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Hendrix S, Tan JME, Ndoj K, Kingma J, Valiloo M, Zijlstra LF, Ottenhoff R, Seidah NG, Loregger A, Kober DL, Zelcer N. SPRING is a Dedicated Licensing Factor for SREBP-Specific Activation by S1P. Mol Cell Biol 2024; 44:123-137. [PMID: 38747374 PMCID: PMC11110692 DOI: 10.1080/10985549.2024.2348711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 04/10/2024] [Indexed: 05/18/2024] Open
Abstract
SREBP transcription factors are central regulators of lipid metabolism. Their proteolytic activation requires ER to the Golgi translocation and subsequent cleavage by site-1-protease (S1P). Produced as a proprotein, S1P undergoes autocatalytic cleavage from its precursor S1PA to mature S1PC form. Here, we report that SPRING (previously C12ORF29) and S1P interact through their ectodomains, and that this facilitates the autocatalytic cleavage of S1PA into its mature S1PC form. Reciprocally, we identified a S1P recognition-motif in SPRING and demonstrate that S1P-mediated cleavage leads to secretion of the SPRING ectodomain in cells, and in liver-specific Spring knockout (LKO) mice transduced with AAV-mSpring. By reconstituting SPRING variants into SPRINGKO cells we show that the SPRING ectodomain supports proteolytic maturation of S1P and SREBP signaling, but that S1P-mediated SPRING cleavage is not essential for these processes. Absence of SPRING modestly diminishes proteolytic maturation of S1PA→C and trafficking of S1PC to the Golgi. However, despite reaching the Golgi in SPRINGKO cells, S1PC fails to rescue SREBP signaling. Remarkably, whereas SREBP signaling was severely attenuated in SPRINGKO cells and LKO mice, that of ATF6, another S1P substrate, was unaffected in these models. Collectively, our study positions SPRING as a dedicated licensing factor for SREBP-specific activation by S1P.
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Affiliation(s)
- Sebastian Hendrix
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
| | - Josephine M. E. Tan
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
| | - Klevis Ndoj
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
| | - Jenina Kingma
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
| | - Masoud Valiloo
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
| | - Lobke F. Zijlstra
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
| | - Roelof Ottenhoff
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
| | - Nabil G. Seidah
- Laboratory of Biochemical Neuroendocrinology, Montreal Clinical Research Institute (IRCM), University of Montreal, Montréal, Québec, Canada
| | - Anke Loregger
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
| | - Daniel L. Kober
- Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Noam Zelcer
- Department of Medical Biochemistry, Amsterdam UMC, Amsterdam Cardiovascular Sciences and Gastroenterology and Metabolism, University of Amsterdam, Amsterdam, The Netherlands
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Sikder K, Phillips E, Zhong Z, Wang N, Saunders J, Mothy D, Kossenkov A, Schneider T, Nichtova Z, Csordas G, Margulies KB, Choi JC. Perinuclear damage from nuclear envelope deterioration elicits stress responses that contribute to LMNA cardiomyopathy. SCIENCE ADVANCES 2024; 10:eadh0798. [PMID: 38718107 PMCID: PMC11078192 DOI: 10.1126/sciadv.adh0798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/03/2024] [Indexed: 05/12/2024]
Abstract
Mutations in the LMNA gene encoding lamins A/C cause an array of tissue-selective diseases, with the heart being the most commonly affected organ. Despite progress in understanding the perturbations emanating from LMNA mutations, an integrative understanding of the pathogenesis underlying cardiac dysfunction remains elusive. Using a novel conditional deletion model capable of translatome profiling, we observed that cardiomyocyte-specific Lmna deletion in adult mice led to rapid cardiomyopathy with pathological remodeling. Before cardiac dysfunction, Lmna-deleted cardiomyocytes displayed nuclear abnormalities, Golgi dilation/fragmentation, and CREB3-mediated stress activation. Translatome profiling identified MED25 activation, a transcriptional cofactor that regulates Golgi stress. Autophagy is disrupted in the hearts of these mice, which can be recapitulated by disrupting the Golgi. Systemic administration of modulators of autophagy or ER stress significantly delayed cardiac dysfunction and prolonged survival. These studies support a hypothesis wherein stress responses emanating from the perinuclear space contribute to the LMNA cardiomyopathy development.
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Affiliation(s)
- Kunal Sikder
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia PA, USA
| | - Elizabeth Phillips
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia PA, USA
| | - Zhijiu Zhong
- Translational Research and Pathology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Nadan Wang
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia PA, USA
| | - Jasmine Saunders
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia PA, USA
| | - David Mothy
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia PA, USA
| | - Andrew Kossenkov
- Bioinformatics Facility, The Wistar Institute Cancer Center, Philadelphia, PA, USA
| | - Timothy Schneider
- Mitocare, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Zuzana Nichtova
- Mitocare, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Gyorgy Csordas
- Mitocare, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Kenneth B. Margulies
- Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jason C. Choi
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University, Philadelphia PA, USA
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Lee GE, Bang G, Byun J, Lee CJ, Chen W, Jeung D, An HJ, Kang HC, Lee JY, Lee HS, Hong YS, Kim DJ, Keniry M, Kim JY, Choi JS, Fanto M, Cho SJ, Kim KD, Cho YY. Dysregulated CREB3 cleavage at the nuclear membrane induces karyoptosis-mediated cell death. Exp Mol Med 2024; 56:686-699. [PMID: 38480902 PMCID: PMC10985101 DOI: 10.1038/s12276-024-01195-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 12/17/2023] [Accepted: 01/02/2024] [Indexed: 04/04/2024] Open
Abstract
Cancer cells often exhibit resistance to apoptotic cell death, but they may be vulnerable to other types of cell death. Elucidating additional mechanisms that govern cancer cell death is crucial for developing new therapies. Our research identified cyclic AMP-responsive element-binding protein 3 (CREB3) as a crucial regulator and initiator of a unique cell death mechanism known as karyoptosis. This process is characterized by nuclear shrinkage, deformation, and the loss of nuclear components following nuclear membrane rupture. We found that the N-terminal domain (aa 1-230) of full-length CREB3 (CREB3-FL), which is anchored to the nuclear inner membrane (INM), interacts with lamins and chromatin DNA. This interaction maintains a balance between the outward force exerted by tightly packed DNA and the inward constraining force, thereby preserving INM integrity. Under endoplasmic reticulum (ER) stress, aberrant cleavage of CREB3-FL at the INM leads to abnormal accumulation of the cleaved form of CREB3 (CREB3-CF). This accumulation disrupts the attachment of CREB3-FL to the INM, resulting in sudden rupture of the nuclear membrane and the onset of karyoptosis. Proteomic studies revealed that CREB3-CF overexpression induces a DNA damage response akin to that caused by UVB irradiation, which is associated with cellular senescence in cancer cells. These findings demonstrated that the dysregulation of CREB3-FL cleavage is a key factor in karyoptotic cell death. Consequently, these findings suggest new therapeutic strategies in cancer treatment that exploit the process of karyoptosis.
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Affiliation(s)
- Ga-Eun Lee
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
- BK21-4th, and RCD Control∙Material Research Institute, College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Geul Bang
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Cheongju-si, Chungbuk, 28119, Republic of Korea
| | - Jiin Byun
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
- BK21-4th, and RCD Control∙Material Research Institute, College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Cheol-Jung Lee
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
- Research Center for Materials Analysis, Korea Basic Science Institute, Daejeon, 34133, Republic of Korea
| | - Weidong Chen
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
- BK21-4th, and RCD Control∙Material Research Institute, College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Dohyun Jeung
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
- BK21-4th, and RCD Control∙Material Research Institute, College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Hyun-Jung An
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Han Chang Kang
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
- BK21-4th, and RCD Control∙Material Research Institute, College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Joo Young Lee
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
- BK21-4th, and RCD Control∙Material Research Institute, College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Hye Suk Lee
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
- BK21-4th, and RCD Control∙Material Research Institute, College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Young-Soo Hong
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju-si, Chungbuk, 28116, Republic of Korea
| | - Dae Joon Kim
- Department of Immunology and Microbiology, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, 78504, USA
| | - Megan Keniry
- Department of Biology, University of Texas Rio Grande Valley, Edinburg, TX, 78539, USA
| | - Jin Young Kim
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang, Cheongju-si, Chungbuk, 28119, Republic of Korea
| | - Jin-Sung Choi
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea
| | - Manolis Fanto
- Department of Basic and Clinical Neuroscience, King's College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Sung-Jun Cho
- University of Minnesota, Department of Medicine, 420 Delaware St SE, MMC 284, Minneapolis, MN, 55455, USA
| | - Kwang-Dong Kim
- Division of Applied Life Science (BK21 four), PMBBRC, Gyeongsang National University, Jinju, 52828, Korea
| | - Yong-Yeon Cho
- College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea.
- BK21-4th, and RCD Control∙Material Research Institute, College of Pharmacy, The Catholic University of Korea, Bucheon-si, Gyeonggi-do, 14662, Republic of Korea.
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Wang L, Meng Q, Wang H, Huang X, Yu C, Yin G, Wang D, Jiang H, Huang Z. Luman regulates the activity of the LHCGR promoter. Res Vet Sci 2023; 161:132-137. [PMID: 37384971 DOI: 10.1016/j.rvsc.2023.06.014] [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: 07/09/2021] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/01/2023]
Abstract
Testosterone in male mammals is mainly secreted by testicular Leydig cells, and its secretion process is regulated by the hypothalamic-pituitary-gonadal axis. After receiving the luteinizing hormone (LH) stimulus signal, the lutropin/choriogonadotropin receptor (LHCGR) on the Leydig cell membrane transfers the signal into the cell and finally increases the secretion of testosterone by upregulating the expression of steroid hormone synthase. In previous experiments, we found that interfering with the expression of the Luman protein can significantly increase testosterone secretion in MLTC-1 cells. In this experiment, we found that knockdown of Luman in MLTC-1 cells significantly increased the concentration of cAMP and upregulated the expression of AC and LHCGR. Moreover, an analysis of the activity of the LHCGR promoter by a dual luciferase reporter system showed that knockdown of Luman increased the activity of the LHCGR promoter. Therefore, we believe that knockdown of Luman increased the activity of the LHCGR promoter and upregulated the expression of LHCGR, thereby increasing the concentration of intracellular cAMP and ultimately leading to an increase of testosterone secretion by MLTC-1 cells.
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Affiliation(s)
- Lei Wang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China.
| | - Qingrui Meng
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Hailun Wang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Xiaoyu Huang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Chunchen Yu
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Guangwen Yin
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Dengfeng Wang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Heji Jiang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China
| | - Zhijian Huang
- Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China.
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5
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Mousa MG, Vuppaladhadiam L, Kelly MO, Pietka T, Ek S, Shen KC, Meyer GA, Finck BN, Brookheart RT. Site-1 protease inhibits mitochondrial respiration by controlling the TGF-β target gene Mss51. Cell Rep 2023; 42:112336. [PMID: 37002920 PMCID: PMC10544680 DOI: 10.1016/j.celrep.2023.112336] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 02/17/2023] [Accepted: 03/20/2023] [Indexed: 04/03/2023] Open
Abstract
The mitochondrial response to changes in cellular energy demand is necessary for cellular adaptation and organ function. Many genes are essential in orchestrating this response, including the transforming growth factor (TGF)-β1 target gene Mss51, an inhibitor of skeletal muscle mitochondrial respiration. Although Mss51 is implicated in the pathophysiology of obesity and musculoskeletal disease, how Mss51 is regulated is not entirely understood. Site-1 protease (S1P) is a key activator of several transcription factors required for cellular adaptation. However, the role of S1P in muscle is unknown. Here, we identify S1P as a negative regulator of muscle mass and mitochondrial respiration. S1P disruption in mouse skeletal muscle reduces Mss51 expression and increases muscle mass and mitochondrial respiration. The effects of S1P deficiency on mitochondrial activity are counteracted by overexpressing Mss51, suggesting that one way S1P inhibits respiration is by regulating Mss51. These discoveries expand our understanding of TGF-β signaling and S1P function.
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Affiliation(s)
- Muhammad G Mousa
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Lahari Vuppaladhadiam
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Meredith O Kelly
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Terri Pietka
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Shelby Ek
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Karen C Shen
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gretchen A Meyer
- Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO 63110, USA; Departments of Orthopaedic Surgery and Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA
| | - Brian N Finck
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA
| | - Rita T Brookheart
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, MO 61110, USA.
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6
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Smith BS, Hewitt T, Bakovic M, Lu R. ER stress-associated transcription factor CREB3 is essential for normal Ca 2+, ATP, and ROS homeostasis. Mitochondrion 2023; 69:10-17. [PMID: 36627030 DOI: 10.1016/j.mito.2023.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 12/24/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023]
Abstract
In mammalian cells, mitochondrial respiration produces reactive oxygen species (ROS) such as superoxide (O2-), which is then converted by the SOD1 enzyme into hydrogen peroxide (H2O2), the predominant form of cytosolic ROS. ROS at high levels can be toxic, but below this threshold are important for physiological processes acting as a second messenger similar to Ca2+. Mitochondrial Ca2+ influx from the ER increases ATP and ROS production, while ATP and ROS can regulate Ca2+ homeostasis, leading to an intricate interplay between Ca2+, ROS, and ATP synthesis. The Unfolded Protein Response (UPR) proteins ATF6α and XBP1 contribute to protection from oxidative stress through upregulation of Sod1 and Catalase genes. Here, UPR-associated protein CREB3 is shown to play a role in balancing Ca2+, ROS, and ATP homeostasis. Creb3-deficient mouse embryonic fibroblast cells (MEF-/-) were susceptible to H2O2-induced oxidative stress while having a functioning antioxidant gene expression response compared to MEF+/+. MEF-/- cells also contained elevated basal cytosolic ROS levels, which was attributed to drastically increased basal mitochondrial respiration and spare respiratory capacity relative to MEF+/+. MEF-/- cells also showed an increase in endoplasmic reticulum Ca2+ release and mitochondrial Ca2+ levels hinting at a potential cause for MEF-/- cell mitochondrial dysfunction. These results suggest that CREB3 is essential for maintaining proper Ca2+, ATP, and ROS homeostasis in mammalian cells.
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Affiliation(s)
- Brandon S Smith
- University of Guelph, Department of Molecular and Cellular Biology, Canada
| | - Tristen Hewitt
- University of Guelph, Department of Molecular and Cellular Biology, Canada
| | - Marica Bakovic
- University of Guelph, Department of Human Health & Nutritional Sciences, Canada.
| | - Ray Lu
- University of Guelph, Department of Molecular and Cellular Biology, Canada.
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Proprotein convertases regulate trafficking and maturation of key proteins within the secretory pathway. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 133:1-54. [PMID: 36707198 DOI: 10.1016/bs.apcsb.2022.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Proprotein Convertases (PCs) are serine endoproteases that regulate the homeostasis of protein substrates in the cell. The PCs family counts 9 members-PC1/3, PC2, PC4, PACE4, PC5/6, PC7, Furin, SKI-1/S1P, and PCSK9. The first seven PCs are known as Basic Proprotein Convertases due to their propensity to cleave after polybasic clusters. SKI-1/S1P requires the additional presence of hydrophobic residues for processing, whereas PCSK9 is catalytically dead after autoactivation and exerts its functions using mechanisms alternative to direct cleavage. All PCs traffic through the canonical secretory pathway, reaching different compartments where the various substrates reside. Despite PCs members do not share the same subcellular localization, most of the cellular organelles count one or more Proprotein Convertases, including ER, Golgi stack, endosomes, secretory granules, and plasma membranes. The widespread expression of these enzymes at the systemic level speaks for their importance in the homeostasis of a large number of biological functions. Among others, PCs cleave precursors of hormones and growth factors and activate receptors and transcription factors. Notably, dysregulation of the enzymatic activity of Proprotein Convertases is associated to major human pathologies, such as cardiovascular diseases, cancer, diabetes, infections, inflammation, autoimmunity diseases, and Parkinson. In the current COVID-19 pandemic, Furin has further attracted the attention as a key player for conferring high pathogenicity to SARS-CoV-2. Here, we review the Proprotein Convertases family and their most important substrates along the secretory pathway. Knowledge about the complex functions of PCs is important to identify potential drug strategies targeting this class of enzymes.
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Hartal-Benishay LH, Saadi E, Toubiana S, Shaked L, Lalzar M, Abu Hatoum O, Tal S, Selig S, Barki-Harrington L. MBTPS1 regulates proliferation of colorectal cancer primarily through its action on sterol regulatory element-binding proteins. Front Oncol 2022; 12:1004014. [PMID: 36300096 PMCID: PMC9592115 DOI: 10.3389/fonc.2022.1004014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/05/2022] [Indexed: 11/21/2022] Open
Abstract
Among the main metabolic pathways implicated in cancer cell proliferation are those of cholesterol and fatty acid synthesis, both of which are tightly regulated by sterol regulatory element-binding proteins (SREBPs). SREBPs are activated through specific cleavage by membrane-bound transcription factor protease 1 (MBTPS1), a serine protease that cleaves additional substrates (ATF6, BDNF, CREBs and somatostatin), some of which are also implicated in cell proliferation. The goal of this study was to determine whether MBTPS1 may serve as a master regulator in proliferation of colorectal cancer (CRC). Tumors from CRC patients showed variable levels of MBTPS1 mRNA, which were in positive correlation with the levels of SREBPs and ATF6, and in reverse correlation with BDNF levels. Chemical inhibition of MBTPS1 activity in two CRC-derived cell lines resulted in a marked decrease in the levels of SREBPs, but not of its other substrates and a marked decrease in cell proliferation, which suggested that MBTPS1 activity is critical for proliferation of these cells. In accordance, CRISPR/Cas9 targeted knockout (KO) of the MBTPS1 gene resulted in the survival of only a single clone that presented a phenotype of severely attenuated proliferation and marked downregulation of several energy metabolism pathways. We further showed that survival of the MBTPS1 KO clone was dependent upon significant upregulation of the type-1 interferon pathway, the inhibition of which halted proliferation entirely. Finally, rescue of the MBTPS1 KO cells, resulted in partial restoration of MBTPS1 levels, which was in accordance with partial recovery in proliferation and in SREBP levels. These finding suggest that MBTPS1 plays a critical role in regulating colon cancer proliferation primarily through SREBP-associated lipid metabolism, and as such may serve as a possible therapeutic target in CRC.
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Affiliation(s)
- Liat H. Hartal-Benishay
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Esraa Saadi
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Shir Toubiana
- Department of Genetics and Developmental Biology, Rappaport Faculty of Medicine and Research Institute, Technion, Haifa, Israel
| | - Lior Shaked
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Maya Lalzar
- Bioinformatics Service Unit, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Ossama Abu Hatoum
- Department of Surgery, Ha’emek Medical Center, Afula, Israel
- Department of Medicine, Rappaport Faculty of Medicine and Research Institute, Technion, Haifa, Israel
| | - Sharon Tal
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Sara Selig
- Department of Genetics and Developmental Biology, Rappaport Faculty of Medicine and Research Institute, Technion, Haifa, Israel
- Laboratory of Molecular Medicine, Rambam Health Care Campus, Haifa, Israel
| | - Liza Barki-Harrington
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
- *Correspondence: Liza Barki-Harrington,
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9
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Rohli KE, Boyer CK, Blom SE, Stephens SB. Nutrient Regulation of Pancreatic Islet β-Cell Secretory Capacity and Insulin Production. Biomolecules 2022; 12:335. [PMID: 35204835 PMCID: PMC8869698 DOI: 10.3390/biom12020335] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 01/27/2023] Open
Abstract
Pancreatic islet β-cells exhibit tremendous plasticity for secretory adaptations that coordinate insulin production and release with nutritional demands. This essential feature of the β-cell can allow for compensatory changes that increase secretory output to overcome insulin resistance early in Type 2 diabetes (T2D). Nutrient-stimulated increases in proinsulin biosynthesis may initiate this β-cell adaptive compensation; however, the molecular regulators of secretory expansion that accommodate the increased biosynthetic burden of packaging and producing additional insulin granules, such as enhanced ER and Golgi functions, remain poorly defined. As these adaptive mechanisms fail and T2D progresses, the β-cell succumbs to metabolic defects resulting in alterations to glucose metabolism and a decline in nutrient-regulated secretory functions, including impaired proinsulin processing and a deficit in mature insulin-containing secretory granules. In this review, we will discuss how the adaptative plasticity of the pancreatic islet β-cell's secretory program allows insulin production to be carefully matched with nutrient availability and peripheral cues for insulin signaling. Furthermore, we will highlight potential defects in the secretory pathway that limit or delay insulin granule biosynthesis, which may contribute to the decline in β-cell function during the pathogenesis of T2D.
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Affiliation(s)
- Kristen E. Rohli
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, USA; (K.E.R.); (C.K.B.); (S.E.B.)
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Cierra K. Boyer
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, USA; (K.E.R.); (C.K.B.); (S.E.B.)
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA 52242, USA
| | - Sandra E. Blom
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, USA; (K.E.R.); (C.K.B.); (S.E.B.)
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Samuel B. Stephens
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, USA; (K.E.R.); (C.K.B.); (S.E.B.)
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
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10
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Danyukova T, Schöneck K, Pohl S. Site-1 and site-2 proteases: A team of two in regulated proteolysis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1869:119138. [PMID: 34619164 DOI: 10.1016/j.bbamcr.2021.119138] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/12/2021] [Accepted: 09/06/2021] [Indexed: 12/19/2022]
Abstract
The site-1 and site-2 proteases (S1P and S2P) were identified over 20 years ago, and the functions of both have been addressed in numerous studies ever since. Whereas S1P processes a set of substrates independently of S2P, the latter acts in concert with S1P in a mechanism, called regulated intramembrane proteolysis, that controls lipid metabolism and response to unfolded proteins. This review summarizes the molecular roles that S1P and S2P jointly play in these processes. As S1P and S2P deficiencies mainly affect connective tissues, yet with varying phenotypes, we discuss the segregated functions of S1P and S2P in terms of cell homeostasis and maintenance of the connective tissues. In addition, we provide experimental data that point at S2P, but not S1P, as a critical regulator of cell adaptation to proteotoxicity or lipid imbalance. Therefore, we hypothesize that S2P can also function independently of S1P activity.
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Affiliation(s)
- Tatyana Danyukova
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
| | - Kenneth Schöneck
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
| | - Sandra Pohl
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
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11
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Luman/CREB3 knock-down inhibit hCG induced MLTC-1 apoptosis. Theriogenology 2020; 161:140-150. [PMID: 33310232 DOI: 10.1016/j.theriogenology.2020.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 10/20/2020] [Accepted: 11/17/2020] [Indexed: 12/25/2022]
Abstract
Luman has been reported to be involved in the formation of COP II-mediated transport vesicles that affect protein transportation and secretion. Western blotting, immunohistochemistry, immunofluorescence, and RT-qPCR indicated that Luman is widely expressed in the male mouse reproductive system. In sperm, Luman was mainly located in the sperm tail, and the expression level increased with sperm maturity. In the testis, Luman was located in Leydig cells. In MLTC-1, a high-concentration hCG treatment significantly increased GRP78, ATF6, p-IRE1, and p-EIF2S1 expression but had no effect on Luman expression. To investigate the role of Luman in hCG-induced ER stress (ERS), experiments were conducted to examine the consequences of short hairpin RNA (shRNA)-mediated Luman knockdown in MLTC-1 cells. Luman knockdown decreased the percentage of S phase cells and up-regulated Cyclin A1, Cyclin B1, and Cyclin D2 expression. ELISA and WB results showed that with Luman knockdown, Cyp11a1, p-IRE1, and p-EIF2S1 expression and testosterone secretion were significantly increased, while GRP78 and CHOP expression were decreased. Flow cytometry results showed that Luman knockdown reduced MLTC-1 cell apoptosis. RT-qPCR and WB results showed that Luman knockdown significantly up-regulated BCL-2 expression and decreased Caspase-3 and BAX expression. These data suggest that Luman is widely expressed in the male mouse reproductive system. In MLTC-1 cells, Luman knockdown up-regulated p-IRE1, p-EIF2S1, and BCL-2 expression and decreased GRP78, CHOP, BAX, and Caspase-3 expression. We propose that Luman knockdown reduces cell apoptosis through the ERS pathway, thereby promoting cell survival and testosterone secretion. These findings provide new insights into the role of Luman in hCG-induced ERS.
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12
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Hasmatali JCD, De Guzman J, Zhai R, Yang L, McLean NA, Hutchinson C, Johnston JM, Misra V, Verge VMK. Axotomy Induces Phasic Alterations in Luman/CREB3 Expression and Nuclear Localization in Injured and Contralateral Uninjured Sensory Neurons: Correlation With Intrinsic Axon Growth Capacity. J Neuropathol Exp Neurol 2020; 78:348-364. [PMID: 30863858 DOI: 10.1093/jnen/nlz008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Luman/CREB3 is an important early retrograde axotomy signal regulating acute axon outgrowth in sensory neurons through the adaptive unfolded protein response. As the injury response is transcriptionally multiphasic, a spatiotemporal analysis of Luman/CREB3 localization in rat dorsal root ganglion (DRG) with unilateral L4-L6 spinal nerve injury was conducted to determine if Luman/CREB3 expression was similarly regulated. Biphasic alterations in Luman/CREB3 immunofluorescence and nuclear localization occurred in neurons ipsilateral to 1-hour, 1-day, 2-day, 4-day, and 1-week injury, with a largely parallel, but less avid response contralaterally. This biphasic response was not observed at the transcript level. To assess whether changes in neuronal Luman expression corresponded with an altered intrinsic capacity to grow an axon/neurite in vitro, injury-conditioned and contralateral uninjured DRG neurons underwent a 24-hour axon growth assay. Two-day injury-conditioned neurons exhibited maximal outgrowth capacity relative to naïve, declining at later injury-conditioned timepoints. Only neurons contralateral to 1-week injury exhibited significantly higher axon growth capacity than naïve. In conclusion, alterations in neuronal injury-associated Luman/CREB3 expression support that a multiphasic cell body response occurs and reveal a novel contralateral plasticity in axon growth capacity at 1-week post-injury. These adaptive responses have the potential to inform when repair or therapeutic intervention may be most effective.
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Affiliation(s)
- Jovan C D Hasmatali
- Department of Anatomy, Physiology and Pharmacology.,Cameco MS Neuroscience Research Center.,Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.,Department of Critical Care Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jolly De Guzman
- Department of Anatomy, Physiology and Pharmacology.,Cameco MS Neuroscience Research Center
| | - Ruiling Zhai
- Department of Anatomy, Physiology and Pharmacology.,Cameco MS Neuroscience Research Center
| | - Lisa Yang
- Cameco MS Neuroscience Research Center
| | - Nikki A McLean
- Department of Anatomy, Physiology and Pharmacology.,Cameco MS Neuroscience Research Center
| | - Catherine Hutchinson
- Department of Anatomy, Physiology and Pharmacology.,Cameco MS Neuroscience Research Center
| | - Jayne M Johnston
- Department of Anatomy, Physiology and Pharmacology.,Cameco MS Neuroscience Research Center
| | - Vikram Misra
- Department of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Valerie M K Verge
- Department of Anatomy, Physiology and Pharmacology.,Cameco MS Neuroscience Research Center
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13
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Schmitt BM, Ampofo E, Stumpf H, Montenarh M, Götz C. The stability of CREB3/Luman is regulated by protein kinase CK2 phosphorylation. Biochem Biophys Res Commun 2020; 523:639-644. [PMID: 31941600 DOI: 10.1016/j.bbrc.2019.12.118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 12/22/2019] [Indexed: 01/11/2023]
Abstract
CREB3 (Luman) is a family member of ER resident transcription factors, which are cleaved upon the induction of ER stress. Their N-terminal fragments shuttle into the nucleus where they regulate the transcription of target genes. Here, we found that human CREB3 is phosphorylated within its transcription activation domain on serine 46 by protein kinase CK2. Further analyses revealed that the phosphorylation of this site does neither affect the cleavage by S1P/S2P proteases, nor the nuclear localisation nor the transcriptional activity of CREB3. However, phosphorylation at serine 46 reduced the stability of CREB3.
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Affiliation(s)
- Beate Maria Schmitt
- Institute for Clinical and Experimental Surgery, Saarland University, Building 65, 66424, Homburg, Germany
| | - Emmanuel Ampofo
- Institute for Clinical and Experimental Surgery, Saarland University, Building 65, 66424, Homburg, Germany
| | - Heike Stumpf
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66424, Homburg, Germany
| | - Mathias Montenarh
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66424, Homburg, Germany
| | - Claudia Götz
- Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66424, Homburg, Germany.
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14
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Schweitzer GG, Gan C, Bucelli RC, Wegner D, Schmidt RE, Shinawi M, Finck BN, Brookheart RT. A mutation in Site-1 Protease is associated with a complex phenotype that includes episodic hyperCKemia and focal myoedema. Mol Genet Genomic Med 2019; 7:e00733. [PMID: 31070020 PMCID: PMC6625134 DOI: 10.1002/mgg3.733] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 01/25/2019] [Accepted: 04/04/2019] [Indexed: 01/04/2023] Open
Abstract
Background Site‐1 Protease (S1P) is a Golgi‐resident protein required for the activation of regulatory proteins that drive key cellular functions, including, the unfolded protein response (UPR) and lipid and cholesterol biosynthesis. While disruptions in S1P function have been widely characterized in animal models, to date, the implications of disrupted S1P function in human disease states are not completely known. Methods The patient and both parents underwent whole exome and mitochondrial DNA sequencing, and Sanger sequencing was used to confirm the mutation. Western blotting and immunofluorescence studies were performed on either proband‐derived fibroblasts or on an established cell line to assess protein expression and cellular localization of the mutated S1P protein. Quantitative real‐time PCR and luciferase reporter assays were used to examine activation of S1P target pathways in the context of the S1P mutation. Results We describe a female patient with a de novo heterozygous missense mutation in the transmembrane domain of S1P (p. Pro1003Ser). The patient presented to our neuromuscular clinic with episodic, activity‐induced, focal myoedema and myalgias with hyperCKemia. Her clinical phenotype was complex and included gastrointestinal hypomotility, ocular migraines, and polycystic ovary syndrome. Molecular analysis using proband‐derived fibroblasts and cell lines harboring the Pro1003Ser mutation demonstrated increased activation of UPR and lipid and cholesterol regulatory pathways and localization of S1P Pro1003Ser in the Golgi. Conclusion These findings suggest a critical function for S1P in several human organ systems and implicate an important role for S1P in various human disease states.
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Affiliation(s)
- George G Schweitzer
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Connie Gan
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Robert C Bucelli
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri
| | - Daniel Wegner
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri
| | - Robert E Schmidt
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri
| | - Marwan Shinawi
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri.,Division of Genetics and Genomic Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Brian N Finck
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, Missouri
| | - Rita T Brookheart
- John T. Milliken Department of Medicine, Division of Geriatrics and Nutritional Sciences, Washington University School of Medicine, St. Louis, Missouri
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15
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Wu Y, Xie Z, Chen J, Chen J, Ni W, Ma Y, Huang K, Wang G, Wang J, Ma J, Shen S, Fan S. Circular RNA circTADA2A promotes osteosarcoma progression and metastasis by sponging miR-203a-3p and regulating CREB3 expression. Mol Cancer 2019; 18:73. [PMID: 30940151 PMCID: PMC6444890 DOI: 10.1186/s12943-019-1007-1] [Citation(s) in RCA: 183] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/19/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND As a subclass of noncoding RNAs, circular RNAs (circRNAs) have been demonstrated to play a critical role in regulating gene expression in eukaryotes. Recent studies have revealed the pivotal functions of circRNAs in cancer progression. However, little is known about the role of circTADA2A, also named hsa_circ_0043278, in osteosarcoma (OS). METHODS CircTADA2A was selected from a previously reported circRNA microarray comparing OS cell lines and normal bone cells. QRT-PCR was used to detect the expression of circTADA2A in OS tissue and cell lines. Luciferase reporter, RNA immunoprecipitation (RIP), RNA pull-down and fluorescence in situ hybridization (FISH) assays were performed to confirm the binding of circTADA2A with miR-203a-3p. OS cells were stably transfected with lentiviruses, and Transwell migration, Matrigel invasion, colony formation, proliferation, apoptosis, Western blotting, and in vivo tumorigenesis and metastasis assays were employed to evaluate the roles of circTADA2A, miR-203a-3p and CREB3. RESULTS Our findings demonstrated that circTADA2A was highly expressed in both OS tissue and cell lines, and circTADA2A inhibition attenuated the migration, invasion and proliferation of OS cells in vitro as well as tumorigenesis and metastasis in vivo. A mechanistic study revealed that circTADA2A could readily sponge miR-203a-3p to upregulate the expression of CREB3, which was identified as a driver gene in OS. Furthermore, miR-203a-3p inhibition or CREB3 overexpression could reverse the circTADA2A silencing-induced impairment of malignant tumor behavior. CONCLUSIONS CircTADA2A functions as a tumor promoter in OS to increase malignant tumor behavior through the miR-203a-3p/CREB3 axis, which could be a novel target for OS therapy.
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Affiliation(s)
- Yizheng Wu
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Ziang Xie
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Junxin Chen
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Jiaxin Chen
- Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Sir Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310016, China
| | - Weiyu Ni
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Yan Ma
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Kangmao Huang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Gangliang Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Jiying Wang
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Jianjun Ma
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China.,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China
| | - Shuying Shen
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China. .,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China.
| | - Shunwu Fan
- Department of Orthopaedic Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, 3 East Qingchun Road, Hangzhou, 310016, Zhejiang Province, China. .,Key Laboratory of Musculoskeletal System Degeneration and Regeneration Translational Research of Zhejiang province, Hangzhou, 310016, Zhejiang Province, China.
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16
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Abstract
In summary, we show here that HCV infection is associated with an upregulation of ARF4, which promotes HCV replication. Upon HCV infection, CREB3 was redistributed to nucleus and activated ARF4 transcription. Our studies demonstrate a host factor ARF4 upregulated in HCV replication, which may provide new therapeutic targets for antiviral therapy.
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Affiliation(s)
- Na Zhang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100176, China
| | - Youyang Ke
- Department of Emergency, 171st Hospital of PLA, Jiujiang, 332000, China.
| | - Leiliang Zhang
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100176, China.
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17
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CREBH Regulates Systemic Glucose and Lipid Metabolism. Int J Mol Sci 2018; 19:ijms19051396. [PMID: 29738435 PMCID: PMC5983805 DOI: 10.3390/ijms19051396] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 04/30/2018] [Accepted: 05/06/2018] [Indexed: 12/23/2022] Open
Abstract
The cyclic adenosine monophosphate (cAMP)-responsive element-binding protein H (CREBH, encoded by CREB3L3) is a membrane-bound transcriptional factor that primarily localizes in the liver and small intestine. CREBH governs triglyceride metabolism in the liver, which mediates the changes in gene expression governing fatty acid oxidation, ketogenesis, and apolipoproteins related to lipoprotein lipase (LPL) activation. CREBH in the small intestine reduces cholesterol transporter gene Npc1l1 and suppresses cholesterol absorption from diet. A deficiency of CREBH in mice leads to severe hypertriglyceridemia, fatty liver, and atherosclerosis. CREBH, in synergy with peroxisome proliferator-activated receptor α (PPARα), has a crucial role in upregulating Fgf21 expression, which is implicated in metabolic homeostasis including glucose and lipid metabolism. CREBH binds to and functions as a co-activator for both PPARα and liver X receptor alpha (LXRα) in regulating gene expression of lipid metabolism. Therefore, CREBH has a crucial role in glucose and lipid metabolism in the liver and small intestine.
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18
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Hacker B, Schultheiß C, Döring M, Kurzik-Dumke U. Molecular partners of hNOT/ALG3, the human counterpart of the Drosophila NOT and yeast ALG3 gene, suggest its involvement in distinct cellular processes relevant to congenital disorders of glycosylation, cancer, neurodegeneration and a variety of further pathologies. Hum Mol Genet 2018; 27:1858-1878. [DOI: 10.1093/hmg/ddy087] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 03/06/2018] [Indexed: 01/04/2023] Open
Affiliation(s)
- Benedikt Hacker
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Christoph Schultheiß
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Michael Döring
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
| | - Ursula Kurzik-Dumke
- Laboratory for Comparative Tumour Biology, Institute of Medical Microbiology and Hygiene, University Medical Centre, Johannes Gutenberg University, 55131 Mainz, Germany
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19
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Site-1 protease and lysosomal homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:2162-2168. [PMID: 28693924 DOI: 10.1016/j.bbamcr.2017.06.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 11/22/2022]
Abstract
The Golgi-resident site-1 protease (S1P) is a key regulator of cholesterol homeostasis and ER stress responses by converting latent transcription factors sterol regulatory element binding proteins (SREPBs) and activating transcription factor 6 (ATF6), as well as viral glycoproteins to their active forms. S1P is also essential for lysosome biogenesis via proteolytic activation of the hexameric GlcNAc-1-phosphotransferase complex required for modification of newly synthesized lysosomal enzymes with the lysosomal targeting signal, mannose 6-phosphate. In the absence of S1P, the catalytically inactive α/β-subunit precursor of GlcNAc-1-phosphotransferase fails to be activated and results in missorting of newly synthesized lysosomal enzymes, and lysosomal accumulation of non-degraded material, which are biochemical features of defective GlcNAc-1-phosphotransferase subunits and the associated pediatric lysosomal diseases mucolipidosis type II and III. The early embryonic death of S1P-deficient mice and the importance of various S1P-regulated biological processes, including lysosomal homeostasis, cautioned for clinical inhibition of S1P. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John.
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20
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Barbosa S, Carreira S, O'Hare P. GSK-3-mediated phosphorylation couples ER-Golgi transport and nuclear stabilization of the CREB-H transcription factor to mediate apolipoprotein secretion. Mol Biol Cell 2017; 28:1565-1579. [PMID: 28381424 PMCID: PMC5449154 DOI: 10.1091/mbc.e17-01-0075] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/21/2017] [Accepted: 03/29/2017] [Indexed: 12/13/2022] Open
Abstract
CREB-H plays a key role in regulating secretion in metabolic pathways, particularly triglyceride homeostasis. Phosphorylation at a conserved serine motif, the P-motif, provides an integrated control mechanism of CREB-H function, coupling intercompartmental transport in the cytoplasm with stabilization of the active form in the nucleus. CREB-H, an ER-anchored transcription factor, plays a key role in regulating secretion in metabolic pathways, particularly triglyceride homeostasis. It controls the production both of secretory pathway components and cargoes, including apolipoproteins ApoA-IV and ApoC-II, contributing to VLDL/HDL distribution and lipolysis. The key mechanism controlling CREB-H activity involves its ER retention and forward transport to the Golgi, where it is cleaved by Golgi-resident proteases, releasing the N-terminal product, which traffics to the nucleus to effect transcriptional responses. Here we show that a serine-rich motif termed the P-motif, located in the N-terminus between serines 73 and 90, controls release of the precursor transmembrane form from the ER and its forward transport to the Golgi. This motif is subject to GSK-3 phosphorylation, promoting ER retention, while mutation of target serines and drug inhibition of GSK-3 activity coordinately induce both forward transport of the precursor and cleavage, resulting in nuclear import. We previously showed that for the nuclear product, the P-motif is subject to multiple phosphorylations, which regulate stability by targeting the protein to the SCFFbw1a E3 ubiquitin ligase. Thus phosphorylation at the P-motif provides integrated control of CREB-H function, coupling intercompartmental transport in the cytoplasm with stabilization of the active form in the nucleus.
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Affiliation(s)
- Sónia Barbosa
- Department of Medicine, Imperial College, London W2 1PG, United Kingdom
| | - Suzanne Carreira
- Department of Medicine, Imperial College, London W2 1PG, United Kingdom
| | - Peter O'Hare
- Department of Medicine, Imperial College, London W2 1PG, United Kingdom
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21
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Kang M, Kim J, An HT, Ko J. Human leucine zipper protein promotes hepatic steatosis via induction of apolipoprotein A-IV. FASEB J 2017; 31:2548-2561. [PMID: 28246167 DOI: 10.1096/fj.201601227r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/07/2017] [Indexed: 12/13/2022]
Abstract
The molecular mechanism of stress-induced hepatic steatosis is not well known. Human leucine zipper protein (LZIP) regulates the expression of genes involved in inflammation, cell migration, and stress response. The aim of this study was to determine the regulatory role of LZIP in stress-induced hepatic steatosis. We used a microarray analysis to identify LZIP-induced genes involved in hepatic lipid metabolism. LZIP increased the expression of apolipoprotein A-IV (APOA4) mRNA. In the presence of stress inducer, APOA4 promoter analysis was performed, and LZIP-induced lipid accumulation was monitored in mouse primary cells and human tissues. Under Golgi stress conditions, LZIP underwent proteolytic cleavage and was phosphorylated by AKT to protect against proteasome degradation. The stabilized N-terminal LZIP was translocated to the nucleus, where it directly bound to the APOA4 promoter, leading to APOA4 induction. LZIP-induced APOA4 expression resulted in increased absorption of surrounding free fatty acids. LZIP also promoted hepatic steatosis in mouse liver. Both LZIP and APOA4 were highly expressed in human steatosis samples. Our findings indicate that LZIP is a novel modulator of APOA4 expression and hepatic lipid metabolism. LZIP might be a therapeutic target for developing treatment strategies for hepatic steatosis and related metabolic diseases.-Kang, M., Kim, J., An, H.-T., Ko, J. Human leucine zipper protein promotes hepatic steatosis via induction of apolipoprotein A-IV.
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Affiliation(s)
| | | | | | - Jesang Ko
- Division of Life Sciences, Korea University, Seoul, South Korea
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22
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Luman contributes to brefeldin A-induced prion protein gene expression by interacting with the ERSE26 element. Sci Rep 2017; 7:42285. [PMID: 28205568 PMCID: PMC5304227 DOI: 10.1038/srep42285] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 01/06/2017] [Indexed: 01/17/2023] Open
Abstract
The cellular prion protein (PrP) is essential for transmissible prion diseases, but its exact physiological function remains unclear. Better understanding the regulation of the human prion protein gene (PRNP) expression can provide insight into this elusive function. Spliced XBP1 (sXBP1) was recently shown to mediate endoplasmic reticulum (ER) stress-induced PRNP expression. In this manuscript, we identify Luman, a ubiquitous, non-canonical unfolded protein response (UPR), as a novel regulator of ER stress-induced PRNP expression. Luman activity was transcriptionally and proteolytically activated by the ER stressing drug brefeldin A (BFA) in human neurons, astrocytes, and breast cancer MCF-7 cells. Over-expression of active cleaved Luman (ΔLuman) increased PrP levels, while siRNA-mediated Luman silencing decreased BFA-induced PRNP expression. Site-directed mutagenesis and chromatin immunoprecipitation demonstrated that ΔLuman regulates PRNP expression by interacting with the ER stress response element 26 (ERSE26). Co-over-expression and siRNA-mediated silencing experiments showed that sXBP1 and ΔLuman both up-regulate ER stress-induced PRNP expression. Attempts to understand the function of PRNP up-regulation by Luman excluded a role in atorvastatin-induced neuritogenesis, ER-associated degradation, or proteasomal inhibition-induced cell death. Overall, these results refine our understanding of ER stress-induced PRNP expression and function.
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Zhao F, Wang N, Yi Y, Lin P, Tang K, Wang A, Jin Y. Knockdown of CREB3/Luman by shRNA in Mouse Granulosa Cells Results in Decreased Estradiol and Progesterone Synthesis and Promotes Cell Proliferation. PLoS One 2016; 11:e0168246. [PMID: 27973579 PMCID: PMC5156397 DOI: 10.1371/journal.pone.0168246] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/28/2016] [Indexed: 11/30/2022] Open
Abstract
Luman (also known as LZIP or CREB3) is a transcription factor and a member of the cAMP responsive element-binding (CREB) family proteins. Although Luman has been detected in apoptotic granulosa cells and disorganized atretic bodies, the physiological function of Luman in follicular development has not been reported. Our objective is to determine the role of Luman in folliculogenesis by knocking down Luman expression in mouse GCs (granulosa cells) using shRNA. Luman expression was successfully knocked down in mouse GCs at the mRNA and protein level, as confirmed by real-time quantitative PCR, western blot and immunofluorescence staining, respectively. Knockdown of Luman significantly decreased the concentrations of estradiol (E2) and progesterone (P4) in cell culture medium. Furthermore, Luman knockdown promoted cell proliferation but had no effect on cell apoptosis. To elucidate the regulatory mechanism underlying the effects of Luman knockdown on steroid synthesis and cell cycle, we measured the mRNA and protein expression levels of several related genes. The expression of Star, Cyp19a1, and Cyp1b1, which encode steroidogenic enzymes, was down-regulated, while that of Cyp11a1 and Runx2, which also encode steroidogenic enzymes, was up-regulated. The expression of the cell cycle factors Cyclin A1, Cyclin B1, Cyclin D2, and Cyclin E was significantly up-regulated. Among apoptosis-related genes, only Bcl-2 was down-regulated, while Caspase 3, Bax and p53 were not significantly affected, suggesting that Luman knockdown may regulate cell cycle activity and hormone secretion at the transcriptional and translational level in mouse GCs. The expression of two important genes associated with folliculogenesis in mouse GCs, Has2 and Ptgs2, were also significantly altered by Luman knockdown. In conclusion, the findings of this study indicate that Luman regulates mouse GCs modulation of steroid synthesis, cell cycle activity and other regulators of folliculogenesis.
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Affiliation(s)
- Fan Zhao
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Nan Wang
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yanglei Yi
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Pengfei Lin
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Keqiong Tang
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Aihua Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yaping Jin
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling, Shaanxi, China
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
- * E-mail:
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Horiuchi K, Tohmonda T, Morioka H. The unfolded protein response in skeletal development and homeostasis. Cell Mol Life Sci 2016; 73:2851-69. [PMID: 27002737 PMCID: PMC11108572 DOI: 10.1007/s00018-016-2178-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/06/2016] [Accepted: 03/10/2016] [Indexed: 12/20/2022]
Abstract
Osteoblasts and chondrocytes produce a large number of extracellular matrix proteins to generate and maintain the skeletal system. To cope with their functions as secretory cells, these cells must acquire a considerable capacity for protein synthesis and also the machinery for the quality-control and transport of newly synthesized secreted proteins. The unfolded protein response (UPR) plays a crucial role during the differentiation of these cells to achieve this goal. Unexpectedly, however, studies in the past several years have revealed that the UPR has more extensive functions in skeletal development than was initially assumed, and the UPR critically orchestrates many facets of skeletal development and homeostasis. This review focuses on recent findings on the functions of the UPR in the differentiation of osteoblasts, chondrocytes, and osteoclasts. These findings may have a substantial impact on our understanding of bone metabolism and also on establishing treatments for congenital and acquired skeletal disorders.
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Affiliation(s)
- Keisuke Horiuchi
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
- Department of Anti-aging Orthopedic Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Takahide Tohmonda
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
- Department of Anti-aging Orthopedic Research, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Hideo Morioka
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
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Mirabelli C, Pelletier I, Téoulé F, Vidalain PO, Brisac C, Tangy F, Delpeyroux F, Blondel B. The CREB3-Herp signalling module limits the cytosolic calcium concentration increase and apoptosis induced by poliovirus. J Gen Virol 2016; 97:2194-2200. [PMID: 27405867 DOI: 10.1099/jgv.0.000544] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Poliovirus (PV)-induced apoptosis seems to play a major role in central nervous system (CNS) tissue injury, a crucial feature of the pathogenesis of poliomyelitis. We have previously shown that calcium (Ca2+) flux from the endoplasmic reticulum (ER) to the cytosol during PV infection is involved in apoptosis induction in human neuroblastoma cells. We show here that PV infection is associated with a transient upregulation of Herp (homocysteine-induced ER protein), a protein known to promote the degradation of ER-resident Ca2+ channels. Herp gene transcription is controlled by the transcription factor CREB3 (cAMP response element-binding protein 3). We found that the CREB3/Herp pathway limited the increase in cytosolic Ca2+ concentration and apoptosis early in PV infection. This may reduce the extent of PV-induced damage to the CNS during poliomyelitis.
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Affiliation(s)
- Carmen Mirabelli
- Institut Pasteur, Unité de Biologie des virus entériques, 25 rue du Dr Roux, 75015 Paris, France.,INSERM U994, Paris, France
| | - Isabelle Pelletier
- Institut Pasteur, Unité de Biologie des virus entériques, 25 rue du Dr Roux, 75015 Paris, France.,INSERM U994, Paris, France
| | - François Téoulé
- Institut Pasteur, Unité de Biologie des virus entériques, 25 rue du Dr Roux, 75015 Paris, France.,INSERM U994, Paris, France.,Université Versailles Saint-Quentin, Versailles, France
| | - Pierre-Olivier Vidalain
- Institut Pasteur, Unité de Génomique virale et vaccination, 25 rue du Dr Roux, 75015 Paris, France.,CNRS UMR 3569, Paris, France
| | - Cynthia Brisac
- Institut Pasteur, Unité de Biologie des virus entériques, 25 rue du Dr Roux, 75015 Paris, France.,Université Versailles Saint-Quentin, Versailles, France.,INSERM U994, Paris, France
| | - Frédéric Tangy
- Institut Pasteur, Unité de Génomique virale et vaccination, 25 rue du Dr Roux, 75015 Paris, France.,CNRS UMR 3569, Paris, France
| | - Francis Delpeyroux
- Institut Pasteur, Unité de Biologie des virus entériques, 25 rue du Dr Roux, 75015 Paris, France.,INSERM U994, Paris, France
| | - Bruno Blondel
- Institut Pasteur, Unité de Biologie des virus entériques, 25 rue du Dr Roux, 75015 Paris, France.,INSERM U994, Paris, France
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26
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The Unfolded Protein Response and Cholesterol Biosynthesis Link Luman/CREB3 to Regenerative Axon Growth in Sensory Neurons. J Neurosci 2016; 35:14557-70. [PMID: 26511246 DOI: 10.1523/jneurosci.0012-15.2015] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We recently revealed that the axon endoplasmic reticulum resident transcription factor Luman/CREB3 (herein called Luman) serves as a unique retrograde injury signal in regulation of the intrinsic elongating form of sensory axon regeneration. Here, evidence supports that Luman contributes to axonal regeneration through regulation of the unfolded protein response (UPR) and cholesterol biosynthesis in adult rat sensory neurons. One day sciatic nerve crush injury triggered a robust increase in UPR-associated mRNA and protein expression in both neuronal cell bodies and the injured axons. Knockdown of Luman expression in 1 d injury-conditioned neurons by siRNA attenuated axonal outgrowth to 48% of control injured neurons and was concomitant with reduced UPR- and cholesterol biosynthesis-associated gene expression. UPR PCR-array analysis coupled with qRT-PCR identified and confirmed that four transcripts involved in cholesterol regulation were downregulated >2-fold by the Luman siRNA treatment of the injury-conditioned neurons. Further, the Luman siRNA-attenuated outgrowth could be significantly rescued by either cholesterol supplementation or 2 ng/ml of the UPR inducer tunicamycin, an amount determined to elevate the depressed UPR gene expression to a level equivalent of that observed with crush injury. Using these approaches, outgrowth increased significantly to 74% or 69% that of injury-conditioned controls, respectively. The identification of Luman as a regulator of the injury-induced UPR and cholesterol at levels that benefit the intrinsic ability of axotomized adult rat sensory neurons to undergo axonal regeneration reveals new therapeutic targets to bolster nerve repair.
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Kanemoto S, Kobayashi Y, Yamashita T, Miyamoto T, Cui M, Asada R, Cui X, Hino K, Kaneko M, Takai T, Matsuhisa K, Takahashi N, Imaizumi K. Luman is involved in osteoclastogenesis through the regulation of DC-STAMP expression, stability and localization. J Cell Sci 2015; 128:4353-65. [PMID: 26503158 PMCID: PMC4712816 DOI: 10.1242/jcs.176057] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/19/2015] [Indexed: 01/12/2023] Open
Abstract
Luman (also known as CREB3) is a type-II transmembrane transcription factor belonging to the OASIS family that localizes to the endoplasmic reticulum (ER) membrane under normal conditions. In response to ER stress, OASIS-family members are subjected to regulated intramembrane proteolysis (RIP), following which the cleaved N-terminal fragments translocate to the nucleus. In this study, we show that treatment of bone marrow macrophages (BMMs) with cytokines – macrophage colony-stimulating factor (M-CSF) and RANKL (also known as TNFSF11) – causes a time-dependent increase in Luman expression, and that Luman undergoes RIP and becomes activated during osteoclast differentiation. Small hairpin (sh)RNA-mediated knockdown of Luman in BMMs prevented the formation of multinucleated osteoclasts, concomitant with the suppression of DC-STAMP, a protein that is essential for cell–cell fusion in osteoclastogenesis. The N-terminus of Luman facilitates promoter activity of DC-STAMP, resulting in upregulation of DC-STAMP expression. Furthermore, Luman interacts with DC-STAMP, and controls its stability and localization. These results suggest that Luman regulates the multinucleation of osteoclasts by promoting cell fusion of mononuclear osteoclasts through DC-STAMP induction and intracellular distribution during osteoclastogenesis. Highlighted Article: Luman, an ER-resident transcription factor, regulates the multinucleation of osteoclasts by promoting cell fusion of mononuclear osteoclasts through DC-STAMP induction and transportation during osteoclastogenesis.
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Affiliation(s)
- Soshi Kanemoto
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Yasuhiro Kobayashi
- Institute for Oral Science, Matsumoto Dental University, 1780 Gobara, Hiro-oka, Shiojiri, Nagano 399-0781, Japan
| | - Teruhito Yamashita
- Institute for Oral Science, Matsumoto Dental University, 1780 Gobara, Hiro-oka, Shiojiri, Nagano 399-0781, Japan
| | - Takeshi Miyamoto
- Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Min Cui
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Rie Asada
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Xiang Cui
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Kenta Hino
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Masayuki Kaneko
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Tomoko Takai
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Koji Matsuhisa
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
| | - Naoyuki Takahashi
- Institute for Oral Science, Matsumoto Dental University, 1780 Gobara, Hiro-oka, Shiojiri, Nagano 399-0781, Japan
| | - Kazunori Imaizumi
- Department of Biochemistry, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan
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28
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DeFrancesco-Lisowitz A, Lindborg JA, Niemi JP, Zigmond RE. The neuroimmunology of degeneration and regeneration in the peripheral nervous system. Neuroscience 2015; 302:174-203. [PMID: 25242643 PMCID: PMC4366367 DOI: 10.1016/j.neuroscience.2014.09.027] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 09/08/2014] [Accepted: 09/10/2014] [Indexed: 12/25/2022]
Abstract
Peripheral nerves regenerate following injury due to the effective activation of the intrinsic growth capacity of the neurons and the formation of a permissive pathway for outgrowth due to Wallerian degeneration (WD). WD and subsequent regeneration are significantly influenced by various immune cells and the cytokines they secrete. Although macrophages have long been known to play a vital role in the degenerative process, recent work has pointed to their importance in influencing the regenerative capacity of peripheral neurons. In this review, we focus on the various immune cells, cytokines, and chemokines that make regeneration possible in the peripheral nervous system, with specific attention placed on the role macrophages play in this process.
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Affiliation(s)
| | - J A Lindborg
- Department of Neurosciences, Case Western Reserve University, Cleveland OH 44106-4975
| | - J P Niemi
- Department of Neurosciences, Case Western Reserve University, Cleveland OH 44106-4975
| | - R E Zigmond
- Department of Neurosciences, Case Western Reserve University, Cleveland OH 44106-4975
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29
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Ji C. Advances and New Concepts in Alcohol-Induced Organelle Stress, Unfolded Protein Responses and Organ Damage. Biomolecules 2015; 5:1099-121. [PMID: 26047032 PMCID: PMC4496712 DOI: 10.3390/biom5021099] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 05/23/2015] [Accepted: 05/26/2015] [Indexed: 12/20/2022] Open
Abstract
Alcohol is a simple and consumable biomolecule yet its excessive consumption disturbs numerous biological pathways damaging nearly all organs of the human body. One of the essential biological processes affected by the harmful effects of alcohol is proteostasis, which regulates the balance between biogenesis and turnover of proteins within and outside the cell. A significant amount of published evidence indicates that alcohol and its metabolites directly or indirectly interfere with protein homeostasis in the endoplasmic reticulum (ER) causing an accumulation of unfolded or misfolded proteins, which triggers the unfolded protein response (UPR) leading to either restoration of homeostasis or cell death, inflammation and other pathologies under severe and chronic alcohol conditions. The UPR senses the abnormal protein accumulation and activates transcription factors that regulate nuclear transcription of genes related to ER function. Similarly, this kind of protein stress response can occur in other cellular organelles, which is an evolving field of interest. Here, I review recent advances in the alcohol-induced ER stress response as well as discuss new concepts on alcohol-induced mitochondrial, Golgi and lysosomal stress responses and injuries.
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Affiliation(s)
- Cheng Ji
- GI/Liver Division, Research Center for Liver Disease, Department of Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA.
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30
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HBx induces the proliferation of hepatocellular carcinoma cells via AP1 over-expressed as a result of ER stress. Biochem J 2015; 466:115-21. [PMID: 25428452 DOI: 10.1042/bj20140819] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and chronic hepatitis B virus (HBV) infection is the most common risk factor for HCC. The HBV proteins can induce oncogenic or synergy effects with a hyperproliferative response on transformation into HCC. CREBH (cAMP-responsive, element-binding protein H), activated by stress in the endoplasmic reticulum (ER), is an ER-resident transmembrane bZIP (basic leucine zipper) transcription factor that is specifically expressed in the liver. In the present study, we address the role played by CREBH activated by ER stress in HBV-induced hepatic cell proliferation. We confirmed CREBH activation by ER stress and showed that it occurred as a result of/via hepatitis B virus X (HBx)-induced ER stress. CREBH activated by HBx increased the expression of AP-1 target genes through c-Jun induction. Under pathological conditions such as liver damage or liver regeneration, activated CREBH may have an important role to play in hepatic inflammation and cell proliferation, as an insulin receptor with dual functions under these conditions. We showed that CREBH activated by HBx interacted with HBx protein, leading to a synergistic effect on the expression of AP-1 target genes and the proliferation of HCC cells and mouse primary hepatocytes. In conclusion, in HBV-infected hepatic cells or patients with chronic HBV, CREBH may induce proliferation of hepatic cells in co-operation with HBx, resulting in HCC.
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31
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Cameron TL, Gresshoff IL, Bell KM, Piróg KA, Sampurno L, Hartley CL, Sanford EM, Wilson R, Ermann J, Boot-Handford RP, Glimcher LH, Briggs MD, Bateman JF. Cartilage-specific ablation of XBP1 signaling in mouse results in a chondrodysplasia characterized by reduced chondrocyte proliferation and delayed cartilage maturation and mineralization. Osteoarthritis Cartilage 2015; 23:661-70. [PMID: 25600960 DOI: 10.1016/j.joca.2015.01.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 12/07/2014] [Accepted: 01/04/2015] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the in vivo role of the IRE1/XBP1 unfolded protein response (UPR) signaling pathway in cartilage. DESIGN Xbp1(flox/flox).Col2a1-Cre mice (Xbp1(CartΔEx2)), in which XBP1 activity is ablated specifically from cartilage, were analyzed histomorphometrically by Alizarin red/Alcian blue skeletal preparations and X-rays to examine overall bone growth, histological stains to measure growth plate zone length, chondrocyte organization, and mineralization, and immunofluorescence for collagen II, collagen X, and IHH. Bromodeoxyuridine (BrdU) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analyses were used to measure chondrocyte proliferation and cell death, respectively. Chondrocyte cultures and microdissected growth plate zones were analyzed for expression profiling of chondrocyte proliferation or endoplasmic reticulum (ER) stress markers by Quantitative PCR (qPCR), and of Xbp1 mRNA splicing by RT-PCR to monitor IRE1 activation. RESULTS Xbp1(CartΔEx2) displayed a chondrodysplasia involving dysregulated chondrocyte proliferation, growth plate hypertrophic zone shortening, and IRE1 hyperactivation in chondrocytes. Deposition of collagens II and X in the Xbp1(CartΔEx2) growth plate cartilage indicated that XBP1 is not required for matrix protein deposition or chondrocyte hypertrophy. Analyses of mid-gestation long bones revealed delayed ossification in Xbp1(CartΔEx2) embryos. The rate of chondrocyte cell death was not significantly altered, and only minimal alterations in the expression of key markers of chondrocyte proliferation were observed in the Xbp1(CartΔEx2) growth plate. IRE1 hyperactivation occurred in Xbp1(CartΔEx2) chondrocytes but was not sufficient to induce regulated IRE1-dependent decay (RIDD) or a classical UPR. CONCLUSION Our work suggests roles for XBP1 in regulating chondrocyte proliferation and the timing of mineralization during endochondral ossification, findings which have implications for both skeletal development and disease.
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Affiliation(s)
- T L Cameron
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - I L Gresshoff
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - K M Bell
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - K A Piróg
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Newcastle upon Tyne, UK.
| | - L Sampurno
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - C L Hartley
- Central Manchester University Hospitals NHS Foundation Trust, St Mary's Hospital, Manchester, UK.
| | - E M Sanford
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - R Wilson
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia.
| | - J Ermann
- Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
| | - R P Boot-Handford
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK.
| | - L H Glimcher
- Weill Cornell Medical College, Cornell University, New York, NY, USA.
| | - M D Briggs
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Newcastle upon Tyne, UK.
| | - J F Bateman
- Murdoch Childrens Research Institute, Parkville, Victoria, Australia; Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.
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Sasaki K, Yoshida H. Organelle autoregulation-stress responses in the ER, Golgi, mitochondria and lysosome. J Biochem 2015; 157:185-95. [PMID: 25657091 DOI: 10.1093/jb/mvv010] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Organelle autoregulation is a homeostatic mechanism to regulate the capacity of each organelle according to cellular demands. The endoplasmic reticulum (ER) stress response increases the expression of ER chaperones and ER-associated degradation factors when the capacity of the ER becomes insufficient, e.g. during cellular differentiation or viral propagation, and which can be restored through increased synthesis of secretory or membrane proteins. In the Golgi stress response, insufficient organelle capacity is responded to by augmentation of glycosylation enzyme expression and vesicular transport components. The mitochondrial stress response upregulates mitochondrial chaperone and protease expression in the mitochondrial matrix and intermembrane space when unfolded proteins accumulate in the mitochondria. The lysosome stress response is activated during autophagy to enhance the function of the lysosome by transcriptional induction of lysosome genes including cathepsins. However, many of the molecular mechanisms of organelle autoregulation remain unclear. Here, we review recent discoveries in organelle autoregulation and their molecular mechanisms.
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Affiliation(s)
- Kanae Sasaki
- Department of Molecular Biochemistry, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Hiderou Yoshida
- Department of Molecular Biochemistry, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
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33
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Site-1 protease cleavage site is important for the ER stress-induced activation of membrane-associated transcription factor bZIP28 in Arabidopsis. SCIENCE CHINA-LIFE SCIENCES 2015; 58:270-5. [DOI: 10.1007/s11427-015-4807-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 12/26/2014] [Indexed: 01/17/2023]
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Sensing nerve injury at the axonal ER: activated Luman/CREB3 serves as a novel axonally synthesized retrograde regeneration signal. Proc Natl Acad Sci U S A 2014; 111:16142-7. [PMID: 25349404 DOI: 10.1073/pnas.1407462111] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Luman/cAMP response element binding protein 3 is an endoplasmic reticulum (ER) transmembrane basic leucine zipper transcription factor whose mRNA and protein localize to adult sensory axons, the latter with axonal ER components along the axon length. Here we show that axon-derived Luman plays an important role in relaying information about axonal injury to the neuronal cell body. Axotomy induces axonal Luman synthesis and also release from the axonal ER of Luman's transcriptionally active amino terminus, which is transported to the cell body in an importin-mediated manner. Visualization of the activation and retrograde translocation of Luman into the nucleus in real time both in vivo and in vitro was accomplished using a specially created N- and C-terminal-tagged Luman adenoviral vector. Small interfering RNA used to reduce Luman expression either neuronally or just axonally significantly impaired the ability of 24-h injury-conditioned sensory neurons to extend the regeneration-associated elongating form of axon growth but had no impact on axon outgrowth in naïve neurons. Collectively, these findings link injury-associated axonal ER responses proximal to the site of injury to the intrinsic regenerative growth capacity of adult sensory neurons.
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Zhang C, Dou CE, Xu J, Dong S. DC-STAMP, the key fusion-mediating molecule in osteoclastogenesis. J Cell Physiol 2014; 229:1330-5. [PMID: 24420845 DOI: 10.1002/jcp.24553] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Accepted: 01/08/2014] [Indexed: 12/12/2022]
Abstract
As a member of the mononuclear phagocyte system, osteoclasts (OC) absorb the bone matrix and participate in bone modeling by keeping a balance with osteoblasts (OB) and stromal cells. Mature OC derive from the fusion of mononuclear osteoclasts (mOC) and the fusion is considered as the indispensable process for the osteoclastogenesis and absorbing activity of OC. DC-STAMP (dendritic cell-specific transmembrane protein) has been validated playing a key role in the fusion of mOC. DC-STAMP is mainly expressed in OC, macrophages and dendritic cells (DC). While DC-STAMP was discovered in DC, more attentions have been paid to DC-STAMP in OC in this decade. This review will mainly focus on the function of DC-STAMP in OC. Studies on DC-STAMP in DC may also provide new sight for the study of DC-STAMP in OC. Since the function of DC-STAMP is still poorly understood and few studies have been implemented for illustration, many issues are still unknown and need to be revealed. We will also discuss these questions in this review.
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Affiliation(s)
- Chengcheng Zhang
- Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University, Chongqing, China
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36
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Ying Z, Zhang R, Verge VMK, Misra V. Cloning and characterization of rat Luman/CREB3, a transcription factor highly expressed in nervous system tissue. J Mol Neurosci 2014; 55:347-54. [PMID: 24894591 DOI: 10.1007/s12031-014-0330-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 05/12/2014] [Indexed: 11/24/2022]
Abstract
Human Luman/CREB3 is a basic leucine zipper transcription factor involved in regulation of the unfolded protein response, dendritic cell maturation, and cell migration. But despite reported expression in primary sensory neurons, little is known about its role in the nervous system. To begin investigations into its role in the adult rat nervous system, the rat Luman/CREB3 coding sequence was isolated so its expression within the nervous system could be determined. The rat Luman/CREB3 clone contains a full-length open reading frame encoding 387 amino acids. The recombinant protein generated from this clone activated transcription in a manner equivalent to human Luman/CREB3 from a CAT reporter plasmid construct containing the unfolded protein response element. Quantitative RT-PCR revealed that rat Luman/CREB3 transcripts in a variety of rat tissues with the highest levels in nervous system tissue. In situ hybridization performed on tissue sections confirmed the findings and demonstrated that the Luman/CREB3 mRNA hybridization signal localizes to neurons and satellite glial cells in dorsal root ganglia, the cytoplasm of hepatocytes in liver, and the hippocampal pyramidal cell layers of CA1 and CA3 and the granular cell layer of the dentate gyrus. Collectively, these findings support a role for Luman/CREB3 in the regulation of nervous system function.
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Affiliation(s)
- Zhengxin Ying
- Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E5, Canada
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Arensdorf AM, Diedrichs D, Rutkowski DT. Regulation of the transcriptome by ER stress: non-canonical mechanisms and physiological consequences. Front Genet 2013; 4:256. [PMID: 24348511 PMCID: PMC3844873 DOI: 10.3389/fgene.2013.00256] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 11/08/2013] [Indexed: 12/29/2022] Open
Abstract
The mammalian unfolded protein response (UPR) is propagated by three ER-resident transmembrane proteins, each of which initiates a signaling cascade that ultimately culminates in production of a transcriptional activator. The UPR was originally characterized as a pathway for upregulating ER chaperones, and a comprehensive body of subsequent work has shown that protein synthesis, folding, oxidation, trafficking, and degradation are all transcriptionally enhanced by the UPR. However, the global reach of the UPR extends to genes involved in diverse physiological processes having seemingly little to do with ER protein folding, and this includes a substantial number of mRNAs that are suppressed by stress rather than stimulated. Through multiple non-canonical mechanisms emanating from each of the UPR pathways, the cell dynamically regulates transcription and mRNA degradation. Here we highlight these mechanisms and their increasingly appreciated impact on physiological processes.
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Affiliation(s)
- Angela M Arensdorf
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine Iowa City, IA, USA
| | - Danilo Diedrichs
- Department of Mathematics and Computer Science, Wheaton College Wheaton, IL, USA
| | - D Thomas Rutkowski
- Department of Anatomy and Cell Biology, University of Iowa Carver College of Medicine Iowa City, IA, USA ; Department of Internal Medicine, University of Iowa Carver College of Medicine Iowa City, IA, USA
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Ye J. Roles of regulated intramembrane proteolysis in virus infection and antiviral immunity. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1828:2926-32. [PMID: 24099010 PMCID: PMC3837687 DOI: 10.1016/j.bbamem.2013.05.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 05/06/2013] [Accepted: 05/07/2013] [Indexed: 01/24/2023]
Abstract
Regulated intramembrane proteolysis (RIP) is a signaling mechanism through which transmembrane precursor proteins are cleaved to liberate their cytoplasmic and/or luminal/extracellular fragments from membranes so that these fragments are able to function at a new location. Recent studies have indicated that this proteolytic reaction plays an important role in host-virus interaction. On one hand, RIP transfers the signal from the endoplasmic reticulum (ER) to nucleus to activate antiviral genes in response to alteration of the ER caused by viral infection. On the other hand, RIP can be hijacked by virus to process transmembrane viral protein precursors and to destroy transmembrane antiviral proteins. Understanding this Yin and Yang side of RIP may lead to new strategies to combat viral infection. This article is part of a Special Issue entitled: Intramembrane Proteases.
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Affiliation(s)
- Jin Ye
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9046, USA.
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A CREB3-ARF4 signalling pathway mediates the response to Golgi stress and susceptibility to pathogens. Nat Cell Biol 2013; 15:1473-85. [PMID: 24185178 DOI: 10.1038/ncb2865] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 09/20/2013] [Indexed: 02/07/2023]
Abstract
Treatment of cells with brefeldin A (BFA) blocks secretory vesicle transport and causes a collapse of the Golgi apparatus. To gain more insight into the cellular mechanisms mediating BFA toxicity, we conducted a genome-wide haploid genetic screen that led to the identification of the small G protein ADP-ribosylation factor 4 (ARF4). ARF4 depletion preserves viability, Golgi integrity and cargo trafficking in the presence of BFA, and these effects depend on the guanine nucleotide exchange factor GBF1 and other ARF isoforms including ARF1 and ARF5. ARF4 knockdown cells show increased resistance to several human pathogens including Chlamydia trachomatis and Shigella flexneri. Furthermore, ARF4 expression is induced when cells are exposed to several Golgi-disturbing agents and requires the CREB3 (also known as Luman or LZIP) transcription factor, whose downregulation mimics ARF4 loss. Thus, we have uncovered a CREB3-ARF4 signalling cascade that may be part of a Golgi stress response set in motion by stimuli compromising Golgi capacity.
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Wakabayashi S, Yoshida H. The essential biology of the endoplasmic reticulum stress response for structural and computational biologists. Comput Struct Biotechnol J 2013; 6:e201303010. [PMID: 24688718 PMCID: PMC3962220 DOI: 10.5936/csbj.201303010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/09/2013] [Accepted: 08/10/2013] [Indexed: 11/29/2022] Open
Abstract
The endoplasmic reticulum (ER) stress response is a cytoprotective mechanism that maintains homeostasis of the ER by upregulating the capacity of the ER in accordance with cellular demands. If the ER stress response cannot function correctly, because of reasons such as aging, genetic mutation or environmental stress, unfolded proteins accumulate in the ER and cause ER stress-induced apoptosis, resulting in the onset of folding diseases, including Alzheimer's disease and diabetes mellitus. Although the mechanism of the ER stress response has been analyzed extensively by biochemists, cell biologists and molecular biologists, many aspects remain to be elucidated. For example, it is unclear how sensor molecules detect ER stress, or how cells choose the two opposite cell fates (survival or apoptosis) during the ER stress response. To resolve these critical issues, structural and computational approaches will be indispensable, although the mechanism of the ER stress response is complicated and difficult to understand holistically at a glance. Here, we provide a concise introduction to the mammalian ER stress response for structural and computational biologists.
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Affiliation(s)
- Sadao Wakabayashi
- Department of Molecular Biochemistry, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
| | - Hiderou Yoshida
- Department of Molecular Biochemistry, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan
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41
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Pasquato A, Burri DJ, Kunz S. Current drug discovery strategies against arenavirus infections. Expert Rev Anti Infect Ther 2013; 10:1297-309. [PMID: 23241187 DOI: 10.1586/eri.12.117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Arenaviruses are a large group of emerging viruses including several causative agents of severe hemorrhagic fevers with high mortality in man. Considering the number of people affected and the currently limited therapeutic options, novel efficacious therapeutics against arenaviruses are urgently needed. Over the past decade, significant advances in knowledge about the basic virology of arenaviruses have been accompanied by the development of novel therapeutics targeting different steps of the arenaviral life cycle. High-throughput, small-molecule screens identified potent and broadly active inhibitors of arenavirus entry that were instrumental for the dissection of unique features of arenavirus fusion. Novel inhibitors of arenavirus replication have been successfully tested in animal models and hold promise for application in humans. Late in the arenavirus life cycle, the proteolytic processing of the arenavirus envelope glycoprotein precursor and cellular factors critically involved virion assembly and budding provide further promising 'druggable' targets for novel therapeutics to combat human arenavirus infection.
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Affiliation(s)
- Antonella Pasquato
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
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Expression and localization of Luman RNA and protein during mouse implantation and decidualization. Theriogenology 2013; 80:138-44.e1-2. [PMID: 23683694 DOI: 10.1016/j.theriogenology.2013.02.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 02/25/2013] [Accepted: 02/25/2013] [Indexed: 11/23/2022]
Abstract
Luman (also known as LZIP and CREB3) is a basic leucine zipper transcription factor of the cAMP response element-binding protein/activating transcription factor gene family. Although Luman had specific roles near termination of Drosophila embryogenesis, the physiological functions of Luman in female mammals have apparently not been reported. Therefore, our objective was to investigate the spatiotemporal expression and regulation of Luman in the mouse uterus during the peri-implantation period. Luman protein was clearly present in the luminal and glandular epithelium on days 1 to 4 of pregnancy (day 1, presence of a vaginal plug) and was observed in decidual cells on day 6 of pregnancy. Expression had progressively increased to day 7 when the second decidual zone was formed. On day 8, apoptosis of the decidualized cells was present, and Luman protein expression was decreased (in close association with decidualization). Luman protein was also present in decidual cells of the artificially decidualized uterus. The expression of Luman was regulated by an activated embryo (according to its expression patterns during pseudopregnancy and delayed implantation). Furthermore, expression of Luman was induced by estrogen in ovariectomized mice. We have concluded that Luman might have important roles in embryo implantation and decidualization.
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DenBoer LM, Iyer A, McCluggage ARR, Li Y, Martyn AC, Lu R. JAB1/CSN5 inhibits the activity of Luman/CREB3 by promoting its degradation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:921-9. [PMID: 23583719 DOI: 10.1016/j.bbagrm.2013.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 04/01/2013] [Accepted: 04/03/2013] [Indexed: 12/26/2022]
Abstract
Luman/CREB3 (also called LZIP) is an endoplasmic reticulum (ER)-bound transcription factor that has been implicated in the ER stress response. In this study, we used the region of Luman containing the basic DNA-binding domain as bait in a yeast two-hybrid screen and identified the Jun activation domain-binding protein 1 (JAB1) or the COP9 signalosome complex unit 5 (CSN5) as an interacting protein. We confirmed their direct binding by glutathione S-transferase pull-down assays, and verified the existence of such interaction in the cellular environment by mammalian two-hybrid and co-immunoprecipitation assays. Deletion mapping studies revealed that the MPN domain in JAB1 was essential and sufficient for the binding. JAB1 also colocalized with Luman in transfected cells. More interestingly, the nuclear form of Luman was shown to promote the translocation of JAB1 into the nucleus. We found that overexpression of JAB1 shortened the half-life of Luman by 67%, and repressed its transactivation function on GAL4 and unfolded protein response element (UPRE)-containing promoters. We therefore propose that JAB1 is a novel binding partner of Luman, which negatively regulates the activity of Luman by promoting its degradation.
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Affiliation(s)
- Lisa M DenBoer
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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44
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Rawson RB. The site-2 protease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2801-7. [PMID: 23571157 DOI: 10.1016/j.bbamem.2013.03.031] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 03/06/2013] [Accepted: 03/25/2013] [Indexed: 12/19/2022]
Abstract
The site-2 protease (S2P) is an unusually-hydrophobic integral membrane protease. It cleaves its substrates, which are membrane-bound transcription factors, within membrane-spanning helices. Although structural information for S2P from animals is lacking, the available data suggest that cleavage may occur at or within the lipid bilayer. In mammalian cells, S2P is essential owing to its activation of the sterol regulatory element binding proteins (SREBPs); in the absence of exogenous lipid, cells lacking S2P cannot survive. S2P is also important in the endoplasmic reticulum (ER) stress response, activating several different membrane-bound transcription factors. Human patients harboring reduction-of-function mutations in S2P exhibit an array of pathologies ranging from skin defects to neurological abnormalities. Surprisingly, Drosophila melanogaster lacking S2P are viable and fertile. This article is part of a Special Issue entitled: Intramembrane Proteases.
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45
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The role of the unfolded protein response in diabetes mellitus. Semin Immunopathol 2013; 35:333-50. [PMID: 23529219 DOI: 10.1007/s00281-013-0369-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 03/13/2013] [Indexed: 12/13/2022]
Abstract
The endoplasmic reticulum (ER) plays a key role in the synthesis and modification of secretory and membrane proteins in all eukaryotic cells. Under normal conditions, these proteins are correctly folded and assembled in the ER. However, when cells are exposed to environmental factors such as overproduction of ER proteins, viral infections, or glucose deprivation, the secretory and membrane proteins can accumulate in unfolded or misfolded forms in the lumen of the ER, and consequently, cause stress in the ER. To maintain cellular homeostasis, cells induce several responses to ER stress. In mammalian cells, ER stress responses are induced by a diversity of signal pathways. There are three ER-located transmembrane proteins that play important roles in mammalian ER stress responses: activating transcription factor 6, inositol-requiring protein 1, and protein kinase RNA-like endoplasmic reticulum kinase. ER stress is linked to various diseases, including diabetes. This review highlights the particular importance of ER stress-responsive molecules in insulin biosynthesis, glyconeogenesis, insulin resistance, glucose intolerance, and pancreatic β-cell apoptosis. An understanding of the pathogenic mechanism of diabetes from the aspect of ER stress is crucial in formulating therapeutic strategies.
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46
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Yang Y, Jin Y, Martyn AC, Lin P, Song Y, Chen F, Hu L, Cui C, Li X, Li Q, Lu R, Wang A. Expression pattern implicates a potential role for luman recruitment factor in the process of implantation in uteri and development of preimplantation embryos in mice. J Reprod Dev 2013; 59:245-51. [PMID: 23400243 PMCID: PMC3934142 DOI: 10.1262/jrd.2012-137] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Luman/CREB3 recruitment factor (LRF or CREBRF) was identified as a regulator of Luman
(or CREB3) that is involved in the unfolded protein response during endoplasmic reticulum
stress. Luman is implicated in a multitude of functions ranging from viral infection and
immunity to cancer. The biological function of LRF, however, is unknown. In this paper, we
report that uteri of pregnant mice and embryos displayed enhanced LRF expression at all
stages, and the expressed LRF was found to be localized specifically at implantation
sites. On the other hand, uteri of mice induced for delayed implantation or pseudopregnant
mice showed low levels of LRF expression, suggesting that LRF mediates uterine receptivity
during implantation. Further, expression of LRF was found to be modulated by steroid
hormones such as progesterone and estradiol. This study thereby identifies a potential
role for LRF in the process of implantation in uteri and development of preimplantation
embryos in mice.
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Affiliation(s)
- Yanzhou Yang
- Key Open Laboratory of Animal Biotechnology, Ministry of Agriculture, College of Veterinary Medicine, Northwest A&F University, Yangling Shaanxi 712100, PR China
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47
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Barbosa S, Fasanella G, Carreira S, Llarena M, Fox R, Barreca C, Andrew D, O'Hare P. An orchestrated program regulating secretory pathway genes and cargos by the transmembrane transcription factor CREB-H. Traffic 2013; 14:382-98. [PMID: 23279168 DOI: 10.1111/tra.12038] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 12/21/2012] [Accepted: 12/27/2012] [Indexed: 12/14/2022]
Abstract
CREB3 proteins comprise a set of ER-localized bZip transcription factors defined by the presence of a transmembrane domain. They are regulated by inter-compartmental transport, Golgi cleavage and nuclear transport where they promote appropriate transcriptional responses. Although CREB3 proteins play key roles in differentiation, inflammation and metabolism, a general framework relating their defining features to these diverse activities is lacking. We identify unique features of CREB3 organization including the ATB domain, which we show it is essential for transcriptional activity. This domain is absent in all other human bZip factors, but conserved in Drosophila CREBA, which controls secretory pathway genes (SPGs). Furthermore, each of the five human CREB3 factors was capable of activating SPGs in Drosophila, dependent upon the ATB domain. Expression of the CREB3 protein, CREB-H, in 293 cells, upregulated genes involved in secretory capacity, extracellular matrix formation and lipid metabolism and increased secretion of specific cargos. In liver cells, which normally express CREB-H, the active form specifically induced secretion of apolipoproteins, including ApoA-IV, ApoAI, consistent with data implicating CREB-H in metabolic homeostasis. Based on these data and other recent studies, we propose a general role for the CREB3 family in regulating secretory capacity, with particular relevance to specialized cargos.
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Affiliation(s)
- Sónia Barbosa
- Department of Medicine, Imperial College, London, W2 1PG, UK
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48
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Bodnarchuk TW, Napper S, Rapin N, Misra V. Mechanism for the induction of cell death in ONS-76 medulloblastoma cells by Zhangfei/CREB-ZF. J Neurooncol 2012; 109:485-501. [PMID: 22798206 DOI: 10.1007/s11060-012-0927-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 07/05/2012] [Indexed: 01/07/2023]
Abstract
Cells from medulloblastoma lines do not contain detectable amounts of the basic leucine-zipper protein Zhangfei. However, we have previously shown that expression of this protein in cells of the ONS-76 and UW228 medulloblastoma lines causes the cells to stop growing and develop processes that resemble neurites. Our objective was to determine the molecular mechanisms by which Zhangfei influences ONS-76 cells. We infected ONS-76 cells with adenovirus vectors expressing either Zhangfei or the control protein LacZ and then compared the following parameters in Zhangfei and LacZ-expressing cells: (a) markers of apoptosis, autophagy and macropinocytosis, (b) transcripts for genes involved in neurogenesis and apoptosis, (c) phosphorylation of peptide targets of selected cellular protein kinases, and (d) activation of transcription factors. Zhangfei-expressing cells appeared to succumb to apoptosis. Increased staining for autophagic vesicles and upregulated expression of autophagy response genes in these cells indicated that they were undergoing autophagy, possibly associated with apoptosis. Within our analysis, patterns of gene expression and phosphorylation-mediated signal transduction activity in Zhangfei-expressing cells indicated that the mitogen-activated protein kinase (MAPK) pathway was active. In addition, we found that the transcription factor Brn3a as well as factors implicated in differentiation were also active in Zhangfei-expressing cells. We tested the hypothesis that Zhangfei enhances the expression of Brn3a, a known inducer of TrkA, the high-affinity receptor for nerve growth factor (NGF). TrkA then engages NGF in an autocrine manner triggering the MAPK pathway and leading to differentiation of ONS-76 cells into neuron and glia-like cells-a process that eventually brings about cell death. We showed that: (a) Zhangfei could enhance transcription from the isolated Brn3a promoter, (b) ONS-76 cells produced NGF and (c) antibodies against NGF and inhibitors of TrkA and selected components of the MAPK pathway could partially restore the growth of Zhangfei-expressing ONS-76 cells.
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Affiliation(s)
- Timothy W Bodnarchuk
- Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
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49
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Burnett HF, Audas TE, Liang G, Lu RR. Herpes simplex virus-1 disarms the unfolded protein response in the early stages of infection. Cell Stress Chaperones 2012; 17:473-83. [PMID: 22270612 PMCID: PMC3368031 DOI: 10.1007/s12192-012-0324-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/03/2012] [Accepted: 01/04/2012] [Indexed: 01/12/2023] Open
Abstract
Accumulation of mis- and unfolded proteins during viral replication can cause stress in the endoplasmic reticulum (ER) and trigger the unfolded protein response (UPR). If unchecked, this process may induce cellular changes detrimental to viral replication. In the report, we investigated the impact of HSV-1 on the UPR during lytic replication. We found that HSV-1 effectively disarms the UPR in early stages of viral infection. Only ATF6 activation was detected during early infection, but with no upregulation of target chaperone proteins. Activity of the eIF2α/ATF4 signaling arm increased at the final stage of HSV-1 replication, which may indicate completion of virion assembly and egress, thus releasing suppression of the UPR. We also found that the promoter of viral ICP0 was responsive to ER stress, an apparent mimicry of cellular UPR genes. These results suggest that HSV-1 may use ICP0 as a sensor to modulate the cellular stress response.
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Affiliation(s)
- Heather F. Burnett
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON Canada N1G 2W1
| | - Timothy E. Audas
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON Canada N1G 2W1
| | - Genqing Liang
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON Canada N1G 2W1
| | - Rui Ray Lu
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON Canada N1G 2W1
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50
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Hypopigmentation and maternal-zygotic embryonic lethality caused by a hypomorphic mbtps1 mutation in mice. G3-GENES GENOMES GENETICS 2012; 2:499-504. [PMID: 22540041 PMCID: PMC3337478 DOI: 10.1534/g3.112.002196] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Accepted: 02/15/2012] [Indexed: 12/28/2022]
Abstract
The site 1 protease, encoded by Mbtps1, mediates the initial cleavage of site 2 protease substrates, including sterol regulatory element binding proteins and CREB/ATF transcription factors. We demonstrate that a hypomorphic mutation of Mbtps1 called woodrat (wrt) caused hypocholesterolemia, as well as progressive hypopigmentation of the coat, that appears to be mechanistically unrelated. Hypopigmentation was rescued by transgenic expression of wild-type Mbtps1, and reciprocal grafting studies showed that normal pigmentation depended upon both cell-intrinsic or paracrine factors, as well as factors that act systemically, both of which are lacking in wrt homozygotes. Mbtps1 exhibited a maternal-zygotic effect characterized by fully penetrant embryonic lethality of maternal-zygotic wrt mutant offspring and partial embryonic lethality (~40%) of zygotic wrt mutant offspring. Mbtps1 is one of two maternal-zygotic effect genes identified in mammals to date. It functions nonredundantly in pigmentation and embryogenesis.
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