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Wang H, Luo W, Chen H, Cai Z, Xu G. Mitochondrial dynamics and mitochondrial autophagy: Molecular structure, orchestrating mechanism and related disorders. Mitochondrion 2024; 75:101847. [PMID: 38246334 DOI: 10.1016/j.mito.2024.101847] [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: 08/07/2023] [Revised: 01/16/2024] [Accepted: 01/17/2024] [Indexed: 01/23/2024]
Abstract
Mitochondrial dynamics and autophagy play essential roles in normal cellular physiological activities, while abnormal mitochondrial dynamics and mitochondrial autophagy can cause cancer and related disorders. Abnormal mitochondrial dynamics usually occur in parallel with mitochondrial autophagy. Both have been reported to have a synergistic effect and can therefore complement or inhibit each other. Progress has been made in understanding the classical mitochondrial PINK1/Parkin pathway and mitochondrial dynamical abnormalities. Still, the mechanisms and regulatory pathways underlying the interaction between mitophagy and mitochondrial dynamics remain unexplored. Like other existing reviews, we review the molecular structure of proteins involved in mitochondrial dynamics and mitochondrial autophagy, and how their abnormalities can lead to the development of related diseases. We will also review the individual or synergistic effects of abnormal mitochondrial dynamics and mitophagy leading to cellular proliferation, differentiation and invasion. In addition, we explore the mechanisms underlying mitochondrial dynamics and mitochondrial autophagy to contribute to targeted and precise regulation of mitochondrial function. Through the study of abnormal mitochondrial dynamics and mitochondrial autophagy regulation mechanisms, as well as the role of early disease development, effective targets for mitochondrial function regulation can be proposed to enable accurate diagnosis and treatment of the associated disorders.
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Affiliation(s)
- Haoran Wang
- Department of Urology, Key Laboratory of Biological Targeting Diagnosis, Therapy and Rehabilitation of Guangdong Higher Education Institutes, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510700, China; Guangzhou Medical University, Guangzhou 511495, China
| | - Wenjun Luo
- Department of Urology, Key Laboratory of Biological Targeting Diagnosis, Therapy and Rehabilitation of Guangdong Higher Education Institutes, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510700, China
| | - Haoyu Chen
- Department of Urology, Key Laboratory of Biological Targeting Diagnosis, Therapy and Rehabilitation of Guangdong Higher Education Institutes, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510700, China
| | - Zhiduan Cai
- Department of Urology, Key Laboratory of Biological Targeting Diagnosis, Therapy and Rehabilitation of Guangdong Higher Education Institutes, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510700, China.
| | - Guibin Xu
- Department of Urology, Key Laboratory of Biological Targeting Diagnosis, Therapy and Rehabilitation of Guangdong Higher Education Institutes, The Fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510700, China; Guangdong Provincial Key Laboratory of Urology, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510230, China.
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2
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Buchanan E, Mahony C, Bam S, Jaffer M, Macleod S, Mangali A, van der Watt M, de Wet S, Theart R, Jacobs C, Loos B, O'Ryan C. Propionic acid induces alterations in mitochondrial morphology and dynamics in SH-SY5Y cells. Sci Rep 2023; 13:13248. [PMID: 37582965 PMCID: PMC10427685 DOI: 10.1038/s41598-023-40130-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 08/04/2023] [Indexed: 08/17/2023] Open
Abstract
Propionic acid (PPA) is used to study the role of mitochondrial dysfunction in neurodevelopmental conditions like autism spectrum disorders. PPA is known to disrupt mitochondrial biogenesis, metabolism, and turnover. However, the effect of PPA on mitochondrial dynamics, fission, and fusion remains challenging to study due to the complex temporal nature of these mechanisms. Here, we use complementary quantitative visualization techniques to examine how PPA influences mitochondrial ultrastructure, morphology, and dynamics in neuronal-like SH-SY5Y cells. PPA (5 mM) induced a significant decrease in mitochondrial area (p < 0.01), Feret's diameter and perimeter (p < 0.05), and in area2 (p < 0.01). Mitochondrial event localiser analysis demonstrated a significant increase in fission and fusion events (p < 0.05) that preserved mitochondrial network integrity under stress. Moreover, mRNA expression of cMYC (p < 0.0001), NRF1 (p < 0.01), TFAM (p < 0.05), STOML2 (p < 0.0001), and OPA1 (p < 0.01) was significantly decreased. This illustrates a remodeling of mitochondrial morphology, biogenesis, and dynamics to preserve function under stress. Our data provide new insights into the influence of PPA on mitochondrial dynamics and highlight the utility of visualization techniques to study the complex regulatory mechanisms involved in the mitochondrial stress response.
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Affiliation(s)
- Erin Buchanan
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, 7700, South Africa
| | - Caitlyn Mahony
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, 7700, South Africa
| | - Sophia Bam
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, 7700, South Africa
| | - Mohamed Jaffer
- Electron Microscope Unit, University of Cape Town, Cape Town, 7700, South Africa
| | - Sarah Macleod
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, 7700, South Africa
| | - Asandile Mangali
- Department of Physiological Sciences, Stellenbosch University, Matieland, Stellenbosch, 7602, South Africa
| | - Mignon van der Watt
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, 7700, South Africa
| | - Sholto de Wet
- Department of Physiological Sciences, Stellenbosch University, Matieland, Stellenbosch, 7602, South Africa
| | - Rensu Theart
- Department of Electrical and Electronic Engineering, Stellenbosch University, Matieland, Stellenbosch, 7602, South Africa
| | - Caron Jacobs
- Department of Pathology, Wellcome Centre for Infectious Diseases Research in Africa and IDM Microscopy Platform, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, 7700, South Africa
| | - Ben Loos
- Department of Physiological Sciences, Stellenbosch University, Matieland, Stellenbosch, 7602, South Africa
| | - Colleen O'Ryan
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, 7700, South Africa.
- Neuroscience Institute, University of Cape Town, Cape Town, 7700, South Africa.
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3
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Yang J, Chen P, Cao Y, Liu S, Wang W, Li L, Li J, Jiang Z, Ma Y, Chen S, Zheng S, Qi X, Jiang H. Chemical inhibition of mitochondrial fission via targeting the DRP1-receptor interaction. Cell Chem Biol 2023; 30:278-294.e11. [PMID: 36827981 DOI: 10.1016/j.chembiol.2023.02.002] [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: 05/19/2022] [Revised: 09/14/2022] [Accepted: 02/03/2023] [Indexed: 02/25/2023]
Abstract
Mitochondrial fission is critical for mitochondrial dynamics and homeostasis. The dynamin superfamily GTPase DRP1 is recruited by three functionally redundant receptors, MFF, MiD49, and MiD51, to mitochondria to drive fission. Here, we exploit high-content live-cell imaging to screen for mitochondrial fission inhibitors and have developed a covalent compound, mitochondrial division inhibitor (MIDI). MIDI treatment potently blocks mitochondrial fragmentation induced by mitochondrial toxins and restores mitochondrial morphology in fusion-defective cells carrying pathogenic mitofusin and OPA1 mutations. Mechanistically, MIDI does not affect DRP1 tetramerization nor DRP1 GTPase activity but does block DRP1 recruitment to mitochondria. Subsequent biochemical and cellular characterizations reveal an unexpected mechanism that MIDI targets DRP1 interaction with multiple receptors via covalent interaction with DRP1-C367. Taken together, beyond developing a potent mitochondrial fission inhibitor that profoundly impacts mitochondrial morphogenesis, our study establishes proof of concept for developing protein-protein interaction inhibitors targeting DRP1.
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Affiliation(s)
- Jun Yang
- School of Life Sciences, Tsinghua University, Beijing 100084, China; National Institute of Biological Sciences, Beijing 102206, China
| | - Peihao Chen
- National Institute of Biological Sciences, Beijing 102206, China; School of Life Sciences, Peking University, Beijing, China
| | - Yu Cao
- National Institute of Biological Sciences, Beijing 102206, China; College of Life Sciences, Beijing Normal University, Beijing, China
| | - Shanshan Liu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Wei Wang
- National Institute of Biological Sciences, Beijing 102206, China; School of Life Sciences, Peking University, Beijing, China
| | - Lin Li
- National Institute of Biological Sciences, Beijing 102206, China
| | - Jiaojiao Li
- National Institute of Biological Sciences, Beijing 102206, China
| | - Zhaodi Jiang
- National Institute of Biological Sciences, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Yan Ma
- National Institute of Biological Sciences, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - She Chen
- National Institute of Biological Sciences, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Sanduo Zheng
- National Institute of Biological Sciences, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China
| | - Xiangbing Qi
- National Institute of Biological Sciences, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China.
| | - Hui Jiang
- School of Life Sciences, Tsinghua University, Beijing 100084, China; National Institute of Biological Sciences, Beijing 102206, China; Beijing Key Laboratory of Cell Biology for Animal Aging, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 102206, China.
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STOML2 restricts mitophagy and increases chemosensitivity in pancreatic cancer through stabilizing PARL-induced PINK1 degradation. Cell Death Dis 2023; 14:191. [PMID: 36906621 PMCID: PMC10008575 DOI: 10.1038/s41419-023-05711-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 02/20/2023] [Accepted: 02/24/2023] [Indexed: 03/13/2023]
Abstract
Pancreatic cancer remains one of the most lethal diseases with a relatively low 5-year survival rate, and gemcitabine-based chemoresistance occurs constantly. Mitochondria, as the power factory in cancer cells, are involved in the process of chemoresistance. The dynamic balance of mitochondria is under the control of mitophagy. Stomatin-like protein 2 (STOML2) is located in the mitochondrial inner membrane and is highly expressed in cancer cells. In this study, using a tissue microarray (TMA), we found that high STOML2 expression was correlated with higher survival of patients with pancreatic cancer. Meanwhile, the proliferation and chemoresistance of pancreatic cancer cells could be retarded by STOML2. In addition, we found that STOML2 was positively related to mitochondrial mass and negatively related to mitophagy in pancreatic cancer cells. STOML2 stabilized PARL and further prevented gemcitabine-induced PINK1-dependent mitophagy. We also generated subcutaneous xenografts to verify the enhancement of gemcitabine therapy induced by STOML2. These findings suggested that STOML2 regulated the mitophagy process through the PARL/PINK1 pathway, thereby reducing the chemoresistance of pancreatic cancer. STOML2-overexpression targeted therapy might be helpful for gemcitabine sensitization in the future.
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Alzaydi MM, Abdul-Salam VB, Whitwell HJ, Russomanno G, Glynos A, Capece D, Szabadkai G, Wilkins MR, Wojciak-Stothard B. Intracellular Chloride Channels Regulate Endothelial Metabolic Reprogramming in Pulmonary Arterial Hypertension. Am J Respir Cell Mol Biol 2023; 68:103-115. [PMID: 36264759 PMCID: PMC9817916 DOI: 10.1165/rcmb.2022-0111oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Mitochondrial fission and a metabolic switch from oxidative phosphorylation to glycolysis are key features of vascular pathology in pulmonary arterial hypertension (PAH) and are associated with exuberant endothelial proliferation and apoptosis. The underlying mechanisms are poorly understood. We describe the contribution of two intracellular chloride channel proteins, CLIC1 and CLIC4, both highly expressed in PAH and cancer, to mitochondrial dysfunction and energy metabolism in PAH endothelium. Pathological overexpression of CLIC proteins induces mitochondrial fragmentation, inhibits mitochondrial cristae formation, and induces metabolic shift toward glycolysis in human pulmonary artery endothelial cells, consistent with changes observed in patient-derived cells. Interactions of CLIC proteins with structural components of the inner mitochondrial membrane offer mechanistic insights. Endothelial CLIC4 excision and mitofusin 2 supplementation have protective effects in human PAH cells and preclinical PAH. This study is the first to demonstrate the key role of endothelial intracellular chloride channels in the regulation of mitochondrial structure, biogenesis, and metabolic reprogramming in expression of the PAH phenotype.
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Affiliation(s)
- Mai M. Alzaydi
- National Heart and Lung Institute,,National Center for Biotechnology, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
| | - Vahitha B. Abdul-Salam
- National Heart and Lung Institute,,Centre for Cardiovascular Medicine and Device Innovation, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Harry J. Whitwell
- National Phenome Centre and Imperial Clinical Phenotyping Centre, and,Section of Bioanalytical Chemistry, Division of Systems Medicine, Department of Metabolism, Digestion, and Reproduction, and
| | - Giusy Russomanno
- National Heart and Lung Institute,,Medical Research Council (MRC) Centre for Drug Safety Science, Department of Pharmacology and Therapeutics, Institute of Systems, Molecular, and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Angelos Glynos
- Mitochondrial Biology Unit, Medical Research Council, University of Cambridge, Cambridge, United Kingdom; and
| | - Daria Capece
- Centre for Cell Signalling and Inflammation, Department of Immunology and Inflammation, Imperial College London, London, United Kingdom
| | - Gyorgy Szabadkai
- Cell and Developmental Biology, University College London, London, United Kingdom
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Assessing the Role of Ancestral Fragments and Selection Signatures by Whole-Genome Scanning in Dehong Humped Cattle at the China-Myanmar Border. BIOLOGY 2022; 11:biology11091331. [PMID: 36138810 PMCID: PMC9495559 DOI: 10.3390/biology11091331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/31/2022] [Accepted: 09/04/2022] [Indexed: 12/05/2022]
Abstract
Dehong humped cattle are precious livestock resources of Yunnan Province, China; they have typical zebu traits. Here, we investigated their genetic characteristics using whole-genome resequencing data of Dehong humped animals (n = 18). When comparing our data with the publicly-available data, we found that Dehong humped cattle have high nucleotide diversity. Based on clustering models in a population structure analysis, Dehong humped cattle had a mutual genome ancestor with Chinese and Indian indicine cattle. While using the RFMix method, it is speculated that the body sizes of Dehong humped cattle were influenced by the Chinese indicine segments and that the immune systems of Dehong humped cattle were affected by additional ancestral segments (Indian indicine). Furthermore, we explored the position selection regions harboring genes in the Dehong humped cattle, which were related to heat tolerance (FILIP1L, ABHD6) and immune responses (GZMM, PRKCZ, STOML2, LRBA, PIK3CD). Notably, missense mutations were detected in the candidate gene ABHD6 (c.870C>A p.Asp290Glu; c.987C>A p.Ser329Arg). The missense mutations may have implications for Dehong humped cattle adaptation to hot environments. This study provides valuable genomic resource data at the genome-wide level and paves the way for future genetic breeding work in the Dehong humped cattle.
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Sharma G, Zaman M, Sabouny R, Joel M, Martens K, Martino D, de Koning AJ, Pfeffer G, Shutt TE. Characterization of a novel variant in the HR1 domain of MFN2 in a patient with ataxia, optic atrophy and sensorineural hearing loss. F1000Res 2022; 10:606. [PMID: 38274408 PMCID: PMC10808857 DOI: 10.12688/f1000research.53230.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/22/2022] [Indexed: 01/27/2024] Open
Abstract
Background: Pathogenic variants in MFN2 cause Charcot-Marie-Tooth disease (CMT) type 2A (CMT2A) and are the leading cause of the axonal subtypes of CMT. CMT2A is characterized by predominantly distal motor weakness and muscle atrophy, with highly variable severity and onset age. Notably, some MFN2 variants can also lead to other phenotypes such as optic atrophy, hearing loss and lipodystrophy. Despite the clear link between MFN2 and CMT2A, our mechanistic understanding of how dysfunction of the MFN2 protein causes human disease pathologies remains incomplete. This lack of understanding is due in part to the multiple cellular roles of MFN2. Though initially characterized for its role in mediating mitochondrial fusion, MFN2 also plays important roles in mediating interactions between mitochondria and other organelles, such as the endoplasmic reticulum and lipid droplets. Additionally, MFN2 is also important for mitochondrial transport, mitochondrial autophagy, and has even been implicated in lipid transfer. Though over 100 pathogenic MFN2 variants have been described to date, only a few have been characterized functionally, and even then, often only for one or two functions. Method: Several MFN2-mediated functions were characterized in fibroblast cells from a patient presenting with cerebellar ataxia, deafness, blindness, and diffuse cerebral and cerebellar atrophy, who harbours a novel homozygous MFN2 variant, D414V, which is found in a region of the HR1 domain of MFN2 where few pathogenic variants occur. Results: We found evidence for impairment of several MFN2-mediated functions. Consistent with reduced mitochondrial fusion, patient fibroblasts exhibited more fragmented mitochondrial networks and had reduced mtDNA copy number. Additionally, patient fibroblasts had reduced oxygen consumption, fewer mitochondrial-ER contacts, and altered lipid droplets that displayed an unusual perinuclear distribution. Conclusion: Overall, this work characterizes D414V as a novel variant in MFN2 and expands the phenotypic presentation of MFN2 variants to include cerebellar ataxia.
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Affiliation(s)
- Govinda Sharma
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Mashiat Zaman
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Rasha Sabouny
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Matthew Joel
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
- Departments of Clinical Neurosciences and Medical Genetics, Cumming School of Medicine, University of Calgary, Hotchkiss Brain Institute, Alberta Child Health Research Institute, Calgary, Alberta, T2N 4N1, Canada
| | - Kristina Martens
- Departments of Clinical Neurosciences and Medical Genetics, Cumming School of Medicine, University of Calgary, Hotchkiss Brain Institute, Alberta Child Health Research Institute, Calgary, Alberta, T2N 4N1, Canada
| | - Davide Martino
- Department of Clinical Neurosciences, Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - A.P. Jason de Koning
- Department of Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
| | - Gerald Pfeffer
- Departments of Clinical Neurosciences and Medical Genetics, Cumming School of Medicine, University of Calgary, Hotchkiss Brain Institute, Alberta Child Health Research Institute, Calgary, Alberta, T2N 4N1, Canada
| | - Timothy E. Shutt
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 4N1, Canada
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Expression pattern of Stomatin-domain proteins in the peripheral olfactory system. Sci Rep 2022; 12:11447. [PMID: 35794236 PMCID: PMC9259621 DOI: 10.1038/s41598-022-15572-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 06/27/2022] [Indexed: 11/29/2022] Open
Abstract
Recent data show that Stomatin-like protein 3 (STOML3), a member of the stomatin-domain family, is expressed in the olfactory sensory neurons (OSNs) where it modulates both spontaneous and evoked action potential firing. The protein family is constituted by other 4 members (besides STOML3): STOM, STOML1, STOML2 and podocin. Interestingly, STOML3 with STOM and STOML1 are expressed in other peripheral sensory neurons: dorsal root ganglia. In here, they functionally interact and modulate the activity of the mechanosensitive Piezo channels and members of the ASIC family. Therefore, we investigated whether STOM and STOML1 are expressed together with STOML3 in the OSNs and whether they could interact. We found that all three are indeed expressed in ONSs, although STOML1 at very low level. STOM and STOML3 share a similar expression pattern and STOML3 is necessary for STOM to properly localize to OSN cilia. In addition, we extended our investigation to podocin and STOML2, and while the former is not expressed in the olfactory system, the latter showed a peculiar expression pattern in multiple cell types. In summary, we provided a first complete description of stomatin-domain protein family in the olfactory system, highlighting the precise compartmentalization, possible interactions and, finally, their functional implications.
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Ma W, Chen Y, Xiong W, Li W, Xu Z, Wang Y, Wei Z, Mou T, Wu Z, Cheng M, Zou Y, Zhu Y, Zhou W, Liu F, Geng Y. STOML2 interacts with PHB through activating MAPK signaling pathway to promote colorectal Cancer proliferation. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2021; 40:359. [PMID: 34781982 PMCID: PMC8591804 DOI: 10.1186/s13046-021-02116-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 09/24/2021] [Indexed: 12/30/2022]
Abstract
BACKGROUND Highly expressed STOML2 has been reported in a variety of cancers, yet few have detailed its function and regulatory mechanism. This research aims to reveal regulatory mechanism of STOML2 and to provide evidence for clinical therapeutics, via exploration of its role in colorectal cancer, and identification of its interacting protein. METHODS Expression level of STOML2 in normal colon and CRC tissue from biobank in Nanfang Hospital was detected by pathologic methods. The malignant proliferation of CRC induced by STOML2 was validated via gain-of-function and loss-of-function experiments, with novel techniques applied, such as organoid culture, orthotopic model and endoscopy monitoring. Yeast two-hybrid assay screened interacting proteins of STOML2, followed by bioinformatics analysis to predict biological function and signaling pathway of candidate proteins. Target protein with most functional similarity to STOML2 was validated with co-immunoprecipitation, and immunofluorescence were conducted to co-localize STOML2 and PHB. Pathway regulated by STOML2 was detected with immunoblotting, and subsequent experimental therapy was conducted with RAF inhibitor Sorafenib. RESULTS STOML2 was significantly overexpressed in colorectal cancer and its elevation was associated with unfavorable prognosis. Knockdown of STOML2 suppressed proliferation of colorectal cancer, thus attenuated subcutaneous and orthotopic tumor growth, while overexpressed STOML2 promoted proliferation in cell lines and organoids. A list of 13 interacting proteins was screened out by yeast two-hybrid assay. DTYMK and PHB were identified to be most similar to STOML2 according to bioinformatics in terms of biological process and signaling pathways; however, co-immunoprecipitation confirmed interaction between STOML2 and PHB, rather than DTYMK, despite its highest rank in previous analysis. Co-localization between STOML2 and PHB was confirmed in cell lines and tissue level. Furthermore, knockdown of STOML2 downregulated phosphorylation of RAF1, MEK1/2, and ERK1/2 on the MAPK signaling pathway, indicating common pathway activated by STOML2 and PHB in colorectal cancer proliferation. CONCLUSIONS This study demonstrated that in colorectal cancer, STOML2 expression is elevated and interacts with PHB through activating MAPK signaling pathway, to promote proliferation both in vitro and in vivo. In addition, combination of screening assay and bioinformatics marks great significance in methodology to explore regulatory mechanism of protein of interest.
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Affiliation(s)
- Wenhui Ma
- Department of Gastrointestinal Surgery, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), No. 1 Jiazi Road, Lunjiao, Shunde District, Foshan City, 528308, Guangdong Province, China.,Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, Guangdong, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China
| | - Yuehong Chen
- Department of Gastrointestinal Surgery, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), No. 1 Jiazi Road, Lunjiao, Shunde District, Foshan City, 528308, Guangdong Province, China.,Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, Guangdong, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China
| | - Wenjun Xiong
- Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China.,Department of Gastrointestinal Surgery, Guangdong Provincial Hospital of Chinese Medicine, the Second Affiliated Hospital of Guangzhou University of Chinese, Guangzhou, Guangdong, China
| | - Wenyi Li
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, Guangdong, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China
| | - Zhuoluo Xu
- Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, Guangdong, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China
| | - Ying Wang
- Departments of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhigang Wei
- Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China
| | - Tingyu Mou
- Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China
| | - Zhaokun Wu
- Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China.,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, Guangdong, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China
| | - Mingzhen Cheng
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, Guangdong, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China
| | - Yini Zou
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, Guangdong, China.,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China
| | - Yu Zhu
- Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China
| | - Weijie Zhou
- Department of Gastrointestinal Surgery, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), No. 1 Jiazi Road, Lunjiao, Shunde District, Foshan City, 528308, Guangdong Province, China. .,Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China. .,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China. .,Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, Guangdong, China. .,Guangdong Provincial Key Laboratory of Molecular Tumor Pathology, Guangzhou, Guangdong, China.
| | - Feng Liu
- Departments of General Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China. .,Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Guangzhou, China. .,Department of Colorectal and Anal Surgery, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, 510180, Guangdong, China.
| | - Yan Geng
- Department of Gastrointestinal Surgery, Shunde Hospital, Southern Medical University (The First People's Hospital of Shunde), No. 1 Jiazi Road, Lunjiao, Shunde District, Foshan City, 528308, Guangdong Province, China.
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Hu Y, Xu Y, Chen W, Qiu Z. Stomatin-Like Protein-2: A Potential Target to Treat Mitochondrial Cardiomyopathy. Heart Lung Circ 2021; 30:1449-1455. [PMID: 34088631 DOI: 10.1016/j.hlc.2021.05.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/16/2021] [Accepted: 05/02/2021] [Indexed: 12/27/2022]
Abstract
Stomatin-like protein-2 (SLP-2) is a mitochondrial-associated protein that is abundant in cardiomyocytes. Many reports have shown that SLP-2 plays an important role in mitochondria. The treatment of mitochondrial cardiomyopathy (MCM) needs further improvement, so the relationship between SLP-2 and MCM is worth exploring. This study reviewed some protective mechanisms of SLP-2 on mitochondria. Published studies have shown that SLP-2 protects mitochondria by stabilising the function of optic atrophy 1 (OPA1), promoting mitofusin (Mfn) 2 expression, interacting with prohibitins and cardiolipin, forming SLP-2-PARL-YME1L (SPY) complex, and stabilising respiratory chain complexes, suggesting that SLP-2 is a new potential target for the treatment of MCM. However, the specific mechanism of SLP-2 needs to be confirmed by further research.
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Affiliation(s)
- Yuntao Hu
- Department of Thoracic and Cardiovascular Surgery, Nanjing First Hospital, Nanjing Medical University, Jiangsu, China
| | - Yueyue Xu
- Department of Thoracic and Cardiovascular Surgery, Nanjing First Hospital, Nanjing Medical University, Jiangsu, China
| | - Wen Chen
- Department of Thoracic and Cardiovascular Surgery, Nanjing First Hospital, Nanjing Medical University, Jiangsu, China.
| | - Zhibing Qiu
- Department of Thoracic and Cardiovascular Surgery, Nanjing First Hospital, Nanjing Medical University, Jiangsu, China.
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11
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Mitochondrial remodelling-a vicious cycle in diabetic complications. Mol Biol Rep 2021; 48:4721-4731. [PMID: 34023988 DOI: 10.1007/s11033-021-06408-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/08/2021] [Indexed: 10/21/2022]
Abstract
Diabetes mellitus (DM) is a chronic, metabolic condition characterized by excessive blood glucose that causes perturbations in physiological functioning of almost all the organs of human body. This devastating metabolic disease has its implications in cognitive decline, heart damage, renal, retinal and neuronal complications that severely affects quality of life and associated with decreased life expectancy. Mitochondria possess adaptive mechanisms to meet the cellular energy demand and combat cellular stress. In recent years mitochondrial homeostasis has been point of focus where several mechanisms regulating mitochondrial health and function are evaluated. Mitochondrial dynamics plays crucial role in maintaining healthy mitochondria in cell under physiological as well as stress condition. Mitochondrial dynamics and corresponding regulating mechanisms have been implicated in progression of metabolic disorders including diabetes and its complications. In current review we have discussed about role of mitochondrial dynamics under physiological and pathological conditions. Also, modulation of mitochondrial fission and fusion in diabetic complications are described. The available literature supports mitochondrial remodelling as reliable target for diabetic complications.
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Chao D, Ariake K, Sato S, Ohtsuka H, Takadate T, Ishida M, Masuda K, Maeda S, Miura T, Mitachi K, Yu XJ, Fujishima F, Mizuma M, Nakagawa K, Morikawa T, Kamei T, Unno M. Stomatin‑like protein 2 induces metastasis by regulating the expression of a rate‑limiting enzyme of the hexosamine biosynthetic pathway in pancreatic cancer. Oncol Rep 2021; 45:90. [PMID: 33846782 PMCID: PMC8042670 DOI: 10.3892/or.2021.8041] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/08/2021] [Indexed: 01/05/2023] Open
Abstract
Stomatin-like protein 2 (SLP-2) is associated with poor prognosis in several types of cancer, including pancreatic cancer (PC); however, the molecular mechanism of its involvement remains elusive. The present study aimed to elucidate the role of this protein in the development of PC. Human PC cell lines AsPC-1 and PANC-1 were transfected by a vector expressing SLP-2 shRNA. Analyses of cell proliferation, migration, invasion, chemosensitivity, and glucose uptake were conducted, while a mouse xenograft model was used to evaluate the functional role of SLP-2 in PC. Immunohistochemical analysis was retrospectively performed on human tissue samples to compare expression between the primary site (n=279) and the liver metastatic site (n=22). Furthermore, microarray analysis was conducted to identify the genes correlated with SLP-2. In vitro analysis demonstrated that cells in which SLP-2 was suppressed exhibited reduced cell motility and glucose uptake, while in vivo analysis revealed a marked decrease in the number of liver metastases. Immunohistochemistry revealed that SLP-2 was increased in liver metastatic sites. Microarray analysis indicated that this protein regulated the expression of glutamine-fructose-6-phosphate transaminase 2 (GFPT2), a rate-limiting enzyme of the hexosamine biosynthesis pathway. SLP-2 contributed to the malignant character of PC by inducing liver metastasis. Cell motility and glucose uptake may be induced via the hexosamine biosynthesis pathway through the expression of GFPT2. The present study revealed a new mechanism of liver metastasis and indicated that SLP-2 and its downstream pathway could provide novel therapeutic targets for PC.
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Affiliation(s)
- Dang Chao
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Kyohei Ariake
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Satoko Sato
- Department of Pathology, Tohoku University Hospital, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Hideo Ohtsuka
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Tatsuyuki Takadate
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Masaharu Ishida
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Kunihiro Masuda
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Shimpei Maeda
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Takayuki Miura
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Katsutaka Mitachi
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Xun Jing Yu
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Fumiyoshi Fujishima
- Department of Pathology, Tohoku University Hospital, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Masamichi Mizuma
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Kei Nakagawa
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Takanori Morikawa
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Takashi Kamei
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
| | - Michiaki Unno
- Department of Surgery, Tohoku University Graduate School of Medicine, Seiryo‑machi, Aoba‑ku, Sendai 980‑8574, Japan
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Guedouari H, Ould Amer Y, Pichaud N, Hebert-Chatelain E. Characterization of the interactome of c-Src within the mitochondrial matrix by proximity-dependent biotin identification. Mitochondrion 2021; 57:257-269. [PMID: 33412331 DOI: 10.1016/j.mito.2020.12.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/09/2020] [Accepted: 12/30/2020] [Indexed: 12/27/2022]
Abstract
C-Src kinase is localized in several subcellular compartments, including mitochondria where it is involved in the regulation of organelle functions and overall metabolism. Surprisingly, the characterization of the intramitochondrial Src interactome has never been fully determined. Using in vitro proximity-dependent biotin identification (BioID) coupled to mass spectrometry, we identified 51 candidate proteins that may interact directly or indirectly with c-Src within the mitochondrial matrix. Pathway analysis suggests that these proteins are involved in a large array of mitochondrial functions such as protein folding and import, mitochondrial organization and transport, oxidative phosphorylation, tricarboxylic acid cycle and metabolism of amino and fatty acids. Among these proteins, we identified 24 tyrosine phosphorylation sites in 17 mitochondrial proteins (AKAP1, VDAC1, VDAC2, VDAC3, LonP1, Hsp90, SLP2, PHB2, MIC60, UBA1, EF-Tu, LRPPRC, ACO2, OAT, ACAT1, ETFβ and ATP5β) as potential substrates for intramitochondrial Src using in silico prediction of tyrosine phospho-sites. Interaction of c-Src with SLP2 and ATP5β was confirmed using coimmunoprecipitation. This study suggests that the intramitochondrial Src could target several proteins and regulate different mitochondrial functions.
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Affiliation(s)
- Hala Guedouari
- Canada Research Chair in Mitochondrial Signaling and Physiopathology, Moncton, NB, Canada; University of Moncton, Dept. of Biology, Moncton, NB, Canada
| | - Yasmine Ould Amer
- Canada Research Chair in Mitochondrial Signaling and Physiopathology, Moncton, NB, Canada; University of Moncton, Dept. of Biology, Moncton, NB, Canada
| | - Nicolas Pichaud
- University of Moncton, Dept. of Chemistry and Biochemistry, Moncton, NB, Canada
| | - Etienne Hebert-Chatelain
- Canada Research Chair in Mitochondrial Signaling and Physiopathology, Moncton, NB, Canada; University of Moncton, Dept. of Biology, Moncton, NB, Canada.
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Murgia M, Tan J, Geyer PE, Doll S, Mann M, Klopstock T. Proteomics of Cytochrome c Oxidase-Negative versus -Positive Muscle Fiber Sections in Mitochondrial Myopathy. Cell Rep 2020; 29:3825-3834.e4. [PMID: 31851916 DOI: 10.1016/j.celrep.2019.11.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 09/30/2019] [Accepted: 11/13/2019] [Indexed: 12/15/2022] Open
Abstract
The mosaic distribution of cytochrome c oxidase+ (COX+) and COX- muscle fibers in mitochondrial disorders allows the sampling of fibers with compensated and decompensated mitochondrial function from the same individual. We apply laser capture microdissection to excise individual COX+ and COX- fibers from the biopsies of mitochondrial myopathy patients. Using mass spectrometry-based proteomics, we quantify >4,000 proteins per patient. While COX+ fibers show a higher expression of respiratory chain components, COX- fibers display protean adaptive responses, including upregulation of mitochondrial ribosomes, translation proteins, and chaperones. Upregulated proteins include C1QBP, required for mitoribosome formation and protein synthesis, and STOML2, which organizes cardiolipin-enriched microdomains and the assembly of respiratory supercomplexes. Factoring in fast/slow fiber type, COX- slow fibers show a compensatory upregulation of beta-oxidation, the AAA+ protease AFG3L1, and the OPA1-dependent cristae remodeling program. These findings reveal compensatory mechanisms in muscle fibers struggling with energy shortage and metabolic stress.
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Affiliation(s)
- Marta Murgia
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany; Department of Biomedical Sciences, University of Padova, Via Ugo Bassi, 58/B, 35131 Padua, Italy
| | - Jing Tan
- Friedrich Baur Institute, Department of Neurology, University of Munich, 80336 Munich, Germany
| | - Philipp E Geyer
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Sophia Doll
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany; NNF Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark.
| | - Thomas Klopstock
- Friedrich Baur Institute, Department of Neurology, University of Munich, 80336 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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15
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Zhang X, Li BY, Fu LJ, Adu-Gyamfi EA, Xu BR, Liu TH, Chen XM, Lan X, Wang YX, Xu HB, Ding YB. Stomatin-like protein 2 (SLP2) regulates the proliferation and invasion of trophoblast cells by modulating mitochondrial functions. Placenta 2020; 100:13-23. [PMID: 32814233 DOI: 10.1016/j.placenta.2020.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 06/01/2020] [Accepted: 07/08/2020] [Indexed: 12/28/2022]
Abstract
INTRODUCTION Stomatin-like protein 2 (SLP2) is highly expressed in human first trimester trophoblast cells, but its functions in placental morpho-physiology remain unknown. This study aimed to determine the role of SLP2 in the proliferation and invasion of human first trimester trophoblast cells. METHODS Immunofluorescence was used to determine the expression and localization of SLP2 in normal and miscarriage human first trimester placenta. Western blot was used to determine the expression of SLP2, PCNA, Cyclin D3, N-cadherin, Vimentin, PGC1α and PPARα in HTR-8/SVneo cells. SLP2 was knocked down in the HTR-8/SVneo cells by using si-Slp2. Wound healing and migration assays were used to determine the effect of SLP2 knockdown on the migration and invasion in the HTR-8/SVneo cells. Mitochondrial membrane potential, reactive oxygen species (ROS), ATP production and biogenesis were measured to assess the effects of SLP2 knockdown on mitochondrial functions. RESULT SLP2 was strongly expressed in the cytotrophoblasts (CTB), syncytiotrophoblast (STB) and extravillous trophoblasts (EVT) of normal pregnancy placenta as compared to miscarriage placenta. SLP2 was highly expressed in the invasive EVT cell lines, HTR-8/SVneo and HPT-8 compared to the CTB cell line JAR. Knockdown of SLP2 significantly inhibited the migration and invasion of HTR-8/SVneo cells and placental villous explants, and repressed mitochondrial biogenesis and functions in HTR-8/SVneo cells. DISCUSSION Silencing of SLP2 inhibited the proliferation, migration and invasion of HTR-8/SVneo cells via the impairment of mitochondrial functions. This indicates that the downregulation of SLP2 in miscarriage placenta could be part of the pathogenesis and pathophysiology of the disease.
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Affiliation(s)
- Xue Zhang
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China
| | - Bing-Yi Li
- Department of Obstetrics and Gyaanecology, the First Affiliated Hospital, Chongqing Medical University, Chongqing, 400016, PR China; Wuhan Medical & Healthcare for Woman and Children, Wuhan, 430015, PR China
| | - Li-Juan Fu
- The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China; School of Traditional Chinese Medicine, Chongqing Medical University, Chongqing, 400016, PR China
| | - Enoch Appiah Adu-Gyamfi
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China
| | - Bai-Ruo Xu
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China
| | - Tai-Hang Liu
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China
| | - Xue-Mei Chen
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China
| | - Xi Lan
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China
| | - Ying-Xiong Wang
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China
| | - Hong-Bing Xu
- Department of Obstetrics and Gyaanecology, the First Affiliated Hospital, Chongqing Medical University, Chongqing, 400016, PR China.
| | - Yu-Bin Ding
- School of Public Health and Management, Chongqing Medical University, Chongqing, 400016, PR China; The Joint International Research Laboratory of Reproduction and Development, Ministry of Education, PR China.
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Liu Q, Li A, Wang L, He W, Zhao L, Wu C, Lu S, Ye X, Zhao H, Shen X, Xiao X, Liu Z. Stomatin-like Protein 2 Promotes Tumor Cell Survival by Activating the JAK2-STAT3-PIM1 Pathway, Suggesting a Novel Therapy in CRC. MOLECULAR THERAPY-ONCOLYTICS 2020; 17:169-179. [PMID: 32346607 PMCID: PMC7177985 DOI: 10.1016/j.omto.2020.03.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 03/24/2020] [Indexed: 12/12/2022]
Abstract
Despite intensive efforts, a considerable proportion of colorectal cancer (CRC) patients develop local recurrence and distant metastasis. Stomatin-like protein 2 (SLP-2), a member of the highly conserved stomatin superfamily, is upregulated across cancer types. However, the biological and functional roles of SLP-2 remain elusive in CRC. Here, we report that high SLP-2 expression was found in CRC tissues and was linked to tumor progression and tumor cell differentiation. Additionally, high SLP-2 expression correlated with poor overall survival (OS) in CRC patients (p < 0.001). SLP-2 knockout (SLP-2KO), generated by CRISPR/Cas9, reduced cell growth, migration, and invasion; induced apoptosis in CRC cells; and reduced tumor xenograft growth in vivo. A 181-compound library screening showed that SLP-2KO produced resistance to JAK2 inhibitors (NVP-BSK805 and TG-101348) and a PIM1 inhibitor (SGI-1776), revealing that the JAK2-STAT3-PIM1 oncogenic pathway was potentially controlled by SLP-2 in CRC. In vitro and in vivo, TG-101348 combined with SGI-1776 was synergistic in CRC (combination index [CI] < 1). Overall, our findings suggest that SLP-2 controls the JAK2-STAT3-PIM1 oncogenic pathway, offering a rationale for a novel therapeutic strategy with combined SGI-1776 and TG-101348 in CRC. Additionally, SLP-2 may be a prognostic marker and biomarker for sensitivity to JAK2 and PIM1 inhibitors.
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Affiliation(s)
- Qiang Liu
- Department of Pathology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Anqi Li
- Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai 200032, China
| | - Lisha Wang
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Wei He
- Department of Pathology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Ling Zhao
- Department of Pathology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Chao Wu
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Shasha Lu
- Department of Hematology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Xuanguang Ye
- Department of Pathology, Jinshan Hospital of Fudan University, Shanghai 201508, China
| | - Huiyong Zhao
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Xiaohan Shen
- Department of Diagnosis, Ningbo Diagnostic Pathology Center, Ningbo 315021, China
| | - Xiuying Xiao
- Department of Oncology, State Key Laboratory for Oncogenes and Related Genes, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Zebing Liu
- Department of Pathology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
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Yu R, Liu T, Ning C, Tan F, Jin SB, Lendahl U, Zhao J, Nistér M. The phosphorylation status of Ser-637 in dynamin-related protein 1 (Drp1) does not determine Drp1 recruitment to mitochondria. J Biol Chem 2019; 294:17262-17277. [PMID: 31533986 DOI: 10.1074/jbc.ra119.008202] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 09/12/2019] [Indexed: 12/30/2022] Open
Abstract
Recruitment of the GTPase dynamin-related protein 1 (Drp1) to mitochondria is a central step required for mitochondrial fission. Reversible Drp1 phosphorylation has been implicated in the regulation of this process, but whether Drp1 phosphorylation at Ser-637 determines its subcellular localization and fission activity remains to be fully elucidated. Here, using HEK 293T cells and immunofluorescence, immunoblotting, RNAi, subcellular fractionation, co-immunoprecipitation assays, and CRISPR/Cas9 genome editing, we show that Drp1 phosphorylated at Ser-637 (Drp1pS637) resides both in the cytosol and on mitochondria. We found that the receptors mitochondrial fission factor (Mff) and mitochondrial elongation factor 1/2 (MIEF1/2) interact with and recruit Drp1pS637 to mitochondria and that elevated Mff or MIEF levels promote Drp1pS637 accumulation on mitochondria. We also noted that protein kinase A (PKA), which mediates phosphorylation of Drp1 on Ser-637, is partially present on mitochondria and interacts with both MIEFs and Mff. PKA knockdown did not affect the Drp1-Mff interaction, but slightly enhanced the interaction between Drp1 and MIEFs. In Drp1-deficient HEK 293T cells, both phosphomimetic Drp1-S637D and phospho-deficient Drp1-S637A variants, like wild-type Drp1, located to the cytosol and to mitochondria and rescued a Drp1 deficiency-induced mitochondrial hyperfusion phenotype. However, Drp1-S637D was less efficient than Drp1-WT and Drp1-S637A in inducing mitochondrial fission. In conclusion, the Ser-637 phosphorylation status in Drp1 is not a determinant that controls Drp1 recruitment to mitochondria.
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Affiliation(s)
- Rong Yu
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Tong Liu
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Chenfei Ning
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Fei Tan
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Shao-Bo Jin
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Urban Lendahl
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jian Zhao
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Monica Nistér
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
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Yu R, Jin SB, Lendahl U, Nistér M, Zhao J. Human Fis1 regulates mitochondrial dynamics through inhibition of the fusion machinery. EMBO J 2019; 38:e99748. [PMID: 30842096 PMCID: PMC6463211 DOI: 10.15252/embj.201899748] [Citation(s) in RCA: 166] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 01/25/2019] [Accepted: 01/29/2019] [Indexed: 12/27/2022] Open
Abstract
Mitochondrial dynamics is important for life. At center stage for mitochondrial dynamics, the balance between mitochondrial fission and fusion is a set of dynamin-related GTPases that drive mitochondrial fission and fusion. Fission is executed by the GTPases Drp1 and Dyn2, whereas the GTPases Mfn1, Mfn2, and OPA1 promote fusion. Recruitment of Drp1 to mitochondria is a critical step in fission. In yeast, Fis1p recruits the Drp1 homolog Dnm1p to mitochondria through Mdv1p and Caf4p, but whether human Fis1 (hFis1) promotes fission through a similar mechanism as in yeast is not established. Here, we show that hFis1-mediated mitochondrial fragmentation occurs in the absence of Drp1 and Dyn2, suggesting that they are dispensable for hFis1 function. hFis1 instead binds to Mfn1, Mfn2, and OPA1 and inhibits their GTPase activity, thus blocking the fusion machinery. Consistent with this, disruption of the fusion machinery in Drp1-/- cells phenocopies the fragmentation phenotype induced by hFis1 overexpression. In sum, our data suggest a novel role for hFis1 as an inhibitor of the fusion machinery, revealing an important functional evolutionary divergence between yeast and mammalian Fis1 proteins.
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Affiliation(s)
- Rong Yu
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Shao-Bo Jin
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Urban Lendahl
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Monica Nistér
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Jian Zhao
- Department of Oncology-Pathology, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
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19
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Ma W, Xu Z, Wang Y, Li W, Wei Z, Chen T, Mou T, Cheng M, Luo J, Luo T, Chen Y, Yu J, Zhou W, Li G. A Positive Feedback Loop of SLP2 Activates MAPK Signaling Pathway to Promote Gastric Cancer Progression. Am J Cancer Res 2018; 8:5744-5757. [PMID: 30555578 PMCID: PMC6276297 DOI: 10.7150/thno.28898] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/16/2018] [Indexed: 12/23/2022] Open
Abstract
Rationale: This study is to validate the clinicopathologic significance and potential prognostic value of SLP2 in gastric cancer (GC), to investigate the biological function and regulation mechanism of SLP2, and to explore potential therapeutic strategies for GC. Methods: The expression of SLP2 in GC tissues from two cohorts was examined by IHC. The biological function and regulation mechanism of SLP2 and PHB was validated via loss-of-function or gain-of-function experiments. In vitro proliferation detection was used to evaluate the therapeutic effects of Sorafenib. Results: We validated that SLP2 was significantly elevated in GC tissues and its elevation was associated with poor prognosis of patients. Loss of SLP2 drastically suppressed the proliferation of GC cells and inhibited the tumor growth, while SLP2 overexpression promoted the progression of GC. Mechanistically, SLP2 competed against E3 ubiquitin ligase SKP2 to bind with PHB and stabilized its expression. Loss of SLP2 significantly suppressed phosphorylation of Raf1, MEK1/2, ERK1/2 and ELK1. Furthermore, phosphorylated ELK1 could in turn activate transcription of SLP2. Finally, we demonstrated that a Raf1 inhibitor, Sorafenib, was sufficient to inhibit the proliferation of GC cells. Conclusion: Our findings demonstrated a positive feedback loop of SLP2 which leads to acceleration of tumor progression and poor survival of GC patients. This finding also provided evidence for the reason of SLP2 elevation. Moreover, we found that sorafenib might be a potential therapeutic drug for GC and disrupting the interaction between SLP2 and PHB might also serve as a potential therapeutic target in GC.
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20
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Gosney JA, Wilkey DW, Merchant ML, Ceresa BP. Proteomics reveals novel protein associations with early endosomes in an epidermal growth factor-dependent manner. J Biol Chem 2018. [PMID: 29523688 DOI: 10.1074/jbc.ra117.000632] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that is an integral component of proliferative signaling. EGFRs on the cell surface become activated upon EGF binding and have an increased rate of endocytosis. Once in the cytoplasm, the EGF·EGFR complex is trafficked to the lysosome for degradation, and signaling is terminated. During trafficking, the EGFR kinase domain remains active, and the internalized EGFR can continue signaling to downstream effectors. Although effector activity varies based on the EGFR's endocytic location, it is not clear how this occurs. In an effort to identify proteins that uniquely associate with the internalized, liganded EGFR in the early endosome, we developed an early endosome isolation strategy to analyze their protein composition. Post-nuclear supernatant from HeLa cells stimulated with and without EGF were separated on an isotonic 17% Percoll gradient. The gradient was fractionated, and early endosomal fractions were pooled and immunoisolated with an EEA1 mAb. The isolated endosomes were validated by immunoblot using antibodies against organelle-specific marker proteins and transmission EM. These early endosomes were also subjected to LC-MS/MS for proteomic analysis. Five proteins were detected in endosomes in a ligand-dependent manner: EGFR, RUFY1, STOML2, PTPN23, and CCDC51. Knockdown of RUFY1 or PTPN23 by RNAi indicated that both proteins play a role in EGFR trafficking. These experiments indicate that endocytic trafficking of activated EGFR changes the protein composition, membrane trafficking, and signaling potential of the early endosome.
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Affiliation(s)
| | - Daniel W Wilkey
- Medicine, University of Louisville, Louisville, Kentucky 40202
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21
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Zanon A, Kalvakuri S, Rakovic A, Foco L, Guida M, Schwienbacher C, Serafin A, Rudolph F, Trilck M, Grünewald A, Stanslowsky N, Wegner F, Giorgio V, Lavdas AA, Bodmer R, Pramstaller PP, Klein C, Hicks AA, Pichler I, Seibler P. SLP-2 interacts with Parkin in mitochondria and prevents mitochondrial dysfunction in Parkin-deficient human iPSC-derived neurons and Drosophila. Hum Mol Genet 2017; 26:2412-2425. [PMID: 28379402 DOI: 10.1093/hmg/ddx132] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 03/16/2017] [Indexed: 12/26/2022] Open
Abstract
Mutations in the Parkin gene (PARK2) have been linked to a recessive form of Parkinson's disease (PD) characterized by the loss of dopaminergic neurons in the substantia nigra. Deficiencies of mitochondrial respiratory chain complex I activity have been observed in the substantia nigra of PD patients, and loss of Parkin results in the reduction of complex I activity shown in various cell and animal models. Using co-immunoprecipitation and proximity ligation assays on endogenous proteins, we demonstrate that Parkin interacts with mitochondrial Stomatin-like protein 2 (SLP-2), which also binds the mitochondrial lipid cardiolipin and functions in the assembly of respiratory chain proteins. SH-SY5Y cells with a stable knockdown of Parkin or SLP-2, as well as induced pluripotent stem cell-derived neurons from Parkin mutation carriers, showed decreased complex I activity and altered mitochondrial network morphology. Importantly, induced expression of SLP-2 corrected for these mitochondrial alterations caused by reduced Parkin function in these cells. In-vivo Drosophila studies showed a genetic interaction of Parkin and SLP-2, and further, tissue-specific or global overexpression of SLP-2 transgenes rescued parkin mutant phenotypes, in particular loss of dopaminergic neurons, mitochondrial network structure, reduced ATP production, and flight and motor dysfunction. The physical and genetic interaction between Parkin and SLP-2 and the compensatory potential of SLP-2 suggest a functional epistatic relationship to Parkin and a protective role of SLP-2 in neurons. This finding places further emphasis on the significance of Parkin for the maintenance of mitochondrial function in neurons and provides a novel target for therapeutic strategies.
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Affiliation(s)
- Alessandra Zanon
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Sreehari Kalvakuri
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | | | - Luisa Foco
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Marianna Guida
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Christine Schwienbacher
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Alice Serafin
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Franziska Rudolph
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
| | - Michaela Trilck
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
| | - Anne Grünewald
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany.,Molecular and Functional Neurobiology Group, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4367 Belvaux, Luxembourg
| | - Nancy Stanslowsky
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany
| | - Florian Wegner
- Department of Neurology, Hannover Medical School, 30625 Hannover, Germany
| | | | - Alexandros A Lavdas
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Rolf Bodmer
- Development, Aging and Regeneration Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Peter P Pramstaller
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy.,Department of Neurology, General Central Hospital, 39100 Bolzano, Italy.,Department of Neurology, University of Lübeck, 23562 Lübeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
| | - Andrew A Hicks
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Irene Pichler
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, 39100 Bolzano, Italy
| | - Philip Seibler
- Institute of Neurogenetics, University of Lübeck, 23562 Lübeck, Germany
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22
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Deng H, Deng Y, Liu F, Chen J, Li Z, Zhao K, Guan X, Liang W. Stomatin-like protein 2 is overexpressed in cervical cancer and involved in tumor cell apoptosis. Oncol Lett 2017; 14:6355-6364. [PMID: 29181097 PMCID: PMC5696708 DOI: 10.3892/ol.2017.7054] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/11/2017] [Indexed: 12/14/2022] Open
Abstract
Stomatin-like protein 2 (SLP-2) is overexpressed in numerous types of human cancer and previous studies revealed that SLP-2 may function in mitochondria. The purpose of the present study was to evaluate the expression of SLP-2 in cervical cancer and the association between SLP-2 expression and clinical features, in addition to investigating the role of SLP-2 in the apoptosis of cervical cancer cells. The expression profile of SLP-2 was determined by quantitative polymerase chain reaction, western blotting and immunohistochemical staining. The effect of SLP-2 on cell apoptosis induced by chemotherapeutics in cervical cancer cells was evaluated using Annexin V staining and terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL) assays. The results indicated that SLP-2 expression in cervical cancer was significantly upregulated at the mRNA and protein levels, compared with that in normal cervical tissues. Immunohistochemical analysis revealed significant correlation between SLP-2 protein expression and clinical characteristics, including the squamous cell carcinoma antigen (P=0.003), deep stromal invasion (P=0.021), lymphovascular space involvement (P=0.044) and pelvic lymph node metastasis (P<0.001), which served as independent prognostic factors for predicting the shortening of overall survival time in patients with early-stage cervical cancer. In addition, TUNEL and Annexin V binding assays revealed that silencing SLP-2 expression significantly enhanced the sensitivity of cervical cancer cells to apoptosis induced by chemotherapeutics. Taken together, the results of the present study suggest that SLP-2 may be a progressive gene in the development of cervical cancer. Overexpression of SLP-2 serves an important role in the apoptosis of human cervical cancer cells.
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Affiliation(s)
- Huan Deng
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Oncology, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong 510630, P.R. China
| | - Yongjian Deng
- Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Feiye Liu
- Cancer Center, Traditional Chinese Medicine-Integrated Hospital, Southern Medical University, Guangzhou, Guangdong 510315, P.R. China
| | - Jie Chen
- Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Zheng Li
- Department of Obstetrics and Gynecology, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Kelei Zhao
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Xiaoqian Guan
- Department of Oncology, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong 510630, P.R. China
| | - Weijiang Liang
- Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
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23
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Lee SY, Kang MG, Shin S, Kwak C, Kwon T, Seo JK, Kim JS, Rhee HW. Architecture Mapping of the Inner Mitochondrial Membrane Proteome by Chemical Tools in Live Cells. J Am Chem Soc 2017; 139:3651-3662. [DOI: 10.1021/jacs.6b10418] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | | | - Sanghee Shin
- Center
for RNA Research, Institute of Basic Science (IBS), Seoul 08826, Korea
- School
of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | | | | | | | - Jong-Seo Kim
- Center
for RNA Research, Institute of Basic Science (IBS), Seoul 08826, Korea
- School
of Biological Sciences, Seoul National University, Seoul 08826, Korea
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24
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Wai T, Saita S, Nolte H, Müller S, König T, Richter-Dennerlein R, Sprenger HG, Madrenas J, Mühlmeister M, Brandt U, Krüger M, Langer T. The membrane scaffold SLP2 anchors a proteolytic hub in mitochondria containing PARL and the i-AAA protease YME1L. EMBO Rep 2016; 17:1844-1856. [PMID: 27737933 DOI: 10.15252/embr.201642698] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/13/2016] [Accepted: 09/15/2016] [Indexed: 02/05/2023] Open
Abstract
The SPFH (stomatin, prohibitin, flotillin, HflC/K) superfamily is composed of scaffold proteins that form ring-like structures and locally specify the protein-lipid composition in a variety of cellular membranes. Stomatin-like protein 2 (SLP2) is a member of this superfamily that localizes to the mitochondrial inner membrane (IM) where it acts as a membrane organizer. Here, we report that SLP2 anchors a large protease complex composed of the rhomboid protease PARL and the i-AAA protease YME1L, which we term the SPY complex (for SLP2-PARL-YME1L). Association with SLP2 in the SPY complex regulates PARL-mediated processing of PTEN-induced kinase PINK1 and the phosphatase PGAM5 in mitochondria. Moreover, SLP2 inhibits the stress-activated peptidase OMA1, which can bind to SLP2 and cleaves PGAM5 in depolarized mitochondria. SLP2 restricts OMA1-mediated processing of the dynamin-like GTPase OPA1 allowing stress-induced mitochondrial hyperfusion under starvation conditions. Together, our results reveal an important role of SLP2 membrane scaffolds for the spatial organization of IM proteases regulating mitochondrial dynamics, quality control, and cell survival.
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Affiliation(s)
- Timothy Wai
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Shotaro Saita
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Hendrik Nolte
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Sebastian Müller
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Tim König
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Ricarda Richter-Dennerlein
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Hans-Georg Sprenger
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Joaquin Madrenas
- Microbiome and Disease Tolerance Centre, Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
| | - Mareike Mühlmeister
- Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ulrich Brandt
- Radboud Center for Mitochondrial Medicine, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Marcus Krüger
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany
| | - Thomas Langer
- Institute for Genetics Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), and University of Cologne, Cologne, Germany .,Center for Molecular Medicine (CMMC), University of Cologne, Cologne, Germany
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25
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Morozov YM, Sun YY, Kuan CY, Rakic P. Alteration of SLP2-like immunolabeling in mitochondria signifies early cellular damage in developing and adult mouse brain. Eur J Neurosci 2015; 43:245-57. [PMID: 26547131 DOI: 10.1111/ejn.13124] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 10/27/2015] [Accepted: 11/02/2015] [Indexed: 01/28/2023]
Abstract
Mitochondria play a critical role in various pathways of regulated cell death. Here we propose a novel method for detection of initial derangement of mitochondria in degenerating and dying neuronal cells. The method is based on our recent finding that antibodies directed against the cannabinoid type 1 receptor (CB1) also bind the mitochondrial stomatin-like protein 2 (SLP2) that belongs to an inner mitochondrial membrane protein complex. It is well established that SLP2 regulates mitochondrial biogenesis and respiratory functions. We now show that anti-CB1 antibodies recognize conformational epitopes but not the linear amino acid sequence of SLP2. In addition we found that anti-CB1 serum mostly labels swollen mitochondria with early or advanced stages of pathology in mouse brain while other proteins of the complex may mask epitopes of SLP2 in the normal mitochondria. Although neurons and endothelial cells in healthy brains contain occasional immunopositive mitochondria detectable with anti-CB1 serum, their numbers increase significantly after hypoxic insults in parallel with signs of cellular damage. Moreover, use of electron microscopy suggests relocation of SLP2 from its normal functional position in the inner mitochondrial membrane into the mitochondrial matrix in pathological cells. Thus, SLP2-like immunolabeling serves as an in situ histochemical target detecting early derangement of mitochondria. Anti-CB1 serum is crucial for this purpose because available anti-SLP2 antibodies do not provide selective labeling of mitochondria in the fixed tissue. This new method of detecting mitochondrial dysfunction can benefit the in vitro research of human diseases and developmental disorders by enabling analysis in live animal models.
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Affiliation(s)
- Yury M Morozov
- Department of Neurobiology, Yale University School of Medicine and Kavli Institute for Neuroscience, New Haven, CT, 06510, USA
| | - Yu-Yo Sun
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Chia-Yi Kuan
- Department of Pediatrics, Emory University School of Medicine and Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Pasko Rakic
- Department of Neurobiology, Yale University School of Medicine and Kavli Institute for Neuroscience, New Haven, CT, 06510, USA
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26
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Zhang Z, Liu L, Wu S, Xing D. Drp1, Mff, Fis1, and MiD51 are coordinated to mediate mitochondrial fission during UV irradiation-induced apoptosis. FASEB J 2015; 30:466-76. [PMID: 26432782 DOI: 10.1096/fj.15-274258] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 09/21/2015] [Indexed: 01/08/2023]
Abstract
Mitochondrial fission and proteins vital to this process play essential roles in apoptosis. Several mitochondrial outer membrane proteins, including mitochondrial fission protein 1 (Fis1), mitochondrial fission factor (Mff) and mitochondrial dynamics of 51 kDa protein (MiD51), also known as mitochondrial elongation factor 1 (MEIF1), have been reported to promote mitochondrial fission by recruiting the GTPase dynamin-related protein 1 (Drp1). However, it remains unclear how these fission factors coordinate to control apoptotic mitochondrial fission. Molecular studies have suggested the existence of interaction between Mff and Drp1, but fundamental questions remain concerning their function. In the present study, we reported that the phosphorylation status of Drp1-Ser(637) was essential for its interaction with Mff. UV stimulation induced a decrease in cytoplasmic and mitochondrial Drp1 phosphorylation on Ser(637) and enhanced the interaction between Drp1 and Mff, resulting in mitochondrial fragmentation. Simultaneously, the interaction increased markedly between Fis1 and MiD51/MIEF1, whereas the interaction between Drp1 and MiD51/MIEF1 decreased significantly after UV irradiation, which suggests that Fis1 competitively binds to MiD51/MIEF1 to activate Drp1 indirectly. Moreover, Mff-Drp1 binding and Mff-mediated recruitment of Drp1 to mitochondria did not require Bax during UV stimulation. Our study revealed a novel role of Mff in regulation of mitochondrial fission and showed how the fission proteins are orchestrated to mediate the fission process during apoptosis.
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Affiliation(s)
- Zhenzhen Zhang
- Ministry of Education Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
| | - Lei Liu
- Ministry of Education Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
| | - Shengnan Wu
- Ministry of Education Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
| | - Da Xing
- Ministry of Education Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
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27
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Chowdhury SM, Zhu X, Aloor JJ, Azzam KM, Gabor KA, Ge W, Addo KA, Tomer KB, Parks JS, Fessler MB. Proteomic Analysis of ABCA1-Null Macrophages Reveals a Role for Stomatin-Like Protein-2 in Raft Composition and Toll-Like Receptor Signaling. Mol Cell Proteomics 2015; 14:1859-70. [PMID: 25910759 DOI: 10.1074/mcp.m114.045179] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Indexed: 11/06/2022] Open
Abstract
Lipid raft membrane microdomains organize signaling by many prototypical receptors, including the Toll-like receptors (TLRs) of the innate immune system. Raft-localization of proteins is widely thought to be regulated by raft cholesterol levels, but this is largely on the basis of studies that have manipulated cell cholesterol using crude and poorly specific chemical tools, such as β-cyclodextrins. To date, there has been no proteome-scale investigation of whether endogenous regulators of intracellular cholesterol trafficking, such as the ATP binding cassette (ABC)A1 lipid efflux transporter, regulate targeting of proteins to rafts. Abca1(-/-) macrophages have cholesterol-laden rafts that have been reported to contain increased levels of select proteins, including TLR4, the lipopolysaccharide receptor. Here, using quantitative proteomic profiling, we identified 383 proteins in raft isolates from Abca1(+/+) and Abca1(-/-) macrophages. ABCA1 deletion induced wide-ranging changes to the raft proteome. Remarkably, many of these changes were similar to those seen in Abca1(+/+) macrophages after lipopolysaccharide exposure. Stomatin-like protein (SLP)-2, a member of the stomatin-prohibitin-flotillin-HflK/C family of membrane scaffolding proteins, was robustly and specifically increased in Abca1(-/-) rafts. Pursuing SLP-2 function, we found that rafts of SLP-2-silenced macrophages had markedly abnormal composition. SLP-2 silencing did not compromise ABCA1-dependent cholesterol efflux but reduced macrophage responsiveness to multiple TLR ligands. This was associated with reduced raft levels of the TLR co-receptor, CD14, and defective lipopolysaccharide-induced recruitment of the common TLR adaptor, MyD88, to rafts. Taken together, we show that the lipid transporter ABCA1 regulates the protein repertoire of rafts and identify SLP-2 as an ABCA1-dependent regulator of raft composition and of the innate immune response.
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Affiliation(s)
| | - Xuewei Zhu
- ¶Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157
| | - Jim J Aloor
- From the ‡Laboratory of Respiratory Biology and
| | | | | | - William Ge
- From the ‡Laboratory of Respiratory Biology and
| | | | - Kenneth B Tomer
- §Laboratory of Structural Biology, National Institute of Environmental Health Sciences, NIH, Research Triangle Park, NC 27709
| | - John S Parks
- ¶Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157
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28
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Chowdhury I, Thompson WE, Thomas K. Prohibitins role in cellular survival through Ras-Raf-MEK-ERK pathway. J Cell Physiol 2014; 229:998-1004. [PMID: 24347342 DOI: 10.1002/jcp.24531] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 12/11/2013] [Indexed: 12/15/2022]
Abstract
Prohibitins are members of a highly conserved protein family containing the stomatin/prohibitin/flotillin/HflK/C (SPFH) domain (also known as the prohibitin [PHB] domain) found in unicellular eukaryotes, fungi, plants, animals, and humans. Two highly homologous members of prohibitins expressed in eukaryotes are prohibitin (PHB; B-cell receptor associated protein-32, BAP-32) and prohibitin 2/repressor of estrogen receptor activity (PHB2, REA, BAP-37). Both PHB and REA/PHB2 are ubiquitously expressed and are present in multiple cellular compartments including the mitochondria, nucleus, and the plasma membrane. Multiple functions have been attributed to the mitochondrial and nuclear PHB and PHB2/REA including cellular differentiation, anti-proliferation, and morphogenesis. One of the major functions of the prohibitins are in maintaining the functional integrity of the mitochondria and protecting cells from various stresses. In the present review, we focus on the recent research developments indicating that PHB and PHB2/REA are involved in maintaining cellular survival through the Ras-Raf-MEK-Erk pathway. Understanding the molecular mechanisms by which the intracellular signaling pathways utilize prohibitins in governing cellular survival is likely to result in development of therapeutic strategies to overcome various human pathological disorders such as diabetes, obesity, neurological diseases, inflammatory bowel disease, and cancer.
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Affiliation(s)
- Indrajit Chowdhury
- Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, Georgia; Reproductive Science Research Program, Morehouse School of Medicine, Atlanta, Georgia
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29
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Abstract
Parkinson’s disease (PD) is a progressively debilitating neurodegenerative syndrome. Although best described as a movement disorder, the condition has prominent autonomic, cognitive, psychiatric, sensory and sleep components. Striatal dopaminergic innervation and nigral neurons are progressively lost, with associated Lewy pathology readily apparent on autopsy. Nevertheless, knowledge of the molecular events leading to this pathophysiology is limited. Current therapies offer symptomatic benefit but they fail to slow progression and patients continue to deteriorate. Recent discoveries in sporadic, Mendelian and more complex forms of parkinsonism provide novel insight into disease etiology; 28 genes, including those encoding alpha-synuclein (SNCA), leucine-rich repeat kinase 2 (LRRK2) and microtubule-associated protein tau (MAPT), have been linked and/or associated with PD. A consensus regarding the affected biological pathways and molecular processes has also started to emerge. In early-onset and more a typical PD, deficits in mitophagy pathways and lysosomal function appear to be prominent. By contrast, in more typical late-onset PD, chronic, albeit subtle, dysfunction in synaptic transmission, early endosomal trafficking and receptor recycling, as well as chaperone-mediated autophagy, provide a unifying synthesis of the molecular pathways involved. Disease-modification (neuroprotection) is no longer such an elusive goal given the unparalleled opportunity for diagnosis, translational neuroscience and therapeutic development provided by genetic discovery.
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Affiliation(s)
- Michelle K Lin
- Djavad Mowafaghian Centre for Brain Health, Centre for Applied Neurogenetics, Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Matthew J Farrer
- Djavad Mowafaghian Centre for Brain Health, Centre for Applied Neurogenetics, Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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30
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Gehl B, Sweetlove LJ. Mitochondrial Band-7 family proteins: scaffolds for respiratory chain assembly? FRONTIERS IN PLANT SCIENCE 2014; 5:141. [PMID: 24782879 PMCID: PMC3986555 DOI: 10.3389/fpls.2014.00141] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/24/2014] [Indexed: 05/28/2023]
Abstract
The band-7 protein family comprises a diverse set of membrane-bound proteins characterized by the presence of a conserved domain. The exact function of this band-7 domain remains elusive, but examples from animal and bacterial stomatin-type proteins demonstrate binding to lipids and the ability to assemble into membrane-bound oligomers that form putative scaffolds. Some members, such as prohibitins (PHB) and human stomatin-like protein 2 (HsSLP2), localize to the mitochondrial inner membrane where they function in cristae formation and hyperfusion. In Arabidopsis, the band-7 protein family has diversified and includes plant-specific members. Mitochondrial-localized members include prohibitins (AtPHBs) and two stomatin-like proteins (AtSLP1 and -2). Studies into PHB function in plants have demonstrated an involvement in root meristem proliferation and putative scaffold formation for mAAA proteases, but it remains unknown how these roles are achieved at the molecular level. In this minireview we summarize the current status of band-7 protein functions in Arabidopsis, and speculate how the mitochondrial members might recruit specific lipids to form microdomains that could shape the organization and functioning of the respiratory chain.
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Affiliation(s)
| | - Lee J. Sweetlove
- *Correspondence: Lee J. Sweetlove, Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK e-mail:
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31
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Gehl B, Lee CP, Bota P, Blatt MR, Sweetlove LJ. An Arabidopsis stomatin-like protein affects mitochondrial respiratory supercomplex organization. PLANT PHYSIOLOGY 2014; 164:1389-400. [PMID: 24424325 PMCID: PMC3938628 DOI: 10.1104/pp.113.230383] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Stomatins belong to the band-7 protein family, a diverse group of conserved eukaryotic and prokaryotic membrane proteins involved in the formation of large protein complexes as protein-lipid scaffolds. The Arabidopsis (Arabidopsis thaliana) genome contains two paralogous genes encoding stomatin-like proteins (SLPs; AtSLP1 and AtSLP2) that are phylogenetically related to human SLP2, a protein involved in mitochondrial fusion and protein complex formation in the mitochondrial inner membrane. We used reverse genetics in combination with biochemical methods to investigate the function of AtSLPs. We demonstrate that both SLPs localize to mitochondrial membranes. SLP1 migrates as a large (approximately 3 MDa) complex in blue-native gel electrophoresis. Remarkably, slp1 knockout mutants have reduced protein and activity levels of complex I and supercomplexes, indicating that SLP affects the assembly and/or stability of these complexes. These findings point to a role for SLP1 in the organization of respiratory supercomplexes in Arabidopsis.
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Ghose P, Park EC, Tabakin A, Salazar-Vasquez N, Rongo C. Anoxia-reoxygenation regulates mitochondrial dynamics through the hypoxia response pathway, SKN-1/Nrf, and stomatin-like protein STL-1/SLP-2. PLoS Genet 2013; 9:e1004063. [PMID: 24385935 PMCID: PMC3873275 DOI: 10.1371/journal.pgen.1004063] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 11/12/2013] [Indexed: 12/04/2022] Open
Abstract
Many aerobic organisms encounter oxygen-deprived environments and thus must have adaptive mechanisms to survive such stress. It is important to understand how mitochondria respond to oxygen deprivation given the critical role they play in using oxygen to generate cellular energy. Here we examine mitochondrial stress response in C. elegans, which adapt to extreme oxygen deprivation (anoxia, less than 0.1% oxygen) by entering into a reversible suspended animation state of locomotory arrest. We show that neuronal mitochondria undergo DRP-1-dependent fission in response to anoxia and undergo refusion upon reoxygenation. The hypoxia response pathway, including EGL-9 and HIF-1, is not required for anoxia-induced fission, but does regulate mitochondrial reconstitution during reoxygenation. Mutants for egl-9 exhibit a rapid refusion of mitochondria and a rapid behavioral recovery from suspended animation during reoxygenation; both phenotypes require HIF-1. Mitochondria are significantly larger in egl-9 mutants after reoxygenation, a phenotype similar to stress-induced mitochondria hyperfusion (SIMH). Anoxia results in mitochondrial oxidative stress, and the oxidative response factor SKN-1/Nrf is required for both rapid mitochondrial refusion and rapid behavioral recovery during reoxygenation. In response to anoxia, SKN-1 promotes the expression of the mitochondrial resident protein Stomatin-like 1 (STL-1), which helps facilitate mitochondrial dynamics following anoxia. Our results suggest the existence of a conserved anoxic stress response involving changes in mitochondrial fission and fusion. Oxygen deprivation plays a role in multiple human diseases ranging from heart attack, ischemic stroke, and traumatic injury. Aerobic organisms use oxygen to generate cellular energy in mitochondria; thus, oxygen deprivation results in energy depletion. Low oxygen can be catastrophic in tissues like the nervous system, which has high-energy demands and few glycolytic reserves. By contrast, other cells, including stem cells and cancerous cells within tumors, adapt and thrive in low oxygen. We are just beginning to understand how different organisms and even different cell types within the same organism respond to low oxygen conditions. The response of mitochondria to oxygen deprivation is particularly critical given their role in aerobic energy production. In addition, mitochondria actively injure cells during oxygen deprivation through the generation of reactive oxygen species, the disruption of calcium homeostasis, and the activation of cell death pathways. Here we use a genetic approach to show that mitochondria undergo fission during oxygen deprivation and refusion upon oxygen restoration. The hypoxia response pathway and the oxidative stress response pathway together modulate this response. We identify a new factor, stomatin-like protein, as a promoter of mitochondrial fusion in response to oxygen deprivation stress. Our findings uncover a new mechanism – regulated mitochondrial dynamics – by which cells adapt to oxygen deprivation stress.
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Affiliation(s)
- Piya Ghose
- The Waksman Institute, Department of Genetics, Rutgers The State University of New Jersey, Piscataway, New Jersey, United States of America
- The Graduate Program in Neuroscience, Rutgers The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Eun Chan Park
- The Waksman Institute, Department of Genetics, Rutgers The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Alexandra Tabakin
- The Waksman Institute, Department of Genetics, Rutgers The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Nathaly Salazar-Vasquez
- The Waksman Institute, Department of Genetics, Rutgers The State University of New Jersey, Piscataway, New Jersey, United States of America
- The Graduate Program in Genetics and Microbiology, Rutgers The State University of New Jersey, Piscataway, New Jersey, United States of America
| | - Christopher Rongo
- The Waksman Institute, Department of Genetics, Rutgers The State University of New Jersey, Piscataway, New Jersey, United States of America
- * E-mail:
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Liu T, Yu R, Jin SB, Han L, Lendahl U, Zhao J, Nistér M. The mitochondrial elongation factors MIEF1 and MIEF2 exert partially distinct functions in mitochondrial dynamics. Exp Cell Res 2013; 319:2893-904. [DOI: 10.1016/j.yexcr.2013.07.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/08/2013] [Accepted: 07/12/2013] [Indexed: 10/26/2022]
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Disatnik MH, Ferreira JCB, Campos JC, Gomes KS, Dourado PMM, Qi X, Mochly-Rosen D. Acute inhibition of excessive mitochondrial fission after myocardial infarction prevents long-term cardiac dysfunction. J Am Heart Assoc 2013; 2:e000461. [PMID: 24103571 PMCID: PMC3835263 DOI: 10.1161/jaha.113.000461] [Citation(s) in RCA: 240] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Background Ischemia and reperfusion (IR) injury remains a major cause of morbidity and mortality and multiple molecular and cellular pathways have been implicated in this injury. We determined whether acute inhibition of excessive mitochondrial fission at the onset of reperfusion improves mitochondrial dysfunction and cardiac contractility postmyocardial infarction in rats. Methods and Results We used a selective inhibitor of the fission machinery, P110, which we have recently designed. P110 treatment inhibited the interaction of fission proteins Fis1/Drp1, decreased mitochondrial fission, and improved bioenergetics in three different rat models of IR, including primary cardiomyocytes, ex vivo heart model, and an in vivo myocardial infarction model. Drp1 transiently bound to the mitochondria following IR injury and P110 treatment blocked this Drp1 mitochondrial association. Compared with control treatment, P110 (1 μmol/L) decreased infarct size by 28±2% and increased adenosine triphosphate levels by 70+1% after IR relative to control IR in the ex vivo model. Intraperitoneal injection of P110 (0.5 mg/kg) at the onset of reperfusion in an in vivo model resulted in improved mitochondrial oxygen consumption by 68% when measured 3 weeks after ischemic injury, improved cardiac fractional shortening by 35%, reduced mitochondrial H2O2 uncoupling state by 70%, and improved overall mitochondrial functions. Conclusions Together, we show that excessive mitochondrial fission at reperfusion contributes to long‐term cardiac dysfunction in rats and that acute inhibition of excessive mitochondrial fission at the onset of reperfusion is sufficient to result in long‐term benefits as evidenced by inhibiting cardiac dysfunction 3 weeks after acute myocardial infarction.
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Affiliation(s)
- Marie-Hélène Disatnik
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, 94305, CA
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Zhang J, Wu M, Wang LJ, Zhang HQ, Shi GY, Ba N, Zhang ZS, Yan L, Zheng XK, Xing X. Expression of SLP-2 in colorectal cancer. Shijie Huaren Xiaohua Zazhi 2013; 21:2228-2231. [DOI: 10.11569/wcjd.v21.i22.2228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the expression of stomatin like protein 2 (SLP-2) in colorectal cancer.
METHODS: The mRNA and protein expression of SLP-2 was detected by RT-PCR in 40 cases and by immunohistochemistry in 50 cases of human colorectal cancer and matched tumor-adjacent tissue. The relationship between SLP-2 protein expression and clinical and pathologic characteristics of colorectal cancer was analyzed.
RESULTS: The expression level of SLP-2 mRNA was significantly higher in colorectal cancer than in tumor-adjacent tissue (1.31 ± 0.28 vs 0.74 ± 0.16, P < 0.05). The positive rate of SLP-2 protein expression was also significantly higher in colorectal cancer than in tumor-adjacent tissue (70.0% vs 22%, P < 0.05). Expression of SLP-2 protein in colorectal cancer was associated with lymph nodes metastasis and TNM stage (both P < 0.05).
CONCLUSION: The expression of SLP-2 is increased in colorectal cancer. SLP-2 may play important roles in the occurrence, development and metastasis of colorectal cancer.
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Zhang J, Wu M, Wang LJ, Zhang HQ, Shi GY, Ba N, Zhang ZS, Yan L, Zheng XK. Effect of siRNA-mediated SLP-2 silencing on tumor cell proliferation and apoptosis in nude mice bearing gastric tumor xenografts. Shijie Huaren Xiaohua Zazhi 2013; 21:1740-1744. [DOI: 10.11569/wcjd.v21.i18.1740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of siRNA-mediated SLP-2 silencing on tumor cell proliferation and apoptosis in nude mice bearing gastric tumor xenografts.
METHODS: Chemically modified SLP-2 siRNA was designed and constructed. A tumor-bearing model was developed by inoculation of gastric cancer SGC-7901 cells into BALB/c nude mice subcutaneously. All mice were randomized into three groups: a SLP-2 siRNA-transfected group, a negative control group and a blank control group. Chemically modified SLP-2 siRNA and a negative control siRNA were injected into tumor xenografts of the SLP-2 siRNA transfected group and negative control group, respectively, while the blank control group only received an injection of equal volume of saline. Tumor volume was recorded and the apoptosis index was observed. The expression of SLP-2 mRNA and protein in tumor tissue was measured by RT-PCR and immunohistochemistry.
RESULTS: Compared to the two control groups, tumor volume was significantly decreased in the SLP-2 siRNA transfected group (P = 0.009, 0.003), and the reduced rate of tumor growth was 26.74% and 30.15%. The number of apoptotic cells and apoptosis index showed no significant differences between the SLP-2 siRNA transfected group and the two control groups (both P > 0.05).
CONCLUSION: SiRNA-mediated SLP-2 silencing inhibits tumor cell growth but has no significant effect on tumor cell apoptosis in tumor xenografts.
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Morozov YM, Dominguez MH, Varela L, Shanabrough M, Koch M, Horvath TL, Rakic P. Antibodies to cannabinoid type 1 receptor co-react with stomatin-like protein 2 in mouse brain mitochondria. Eur J Neurosci 2013; 38:2341-8. [PMID: 23617247 DOI: 10.1111/ejn.12237] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 03/26/2013] [Accepted: 03/31/2013] [Indexed: 01/16/2023]
Abstract
Anti-cannabinoid type 1 receptor (CB1 ) polyclonal antibodies are widely used to detect the presence of CB1 in a variety of brain cells and their organelles, including neuronal mitochondria. Surprisingly, we found that anti-CB1 sera, in parallel with CB1 , also recognize the mitochondrial protein stomatin-like protein 2. In addition, we show that the previously reported effect of synthetic cannabinoid WIN 55,212-2 on mitochondrial complex III respiration is not detectable in purified mitochondrial preparations. Thus, our study indicates that a direct relationship between endocannabinoid signaling and mitochondrial functions in the cerebral cortex seems unlikely, and that caution should be taken interpreting findings obtained using anti-CB1 antibodies.
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Affiliation(s)
- Yury M Morozov
- Department of Neurobiology, Yale University School of Medicine and Kavli Institute for Neuroscience, New Haven, CT, USA.
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Qi X, Qvit N, Su YC, Mochly-Rosen D. A novel Drp1 inhibitor diminishes aberrant mitochondrial fission and neurotoxicity. J Cell Sci 2012; 126:789-802. [PMID: 23239023 DOI: 10.1242/jcs.114439] [Citation(s) in RCA: 291] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Excessive mitochondrial fission is associated with the pathology of a number of neurodegenerative diseases. Therefore, inhibitors of aberrant mitochondrial fission could provide important research tools in addition to potential leads for drug development. Using a rational approach, we designed a novel and selective peptide inhibitor, P110, of excessive mitochondrial fission. P110 inhibits Drp1 enzyme activity and blocks Drp1/Fis1 interaction in vitro and in cultured neurons, whereas it has no effect on the interaction between Drp1 and other mitochondrial adaptors, as demonstrated by co-immunoprecipitation. Furthermore, using a model of Parkinson's disease (PD) in culture, we demonstrated that P110 is neuroprotective by inhibiting mitochondrial fragmentation and reactive oxygen species (ROS) production and subsequently improving mitochondrial membrane potential and mitochondrial integrity. P110 increased neuronal cell viability by reducing apoptosis and autophagic cell death, and reduced neurite loss of primary dopaminergic neurons in this PD cell culture model. We also found that P110 treatment appears to have minimal effects on mitochondrial fission and cell viability under basal conditions. Finally, P110 required the presence of Drp1 to inhibit mitochondrial fission under oxidative stress conditions. Taken together, our findings suggest that P110, as a selective peptide inhibitor of Drp1, might be useful for the treatment of diseases in which excessive mitochondrial fission and mitochondrial dysfunction occur.
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Affiliation(s)
- Xin Qi
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Case Western Reserve University School of Medicine Cleveland, OH 44106 Cleveland, OH 44106 USA.
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Christie DA, Mitsopoulos P, Blagih J, Dunn SD, St-Pierre J, Jones RG, Hatch GM, Madrenas J. Stomatin-like Protein 2 Deficiency in T Cells Is Associated with Altered Mitochondrial Respiration and Defective CD4+T Cell Responses. THE JOURNAL OF IMMUNOLOGY 2012; 189:4349-60. [DOI: 10.4049/jimmunol.1103829] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Escobar-Henriques M, Anton F. Mechanistic perspective of mitochondrial fusion: tubulation vs. fragmentation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:162-75. [PMID: 22884630 DOI: 10.1016/j.bbamcr.2012.07.016] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 07/28/2012] [Accepted: 07/30/2012] [Indexed: 01/02/2023]
Abstract
Mitochondrial fusion is a fundamental process driven by dynamin related GTPase proteins (DRPs), in contrast to the general SNARE-dependence of most cellular fusion events. The DRPs Mfn1/Mfn2/Fzo1 and OPA1/Mgm1 are the key effectors for fusion of the mitochondrial outer and inner membranes, respectively. In order to promote fusion, these two DRPs require post-translational modifications and proteolysis. OPA1/Mgm1 undergoes partial proteolytic processing, which results in a combination between short and long isoforms. In turn, ubiquitylation of mitofusins, after oligomerization and GTP hydrolysis, promotes and positively regulates mitochondrial fusion. In contrast, under conditions of mitochondrial dysfunction, negative regulation by proteolysis on these DRPs results in mitochondrial fragmentation. This occurs by complete processing of OPA1 and via ubiquitylation and degradation of mitofusins. Mitochondrial fragmentation contributes to the elimination of damaged mitochondria by mitophagy, and may play a protective role against Parkinson's disease. Moreover, a link of Mfn2 to Alzheimer's disease is emerging and mutations in Mfn2 or OPA1 cause Charcot-Marie-Tooth type 2A neuropathy or autosomal-dominant optic atrophy. Here, we summarize our current understanding on the molecular mechanisms promoting or inhibiting fusion of mitochondrial membranes, which is essential for cellular survival and disease control. This article is part of a Special Issue entitled: Mitochondrial dynamics and physiology.
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Zhao J, Lendahl U, Nistér M. Regulation of mitochondrial dynamics: convergences and divergences between yeast and vertebrates. Cell Mol Life Sci 2012; 70:951-76. [PMID: 22806564 PMCID: PMC3578726 DOI: 10.1007/s00018-012-1066-6] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 06/18/2012] [Accepted: 06/19/2012] [Indexed: 12/20/2022]
Abstract
In eukaryotic cells, the shape of mitochondria can be tuned to various physiological conditions by a balance of fusion and fission processes termed mitochondrial dynamics. Mitochondrial dynamics controls not only the morphology but also the function of mitochondria, and therefore is crucial in many aspects of a cell’s life. Consequently, dysfunction of mitochondrial dynamics has been implicated in a variety of human diseases including cancer. Several proteins important for mitochondrial fusion and fission have been discovered over the past decade. However, there is emerging evidence that there are as yet unidentified proteins important for these processes and that the fusion/fission machinery is not completely conserved between yeast and vertebrates. The recent characterization of several mammalian proteins important for the process that were not conserved in yeast, may indicate that the molecular mechanisms regulating and controlling the morphology and function of mitochondria are more elaborate and complex in vertebrates. This difference could possibly be a consequence of different needs in the different cell types of multicellular organisms. Here, we review recent advances in the field of mitochondrial dynamics. We highlight and discuss the mechanisms regulating recruitment of cytosolic Drp1 to the mitochondrial outer membrane by Fis1, Mff, and MIEF1 in mammals and the divergences in regulation of mitochondrial dynamics between yeast and vertebrates.
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Affiliation(s)
- Jian Zhao
- Department of Oncology-Pathology, Karolinska Institutet, CCK R8:05, Karolinska University Hospital Solna, 171 76, Stockholm, Sweden,
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Abstract
AIM: To investigate the expression of stomatin-like protein 2 (SLP-2) in gastric adenocarcinoma and to analyze its significance.
METHODS: The expression of SLP-2 mRNA and protein was detected by RT-PCR in 40 cases and by immunohistochemistry in 45 cases of human gastric adenocarcinoma and adjacent tumor-free tissue, respectively. The relationship between SLP-2 expression and clinicopathologic characteristics of gastric adenocarcinoma was then analyzed.
RESULTS: The expression of SLP-2 mRNA and protein in gastric adenocarcinoma was significantly higher than that in adjacent tumor-free tissue (68.9% vs 26.7%, 1.12 ± 0.47 vs 0.63 ± 0.31, both P < 0.01). SLP-2 expression in gastric adenocarcinoma was associated with lymph node metastasis and TNM stage (χ2 = 5.32, 4.78, both P < 0.05), but not with other clinicopathologic characteristics (all P > 0.05).
CONCLUSION: The expression of SLP-2 is increased in gastric adenocarcinoma. SLP-2 may play important roles in the occurrence, development and metastasis of gastric adenocarcinoma.
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Christie DA, Kirchhof MG, Vardhana S, Dustin ML, Madrenas J. Mitochondrial and plasma membrane pools of stomatin-like protein 2 coalesce at the immunological synapse during T cell activation. PLoS One 2012; 7:e37144. [PMID: 22623988 PMCID: PMC3356372 DOI: 10.1371/journal.pone.0037144] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 04/13/2012] [Indexed: 01/29/2023] Open
Abstract
Stomatin-like protein 2 (SLP-2) is a member of the stomatin-prohibitin-flotillin-HflC/K (SPFH) superfamily. Recent evidence indicates that SLP-2 is involved in the organization of cardiolipin-enriched microdomains in mitochondrial membranes and the regulation of mitochondrial biogenesis and function. In T cells, this role translates into enhanced T cell activation. Although the major pool of SLP-2 is associated with mitochondria, we show here that there is an additional pool of SLP-2 associated with the plasma membrane of T cells. Both plasma membrane-associated and mitochondria-associated pools of SLP-2 coalesce at the immunological synapse (IS) upon T cell activation. SLP-2 is not required for formation of IS nor for the re-localization of mitochondria to the IS because SLP-2-deficient T cells showed normal re-localization of these organelles in response to T cell activation. Interestingly, upon T cell activation, we found the surface pool of SLP-2 mostly excluded from the central supramolecular activation complex, and enriched in the peripheral area of the IS where signalling TCR microclusters are located. Based on these results, we propose that SLP-2 facilitates the compartmentalization not only of mitochondrial membranes but also of the plasma membrane into functional microdomains. In this latter location, SLP-2 may facilitate the optimal assembly of TCR signalosome components. Our data also suggest that there may be a net exchange of membrane material between mitochondria and plasma membrane, explaining the presence of some mitochondrial proteins in the plasma membrane.
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Affiliation(s)
- Darah A. Christie
- The Centre for Human Immunology, Robarts Research Institute, and the Departments of Microbiology and Immunology, and Medicine, The University of Western Ontario, London, Ontario, Canada
| | - Mark G. Kirchhof
- The Centre for Human Immunology, Robarts Research Institute, and the Departments of Microbiology and Immunology, and Medicine, The University of Western Ontario, London, Ontario, Canada
| | - Santosh Vardhana
- Program in Molecular Pathogenesis, Skirball Institute of Biomolecular Medicine, New York, New York, United States of America
| | - Michael L. Dustin
- Program in Molecular Pathogenesis, Skirball Institute of Biomolecular Medicine, New York, New York, United States of America
| | - Joaquín Madrenas
- The Centre for Human Immunology, Robarts Research Institute, and the Departments of Microbiology and Immunology, and Medicine, The University of Western Ontario, London, Ontario, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec, Canada
- * E-mail:
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Stomatin-domain proteins. Eur J Cell Biol 2012; 91:240-5. [DOI: 10.1016/j.ejcb.2011.01.018] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2011] [Revised: 01/26/2011] [Accepted: 01/27/2011] [Indexed: 11/18/2022] Open
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Abstract
Apoptosis is a process of programmed cell death that serves as a major mechanism for the precise regulation of cell numbers, and as a defense mechanism to remove unwanted and potentially dangerous cells. Studies in nematode, Drosophila and mammals have shown that, although regulation of the cell death machinery is somehow different from one species to another, it is controlled by homologous proteins and involves mitochondria. In mammals, activation of caspases (cysteine proteases that are the main executioners of apoptosis) is under the tight control of the Bcl-2 family proteins, named in reference to the first discovered mammalian cell death regulator. These proteins mainly act by regulating the release of caspases activators from mitochondria. Although for a long time the absence of mitochondrial changes was considered as a hallmark of apoptosis, mitochondria appear today as the central executioner of apoptosis. In this chapter, we present the current view on the mitochondrial pathway of apoptosis with a particular attention to new aspects of the regulation of the Bcl-2 proteins family control of mitochondrial membrane permeabilization: the mechanisms implicated in their mitochondrial targeting and activation during apoptosis, the function(s) of the oncosuppressive protein p53 at the mitochondria and the role of the processes of mitochondrial fusion and fission.
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46
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Genda EN, Jackson JG, Sheldon AL, Locke SF, Greco TM, O'Donnell JC, Spruce LA, Xiao R, Guo W, Putt M, Seeholzer S, Ischiropoulos H, Robinson MB. Co-compartmentalization of the astroglial glutamate transporter, GLT-1, with glycolytic enzymes and mitochondria. J Neurosci 2011; 31:18275-88. [PMID: 22171032 PMCID: PMC3259858 DOI: 10.1523/jneurosci.3305-11.2011] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Efficient excitatory transmission depends on a family of transporters that use the Na(+)-electrochemical gradient to maintain low synaptic concentrations of glutamate. These transporters consume substantial energy in the spatially restricted space of fine astrocytic processes. GLT-1 (EAAT2) mediates the bulk of this activity in forebrain. To date, relatively few proteins have been identified that associate with GLT-1. In the present study, GLT-1 immunoaffinity isolates were prepared from rat cortex using three strategies and analyzed by liquid chromatography-coupled tandem mass spectrometry. In addition to known interacting proteins, the analysis identified glycolytic enzymes and outer mitochondrial proteins. Using double-label immunofluorescence, GLT-1 was shown to colocalize with the mitochondrial matrix protein, ubiquinol-cytochrome c reductase core protein 2 or the inner mitochondrial membrane protein, ADP/ATP translocase, in rat cortex. In biolistically transduced hippocampal slices, fluorescently tagged GLT-1 puncta overlapped with fluorescently tagged mitochondria along fine astrocytic processes. In a Monte Carlo-type computer simulation, this overlap was significantly more frequent than would occur by chance. Furthermore, fluorescently tagged hexokinase-1 overlapped with mitochondria or GLT-1, strongly suggesting that GLT-1, mitochondria, and the first step in glycolysis are cocompartmentalized in astrocytic processes. Acute inhibition of glycolysis or oxidative phosphorylation had no effect on glutamate uptake in hippocampal slices, but simultaneous inhibition of both processes significantly reduced transport. Together with previous results, these studies show that GLT-1 cocompartmentalizes with Na(+)/K(+) ATPase, glycolytic enzymes, and mitochondria, providing a mechanism to spatially match energy and buffering capacity to the demands imposed by transport.
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Affiliation(s)
| | - Joshua G. Jackson
- 1Children's Hospital of Philadelphia Research Institute and
- 2Departments of Pediatrics,
| | - Amanda L. Sheldon
- 1Children's Hospital of Philadelphia Research Institute and
- 2Departments of Pediatrics,
- 3Neuroscience,
| | | | - Todd M. Greco
- 1Children's Hospital of Philadelphia Research Institute and
- 2Departments of Pediatrics,
- 3Neuroscience,
| | - John C. O'Donnell
- 1Children's Hospital of Philadelphia Research Institute and
- 4Pharmacology, and
| | - Lynn A. Spruce
- 1Children's Hospital of Philadelphia Research Institute and
| | - Rui Xiao
- 5Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Wensheng Guo
- 5Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Mary Putt
- 5Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | | | - Harry Ischiropoulos
- 1Children's Hospital of Philadelphia Research Institute and
- 2Departments of Pediatrics,
- 4Pharmacology, and
| | - Michael B. Robinson
- 1Children's Hospital of Philadelphia Research Institute and
- 2Departments of Pediatrics,
- 4Pharmacology, and
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Smith AC, Blackshaw JA, Robinson AJ. MitoMiner: a data warehouse for mitochondrial proteomics data. Nucleic Acids Res 2011; 40:D1160-7. [PMID: 22121219 PMCID: PMC3245170 DOI: 10.1093/nar/gkr1101] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
MitoMiner (http://mitominer.mrc-mbu.cam.ac.uk/) is a data warehouse for the storage and analysis of mitochondrial proteomics data gathered from publications of mass spectrometry and green fluorescent protein tagging studies. In MitoMiner, these data are integrated with data from UniProt, Gene Ontology, Online Mendelian Inheritance in Man, HomoloGene, Kyoto Encyclopaedia of Genes and Genomes and PubMed. The latest release of MitoMiner stores proteomics data sets from 46 studies covering 11 different species from eumetazoa, viridiplantae, fungi and protista. MitoMiner is implemented by using the open source InterMine data warehouse system, which provides a user interface allowing users to upload data for analysis, personal accounts to store queries and results and enables queries of any data in the data model. MitoMiner also provides lists of proteins for use in analyses, including the new MitoMiner mitochondrial proteome reference sets that specify proteins with substantial experimental evidence for mitochondrial localization. As further mitochondrial proteomics data sets from normal and diseased tissue are published, MitoMiner can be used to characterize the variability of the mitochondrial proteome between tissues and investigate how changes in the proteome may contribute to mitochondrial dysfunction and mitochondrial-associated diseases such as cancer, neurodegenerative diseases, obesity, diabetes, heart failure and the ageing process.
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Affiliation(s)
- Anthony C Smith
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
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Fyfe JC, Al-Tamimi RA, Liu J, Schäffer AA, Agarwala R, Henthorn PS. A novel mitofusin 2 mutation causes canine fetal-onset neuroaxonal dystrophy. Neurogenetics 2011; 12:223-32. [PMID: 21643798 PMCID: PMC3165057 DOI: 10.1007/s10048-011-0285-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 05/09/2011] [Indexed: 12/21/2022]
Abstract
We recently reported autosomal recessive fetal-onset neuroaxonal dystrophy (FNAD) in a large family of dogs that is not caused by mutation in the PLA2G6 locus (Fyfe et al., J Comp Neurol 518:3771-3784, 2010). Here, we report a genome-wide linkage analysis using 333 microsatellite markers to map canine FNAD to the telomeric end of chromosome 2. The interval of zero recombination was refined by single-nucleotide polymorphism (SNP) haplotype analysis to ~200 kb, and the included genes were sequenced. We found a homozygous 3-nucleotide deletion in exon 14 of mitofusin 2 (MFN2), predicting loss of a glutamate residue at position 539 in the protein of affected dogs. RT-PCR demonstrated near normal expression of the mutant mRNA, but MFN2 expression was undetectable to very low on western blots of affected dog brainstem, cerebrum, kidney, and cultured fibroblasts and by immunohistochemistry on brainstem sections. MFN2 is a multifunctional, membrane-bound GTPase of mitochondria and endoplasmic reticulum most commonly associated with human Charcot-Marie-Tooth disease type 2A2. The canine disorder extends the range of MFN2-associated phenotypes and suggests MFN2 as a candidate gene for rare cases of human FNAD.
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Affiliation(s)
- John C Fyfe
- Laboratory of Comparative Medical Genetics, Department of Microbiology and Molecular Genetics, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
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Stomatin-like protein 2 binds cardiolipin and regulates mitochondrial biogenesis and function. Mol Cell Biol 2011; 31:3845-56. [PMID: 21746876 DOI: 10.1128/mcb.05393-11] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Stomatin-like protein 2 (SLP-2) is a widely expressed mitochondrial inner membrane protein of unknown function. Here we show that human SLP-2 interacts with prohibitin-1 and -2 and binds to the mitochondrial membrane phospholipid cardiolipin. Upregulation of SLP-2 expression increases cardiolipin content and the formation of metabolically active mitochondrial membranes and induces mitochondrial biogenesis. In human T lymphocytes, these events correlate with increased complex I and II activities, increased intracellular ATP stores, and increased resistance to apoptosis through the intrinsic pathway, ultimately enhancing cellular responses. We propose that the function of SLP-2 is to recruit prohibitins to cardiolipin to form cardiolipin-enriched microdomains in which electron transport complexes are optimally assembled. Likely through the prohibitin functional interactome, SLP-2 then regulates mitochondrial biogenesis and function.
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Human MIEF1 recruits Drp1 to mitochondrial outer membranes and promotes mitochondrial fusion rather than fission. EMBO J 2011; 30:2762-78. [PMID: 21701560 PMCID: PMC3160255 DOI: 10.1038/emboj.2011.198] [Citation(s) in RCA: 273] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 05/23/2011] [Indexed: 11/26/2022] Open
Abstract
Mitochondrial morphology depends on the balance between fission and fusion events. This study identifies a receptor for the fission factor Drp1 within the mitochondrial outer membrane, which inhibits Drp1-mediated fission and activates fusion. Mitochondrial morphology is controlled by two opposing processes: fusion and fission. Drp1 (dynamin-related protein 1) and hFis1 are two key players of mitochondrial fission, but how Drp1 is recruited to mitochondria and how Drp1-mediated mitochondrial fission is regulated in mammals is poorly understood. Here, we identify the vertebrate-specific protein MIEF1 (mitochondrial elongation factor 1; independently identified as MiD51), which is anchored to the outer mitochondrial membrane. Elevated MIEF1 levels induce extensive mitochondrial fusion, whereas depletion of MIEF1 causes mitochondrial fragmentation. MIEF1 interacts with and recruits Drp1 to mitochondria in a manner independent of hFis1, Mff (mitochondrial fission factor) and Mfn2 (mitofusin 2), but inhibits Drp1 activity, thus executing a negative effect on mitochondrial fission. MIEF1 also interacts with hFis1 and elevated hFis1 levels partially reverse the MIEF1-induced fusion phenotype. In addition to inhibiting Drp1, MIEF1 also actively promotes fusion, but in a manner distinct from mitofusins. In conclusion, our findings uncover a novel mechanism which controls the mitochondrial fusion–fission machinery in vertebrates. As MIEF1 is vertebrate-specific, these data also reveal important differences between yeast and vertebrates in the regulation of mitochondrial dynamics.
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