1
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Sato K, Kadowaki T, Takenaka M, Konishi M, Ando M, Onodera T, Tsukuba T. RASEF/Rab45 regulates the formation and sorting of zymogen granules and secretion of digestive enzymes by pancreatic acinar cells. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167310. [PMID: 38901651 DOI: 10.1016/j.bbadis.2024.167310] [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: 03/12/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 06/22/2024]
Abstract
The pancreas is a glandular organ with both endocrine and exocrine functions. Researchers have investigated the roles of several Rab proteins, which are major regulators of membrane trafficking, in pancreatic exocytosis of zymogen granules in exocrine cells, also known as acinar cells. However, detailed molecular mechanisms mediated by Rab proteins are not fully understood. RASEF/Rab45 is an atypical Rab GTPase that contains N-terminal EF-hand and coiled-coil domains, as well as a C-terminal Rab-GTPase domain. In this study, we investigated the in vivo role of RASEF in pancreatic acinar cells using RASEF-knockout (KO) mice. Morphological analyses revealed that pancreatic acinar cells in RASEF-KO mice had an increased number of zymogen granules and abnormal formations of organelles, such as the endoplasmic reticulum (ER) and lysosomes. Biochemical analyses showed that ER proteins were decreased, but digestive enzymes were increased in the RASEF-KO pancreas. Moreover, trypsinogen was activated and co-localized with the endo-lysosomal marker LAMP1 in RASEF-KO pancreas. Upon cerulein administration to induce acute pancreatitis, impaired enzyme release from the pancreas was observed in the serum of RASEF-KO mice. These findings suggest that RASEF likely regulates the formation and sorting of zymogen granules and secretion of digestive enzymes by pancreatic acinar cells.
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Affiliation(s)
- Keiko Sato
- Department of Frontier Oral Science, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto 1-7-1, Nagasaki 852-8588, Japan
| | - Tomoko Kadowaki
- Department of Frontier Oral Science, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto 1-7-1, Nagasaki 852-8588, Japan.
| | - Mamoru Takenaka
- Department of Frontier Oral Science, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto 1-7-1, Nagasaki 852-8588, Japan
| | - Mayo Konishi
- Department of Frontier Oral Science, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto 1-7-1, Nagasaki 852-8588, Japan
| | - Miyabi Ando
- Department of Frontier Oral Science, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto 1-7-1, Nagasaki 852-8588, Japan
| | - Takae Onodera
- Department of Frontier Oral Science, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto 1-7-1, Nagasaki 852-8588, Japan
| | - Takayuki Tsukuba
- Department of Dental Pharmacology, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto 1-7-1, Nagasaki 852-8588, Japan
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2
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Radyk MD, Spatz LB, Peña BL, Brown JW, Burclaff J, Cho CJ, Kefalov Y, Shih C, Fitzpatrick JAJ, Mills JC. ATF3 induces RAB7 to govern autodegradation in paligenosis, a conserved cell plasticity program. EMBO Rep 2021; 22:e51806. [PMID: 34309175 PMCID: PMC8419698 DOI: 10.15252/embr.202051806] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 06/04/2021] [Accepted: 06/18/2021] [Indexed: 12/20/2022] Open
Abstract
Differentiated cells across multiple species and organs can re-enter the cell cycle to aid in injury-induced tissue regeneration by a cellular program called paligenosis. Here, we show that activating transcription factor 3 (ATF3) is induced early during paligenosis in multiple cellular contexts, transcriptionally activating the lysosomal trafficking gene Rab7b. ATF3 and RAB7B are upregulated in gastric and pancreatic digestive-enzyme-secreting cells at the onset of paligenosis Stage 1, when cells massively induce autophagic and lysosomal machinery to dismantle differentiated cell morphological features. Their expression later ebbs before cells enter mitosis during Stage 3. Atf3-/- mice fail to induce RAB7-positive autophagic and lysosomal vesicles, eventually causing increased death of cells en route to Stage 3. Finally, we observe that ATF3 is expressed in human gastric metaplasia and during paligenotic injury across multiple other organs and species. Thus, our findings indicate ATF3 is an evolutionarily conserved gene orchestrating the early paligenotic autodegradative events that must occur before cells are poised to proliferate and contribute to tissue repair.
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Affiliation(s)
- Megan D Radyk
- Division of GastroenterologyDepartment of MedicineWashington University School of MedicineSt. LouisMOUSA
| | - Lillian B Spatz
- Division of GastroenterologyDepartment of MedicineWashington University School of MedicineSt. LouisMOUSA
| | - Bianca L Peña
- Division of GastroenterologyDepartment of MedicineWashington University School of MedicineSt. LouisMOUSA
| | - Jeffrey W Brown
- Division of GastroenterologyDepartment of MedicineWashington University School of MedicineSt. LouisMOUSA
| | - Joseph Burclaff
- Division of GastroenterologyDepartment of MedicineWashington University School of MedicineSt. LouisMOUSA
| | - Charles J Cho
- Division of GastroenterologyDepartment of MedicineWashington University School of MedicineSt. LouisMOUSA
| | - Yan Kefalov
- Division of GastroenterologyDepartment of MedicineWashington University School of MedicineSt. LouisMOUSA
| | - Chien‐Cheng Shih
- Washington University Center for Cellular ImagingWashington University School of MedicineSt. LouisMOUSA
| | - James AJ Fitzpatrick
- Washington University Center for Cellular ImagingWashington University School of MedicineSt. LouisMOUSA
- Departments of Neuroscience and Cell Biology & PhysiologyWashington University School of MedicineSt. LouisMOUSA
- Department of Biomedical EngineeringWashington University in St. LouisSt. LouisMOUSA
| | - Jason C Mills
- Division of GastroenterologyDepartment of MedicineWashington University School of MedicineSt. LouisMOUSA
- Department of Developmental BiologyWashington University School of MedicineSt. LouisMOUSA
- Department of Pathology and ImmunologyWashington University School of MedicineSt. LouisMOUSA
- Present address:
Section of Gastroenterology and HepatologyDepartments of Medicine and PathologyBaylor College of MedicineHoustonTXUSA
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3
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Cyge B, Voronina V, Hoque M, Kim EN, Hall J, Bailey-Lundberg JM, Pazour GJ, Crawford HC, Moon RT, Li FQ, Takemaru KI. Loss of the ciliary protein Chibby1 in mice leads to exocrine pancreatic degeneration and pancreatitis. Sci Rep 2021; 11:17220. [PMID: 34446743 PMCID: PMC8390639 DOI: 10.1038/s41598-021-96597-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 08/12/2021] [Indexed: 12/12/2022] Open
Abstract
Primary cilia protrude from the apical surface of many cell types and act as a sensory organelle that regulates diverse biological processes ranging from chemo- and mechanosensation to signaling. Ciliary dysfunction is associated with a wide array of genetic disorders, known as ciliopathies. Polycystic lesions are commonly found in the kidney, liver, and pancreas of ciliopathy patients and mouse models. However, the pathogenesis of the pancreatic phenotype remains poorly understood. Chibby1 (Cby1), a small conserved coiled-coil protein, localizes to the ciliary base and plays a crucial role in ciliogenesis. Here, we report that Cby1-knockout (KO) mice develop severe exocrine pancreatic atrophy with dilated ducts during early postnatal development. A significant reduction in the number and length of cilia was observed in Cby1-KO pancreta. In the adult Cby1-KO pancreas, inflammatory cell infiltration and fibrosis were noticeable. Intriguingly, Cby1-KO acinar cells showed an accumulation of zymogen granules (ZGs) with altered polarity. Moreover, isolated acini from Cby1-KO pancreas exhibited defective ZG secretion in vitro. Collectively, our results suggest that, upon loss of Cby1, concomitant with ciliary defects, acinar cells accumulate ZGs due to defective exocytosis, leading to cell death and progressive exocrine pancreatic degeneration after birth.
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Affiliation(s)
- Benjamin Cyge
- Graduate Program in Molecular and Cellular Pharmacology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Vera Voronina
- Department of Pharmacology, Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine and Howard Hughes Medical Institute, Seattle, WA, 98195, USA
| | - Mohammed Hoque
- Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Eunice N Kim
- Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Jason Hall
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, 32224, USA
| | - Jennifer M Bailey-Lundberg
- Department of Anesthesiology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Howard C Crawford
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, 32224, USA
- Henry Ford Health System, Detroit, MI, 48202, USA
| | - Randall T Moon
- Department of Pharmacology, Institute for Stem Cell and Regenerative Medicine, University of Washington School of Medicine and Howard Hughes Medical Institute, Seattle, WA, 98195, USA
| | - Feng-Qian Li
- Graduate Program in Molecular and Cellular Pharmacology, Stony Brook University, Stony Brook, NY, 11794, USA
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11974, USA
| | - Ken-Ichi Takemaru
- Graduate Program in Molecular and Cellular Pharmacology, Stony Brook University, Stony Brook, NY, 11794, USA.
- Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, NY, 11794, USA.
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, 11974, USA.
- Department of Pharmacological Sciences, Stony Brook University, BST 7-182, 101 Nicolls Rd., Stony Brook, NY, 11794-8651, USA.
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4
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Wang Y, Guo S, Li D, Tang Y, Li L, Su L, Liu X. YIPF2 promotes chemotherapeutic agent-mediated apoptosis via enhancing TNFRSF10B recycling to plasma membrane in non-small cell lung cancer cells. Cell Death Dis 2020; 11:242. [PMID: 32303681 PMCID: PMC7165181 DOI: 10.1038/s41419-020-2436-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/19/2020] [Accepted: 03/20/2020] [Indexed: 12/19/2022]
Abstract
Non-small cell lung cancer (NSCLC) is the most common histological type of lung cancer, and the identification of the apoptotic process of NSCLC is vital for its treatment. Usually, both the expression level and the cell surface level of TNFRSF10B (TNF Receptor superfamily member 10B) will increase after treatment with some chemotherapeutic agents, which plays a critical role in the apoptosis induction. However, the exact molecular mechanism underlying TNFRSF10B regulation remains largely elusive. Here, we found that TNFRSF10B, along with a vesicular trafficking regulator protein, YIPF2, were upregulated after treatment with pemetrexed (PEM) in NSCLC cells. Besides, YIPF2 increased the surface level of TNFRF10B, while YIPF2 knockdown inhibited the upregulation of TNFRSF10B and its recycling to plasma membrane. In addition, RAB8 decreased the cell surface TNFRSF10B by promoting its removing from plasma membrane to cytoplasm. Furthermore, we found that YIPF2, RAB8 and TNFRSF10B proteins interacted physically with each other. YIPF2 could further inhibit the physical interaction between TNFRSF10B and RAB8, thereby suppressing the removing of TNFRSF10B from plasma membrane to cytoplasm mediated by RAB8 and maintaining its high level on cell surface. Finally, using bioinformatics database, the YIPF2-TNFRSF10B axis was confirmed to be associated with the malignant progression of lung cancer. Taken together, we show that YIPF2 promotes chemotherapeutic agent-mediated apoptosis via enhancing TNFRSF10B recycling to plasma membrane in NSCLC cells. These findings may be beneficial for the development of potential prognostic markers of NSCLC and may provide effective treatment strategy.
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Affiliation(s)
- Yingying Wang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Sen Guo
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Dongmei Li
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Yongkang Tang
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Lei Li
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Ling Su
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China.
| | - Xiangguo Liu
- Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China.
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5
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Molecular architecture of mouse and human pancreatic zymogen granules: protein components and their copy numbers. BIOPHYSICS REPORTS 2018; 4:94-103. [PMID: 29756009 PMCID: PMC5937866 DOI: 10.1007/s41048-018-0055-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 10/17/2017] [Indexed: 01/15/2023] Open
Abstract
A molecular model of pancreatic zymogen granule (ZG) is critical for understanding its functions. We have extensively characterized the composition and membrane topology of rat ZG proteins. In this study, we report the development of targeted proteomics approaches to quantify representative mouse and human ZG proteins using LC-SRM and heavy isotope-labeled synthetic peptides. The absolute quantities of mouse Rab3D and VAMP8 were determined as 1242 ± 218 and 2039 ± 151 (mean ± SEM) copies per ZG. The size distribution and the averaged diameter of ZGs 750 ± 23 nm (mean ± SEM) were determined by atomic force microscopy. The absolute quantification of Rab3D was then validated using semi-quantitative Western blotting with purified GST-Rab3D proteins as an internal standard. To extend our proteomics analysis to human pancreas, ZGs were purified using human acini obtained from pancreatic islet transplantation center. One hundred and eighty human ZG proteins were identified for the first time including both the membrane and the content proteins. Furthermore, the copy number per ZG of human Rab3D and VAMP8 were determined to be 1182 ± 45 and 485 ± 15 (mean ± SEM). The comprehensive proteomic analyses of mouse and human pancreatic ZGs have the potential to identify species-specific ZG proteins. The determination of protein copy numbers on pancreatic ZGs represents a significant advance towards building a quantitative molecular model of a prototypical secretory vesicle using targeted proteomics approaches. The identification of human ZG proteins lays a foundation for subsequent studies of altered ZG compositions and secretion in pancreatic diseases.
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6
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Sericin improves heart and liver mitochondrial architecture in hypercholesterolaemic rats and maintains pancreatic and adrenal cell biosynthesis. Exp Cell Res 2017; 358:301-314. [DOI: 10.1016/j.yexcr.2017.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 06/17/2017] [Accepted: 07/01/2017] [Indexed: 01/07/2023]
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7
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Vogel GF, Janecke AR, Krainer IM, Gutleben K, Witting B, Mitton SG, Mansour S, Ballauff A, Roland JT, Engevik AC, Cutz E, Müller T, Goldenring JR, Huber LA, Hess MW. Abnormal Rab11-Rab8-vesicles cluster in enterocytes of patients with microvillus inclusion disease. Traffic 2017; 18:453-464. [PMID: 28407399 DOI: 10.1111/tra.12486] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/05/2017] [Accepted: 04/05/2017] [Indexed: 12/14/2022]
Abstract
Microvillus inclusion disease (MVID) is a congenital enteropathy characterized by accumulation of vesiculo-tubular endomembranes in the subapical cytoplasm of enterocytes, historically termed "secretory granules." However, neither their identity nor pathophysiological significance is well defined. Using immunoelectron microscopy and tomography, we studied biopsies from MVID patients (3× Myosin 5b mutations and 1× Syntaxin3 mutation) and compared them to controls and genome-edited CaCo2 cell models, harboring relevant mutations. Duodenal biopsies from 2 patients with novel Myosin 5b mutations and typical clinical symptoms showed unusual ultrastructural phenotypes: aberrant subapical vesicles and tubules were prominent in the enterocytes, though other histological hallmarks of MVID were almost absent (ectopic intra-/intercellular microvilli, brush border atrophy). We identified these enigmatic vesiculo-tubular organelles as Rab11-Rab8-positive recycling compartments of altered size, shape and location harboring the apical SNARE Syntaxin3, apical transporters sodium-hydrogen exchanger 3 (NHE3) and cystic fibrosis transmembrane conductance regulator. Our data strongly indicate that in MVID disrupted trafficking between cargo vesicles and the apical plasma membrane is the primary cause of a defect of epithelial polarity and subsequent facultative loss of brush border integrity, leading to malabsorption. Furthermore, they support the notion that mislocalization of transporters, such as NHE3 substantially contributes to the reported sodium loss diarrhea.
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Affiliation(s)
- Georg F Vogel
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria.,Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Paediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Andreas R Janecke
- Department of Paediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Iris M Krainer
- Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria.,Department of Paediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Karin Gutleben
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | - Barbara Witting
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Sahar Mansour
- Human Genetics Research Center, St. George's University of London, London, UK
| | | | - Joseph T Roland
- Section of Surgical Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.,Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee.,Departments of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Amy C Engevik
- Section of Surgical Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.,Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee.,Departments of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Ernest Cutz
- Division of Pathology, Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Canada
| | - Thomas Müller
- Department of Paediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - James R Goldenring
- Section of Surgical Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.,Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, Tennessee.,Departments of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Lukas A Huber
- Division of Cell Biology, Medical University of Innsbruck, Innsbruck, Austria
| | - Michael W Hess
- Division of Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
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8
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Schrader TA, Schrader M. siRNA-mediated Silencing of Peroxisomal Genes in Mammalian Cells. Methods Mol Biol 2017; 1595:69-79. [PMID: 28409453 DOI: 10.1007/978-1-4939-6937-1_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
RNAi technologies are a valuable tool in the identification and investigation of proteins that are involved in peroxisome biogenesis and function. Small interfering RNA (siRNA) has developed into the most commonly used RNAi tool for the induction of transient, short-term silencing of protein coding genes. Although siRNA can induce gene knockdown in a variety of mammalian cell lines, their utility is limited by efficient uptake of synthetic oligonucleotides into the cells. Here, we describe different transfection methods that have been successfully used by us to silence peroxisomal genes in a variety of cell lines, including primary human skin fibroblasts, which are usually difficult to transfect.
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Affiliation(s)
- Tina A Schrader
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, Devon, UK
| | - Michael Schrader
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, Devon, UK.
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9
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Aroso M, Agricola B, Hacker C, Schrader M. Proteoglycans support proper granule formation in pancreatic acinar cells. Histochem Cell Biol 2015; 144:331-46. [PMID: 26105026 DOI: 10.1007/s00418-015-1339-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2015] [Indexed: 12/31/2022]
Abstract
Zymogen granules (ZG) are specialized organelles in the exocrine pancreas which allow digestive enzyme storage and regulated secretion. The molecular mechanisms of their biogenesis and the sorting of zymogens are still incompletely understood. Here, we investigated the role of proteoglycans in granule formation and secretion of zymogens in pancreatic AR42J cells, an acinar model system. Cupromeronic Blue cytochemistry and biochemical studies revealed an association of proteoglycans primarily with the granule membrane. Removal of proteoglycans by carbonate treatment led to a loss of membrane curvature indicating a supportive role in the maintenance of membrane shape and stability. Chemical inhibition of proteoglycan synthesis impaired the formation of normal electron-dense granules in AR42J cells and resulted in the formation of unusually small granule structures. These structures still contained the zymogen carboxypeptidase, a cargo molecule of secretory granules, but migrated to lighter fractions after density gradient centrifugation. Furthermore, the basal secretion of amylase was increased in AR42J cells after inhibitor treatment. In addition, irregular-shaped granules appeared in pancreatic lobules. We conclude that the assembly of a proteoglycan scaffold at the ZG membrane is supporting efficient packaging of zymogens and the proper formation of stimulus-competent storage granules in acinar cells of the pancreas.
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Affiliation(s)
- Miguel Aroso
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal
| | - Brigitte Agricola
- Department of Cell Biology and Cell Pathology, University of Marburg, 35037, Marburg, Germany
| | - Christian Hacker
- College of Life and Environmental Sciences, Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - Michael Schrader
- Centre for Cell Biology and Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal. .,College of Life and Environmental Sciences, Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
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10
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Gómez-Lázaro M, Rinn C, Aroso M, Amado F, Schrader M. Proteomic analysis of zymogen granules. Expert Rev Proteomics 2014; 7:735-47. [DOI: 10.1586/epr.10.31] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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11
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Modulating zymogen granule formation in pancreatic AR42J cells. Exp Cell Res 2012; 318:1855-66. [PMID: 22683857 DOI: 10.1016/j.yexcr.2012.05.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 05/11/2012] [Accepted: 05/24/2012] [Indexed: 01/07/2023]
Abstract
Zymogen granules (ZG) are specialized organelles in the exocrine pancreas which allow digestive enzyme storage and regulated secretion. To investigate ZG biogenesis, cargo sorting and packaging, suitable cellular model systems are required. Here, we demonstrate that granule formation in pancreatic AR42J cells, an acinar model system, can be modulated by altering the growth conditions in cell culture. We find that cultivation of AR42J cells in Panserin™ 401, a serum-free medium, enhances the induction of granule formation in the presence or absence of dexamethasone when compared to standard conditions including serum. Biochemical and morphological studies revealed an increase in ZG markers on the mRNA and protein level, as well as in granule size compared to standard conditions. Our data indicate that this effect is related to pronounced differentiation of AR42J cells. To address if enhanced expression of ZG proteins promotes granule formation, we expressed several zymogens and ZG membrane proteins in unstimulated AR42J cells and in constitutively secreting COS-7 cells. Neither single expression nor co-expression was sufficient to initiate granule formation in AR42J cells or the formation of granule-like structures in COS-7 cells as described for neuroendocrine cargo proteins. The importance of our findings for granule formation in exocrine cells is discussed.
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12
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Peränen J. Rab8 GTPase as a regulator of cell shape. Cytoskeleton (Hoboken) 2011; 68:527-39. [PMID: 21850707 DOI: 10.1002/cm.20529] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 08/08/2011] [Accepted: 08/09/2011] [Indexed: 12/14/2022]
Abstract
Endogenous Rab8 is found in dynamic cell structures like filopodia, lamellipodia, protrusions, ruffles, and primary cilia. Activation of Rab8 is linked to the formation of these actin containing structures, whereas inhibition of Rab8 affects negatively their appearance. The activity of Rab8 is controlled by specific guanine nucleotide exchange factors and GTPase activating proteins. Rab8 regulates a membrane recycling pathway that is linked to Arf6, EHD1, Myo5, and Rab11. A hypothesis is presented on the role of Rab8 in the formation of new cell surface domains. The review focuses on the function of Rab8 in cell migration, epithelial polarization, neuron differentiation, and ciliogenesis.
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Affiliation(s)
- Johan Peränen
- Institute of Biotechnology, University of Helsinki, Finland.
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13
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Bonekamp NA, Vormund K, Jacob R, Schrader M. Dynamin-like protein 1 at the Golgi complex: A novel component of the sorting/targeting machinery en route to the plasma membrane. Exp Cell Res 2010; 316:3454-67. [DOI: 10.1016/j.yexcr.2010.07.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2010] [Revised: 07/25/2010] [Accepted: 07/29/2010] [Indexed: 12/23/2022]
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14
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Borta H, Aroso M, Rinn C, Gomez-Lazaro M, Vitorino R, Zeuschner D, Grabenbauer M, Amado F, Schrader M. Analysis of low abundance membrane-associated proteins from rat pancreatic zymogen granules. J Proteome Res 2010; 9:4927-39. [PMID: 20707389 DOI: 10.1021/pr100052q] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Zymogen granules (ZG) are specialized storage organelles in the exocrine pancreas that allow the sorting, packaging, and regulated apical secretion of digestive enzymes. As there is a critical need for further understanding of the key processes in regulated secretion to develop new therapeutic options in medicine, we applied a suborganellar proteomics approach to identify peripheral membrane-associated ZG proteins. We focused on the analysis of a "basic" group (pH range 6.2-11) with about 46 spots among which 44 were identified by tandem mass spectrometry. These spots corresponded to 16 unique proteins, including rat mast cell chymase (RMCP-1) and peptidyl-prolyl cis-trans isomerase B (PpiB; cyclophilin B), an ER-resident protein. To confirm that these proteins were specific to zymogen granules and not contaminants of the preparation, we conducted a series of validation experiments. Immunoblotting of ZG subfractions revealed that chymase and PpiB behaved like bona fide peripheral membrane proteins. Their expression in rat pancreas was regulated by feeding behavior. Ultrastructural and immunofluorescence studies confirmed their ZG localization. Furthermore, a chymase-YFP fusion protein was properly targeted to ZG in pancreatic AR42J cells. Interestingly, for both proteins, proteoglycan-binding properties have been reported. The importance of our findings for sorting and packaging during ZG formation is discussed.
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Affiliation(s)
- Heike Borta
- Department of Cell Biology and Cell Pathology, Philipps University of Marburg, Robert Koch Strasse 6, Marburg, Germany
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15
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Vieira SI, Rebelo S, Esselmann H, Wiltfang J, Lah J, Lane R, Small SA, Gandy S, da Cruz E Silva EF, da Cruz E Silva OA. Retrieval of the Alzheimer's amyloid precursor protein from the endosome to the TGN is S655 phosphorylation state-dependent and retromer-mediated. Mol Neurodegener 2010; 5:40. [PMID: 20937087 PMCID: PMC2994555 DOI: 10.1186/1750-1326-5-40] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 10/11/2010] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Retrograde transport of several transmembrane proteins from endosomes to the trans-Golgi network (TGN) occurs via Rab 5-containing endosomes, mediated by clathrin and the recently characterized retromer complex. This complex and one of its putative sorting receptor components, SorLA, were reported to be associated to late onset Alzheimer's disease (AD). The pathogenesis of this neurodegenerative disorder is still elusive, although accumulation of amyloidogenic Abeta is a hallmark. This peptide is generated from the sucessive β- and γ- secretase proteolysis of the Alzheimer's amyloid precursor protein (APP), events which are associated with endocytic pathway compartments. Therefore, APP targeting and time of residence in endosomes would be predicted to modulate Abeta levels. However, the formation of an APP- and retromer-containing protein complex with potential functions in retrieval of APP from the endosome to the TGN had, to date, not been demonstrated directly. Further, the motif(s) in APP that regulate its sorting to the TGN have not been characterized. RESULTS Through the use of APP-GFP constructs, we show that APP containing endocytic vesicles targeted for the TGN, are also immunoreactive for clathrin-, Rab 5- and VPS35. Further, they frequently generate protruding tubules near the TGN, supporting an association with a retromer-mediated pathway. Importantly, we show for the first time, that mimicking APP phosphorylation at S655, within the APP 653YTSI656 basolateral motif, enhances APP retrieval via a retromer-mediated process. The phosphomimetic APP S655E displays decreased APP lysosomal targeting, enhanced mature half-life, and decreased tendency towards Abeta production. VPS35 downregulation impairs the phosphorylation dependent APP retrieval to the TGN, and decreases APP half-life. CONCLUSIONS We reported for the first time the importance of APP phosphorylation on S655 in regulating its retromer-mediated sorting to the TGN or lysosomes. Significantly, the data are consistent with known interactions involving the retromer, SorLA and APP. Further, these findings add to our understanding of APP targeting and potentially contribute to our knowledge of sporadic AD pathogenesis representing putative new targets for AD therapeutic strategies.
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Affiliation(s)
- Sandra I Vieira
- Neuroscience, Centre for Cell Biology, Health Sciences Department SACS, University of Aveiro, Aveiro 3810, Portugal.
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Raffaniello R, Fedorova D, Ip D, Rafiq S. Hsp90 Co-localizes with Rab-GDI-1 and regulates agonist-induced amylase release in AR42J cells. Cell Physiol Biochem 2009; 24:369-78. [PMID: 19910677 DOI: 10.1159/000257429] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2009] [Indexed: 11/19/2022] Open
Abstract
Rab proteins are small GTPases required for vesicle trafficking through the secretory and endocytic pathways. Rab GDP-dissociation inhibitor (rab-GDI) regulates Rab protein function and localization by maintaining Rab proteins in the GDP-bound conformation. Two isoforms of rab-GDI are present in most mammalian cells: GDI-1 and GDI-2. It has recently been demonstrated that a Heat shock protein 90 (Hsp90) chaperone complex regulates the interactions between Rab proteins and Rab-GDI-1. The AR42J cell line is derived from rat pancreatic exocrine tumor cells and develops an acinar-like phenotype when treated with dexamethasone (Dex). The aim of the present study was to examine the expression of rab-GDI isoforms and Hsp90 in AR42J cells in the presence or absence of Dex. Rab-GDI:Hsp90 interactions were also examined. Both rab-GDI isoforms were detected in AR42J cells by immunoblotting. In Dex-treated cells, quantitative immunoblotting revealed that rab-GDI-1 expression increased by 28%, although this change was not statistically significant. Rab-GDI-2 levels were unaltered by Dex treatment. Approximately 21% rab-GDI-1 was membrane associated, whereas rab-GDI-2 was exclusively cytosolic. Dex treatment did not affect the subcellular distribution of rab-GDI isoforms. Hsp90 was present in the cytosolic and membrane fractions of AR42J cells and co-immunoprecipitated with cytosolic rab-GDI-1. Moreover, density gradient centrifugation of AR42J cell membranes revealed that Hsp90 and rab-GDI-1 co-localize on low- and high-density membrane fractions, including amylase-containing secretory granules. The Hsp90 inhibitor, geldanamycin, inhibited CCK-8-induced amylase release from these cells in a dose-dependent manner. Our results indicate that as AR42J cells differentiate into acinar-like cells, rab-GDI isoform expression and localization is not significantly altered. Moreover, our findings suggest that Hsp90 regulates agonist-induced secretion in exocrine cells by interacting with rab-GDI-1.
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Jacobs DT, Weigert R, Grode KD, Donaldson JG, Cheney RE. Myosin Vc is a molecular motor that functions in secretory granule trafficking. Mol Biol Cell 2009; 20:4471-88. [PMID: 19741097 DOI: 10.1091/mbc.e08-08-0865] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Class V myosins are actin-based motor proteins that have critical functions in organelle trafficking. Of the three class V myosins expressed in mammals, relatively little is known about Myo5c except that it is abundant in exocrine tissues. Here we use MCF-7 cells to identify the organelles that Myo5c associates with, image the dynamics of Myo5c in living cells, and test the functions of Myo5c. Endogenous Myo5c localizes to two distinct compartments: small puncta and slender tubules. Myo5c often exhibits a highly polarized distribution toward the leading edge in migrating cells and is clearly distinct from the Myo5a or Myo5b compartments. Imaging with GFP-Myo5c reveals that Myo5c puncta move slowly (approximately 30 nm/s) and microtubule independently, whereas tubules move rapidly (approximately 440 nm/s) and microtubule dependently. Myo5c puncta colocalize with secretory granule markers such as chromogranin A and Rab27b, whereas Myo5c tubules are labeled by Rab8a. TIRF imaging indicates that the granules can be triggered to undergo secretion. To test if Myo5c functions in granule trafficking, we used the Myo5c tail as a dominant negative and found that it dramatically perturbs the distribution of granule markers. These results provide the first live-cell imaging of Myo5c and indicate that Myo5c functions in secretory granule trafficking.
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Affiliation(s)
- Damon T Jacobs
- Department of Cell and Molecular Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Williams JA, Chen X, Sabbatini ME. Small G proteins as key regulators of pancreatic digestive enzyme secretion. Am J Physiol Endocrinol Metab 2009; 296:E405-14. [PMID: 19088252 PMCID: PMC2660147 DOI: 10.1152/ajpendo.90874.2008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Small GTP-binding (G) proteins act as molecular switches to regulate a number of cellular processes, including vesicular transport. Emerging evidence indicates that small G proteins regulate a number of steps in the secretion of pancreatic acinar cells. Diverse small G proteins have been localized at discrete compartments along the secretory pathway and particularly on the secretory granule. Rab3D, Rab27B, and Rap1 are present on the granule membrane and play a role in the steps leading up to exocytosis. Whether the function of these G proteins is simply to ensure appropriate targeting or if they are involved as regulatory molecules is discussed. Most evidence suggests that Rab3D and Rab27B play a role in tethering the secretory granule to its target membrane. Other Rabs have been identified on the secretory granule that are associated with different steps in the secretory pathway. The Rho family small G proteins RhoA and Rac1 also regulate secretion through remodeling of the actin cytoskeleton. Possible mechanisms for regulation of these G proteins and their effector molecules are considered.
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Affiliation(s)
- John A Williams
- Dept. of Molecular and Integrative Physiology, Univ. of Michigan, Ann Arbor, MI 48109, USA.
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Urwyler S, Nyfeler Y, Ragaz C, Lee H, Mueller LN, Aebersold R, Hilbi H. Proteome analysis of Legionella vacuoles purified by magnetic immunoseparation reveals secretory and endosomal GTPases. Traffic 2008; 10:76-87. [PMID: 18980612 DOI: 10.1111/j.1600-0854.2008.00851.x] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Legionella pneumophila, the causative agent of Legionnaires' disease, replicates in macrophages and amoebae within 'Legionella-containing vacuoles' (LCVs), which communicate with the early secretory pathway and the endoplasmic reticulum. Formation of LCVs requires the bacterial Icm/Dot type IV secretion system. The Icm/Dot-translocated effector protein SidC selectively anchors to LCVs by binding the host lipid phosphatidylinositol-4-phosphate (PtdIns(4)P). Here, we describe a novel and simple approach to purify intact vacuoles formed by L. pneumophila within Dictyostelium discoideum by using magnetic immunoseparation with an antibody against SidC, followed by density gradient centrifugation. To monitor LCV purification by fluorescence microscopy, we used Dictyostelium producing the LCV marker calnexin-GFP and L. pneumophila labeled with the red fluorescent protein DsRed. A proteome analysis of purified LCVs by liquid chromatography coupled to tandem mass spectrometry revealed 566 host proteins, including known LCV components, such as the small GTPases Arf1, Rab1 and Rab7. Rab8, an endosomal regulator of the late secretory pathway originating from the trans Golgi network, and the endosomal GTPase Rab14 were identified as novel LCV components, which were found to be present on vacuoles harboring wild-type but not Icm/Dot-deficient L. pneumophila. Thus, LCVs also communicate with the late secretory and endosomal pathways. Depletion of Rab8 or Arf1 by RNA interference reduced the amount of SidC on LCVs, indicating that the GTPases promote the recruitment of Legionella effectors by regulating the level of PtdIns(4)P.
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Affiliation(s)
- Simon Urwyler
- Institute of Microbiology, Department of Biology, ETH Zurich, Zurich, Switzerland
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Cramm-Behrens CI, Dienst M, Jacob R. Apical cargo traverses endosomal compartments on the passage to the cell surface. Traffic 2008; 9:2206-20. [PMID: 18785995 DOI: 10.1111/j.1600-0854.2008.00829.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Epithelial polarity is based on intracellular sorting machinery that maintains the asymmetric distribution of lipids and proteins to the cell surface. Dependent on their lipid raft affinity, newly synthesized apical polypeptides are segregated into distinct vesicle populations subsequent to the passage through the Golgi apparatus. Using a combined fluorescence microscopic and biochemical approach, we found that lipid raft-associated sucrase-isomaltase (SI) as well as non-raft-associated lactase-phlorizin hydrolase (LPH) traverse endosomal compartments before entering the apical membrane. Fluorescent fusion proteins of both hydrolases were co-stained with Rab4-, Rab8- and Rab11-positive endosomes in polarized Madin-Darby canine kidney and non-polarized COS-1 cells. Immunoisolation of post-Golgi vesicles subsequent to different times of TGN release revealed that LPH and SI navigate in chronological order through Rab4-, Rab8- and Rab11-positive endosomes. Thereafter, the two hydrolases are segregated into distinct vesicle populations. In addition, apical membrane traffic could be significantly inhibited by RNA interference-mediated depletion of these guanosine triphosphatases. These results suggest that in epithelial cells, lipid raft-dependent and -independent apical cargo follow a transendosomal route.
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