M, Mannella C, Epand R, Lacombe ML. Mitochondrial cardiolipin/phospholipid trafficking: the role of membrane contact site complexes and lipid transfer proteins. Chem Phys Lipids 2013; 179:32-41. [PMID: 24373850 DOI: 10.1016/j.chemphyslip.2013.12.008] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/17/2013] [Accepted: 12/19/2013] [Indexed: 11/18/2022]
Abstract
Historically, cellular trafficking of lipids has received much less attention than protein trafficking, mostly because its biological importance was underestimated, involved sorting and translocation mechanisms were not known, and analytical tools were limiting. This has changed during the last decade, and we discuss here some progress made in respect to mitochondria and the trafficking of phospholipids, in particular cardiolipin. Different membrane contact site or junction complexes and putative lipid transfer proteins for intra- and intermembrane lipid translocation have been described, involving mitochondrial inner and outer membrane, and the adjacent membranes of the endoplasmic reticulum. An image emerges how cardiolipin precursors, remodeling intermediates, mature cardiolipin and its oxidation products could migrate between membranes, and how this trafficking is involved in cardiolipin biosynthesis and cell signaling events. Particular emphasis in this review is given to mitochondrial nucleoside diphosphate kinase D and mitochondrial creatine kinases, which emerge to have roles in both, membrane junction formation and lipid transfer.
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Affiliation(s)
- Uwe Schlattner
- Univ. Grenoble-Alpes, Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), Grenoble, France; Inserm, U1055, Grenoble, France.
| | - Malgorzata Tokarska-Schlattner
- Univ. Grenoble-Alpes, Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), Grenoble, France; Inserm, U1055, Grenoble, France
| | - Denis Rousseau
- Univ. Grenoble-Alpes, Laboratory of Fundamental and Applied Bioenergetics (LBFA) and SFR Environmental and Systems Biology (BEeSy), Grenoble, France; Inserm, U1055, Grenoble, France
| | - Mathieu Boissan
- UPMC Université Paris 06, Paris, France; Inserm, UMRS938, Paris, France; Hôpital Tenon, AP-HP, Service de Biochimie et Hormonologie, Paris, France
| | - Carmen Mannella
- Wadsworth Center, New York State Department of Health, Albany, NY, USA
| | - Richard Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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The C-terminal transmembrane domain of human phospholipid scramblase 1 is essential for the protein flip-flop activity and Ca²⁺-binding. J Membr Biol 2013; 247:155-65. [PMID: 24343571 DOI: 10.1007/s00232-013-9619-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 11/26/2013] [Indexed: 10/25/2022]
Abstract
Human phospholipid scramblase 1 (SCR) is a 318 amino acid protein that was originally described as catalyzing phospholipid transbilayer (flip-flop) motion in plasma membranes in a Ca²⁺-dependent, ATP-independent way. Further studies have suggested an intranuclear role for this protein in addition. A putative transmembrane domain located at the C terminus (aa 291-309) has been related to the flip-flop catalysis. In order to clarify the role of the C-terminal region of SCR, a mutant was produced (SCRΔ) in which the last 28 amino acid residues were lacking, including the α-helix. SCRΔ had lost the scramblase activity and its affinity for Ca²⁺ was decreased by one order of magnitude. Fluorescence and IR spectroscopic studies revealed that the C-terminal region of SCR was essential for the proper folding of the protein. Moreover, it was found that Ca²⁺ exerted an overall destabilizing effect on SCR, which might facilitate its binding to membranes.
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Membrane binding and insertion of the predicted transmembrane domain of human scramblase 1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:388-97. [PMID: 24099740 DOI: 10.1016/j.bbamem.2013.09.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 09/19/2013] [Accepted: 09/25/2013] [Indexed: 10/26/2022]
Abstract
Human phospholipid scramblase 1 (SCR) was originally described as an intrinsic membrane protein catalyzing transbilayer phospholipid transfer in the absence of ATP. More recently, a role as a nuclear transcription factor has been proposed for SCR, either in addition or alternatively to its capacity to facilitate phospholipid flip-flop. Uncertainties exist as well from the structural point of view. A predicted α-helix (aa residues 288-306) located near the C-terminus has been alternatively proposed as a transmembrane domain, or as a protein core structural element. This paper explores the possibilities of the above helical segment as a transmembrane domain. To this aim two peptides were synthesized, one corresponding to the 19 α-helical residues, and one containing both the helix and the subsequent 12-residues constituting the C-end of the protein. The interaction of these peptides with lipid monolayers and bilayers was tested with Langmuir balance surface pressure measurements, proteoliposome reconstitution and analysis, differential scanning calorimetry, tests of bilayer permeability, and fluorescence confocal microscopy. Bilayers of 28 different lipid compositions were examined in which lipid electric charge, bilayer fluidity and lateral heterogeneity (domain formation) were varied. All the results concur in supporting the idea that the 288-306 peptide of SCR becomes membrane inserted in the presence of lipid bilayers. Thus, the data are in agreement with the possibility of SCR as an integral membrane protein, without rejecting alternative cell locations.
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Key Words
- 1,1,1,3,3,3-hexafluoro-2-propanol
- 1,1′-dioctadecyl-3,3,3′,3′-tetramethyl-indodicarbocyanine
- 8-aminonaphtalene-1,3,6-trisulfonic acid sodium salt
- ANTS
- DID
- DPX
- GUVs
- HFIP
- LUVs
- Lipid phases
- MLVs
- PC
- PE
- PG
- PI
- PLSCR1
- PS
- SCR
- SCR 288–306 peptide
- SCR 288–318 peptide
- Scramblase
- TM
- TM19
- TM31C
- Transbilayer
- Transmembrane helix
- giant unilamellar vesicles
- human phospholipid scramblase 1, or hPLSCR1
- large unilamellar vesicles
- multilamellar vesicles
- p-xylene-bis(pyridinium) bromide
- pSM
- palmitoyl sphingomyelin
- phosphatidylcholine
- phosphatidylethanolamine
- phosphatidylglycerol
- phosphatidylinositol
- phosphatidylserine
- transmembrane
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Francis VG, Mohammed AM, Aradhyam GK, Gummadi SN. The single C-terminal helix of human phospholipid scramblase 1 is required for membrane insertion and scrambling activity. FEBS J 2013; 280:2855-69. [PMID: 23590222 DOI: 10.1111/febs.12289] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 03/12/2013] [Accepted: 04/15/2013] [Indexed: 11/29/2022]
Abstract
Human phospholipid scramblase 1 (hPLSCR1) belongs to the ATP-independent class of phospholipid translocators which possess a single EF-hand-like Ca(2+)-binding motif and also a C-terminal helix (CTH). The CTH domain of hPLSCR1 was believed to be a putative single transmembrane helix at the C-terminus. Recent homology modeling studies by Bateman et al. predicted that the hydrophobic nature of this helix is due to its packing in the core of the protein domain and proposed that this is not a true transmembrane helix [Bateman A, Finn RD, Sims PJ, Wiedmer T, Biegert A & Johannes S. Bioinformatics 2008, 25, 159]. To determine the exact function of the CTH of hPLSCR1, we deleted the CTH domain and determined: (a) whether CTH plays any role beyond membrane anchorage, (b) the functional consequences of CTH deletion, and (c) any conformational changes associated with CTH in a lipid environment. In vitro reconstitution studies confirm that the predicted CTH is required for membrane insertion and scrambling activity. CTH deletion caused a 50% decrease in binding affinity of Ca(2+) for ∆CTH-hPLSCR1 (K(a) = 115 μM) compared with hPLSCR1 (K(a) = 249 μM). Far UV-CD studies revealed that the CTH peptide adopts α-helicity only in the presence of SDS micelles and negatively charged vesicles, indicating that electrostatic interactions are required for insertion of the peptide. CTH peptide-quenching studies confirm that the predicted CTH inserts into the membrane and its ability to interact with the membrane depends on the presence of charge interactions. TOXCAT assay revealed that CTH of hPLSCR1 does not oligomerize in the membrane. We conclude that CTH is required for membrane insertion and Ca(2+) coordination and also plays an important role in the functional conformation of hPLSCR1.
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Affiliation(s)
- Vincent G Francis
- Department of Biotechnology, Indian Institute of Technology Madras, Chennai, India
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Wogonoside induces cell cycle arrest and differentiation by affecting expression and subcellular localization of PLSCR1 in AML cells. Blood 2013; 121:3682-91. [DOI: 10.1182/blood-2012-11-466219] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Key Points
Wogonoside induces cell cycle arrest and differentiation. Wogonoside acts by changing PLSCR1 expression and subcellular localization in the nucleus and by PLSCR1-related molecular events.
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ALG-2-interacting Tubby-like protein superfamily member PLSCR3 is secreted by an exosomal pathway and taken up by recipient cultured cells. Biosci Rep 2013; 33:e00026. [PMID: 23350699 PMCID: PMC3590573 DOI: 10.1042/bsr20120123] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
PLSCRs (phospholipid scramblases) are palmitoylated membrane-associating proteins. Regardless of the given names, their physiological functions are not clear and thought to be unrelated to phospholipid scrambling activities observed in vitro. Using a previously established cell line of HEK-293 (human embryonic kidney-293) cells constitutively expressing human Scr3 (PLSCR3) that interacts with ALG-2 (apoptosis-linked gene 2) Ca2+-dependently, we found that Scr3 was secreted into the culture medium. Secretion of Scr3 was suppressed by 2-BP (2-bromopalmitate, a palmitoylation inhibitor) and by GW4869 (an inhibitor of ceramide synthesis). Secreted Scr3 was recovered in exosomal fractions by sucrose density gradient centrifugation. Palmitoylation sites and the N-terminal Pro-rich region were necessary for efficient secretion, but ABSs (ALG-2-binding sites) were dispensable. Overexpression of GFP (green fluorescent protein)-fused VPS4BE235Q, a dominant negative mutant of an AAA (ATPase associated with various cellular activities) ATPase with a defect in disassembling ESCRT (endosomal sorting complex required for transport)-III subunits, significantly reduced secretion of Scr3. Immunofluorescence microscopic analyses showed that Scr3 was largely localized to enlarged endosomes induced by overexpression of a GFP-fused constitutive active mutant of Rab5A (GFP–Rab5AQ79L). Secreted Scr3 was taken up by HeLa cells, suggesting that Scr3 functions as a cell-to-cell transferable modulator carried by exosomes in a paracrine manner.
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Fan CW, Chen CY, Chen KT, Shen CR, Kuo YB, Chen YS, Chou YP, Wei WS, Chan EC. Blockade of phospholipid scramblase 1 with its N-terminal domain antibody reduces tumorigenesis of colorectal carcinomas in vitro and in vivo. J Transl Med 2012; 10:254. [PMID: 23259795 PMCID: PMC3551821 DOI: 10.1186/1479-5876-10-254] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Accepted: 12/19/2012] [Indexed: 12/04/2022] Open
Abstract
Background Membrane-bound phospholipid scramblase 1 (PLSCR1) is involved in both lipid trafficking and cell signaling. Previously, we showed that PLSCR1 is overexpressed in many colorectal carcinomas (CRCs). In the present study, we investigated the tumorigenic role of PLSCR1 in CRC and suggest that it is a potential therapeutic target. Methods To identify PLSCR1 as a therapeutic target, we studied the tumorigenic properties of CRC cell lines treated with a monoclonal antibody (NP1) against the N-terminus of PLSCR1 in vitro and in vivo. We also investigated cell cycle status and epidermal growth factor receptor–related pathways and downstream effectors of PLSCR1 after blocking its function with NP1. Results Treating CRC cells with NP1 in vitro and in vivo decreased cell proliferation, anchorage-independent growth, migration, and invasion. Adding NP1 to the CRC cell line HT29 caused arrest at G1/S. Treating HT29 cells with NP1 significantly decreased the expression of cyclin D1 and phosphorylation levels of Src, the adaptor protein Shc, and Erks. The reduced level of cyclin D1 led to an increase in the activated form of the tumor suppressor retinoblastoma protein via dephosphorylation. These actions led to attenuation of tumorigenesis. Conclusions Therefore, PLSCR1 may serve as a potential therapeutic target for CRC.
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Affiliation(s)
- Chung-Wei Fan
- Department of Colorectal Surgery, Chang Gung Memorial Hospital, Keelung, Taiwan
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Bu Z, Liu R, Shang B, Cao Z, Pan Y, Zhou Q, Ruan C. A monoclonal antibody SZ-117 that recognizes filamin A derived from tumor cells. Hybridoma (Larchmt) 2012; 31:214-8. [PMID: 22741587 DOI: 10.1089/hyb.2011.0109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
SZ117 is a monoclonal antibody against matrix metalloproteinase-2 (MMP-2) and exhibits anti-tumor angiogenic effect. In this study, we observed that SZ117 bound to a 280 kDa protein, which was detected in tumor cell-derived Matrigel and various tumor cells. Using immunoprecipitation, mass spectrometry analysis, and Western blot analysis, we identified the 280 kDa protein as filamin A and found that filamin A and its degraded products, notably a 53 kDa fragment, were released from a variety of tumor cells. This suggests that SZ117 is useful in the study of the pathogenesis of filamin A and that blockage of filamin A by SZ117 might contribute to the anti-tumor angiogenic effect of the monoclonal antibody.
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Affiliation(s)
- Zibin Bu
- Cyrus Tang Hematology Center, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University; Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, Soochow University, Suzhou, Jiangsu, China
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Kesherwani V, Agrawal SK. Regulation of inositol 1,4,5-triphosphate receptor, type 1 (IP3R1) in hypoxic/reperfusion injury of white matter. Neurol Res 2012; 34:504-11. [PMID: 22643045 DOI: 10.1179/1743132812y.0000000038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE Calcium overloading is responsible for initiating the cell death in neuronal tissue after hypoxic injury. Inositol 1,4,5-triphosphate receptors (IP3Rs) is an important calcium channel which regulates cellular calcium homeostasis. IP3R1 is widely expressed in brain and spinal tissue. In the present study, we have studied the regulation of IP3R1 in hypoxic/reperfusion injury of spinal cord dorsal column in vitro. METHODS Dorsal columns were isolated from the spinal cord of adult rats and injury was induced by exposing to hypoxic condition for 1 hour. After injury, reperfusion was carried out for 0, 2, 4, and 8 hours. Tissues were collected and processed for western blotting, immunohistochemistry and real-time PCR. RESULTS In the present study, we have found increased expression of IP3R1 after hypoxic/reperfusion injury of spinal cord dorsal column in vitro. Maximum expression of IP3R1 has been seen at 4 hours after hypoxia. Double immunofluorescence studies show the localization of IP3R1 in axons and astrocytes. Further identifying the signaling pathway involved in the regulation, we found Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN-62 and c-Jun N-terminal kinase (JNK) inhibitor SP600125 reduced the expression of IP3R1 suggesting the role of CaMKII and JNK in the regulation of IP3R1 expression. We did not find role of ERK and p38 in the regulation IP3R1 expression in hypoxic/reperfusion injury of dorsal column in vitro. DISCUSSION The result presented in this study showed that IP3R1 expression is increased in hypoxic/reperfusion injury of spinal cord white matter and it is regulated by the CaMKII-JNK pathway.
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Affiliation(s)
- Varun Kesherwani
- Division of Neurosurgery, Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198-6250, USA
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