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Tsvilovskyy V, Ottenheijm R, Kriebs U, Schütz A, Diakopoulos KN, Jha A, Bildl W, Wirth A, Böck J, Jaślan D, Ferro I, Taberner FJ, Kalinina O, Hildebrand S, Wissenbach U, Weissgerber P, Vogt D, Eberhagen C, Mannebach S, Berlin M, Kuryshev V, Schumacher D, Philippaert K, Camacho-Londoño JE, Mathar I, Dieterich C, Klugbauer N, Biel M, Wahl-Schott C, Lipp P, Flockerzi V, Zischka H, Algül H, Lechner SG, Lesina M, Grimm C, Fakler B, Schulte U, Muallem S, Freichel M. OCaR1 endows exocytic vesicles with autoregulatory competence by preventing uncontrolled Ca2+ release, exocytosis, and pancreatic tissue damage. J Clin Invest 2024; 134:e169428. [PMID: 38557489 PMCID: PMC10977991 DOI: 10.1172/jci169428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 02/13/2024] [Indexed: 04/04/2024] Open
Abstract
Regulated exocytosis is initiated by increased Ca2+ concentrations in close spatial proximity to secretory granules, which is effectively prevented when the cell is at rest. Here we showed that exocytosis of zymogen granules in acinar cells was driven by Ca2+ directly released from acidic Ca2+ stores including secretory granules through NAADP-activated two-pore channels (TPCs). We identified OCaR1 (encoded by Tmem63a) as an organellar Ca2+ regulator protein integral to the membrane of secretory granules that controlled Ca2+ release via inhibition of TPC1 and TPC2 currents. Deletion of OCaR1 led to extensive Ca2+ release from NAADP-responsive granules under basal conditions as well as upon stimulation of GPCR receptors. Moreover, OCaR1 deletion exacerbated the disease phenotype in murine models of severe and chronic pancreatitis. Our findings showed OCaR1 as a gatekeeper of Ca2+ release that endows NAADP-sensitive secretory granules with an autoregulatory mechanism preventing uncontrolled exocytosis and pancreatic tissue damage.
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Affiliation(s)
- Volodymyr Tsvilovskyy
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Roger Ottenheijm
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Ulrich Kriebs
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Aline Schütz
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Kalliope Nina Diakopoulos
- Comprehensive Cancer Center München, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Archana Jha
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, USA
| | - Wolfgang Bildl
- Institute for Physiology, University of Freiburg, Freiburg, Germany
| | - Angela Wirth
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Julia Böck
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Dawid Jaślan
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Irene Ferro
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Francisco J. Taberner
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández–Consejo Superior de Investigaciones Científicas, Sant Joan d’Alacant, Spain
| | - Olga Kalinina
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany
| | - Staffan Hildebrand
- Institut für Pharmakologie und Toxikologie, Universität Bonn, Bonn, Germany
| | - Ulrich Wissenbach
- Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Petra Weissgerber
- Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Dominik Vogt
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Carola Eberhagen
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Stefanie Mannebach
- Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Michael Berlin
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Vladimir Kuryshev
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Dagmar Schumacher
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Koenraad Philippaert
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | | | - Ilka Mathar
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Christoph Dieterich
- University Hospital Heidelberg, Department of Medicine III: Cardiology, Angiology and Pneumology, Heidelberg, Germany
| | - Norbert Klugbauer
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Fakultät für Medizin, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPS-M) and Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, and DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Christian Wahl-Schott
- Walter Brendel Centre of Experimental Medicine, Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Medical Faculty, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Peter Lipp
- Institute for Molecular Cell Biology, Center for Molecular Signaling (PZMS), Universität des Saarlandes, Homburg, Germany
| | - Veit Flockerzi
- Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Hans Zischka
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Toxicology and Environmental Hygiene, Technical University Munich, School of Medicine, Munich, Germany
| | - Hana Algül
- Comprehensive Cancer Center München, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Stefan G. Lechner
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Marina Lesina
- Comprehensive Cancer Center München, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Christian Grimm
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
- Immunology, Infection and Pandemic Research (IIP), Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Munich, Germany
| | - Bernd Fakler
- Institute for Physiology, University of Freiburg, Freiburg, Germany
| | - Uwe Schulte
- Institute for Physiology, University of Freiburg, Freiburg, Germany
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, USA
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
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2
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Takahashi K, Mashima H, Sekine M, Uehara T, Asano T, Sun-Wada GH, Wada Y, Ohnishi H. Rab7 localized on zymogen granules is involved in maturation but not in autophagy or regulated exocytosis in pancreatic acinar cells. Sci Rep 2023; 13:22084. [PMID: 38087030 PMCID: PMC10716180 DOI: 10.1038/s41598-023-49520-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 12/08/2023] [Indexed: 12/18/2023] Open
Abstract
Rab7 is known to function in the autophagy and endocytosis pathways in eukaryocytes and is related to various diseases. We recently reported that Rab7 plays a protective role against acute pancreatitis. However, its physiological function in exocytic cells remains unclear. Therefore, we investigated the role of Rab7 in pancreas-specific Rab7 knockout mice (Rab7Δpan). Immunofluorescence microscopy revealed that Rab7 colocalized with amylase in pancreatic acinar cells of wild-type mice, but not in Rab7Δpan mice. Western blotting confirmed Rab7 localization in the zymogen granule (ZG) membranes of wild-type mice. Cholecystokinin (CCK)-stimulated amylase secretion examined using isolated pancreatic acini was similar in Rab7Δpan and wild-type mice. In contrast, electron microscopy revealed that the diameters of ZGs were shorter and the number of ZGs was larger in the pancreatic acinar cells of Rab7Δpan mice than in those of wild-type mice. However, the number of ZGs decreased in both Rab7Δpan and wild-type mice after 24 h of starvation. In addition, the amount of amylase in the pancreas was decreased in both Rab7Δpan and wild-type mice. These data indicate that Rab7 localized on ZGs plays a crucial role in the maturation of ZGs but not in their autophagy or regulated exocytosis in pancreatic acinar cells.
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Affiliation(s)
- Kenichi Takahashi
- Department of Gastroenterology, Akita University Graduate School of Medicine, Akita, Japan
| | - Hirosato Mashima
- Department of Gastroenterology, Jichi Medical University Saitama Medical Center, 1-847 Amanuma-Cho, Omiya-Ku, Saitama, 330-8503, Japan.
| | - Masanari Sekine
- Department of Gastroenterology, Jichi Medical University Saitama Medical Center, 1-847 Amanuma-Cho, Omiya-Ku, Saitama, 330-8503, Japan
| | - Takeshi Uehara
- Department of Gastroenterology, Jichi Medical University Saitama Medical Center, 1-847 Amanuma-Cho, Omiya-Ku, Saitama, 330-8503, Japan
| | - Takeharu Asano
- Department of Gastroenterology, Jichi Medical University Saitama Medical Center, 1-847 Amanuma-Cho, Omiya-Ku, Saitama, 330-8503, Japan
| | - Ge-Hong Sun-Wada
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College, Kyoto, Japan
| | - Yoh Wada
- Division of Biological Science, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Hirohide Ohnishi
- Department of Gastroenterology, Jichi Medical University Saitama Medical Center, 1-847 Amanuma-Cho, Omiya-Ku, Saitama, 330-8503, Japan
- Japan Organization of Occupational Health and Safety, Kawasaki, Kanagawa, Japan
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3
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Deletion in chromosome 6 spanning alpha-synuclein and multimerin1 loci in the Rab27a/b double knockout mouse. Sci Rep 2022; 12:9837. [PMID: 35701443 PMCID: PMC9197848 DOI: 10.1038/s41598-022-13557-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 05/25/2022] [Indexed: 11/08/2022] Open
Abstract
We report an incidental 358.5 kb deletion spanning the region encoding for alpha-synuclein (αsyn) and multimerin1 (Mmrn1) in the Rab27a/Rab27b double knockout (DKO) mouse line previously developed by Tolmachova and colleagues in 2007. Western blot and RT-PCR studies revealed lack of αsyn expression at either the mRNA or protein level in Rab27a/b DKO mice. PCR of genomic DNA from Rab27a/b DKO mice demonstrated at least partial deletion of the Snca locus using primers targeted to exon 4 and exon 6. Most genes located in proximity to the Snca locus, including Atoh1, Atoh2, Gm5570, Gm4410, Gm43894, and Grid2, were shown not to be deleted by PCR except for Mmrn1. Using whole genomic sequencing, the complete deletion was mapped to chromosome 6 (60,678,870–61,037,354), a slightly smaller deletion region than that previously reported in the C57BL/6J substrain maintained by Envigo. Electron microscopy of cortex from these mice demonstrates abnormally enlarged synaptic terminals with reduced synaptic vesicle density, suggesting potential interplay between Rab27 isoforms and αsyn, which are all highly expressed at the synaptic terminal. Given this deletion involving several genes, the Rab27a/b DKO mouse line should be used with caution or with appropriate back-crossing to other C57BL/6J mouse substrain lines without this deletion.
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Abu-Libdeh B, Mor-Shaked H, Atawna AA, Gillis D, Halstuk O, Shaul-Lotan N, Slae M, Sultan M, Meiner V, Elpeleg O, Harel T. Homozygous variant in MADD, encoding a Rab guanine nucleotide exchange factor, results in pleiotropic effects and a multisystemic disorder. Eur J Hum Genet 2021; 29:977-987. [PMID: 33723354 DOI: 10.1038/s41431-021-00844-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 01/20/2021] [Accepted: 02/24/2021] [Indexed: 12/20/2022] Open
Abstract
Rab proteins coordinate inter-organellar vesicle-mediated transport, facilitating intracellular communication, protein recycling, and signaling processes. Dysfunction of Rab proteins or their direct interactors leads to a wide range of diseases with diverse manifestations. We describe seven individuals from four consanguineous Arab Muslim families with an infantile-lethal syndrome, including failure to thrive (FTT), chronic diarrhea, neonatal respiratory distress, variable pituitary dysfunction, and distal arthrogryposis. Exome sequencing analysis in the independent families, followed by an internal gene-matching process using a local exome database, identified a homozygous splice-site variant in MADD (c.2816 + 1 G > A) on a common haplotype. The variant segregated with the disease in all available family members. Determination of cDNA sequence verified single exon skipping, resulting in an out-of-frame deletion. MADD encodes a Rab guanine nucleotide exchange factor (GEF), which activates RAB3 and RAB27A/27B and is thus a crucial regulator of neuromuscular junctions and endocrine secretory granule release. Moreover, MADD protects cells from caspase-mediated TNF-α-induced apoptosis. The combined roles of MADD and its downstream effectors correlate with the phenotypic spectrum of disease, and call for additional studies to confirm the pathogenic mechanism and to investigate possible therapeutic avenues through modulation of TNF-α signaling.
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Affiliation(s)
- Bassam Abu-Libdeh
- Department of Pediatrics, Makassed Hospital and Faculty of Medicine, Al-Quds University, East Jerusalem, Palestine
| | - Hagar Mor-Shaked
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Amir A Atawna
- Department of Neonatology, Makassed Hospital, East Jerusalem, Palestine
| | - David Gillis
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Pediatrics, Hadassah Medical Center, Jerusalem, Israel
| | - Orli Halstuk
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nava Shaul-Lotan
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel
| | - Mordechai Slae
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Pediatrics, Hadassah Medical Center, Jerusalem, Israel
| | - Mutaz Sultan
- Department of Pediatrics, Makassed Hospital and Faculty of Medicine, Al-Quds University, East Jerusalem, Palestine
| | - Vardiella Meiner
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tamar Harel
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel. .,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
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5
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Fu R, Edman MC, Hamm-Alvarez SF. Rab27a Contributes to Cathepsin S Secretion in Lacrimal Gland Acinar Cells. Int J Mol Sci 2021; 22:1630. [PMID: 33562815 PMCID: PMC7914720 DOI: 10.3390/ijms22041630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 01/30/2021] [Accepted: 02/02/2021] [Indexed: 02/06/2023] Open
Abstract
Altered lacrimal gland (LG) secretion is a feature of autoimmune dacryoadenitis in Sjögren's syndrome (SS). Cathepsin S (CTSS) is increased in tears of SS patients, which may contribute to disease. Rab3D and Rab27a/b isoforms are effectors of exocytosis in LG, but Rab27a is poorly studied. To investigate whether Rab27a mediates CTSS secretion, we utilized quantitative confocal fluorescence microscopy of LG from SS-model male NOD and control male BALB/c mice, showing that Rab27a-enriched vesicles containing CTSS were increased in NOD mouse LG. Live-cell imaging of cultured lacrimal gland acinar cells (LGAC) transduced with adenovirus encoding wild-type (WT) mCFP-Rab27a revealed carbachol-stimulated fusion and depletion of mCFP-Rab27a-enriched vesicles. LGAC transduced with dominant-negative (DN) mCFP-Rab27a exhibited significantly reduced carbachol-stimulated CTSS secretion by 0.5-fold and β-hexosaminidase by 0.3-fold, relative to stimulated LGAC transduced with WT mCFP-Rab27a. Colocalization of Rab27a and endolysosomal markers (Rab7, Lamp2) with the apical membrane was increased in both stimulated BALB/c and NOD mouse LG, but the extent of colocalization was much greater in NOD mouse LG. Following stimulation, Rab27a colocalization with endolysosomal membranes was decreased. In conclusion, Rab27a participates in CTSS secretion in LGAC though the major regulated pathway, and through a novel endolysosomal pathway that is increased in SS.
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Affiliation(s)
- Runzhong Fu
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA;
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA;
| | - Maria C. Edman
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA;
| | - Sarah F. Hamm-Alvarez
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA;
- Department of Ophthalmology, Roski Eye Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA;
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6
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Schneeberger PE, Kortüm F, Korenke GC, Alawi M, Santer R, Woidy M, Buhas D, Fox S, Juusola J, Alfadhel M, Webb BD, Coci EG, Abou Jamra R, Siekmeyer M, Biskup S, Heller C, Maier EM, Javaher-Haghighi P, Bedeschi MF, Ajmone PF, Iascone M, Peeters H, Ballon K, Jaeken J, Rodríguez Alonso A, Palomares-Bralo M, Santos-Simarro F, Meuwissen MEC, Beysen D, Kooy RF, Houlden H, Murphy D, Doosti M, Karimiani EG, Mojarrad M, Maroofian R, Noskova L, Kmoch S, Honzik T, Cope H, Sanchez-Valle A, Gelb BD, Kurth I, Hempel M, Kutsche K. Biallelic MADD variants cause a phenotypic spectrum ranging from developmental delay to a multisystem disorder. Brain 2020; 143:2437-2453. [PMID: 32761064 PMCID: PMC7447524 DOI: 10.1093/brain/awaa204] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 12/22/2022] Open
Abstract
In pleiotropic diseases, multiple organ systems are affected causing a variety of clinical manifestations. Here, we report a pleiotropic disorder with a unique constellation of neurological, endocrine, exocrine, and haematological findings that is caused by biallelic MADD variants. MADD, the mitogen-activated protein kinase (MAPK) activating death domain protein, regulates various cellular functions, such as vesicle trafficking, activity of the Rab3 and Rab27 small GTPases, tumour necrosis factor-α (TNF-α)-induced signalling and prevention of cell death. Through national collaboration and GeneMatcher, we collected 23 patients with 21 different pathogenic MADD variants identified by next-generation sequencing. We clinically evaluated the series of patients and categorized the phenotypes in two groups. Group 1 consists of 14 patients with severe developmental delay, endo- and exocrine dysfunction, impairment of the sensory and autonomic nervous system, and haematological anomalies. The clinical course during the first years of life can be potentially fatal. The nine patients in Group 2 have a predominant neurological phenotype comprising mild-to-severe developmental delay, hypotonia, speech impairment, and seizures. Analysis of mRNA revealed multiple aberrant MADD transcripts in two patient-derived fibroblast cell lines. Relative quantification of MADD mRNA and protein in fibroblasts of five affected individuals showed a drastic reduction or loss of MADD. We conducted functional tests to determine the impact of the variants on different pathways. Treatment of patient-derived fibroblasts with TNF-α resulted in reduced phosphorylation of the extracellular signal-regulated kinases 1 and 2, enhanced activation of the pro-apoptotic enzymes caspase-3 and -7 and increased apoptosis compared to control cells. We analysed internalization of epidermal growth factor in patient cells and identified a defect in endocytosis of epidermal growth factor. We conclude that MADD deficiency underlies multiple cellular defects that can be attributed to alterations of TNF-α-dependent signalling pathways and defects in vesicular trafficking. Our data highlight the multifaceted role of MADD as a signalling molecule in different organs and reveal its physiological role in regulating the function of the sensory and autonomic nervous system and endo- and exocrine glands.
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Affiliation(s)
- Pauline E Schneeberger
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fanny Kortüm
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Georg Christoph Korenke
- Klinik für Neuropädiatrie und angeborene Stoffwechselerkrankungen, Klinikum Oldenburg, Oldenburg, Germany
| | - Malik Alawi
- Bioinformatics Core Unit, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - René Santer
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Mathias Woidy
- Department of Pediatrics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Daniela Buhas
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Canada
- Human Genetics Department, McGill University, Montreal, Canada
| | - Stephanie Fox
- Division of Medical Genetics, Department of Specialized Medicine, McGill University Health Centre, Montreal, Canada
- Human Genetics Department, McGill University, Montreal, Canada
| | | | - Majid Alfadhel
- Division of Genetics, Department of Pediatrics, King Abdullah specialized Children's Hospital, King Abdulaziz Medical City, Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia
- King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia
| | - Bryn D Webb
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Emanuele G Coci
- Department for Neuropediatrics, University Children's Hospital, Ruhr University Bochum, Bochum, Germany
- Department of Pediatrics, Prignitz Hospital, Brandenburg Medical School, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, University Medical Center Leipzig, Leipzig, Germany
| | - Manuela Siekmeyer
- Universitätsklinikum Leipzig - AöR, University of Leipzig, Hospital for Children and Adolescents, Leipzig, Germany
| | - Saskia Biskup
- CeGaT GmbH and Praxis für Humangenetik Tübingen, Tübingen, Germany
| | - Corina Heller
- CeGaT GmbH and Praxis für Humangenetik Tübingen, Tübingen, Germany
| | - Esther M Maier
- Dr. von Hauner Children's Hospital, University of Munich, Munich, Germany
| | | | - Maria F Bedeschi
- Medical Genetic Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Paola F Ajmone
- Child and Adolescent Neuropsychiatric Unit, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Maria Iascone
- Laboratorio di Genetica Medica, ASST Papa Giovanni XXIII, Bergamo, Italy
| | - Hilde Peeters
- Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - Katleen Ballon
- Centre for Developmental Disabilities, Department of Development and Regeneration, KU Leuven, Leuven, Belgium
| | - Jaak Jaeken
- Center for Metabolic Diseases, KU Leuven, Leuven, Belgium
| | - Aroa Rodríguez Alonso
- Unidad de Patología Compleja, Servicio de Pediatría, Hospital Universitario La Paz, Madrid, Spain
| | - María Palomares-Bralo
- Instituto de Genética Médica y Molecular (INGEMM), Hospital Universitario La Paz, IdiPAZ, CIBERER, ISCIII, Madrid, Spain
| | - Fernando Santos-Simarro
- Instituto de Genética Médica y Molecular (INGEMM), Hospital Universitario La Paz, IdiPAZ, CIBERER, ISCIII, Madrid, Spain
| | | | - Diane Beysen
- Department of Pediatric Neurology, University Hospital Antwerp, Antwerp, Belgium
| | - R Frank Kooy
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Henry Houlden
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - David Murphy
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | | | - Ehsan G Karimiani
- Next Generation Genetic Polyclinic, Mashhad, Iran
- Genetics Research Centre, Molecular and Clinical Sciences Institute, St. George's, University, London, UK
| | - Majid Mojarrad
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
- Genetic Center of Khorasan Razavi, Mashhad, Iran
| | - Reza Maroofian
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and The National Hospital for Neurology and Neurosurgery, London, UK
| | - Lenka Noskova
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Stanislav Kmoch
- Research Unit for Rare Diseases, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Tomas Honzik
- Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Heidi Cope
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
| | - Amarilis Sanchez-Valle
- Division of Genetics and Metabolism, College of Medicine, University of South Florida, Tampa, Florida, USA
| | - Bruce D Gelb
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, USA
- Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Ingo Kurth
- Institute of Human Genetics, Medical Faculty, RWTH Aachen University, Aachen, Germany
- Institute of Human Genetics, Jena University Hospital, Jena, Germany
| | - Maja Hempel
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Kerstin Kutsche
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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7
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Li Z, Fang R, Fang J, He S, Liu T. Functional implications of Rab27 GTPases in Cancer. Cell Commun Signal 2018; 16:44. [PMID: 30081925 PMCID: PMC6080553 DOI: 10.1186/s12964-018-0255-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 07/27/2018] [Indexed: 12/14/2022] Open
Abstract
Background The Rab27 family of small GTPases promotes the progression of breast cancer, melanoma, and other human cancers. In this review, we discuss the role of Rab27 GTPases in cancer progression and the potential applications of these targets in cancer treatment. Main body Elevated expression of Rab27 GTPases is associated with poor prognosis and cancer metastasis. Moreover, these GTPases govern a variety of oncogenic functions, including cell proliferation, cell motility, and chemosensitivity. In addition, small GTPases promote tumor growth and metastasis by enhancing exosome secretion, which alters intracellular microRNA levels, signaling molecule expression, and the tumor microenvironment. Conclusion Rab27 GTPases may have applications as prognostic markers and therapeutic targets in cancer treatment.
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Affiliation(s)
- Zhihong Li
- Department of Orthopaedics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Rui Fang
- Department of Orthopaedics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jia Fang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Shasha He
- Department of Oncology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, People's Republic of China.
| | - Tang Liu
- Department of Orthopaedics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
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8
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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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9
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Bustos MA, Lucchesi O, Ruete MC, Tomes CN. Membrane-permeable Rab27A is a regulator of the acrosome reaction: Role of geranylgeranylation and guanine nucleotides. Cell Signal 2018; 44:72-81. [PMID: 29337043 DOI: 10.1016/j.cellsig.2018.01.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 12/18/2017] [Accepted: 01/09/2018] [Indexed: 12/11/2022]
Abstract
The acrosome reaction is the regulated exocytosis of mammalian sperm's single secretory granule, essential for fertilization. It relies on small GTPases, the cAMP binding protein Epac, and the SNARE complex, among other components. Here, we describe a novel tool to investigate Rab27-related signaling pathways: a hybrid recombinant protein consisting of human Rab27A fused to TAT, a cell penetrating peptide. With this tool, we aimed to unravel the connection between Rab3, Rab27 and Rap1 in sperm exocytosis and to deepen our understanding about how isoprenylation and guanine nucleotides influence the behaviour of Rab27 in exocytosis. Our results show that TAT-Rab27A-GTP-γ-S permeated into live sperm and triggered acrosomal exocytosis per se when geraylgeranylated but inhibited it when not lipid-modified. Likewise, an impermeant version of Rab27A elicited exocytosis in streptolysin O-permeabilized - but not in non-permeabilized - cells when geranylgeranylated and active. When GDP-β-S substituted for GTP-γ-S, isoprenylated TAT-Rab27A inhibited the acrosome reaction triggered by progesterone and an Epac-selective cAMP analogue, whereas the non-isoprenylated protein did not. Geranylgeranylated TAT-Rab27A-GTP-γ-S promoted the exchange of GDP for GTP on Rab3 and Rap1 detected by far-immunofluorescence with Rab3-GTP and Rap1-GTP binding cassettes. In contrast, TAT-Rab27A lacking isoprenylation or loaded with GDP-β-S prevented the activation of Rab3 and Rap1 elicited by progesterone. Challenging streptolysin O-permeabilized human sperm with calcium increased the population of sperm with Rap1-GTP, Rab3-GTP and Rab27-GTP in the acrosomal region; pretreatment with anti-Rab27 antibodies prevented the activation of all three. The novel findings reported here include: the description of membrane permeant TAT-Rab27A as a trustworthy tool to unveil the regulation of the human sperm acrosome reaction by Rab27 under physiological conditions; that the activation of endogenous Rab27 is required for that of Rab3 and Rap1; and the connection between Epac and Rab27 and between Rab27 and the configuration of the SNARE complex. Moreover, we present direct evidence that Rab27A's lipid modification, and activation/inactivation status correlate with its stimulatory or inhibitory roles in exocytosis.
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Affiliation(s)
- Matías A Bustos
- Instituto de Histologia y Embriologia de Mendoza (IHEM) Dr. Mario H. Burgos-CONICET, Universidad Nacional de Cuyo, casilla de correo 56, 5500 Mendoza, Argentina
| | - Ornella Lucchesi
- Instituto de Histologia y Embriologia de Mendoza (IHEM) Dr. Mario H. Burgos-CONICET, Universidad Nacional de Cuyo, casilla de correo 56, 5500 Mendoza, Argentina
| | - María C Ruete
- Instituto de Histologia y Embriologia de Mendoza (IHEM) Dr. Mario H. Burgos-CONICET, Universidad Nacional de Cuyo, casilla de correo 56, 5500 Mendoza, Argentina
| | - Claudia N Tomes
- Instituto de Histologia y Embriologia de Mendoza (IHEM) Dr. Mario H. Burgos-CONICET, Universidad Nacional de Cuyo, casilla de correo 56, 5500 Mendoza, Argentina.
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10
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Takahashi K, Mashima H, Miura K, Maeda D, Goto A, Goto T, Sun-Wada GH, Wada Y, Ohnishi H. Disruption of Small GTPase Rab7 Exacerbates the Severity of Acute Pancreatitis in Experimental Mouse Models. Sci Rep 2017; 7:2817. [PMID: 28588238 PMCID: PMC5460112 DOI: 10.1038/s41598-017-02988-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 04/21/2017] [Indexed: 01/25/2023] Open
Abstract
Although aberrations of intracellular vesicle transport systems towards lysosomes including autophagy and endocytosis are involved in the onset and progression of acute pancreatitis, the molecular mechanisms underlying such aberrations remain unclear. The pathways of autophagy and endocytosis are closely related, and Rab7 plays crucial roles in both. In this study, we analyzed the function of Rab7 in acute pancreatitis using pancreas-specific Rab7 knockout (Rab7Δpan) mice. In Rab7Δpan pancreatic acinar cells, the maturation steps of both endosomes and autophagosomes were deteriorated, and the lysosomal functions were affected. In experimental models of acute pancreatitis, the histopathological severity, serum amylase concentration and intra-pancreatic trypsin activity were significantly higher in Rab7Δpan mice than in wild-type mice. Furthermore, the autophagy process was blocked in Rab7Δpan pancreas compared with wild-type mice. In addition, larger autophagic vacuoles that colocalize with early endosome antigen 1 (EEA1) but not with lysosomal-associated membrane protein (LAMP)-1 were much more frequently formed in Rab7Δpan pancreatic acinar cells. Accordingly, Rab7 deficiency exacerbates the severity of acute pancreatitis by impairing the autophagic and endocytic pathways toward lysosomes.
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Affiliation(s)
- Kenichi Takahashi
- Department of Gastroenterology and Hepato-Biliary-Pancreatology, Akita University Graduate School of Medicine, Akita, Japan
| | - Hirosato Mashima
- Department of Gastroenterology, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Kouichi Miura
- Department of Gastroenterology and Hepato-Biliary-Pancreatology, Akita University Graduate School of Medicine, Akita, Japan
| | - Daichi Maeda
- Department of Cellular and Organ Pathology, Akita University Graduate School of Medicine, Akita, Japan
| | - Akiteru Goto
- Department of Cellular and Organ Pathology, Akita University Graduate School of Medicine, Akita, Japan
| | - Takashi Goto
- Department of Gastroenterology and Hepato-Biliary-Pancreatology, Akita University Graduate School of Medicine, Akita, Japan
| | - Ge-Hong Sun-Wada
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College, Kyoto, Japan
| | - Yoh Wada
- Division of Biological Science, Institute of Scientific and Industrial Research, Osaka University, Osaka, Japan
| | - Hirohide Ohnishi
- Department of Gastroenterology, Saitama Medical Center, Jichi Medical University, Saitama, Japan.
- Japan Organization of Occupational Health and Safety, Kanagawa, Japan.
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11
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Meng Z, Edman MC, Hsueh PY, Chen CY, Klinngam W, Tolmachova T, Okamoto CT, Hamm-Alvarez SF. Imbalanced Rab3D versus Rab27 increases cathepsin S secretion from lacrimal acini in a mouse model of Sjögren's Syndrome. Am J Physiol Cell Physiol 2016; 310:C942-54. [PMID: 27076615 DOI: 10.1152/ajpcell.00275.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 04/06/2016] [Indexed: 02/04/2023]
Abstract
The mechanism responsible for the altered spectrum of tear proteins secreted by lacrimal gland acinar cells (LGAC) in patients with Sjögren's Syndrome (SS) remains unknown. We have previously identified increased cathepsin S (CTSS) activity as a unique characteristic of tears of patients with SS. Here, we investigated the role of Rab3D, Rab27a, and Rab27b proteins in the enhanced release of CTSS from LGAC. Similar to patients with SS and to the male nonobese diabetic (NOD) mouse model of SS, CTSS activity was elevated in tears of mice lacking Rab3D. Findings of lower gene expression and altered localization of Rab3D in NOD LGAC reinforce a role for Rab3D in suppressing excess CTSS release under physiological conditions. However, CTSS activity was significantly reduced in tears of mice lacking Rab27 isoforms. The reliance of CTSS secretion on Rab27 activity was supported by in vitro findings that newly synthesized CTSS was detected in and secreted from Rab27-enriched secretory vesicles and that expression of dominant negative Rab27b reduced carbachol-stimulated secretion of CTSS in cultured LGAC. High-resolution 3D-structured illumination microscopy revealed microdomains of Rab3D and Rab27 isoforms on the same secretory vesicles but present in different proportions on different vesicles, suggesting that changes in their relative association with secretory vesicles may tailor the vesicle contents. We propose that a loss of Rab3D from secretory vesicles, leading to disproportionate Rab27-to-Rab3D activity, may contribute to the enhanced release of CTSS in tears of patients with SS.
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Affiliation(s)
- Zhen Meng
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Maria C Edman
- Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Pang-Yu Hsueh
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Chiao-Yu Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Wannita Klinngam
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | | | - Curtis T Okamoto
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
| | - Sarah F Hamm-Alvarez
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California; Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California;
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12
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Wankel B, Ouyang J, Guo X, Hadjiolova K, Miller J, Liao Y, Tham DKL, Romih R, Andrade LR, Gumper I, Simon JP, Sachdeva R, Tolmachova T, Seabra MC, Fukuda M, Schaeren-Wiemers N, Hong WJ, Sabatini DD, Wu XR, Kong X, Kreibich G, Rindler MJ, Sun TT. Sequential and compartmentalized action of Rabs, SNAREs, and MAL in the apical delivery of fusiform vesicles in urothelial umbrella cells. Mol Biol Cell 2016; 27:1621-34. [PMID: 27009205 PMCID: PMC4865319 DOI: 10.1091/mbc.e15-04-0230] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 03/17/2016] [Indexed: 01/28/2023] Open
Abstract
As major urothelial differentiation products, uroplakins are targeted to the apical surface of umbrella cells. Via the sequential actions of Rabs 11, 8, and 27b and their effectors, uroplakin vesicles are transported to a subapical zone above a K20 network and fuse, via a SNARE-mediated and MAL-facilitated step, with the urothelial apical membrane. Uroplakins (UPs) are major differentiation products of urothelial umbrella cells and play important roles in forming the permeability barrier and in the expansion/stabilization of the apical membrane. Further, UPIa serves as a uropathogenic Escherichia coli receptor. Although it is understood that UPs are delivered to the apical membrane via fusiform vesicles (FVs), the mechanisms that regulate this exocytic pathway remain poorly understood. Immunomicroscopy of normal and mutant mouse urothelia show that the UP-delivering FVs contained Rab8/11 and Rab27b/Slac2-a, which mediate apical transport along actin filaments. Subsequently a Rab27b/Slp2-a complex mediated FV–membrane anchorage before SNARE-mediated and MAL-facilitated apical fusion. We also show that keratin 20 (K20), which forms a chicken-wire network ∼200 nm below the apical membrane and has hole sizes allowing FV passage, defines a subapical compartment containing FVs primed and strategically located for fusion. Finally, we show that Rab8/11 and Rab27b function in the same pathway, Rab27b knockout leads to uroplakin and Slp2-a destabilization, and Rab27b works upstream from MAL. These data support a unifying model in which UP cargoes are targeted for apical insertion via sequential interactions with Rabs and their effectors, SNAREs and MAL, and in which K20 plays a key role in regulating vesicular trafficking.
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Affiliation(s)
- Bret Wankel
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Jiangyong Ouyang
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Xuemei Guo
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Krassimira Hadjiolova
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Jeremy Miller
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Yi Liao
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Daniel Kai Long Tham
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Rok Romih
- Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Leonardo R Andrade
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Iwona Gumper
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Jean-Pierre Simon
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Rakhee Sachdeva
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Tanya Tolmachova
- Molecular and Cellular Medicine, Imperial College, London SW7 2AZ, United Kingdom
| | - Miguel C Seabra
- Molecular and Cellular Medicine, Imperial College, London SW7 2AZ, United Kingdom
| | - Mitsunori Fukuda
- Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Sendai 980-8578, Japan
| | - Nicole Schaeren-Wiemers
- Neurobiology Laboratory, Department of Biomedicine, University Hospital Basel, University of Basel, CH-4031 Basel, Switzerland
| | - Wan Jin Hong
- Cancer and Developmental Cell Biology Division, Institute of Molecular and Cell Biology, A*STAR, Biopolis, Singapore 138673
| | - David D Sabatini
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Xue-Ru Wu
- Department of Urology, New York University School of Medicine, New York, NY10016
| | - Xiangpeng Kong
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY10016
| | - Gert Kreibich
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Michael J Rindler
- Department of Cell Biology, New York University School of Medicine, New York, NY10016
| | - Tung-Tien Sun
- Department of Cell Biology, New York University School of Medicine, New York, NY10016 Department of Urology, New York University School of Medicine, New York, NY10016 Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY10016 Department of Dermatology, New York University School of Medicine, New York, NY10016
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13
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Hou Y, Ernst SA, Lentz SI, Williams JA. Genetic deletion of Rab27B in pancreatic acinar cells affects granules size and has inhibitory effects on amylase secretion. Biochem Biophys Res Commun 2016; 471:610-5. [PMID: 26845357 DOI: 10.1016/j.bbrc.2016.01.180] [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] [Received: 01/22/2016] [Accepted: 01/29/2016] [Indexed: 11/26/2022]
Abstract
Small G protein Rab27B is expressed in various secretory cell types and plays a role in mediating secretion. In pancreatic acinar cells, Rab27B was found to be expressed on the zymogen granule membrane and by overexpression to regulate the secretion of zymogen granules. However, the effect of Rab27B deletion on the physiology of pancreatic acinar cells is unknown. In the current study, we utilized the Rab27B KO mouse model to better understand the role of Rab27B in the secretion of pancreatic acinar cells. Our data show that Rab27B deficiency had no obvious effects on the expression of major digestive enzymes and other closely related proteins, e.g. similar small G proteins, such as Rab3D and Rab27A, and putative downstream effectors. The overall morphology of acinar cells was not changed in the knockout pancreas. However, the size of zymogen granules was decreased in KO acinar cells, suggesting a role of Rab27B in regulating the maturation of secretory granules. The secretion of digestive enzymes was moderately decreased in KO acini, compared with the WT control. These data indicate that Rab27B is involved at a different steps of zymogen granule maturation and secretion, which is distinct from that of Rab3D.
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Affiliation(s)
- Yanan Hou
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Stephen A Ernst
- Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Stephen I Lentz
- Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - John A Williams
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
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14
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Felix JF, Bradfield JP, Monnereau C, van der Valk RJP, Stergiakouli E, Chesi A, Gaillard R, Feenstra B, Thiering E, Kreiner-Møller E, Mahajan A, Pitkänen N, Joro R, Cavadino A, Huikari V, Franks S, Groen-Blokhuis MM, Cousminer DL, Marsh JA, Lehtimäki T, Curtin JA, Vioque J, Ahluwalia TS, Myhre R, Price TS, Vilor-Tejedor N, Yengo L, Grarup N, Ntalla I, Ang W, Atalay M, Bisgaard H, Blakemore AI, Bonnefond A, Carstensen L, Eriksson J, Flexeder C, Franke L, Geller F, Geserick M, Hartikainen AL, Haworth CMA, Hirschhorn JN, Hofman A, Holm JC, Horikoshi M, Hottenga JJ, Huang J, Kadarmideen HN, Kähönen M, Kiess W, Lakka HM, Lakka TA, Lewin AM, Liang L, Lyytikäinen LP, Ma B, Magnus P, McCormack SE, McMahon G, Mentch FD, Middeldorp CM, Murray CS, Pahkala K, Pers TH, Pfäffle R, Postma DS, Power C, Simpson A, Sengpiel V, Tiesler CMT, Torrent M, Uitterlinden AG, van Meurs JB, Vinding R, Waage J, Wardle J, Zeggini E, Zemel BS, Dedoussis GV, Pedersen O, Froguel P, Sunyer J, Plomin R, Jacobsson B, Hansen T, Gonzalez JR, Custovic A, Raitakari OT, Pennell CE, Widén E, Boomsma DI, Koppelman GH, Sebert S, Järvelin MR, Hyppönen E, McCarthy MI, Lindi V, Harri N, Körner A, Bønnelykke K, Heinrich J, Melbye M, Rivadeneira F, Hakonarson H, Ring SM, Smith GD, Sørensen TIA, Timpson NJ, Grant SFA, Jaddoe VWV. Genome-wide association analysis identifies three new susceptibility loci for childhood body mass index. Hum Mol Genet 2016; 25:389-403. [PMID: 26604143 PMCID: PMC4854022 DOI: 10.1093/hmg/ddv472] [Citation(s) in RCA: 218] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 11/15/2015] [Indexed: 12/24/2022] Open
Abstract
A large number of genetic loci are associated with adult body mass index. However, the genetics of childhood body mass index are largely unknown. We performed a meta-analysis of genome-wide association studies of childhood body mass index, using sex- and age-adjusted standard deviation scores. We included 35 668 children from 20 studies in the discovery phase and 11 873 children from 13 studies in the replication phase. In total, 15 loci reached genome-wide significance (P-value < 5 × 10(-8)) in the joint discovery and replication analysis, of which 12 are previously identified loci in or close to ADCY3, GNPDA2, TMEM18, SEC16B, FAIM2, FTO, TFAP2B, TNNI3K, MC4R, GPR61, LMX1B and OLFM4 associated with adult body mass index or childhood obesity. We identified three novel loci: rs13253111 near ELP3, rs8092503 near RAB27B and rs13387838 near ADAM23. Per additional risk allele, body mass index increased 0.04 Standard Deviation Score (SDS) [Standard Error (SE) 0.007], 0.05 SDS (SE 0.008) and 0.14 SDS (SE 0.025), for rs13253111, rs8092503 and rs13387838, respectively. A genetic risk score combining all 15 SNPs showed that each additional average risk allele was associated with a 0.073 SDS (SE 0.011, P-value = 3.12 × 10(-10)) increase in childhood body mass index in a population of 1955 children. This risk score explained 2% of the variance in childhood body mass index. This study highlights the shared genetic background between childhood and adult body mass index and adds three novel loci. These loci likely represent age-related differences in strength of the associations with body mass index.
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Affiliation(s)
- Janine F Felix
- The Generation R Study Group, Department of Pediatrics, Department of Epidemiology,
| | | | - Claire Monnereau
- The Generation R Study Group, Department of Pediatrics, Department of Epidemiology
| | | | | | | | - Romy Gaillard
- The Generation R Study Group, Department of Pediatrics, Department of Epidemiology
| | - Bjarke Feenstra
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Elisabeth Thiering
- Institute of Epidemiology I, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany, Division of Metabolic and Nutritional Medicine, Dr von Hauner Children's Hospital, University of Munich Medical Center, Munich, Germany
| | - Eskil Kreiner-Møller
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital
| | | | - Niina Pitkänen
- Research Centre of Applied and Preventive Cardiovascular Medicine, Institute of Clinical Medicine, Neurology
| | - Raimo Joro
- Institute of Biomedicine, Physiology, University of Eastern Finland, Kuopio, Finland
| | - Alana Cavadino
- Centre for Environmental and Preventive Medicine, Wolfson Institute of Preventive Medicine, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, UK, Population, Policy and Practice, UCL Institute of Child Health
| | | | - Steve Franks
- Institute of Reproductive and Developmental Biology
| | - Maria M Groen-Blokhuis
- Department of Biological Psychology, VU University Amsterdam, NCA Neuroscience Campus Amsterdam, EMGO+ Institute for Health and Care Research, Amsterdam, the Netherlands
| | - Diana L Cousminer
- Institute for Molecular Medicine, Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Julie A Marsh
- School of Women's and Infants' Health, The University of Western Australia, Perth, Australia
| | - Terho Lehtimäki
- Department of Clinical Chemistry, Fimlab Laboratories, Tampere, Finland, Department of Clinical Chemistry
| | - John A Curtin
- Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester and University Hospital of South Manchester, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Jesus Vioque
- Universidad Miguel Hernandez, Elche-Alicante, Spain, CIBER Epidemiología y Salud Pública (CIBERESP), Spain
| | - Tarunveer S Ahluwalia
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital, Novo Nordisk Foundation Centre for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, Steno Diabetes Center, Gentofte, Denmark
| | - Ronny Myhre
- Department of Genes and Envrionment, Division of Epidemiology
| | - Thomas S Price
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania Perelman School of Medicine, USA
| | - Natalia Vilor-Tejedor
- CIBER Epidemiología y Salud Pública (CIBERESP), Spain, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain, Pompeu Fabra University (UPF), Barcelona, Spain
| | - Loïc Yengo
- CNRS UMR8199, Pasteur Institute Lille, France, European Genomic Institute for Diabetes (EGID), Lille, France
| | - Niels Grarup
- Novo Nordisk Foundation Centre for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ioanna Ntalla
- Department of Health Sciences, University of Leicester, Leicester, UK, Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University, Athens, Greece
| | - Wei Ang
- School of Women's and Infants' Health, The University of Western Australia, Perth, Australia
| | - Mustafa Atalay
- Institute of Biomedicine, Physiology, University of Eastern Finland, Kuopio, Finland
| | - Hans Bisgaard
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital
| | - Alexandra I Blakemore
- Section of Investigative Medicine, Division of Diabetes, Endocrinology, and Metabolism, Faculty of Medicine, Imperial College, London, UK
| | - Amelie Bonnefond
- CNRS UMR8199, Pasteur Institute Lille, France, European Genomic Institute for Diabetes (EGID), Lille, France
| | - Lisbeth Carstensen
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | | | | | - Johan Eriksson
- National Institute for Health and Welfare, Helsinki, Finland
| | - Claudia Flexeder
- Institute of Epidemiology I, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany
| | | | - Frank Geller
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark
| | - Mandy Geserick
- Center of Pediatric Research, Department of Women's and Child Health, LIFE Child (Leipzig Research Center for Civilization Diseases)
| | | | | | - Joel N Hirschhorn
- Division of Endocrinology and Center for Basic and Translational Obesity Research, Boston Children's Hospital, Boston, USA, Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, USA, Department of Genetics, Harvard Medical School, Boston, USA
| | - Albert Hofman
- The Generation R Study Group, Department of Epidemiology
| | - Jens-Christian Holm
- The Children's Obesity Clinic, Department of Pediatrics, Copenhagen University Hospital Holbæk, The Danish Childhood Obesity Biobank, Denmark, Institute of Medicine, Copenhagen University, Copenhagen, Denmark
| | - Momoko Horikoshi
- Wellcome Trust Centre for Human Genetics, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - Jouke Jan Hottenga
- Department of Biological Psychology, VU University Amsterdam, NCA Neuroscience Campus Amsterdam, EMGO+ Institute for Health and Care Research, Amsterdam, the Netherlands
| | - Jinyan Huang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haja N Kadarmideen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Mika Kähönen
- Department of Clinical Physiology, University of Tampere School of Medicine, Tampere, Finland, Department of Clinical Physiology, Tampere University Hospital, Tampere, Finland
| | - Wieland Kiess
- Center of Pediatric Research, Department of Women's and Child Health
| | - Hanna-Maaria Lakka
- Institute of Biomedicine, Physiology, University of Eastern Finland, Kuopio, Finland
| | - Timo A Lakka
- Institute of Biomedicine, Physiology, University of Eastern Finland, Kuopio, Finland, Kuopio Research Institute of Exercise Medicine, Kuopio, Finland, Department of Clinical Physiology and Nuclear Medicine, Kuopio University Hospital, Kuopio, Finland
| | - Alexandra M Lewin
- Department of Epidemiology and Biostatistics, MRC Health Protection Agency (HPE) Centre for Environment and Health, School of Public Health, Imperial College London, UK
| | - Liming Liang
- Department of Epidemiology, Department of Biostatistics, Harvard School of Public Health, Boston, USA
| | - Leo-Pekka Lyytikäinen
- Department of Clinical Chemistry, Fimlab Laboratories, Tampere, Finland, Department of Clinical Chemistry
| | - Baoshan Ma
- College of Information Science and Technology, Dalian Maritime University, Dalian, Liaoning Province, China
| | - Per Magnus
- Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway
| | - Shana E McCormack
- Division of Human Genetics, Division of Endocrinology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - George McMahon
- MRC Integrative Epidemiology Unit at the University of Bristol
| | | | - Christel M Middeldorp
- Department of Biological Psychology, VU University Amsterdam, NCA Neuroscience Campus Amsterdam, EMGO+ Institute for Health and Care Research, Amsterdam, the Netherlands
| | - Clare S Murray
- Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester and University Hospital of South Manchester, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Katja Pahkala
- Research Centre of Applied and Preventive Cardiovascular Medicine, Department of Health and Physical Activity, Paavo Nurmi Centre, Sports and Exercise Medicine Unit
| | - Tune H Pers
- Division of Endocrinology and Center for Basic and Translational Obesity Research, Boston Children's Hospital, Boston, USA, Medical and Population Genetics Program, Broad Institute of MIT and Harvard, Cambridge, USA
| | - Roland Pfäffle
- Center of Pediatric Research, Department of Women's and Child Health, CrescNet, Medical Faculty, University of Leipzig, Germany
| | - Dirkje S Postma
- Department of Pulmonology, GRIAC (Groningen Research Institute for Asthma and COPD)
| | - Christine Power
- Population, Policy and Practice, UCL Institute of Child Health
| | - Angela Simpson
- Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester and
| | - Verena Sengpiel
- Department of Obstetrics and Gynecology, Sahlgrenska Academy, Sahlgrenska University Hosptial, Gothenburg, Sweden
| | - Carla M T Tiesler
- Institute of Epidemiology I, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany, Division of Metabolic and Nutritional Medicine, Dr von Hauner Children's Hospital, University of Munich Medical Center, Munich, Germany
| | - Maties Torrent
- CIBER Epidemiología y Salud Pública (CIBERESP), Spain, Area de Salut de Menorca, ib-salut, Menorca, Spain
| | - André G Uitterlinden
- The Generation R Study Group, Department of Epidemiology, Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Joyce B van Meurs
- Department of Epidemiology, Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Rebecca Vinding
- Department of Pediatrics, Naestved Hospital, Naestved, Denmark, COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital
| | - Johannes Waage
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital
| | - Jane Wardle
- Department of Epidemiology and Public Health, University College London, UK
| | - Eleftheria Zeggini
- Wellcome Trust Sanger Institute, The Morgan Building, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, UK
| | - Babette S Zemel
- Division of Gastroenterology, Hepatology and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA, USA, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - George V Dedoussis
- Department of Nutrition and Dietetics, School of Health Science and Education, Harokopio University, Athens, Greece
| | - Oluf Pedersen
- Novo Nordisk Foundation Centre for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Philippe Froguel
- CNRS UMR8199, Pasteur Institute Lille, France, Department of Genomics of Common Disease, School of Public Health, Imperial College London, Hammersmith Hospital, London, UK
| | - Jordi Sunyer
- CIBER Epidemiología y Salud Pública (CIBERESP), Spain, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain, Pompeu Fabra University (UPF), Barcelona, Spain, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
| | - Robert Plomin
- King's College London, MRC Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, Psychology and Neuroscience, De Crespigny Park, London, UK
| | - Bo Jacobsson
- Department of Genes and Envrionment, Division of Epidemiology, Department of Obstetrics and Gynecology, Sahlgrenska Academy, Sahlgrenska University Hosptial, Gothenburg, Sweden
| | - Torben Hansen
- Novo Nordisk Foundation Centre for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Juan R Gonzalez
- CIBER Epidemiología y Salud Pública (CIBERESP), Spain, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain, Pompeu Fabra University (UPF), Barcelona, Spain
| | - Adnan Custovic
- Centre for Respiratory Medicine and Allergy, Institute of Inflammation and Repair, University of Manchester and University Hospital of South Manchester, Manchester Academic Health Sciences Centre, Manchester, UK
| | - Olli T Raitakari
- Research Centre of Applied and Preventive Cardiovascular Medicine, Department of Clinical Physiology and Nuclear Medicine
| | - Craig E Pennell
- School of Women's and Infants' Health, The University of Western Australia, Perth, Australia
| | - Elisabeth Widén
- Institute for Molecular Medicine, Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Dorret I Boomsma
- Department of Biological Psychology, VU University Amsterdam, NCA Neuroscience Campus Amsterdam, EMGO+ Institute for Health and Care Research, Amsterdam, the Netherlands
| | - Gerard H Koppelman
- Department of Pediatric Pulmonology and Pediatric Allergology, Beatrix Children's Hospital, GRIAC (Groningen Research Institute for Asthma and COPD), University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Sylvain Sebert
- Centre for Life Course Epidemiology, Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Marjo-Riitta Järvelin
- Centre for Life Course Epidemiology, Biocenter Oulu, University of Oulu, Oulu, Finland, Department of Epidemiology and Biostatistics, MRC Health Protection Agency (HPE) Centre for Environment and Health, School of Public Health, Imperial College London, UK, Unit of Primary Care, Oulu University Hospital, Oulu, Finland, Department of Children and Young People and Families, National Institute for Health and Welfare, Oulu, Finland
| | - Elina Hyppönen
- Population, Policy and Practice, UCL Institute of Child Health, School of Population Health and Sansom Institute, University of South Australia, Adelaide, Australia, South Australian Health and Medical Research Institute, Adelaide, Australia
| | - Mark I McCarthy
- Wellcome Trust Centre for Human Genetics, Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK, Oxford National Institute for Health Research (NIHR) Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Virpi Lindi
- Institute of Biomedicine, Physiology, University of Eastern Finland, Kuopio, Finland
| | - Niinikoski Harri
- Department of Pediatrics, Turku University Hospital, University of Turku, Turku, Finland
| | - Antje Körner
- Center of Pediatric Research, Department of Women's and Child Health
| | - Klaus Bønnelykke
- COPSAC, Copenhagen Prospective Studies on Asthma in Childhood, Herlev and Gentofte Hospital
| | - Joachim Heinrich
- Institute of Epidemiology I, Helmholtz Zentrum München-German Research Center for Environmental Health, Neuherberg, Germany
| | - Mads Melbye
- Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA and
| | - Fernando Rivadeneira
- The Generation R Study Group, Department of Epidemiology, Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Hakon Hakonarson
- Center for Applied Genomics, Division of Human Genetics, Department of Obstetrics and Gynecology, Sahlgrenska Academy, Sahlgrenska University Hosptial, Gothenburg, Sweden
| | - Susan M Ring
- MRC Integrative Epidemiology Unit at the University of Bristol, Avon Longitudinal Study of Parents and Children (ALSPAC), School of Social and Community Medicine, University of Bristol, Bristol, UK
| | | | - Thorkild I A Sørensen
- MRC Integrative Epidemiology Unit at the University of Bristol, Novo Nordisk Foundation Centre for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark, Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, The Capital Region, Copenhagen, Denmark
| | | | - Struan F A Grant
- Center for Applied Genomics, Division of Human Genetics, Division of Endocrinology, Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Vincent W V Jaddoe
- The Generation R Study Group, Department of Pediatrics, Department of Epidemiology
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15
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Park S, Ahuja M, Kim MS, Brailoiu GC, Jha A, Zeng M, Baydyuk M, Wu LG, Wassif CA, Porter FD, Zerfas PM, Eckhaus MA, Brailoiu E, Shin DM, Muallem S. Fusion of lysosomes with secretory organelles leads to uncontrolled exocytosis in the lysosomal storage disease mucolipidosis type IV. EMBO Rep 2015; 17:266-78. [PMID: 26682800 DOI: 10.15252/embr.201541542] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/04/2015] [Indexed: 01/29/2023] Open
Abstract
Mutations in TRPML1 cause the lysosomal storage disease mucolipidosis type IV (MLIV). The role of TRPML1 in cell function and how the mutations cause the disease are not well understood. Most studies focus on the role of TRPML1 in constitutive membrane trafficking to and from the lysosomes. However, this cannot explain impaired neuromuscular and secretory cells' functions that mediate regulated exocytosis. Here, we analyzed several forms of regulated exocytosis in a mouse model of MLIV and, opposite to expectations, we found enhanced exocytosis in secretory glands due to enlargement of secretory granules in part due to fusion with lysosomes. Preliminary exploration of synaptic vesicle size, spontaneous mEPSCs, and glutamate secretion in neurons provided further evidence for enhanced exocytosis that was rescued by re-expression of TRPML1 in neurons. These features were not observed in Niemann-Pick type C1. These findings suggest that TRPML1 may guard against pathological fusion of lysosomes with secretory organelles and suggest a new approach toward developing treatment for MLIV.
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Affiliation(s)
- Soonhong Park
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD, USA Department of Oral Biology, BK 21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD, USA
| | - Min Seuk Kim
- Department of Oral Physiology, School of Dentistry, Wonkwang University, Iksan City, Korea
| | - G Cristina Brailoiu
- Department of Pharmaceutical Sciences, Jefferson School of Pharmacy, Thomas Jefferson University, Philadelphia, PA, USA
| | - Archana Jha
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD, USA
| | - Mei Zeng
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD, USA
| | - Maryna Baydyuk
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Ling-Gang Wu
- National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Christopher A Wassif
- Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Forbes D Porter
- Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Patricia M Zerfas
- Diagnostic and Research Services Branch, Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, MD, USA
| | - Michael A Eckhaus
- Diagnostic and Research Services Branch, Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, MD, USA
| | - Eugen Brailoiu
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA, USA
| | - Dong Min Shin
- Department of Oral Biology, BK 21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, Molecular Physiology and Therapeutics Branch, NIDCR, NIH, Bethesda, MD, USA
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16
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Rab27A Is Present in Mouse Pancreatic Acinar Cells and Is Required for Digestive Enzyme Secretion. PLoS One 2015; 10:e0125596. [PMID: 25951179 PMCID: PMC4423933 DOI: 10.1371/journal.pone.0125596] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 03/16/2015] [Indexed: 01/24/2023] Open
Abstract
The small G-protein Rab27A has been shown to regulate the intracellular trafficking of secretory granules in various cell types. However, the presence, subcellular localization and functional impact of Rab27A on digestive enzyme secretion by mouse pancreatic acinar cells are poorly understood. Ashen mice, which lack the expression of Rab27A due to a spontaneous mutation, were used to investigate the function of Rab27A in pancreatic acinar cells. Isolated pancreatic acini were prepared from wild-type or ashen mouse pancreas by collagenase digestion, and CCK- or carbachol-induced amylase secretion was measured. Secretion occurring through the major-regulated secretory pathway, which is characterized by zymogen granules secretion, was visualized by Dextran-Texas Red labeling of exocytotic granules. The minor-regulated secretory pathway, which operates through the endosomal/lysosomal pathway, was characterized by luminal cell surface labeling of lysosomal associated membrane protein 1 (LAMP1). Compared to wild-type, expression of Rab27B was slightly increased in ashen mouse acini, while Rab3D and digestive enzymes (amylase, lipase, chymotrypsin and elastase) were not affected. Localization of Rab27B, Rab3D and amylase by immunofluorescence was similar in both wild-type and ashen acinar cells. The GTP-bound states of Rab27B and Rab3D in wild-type and ashen mouse acini also remained similar in amount. In contrast, acini from ashen mice showed decreased amylase release induced by CCK- or carbachol. Rab27A deficiency reduced the apical cell surface labeling of LAMP1, but did not affect that of Dextran-Texas Red incorporation into the fusion pockets at luminal surface. These results show that Rab27A is present in mouse pancreatic acinar cells and mainly regulates secretion through the minor-regulated pathway.
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17
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Yamaoka M, Ishizaki T, Kimura T. Interplay between Rab27a effectors in pancreatic β-cells. World J Diabetes 2015; 6:508-516. [PMID: 25897360 PMCID: PMC4398906 DOI: 10.4239/wjd.v6.i3.508] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 12/24/2014] [Accepted: 02/09/2015] [Indexed: 02/05/2023] Open
Abstract
The small GTPase Rab27a is a member of the Rab family that is involved in membrane trafficking in various kinds of cells. Rab27a has GTP- and GDP-bound forms, and their interconversion regulates intracellular signaling pathways. Typically, only a GTP-bound GTPase binds its specific effectors with the resulting downstream signals controlling specific cellular functions. We previously identified novel Rab27a-interacting proteins. Surprisingly, some of these proteins interacted with GDP-bound Rab27a. The present study reviews recent progress in our understanding of the roles of Rab27a and its effectors in the secretory process. In pancreatic β-cells, GTP-bound Rab27a regulates insulin secretion at the pre-exocytotic stages via its GTP-specific effectors such as Exophilin8/Slac2-c/MyRIP and Slp4/Granuphilin. Glucose stimulation causes insulin exocytosis. Glucose stimulation also converts Rab27a from its GTP- to its GDP-bound form. GDP-bound Rab27a interacts with GDP-specific effectors and controls endocytosis of the secretory membrane. Thus, Rab27a cycling between GTP- and GDP-bound forms synchronizes with the recycling of secretory membrane to re-use the membrane and keep the β-cell volume constant.
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18
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Messenger SW, Falkowski MA, Groblewski GE. Ca²⁺-regulated secretory granule exocytosis in pancreatic and parotid acinar cells. Cell Calcium 2014; 55:369-75. [PMID: 24742357 DOI: 10.1016/j.ceca.2014.03.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/04/2014] [Accepted: 03/09/2014] [Indexed: 01/09/2023]
Abstract
Protein secretion from acinar cells of the pancreas and parotid glands is controlled by G-protein coupled receptor activation and generation of the cellular messengers Ca(2+), diacylglycerol and cAMP. Secretory granule (SG) exocytosis shares some common characteristics with nerve, neuroendocrine and endocrine cells which are regulated mainly by elevated cell Ca(2+). However, in addition to diverse signaling pathways, acinar cells have large ∼1 μm diameter SGs (∼30 fold larger diameter than synaptic vesicles), respond to stimulation at slower rates (seconds versus milliseconds), demonstrate significant constitutive secretion, and in isolated acini, undergo sequential compound SG-SG exocytosis at the apical membrane. Exocytosis proceeds as an initial rapid phase that peaks and declines over 3 min followed by a prolonged phase that decays to near basal levels over 20-30 min. Studies indicate the early phase is triggered by Ca(2+) and involves the SG proteins VAMP2 (vesicle associated membrane protein2), Ca(2+)-sensing protein synatotagmin 1 (syt1) and the accessory protein complexin 2. The molecular details for regulation of VAMP8-mediated SG exocytosis and the prolonged phase of secretion are still emerging. Here we review the known regulatory molecules that impact the sequential exocytic process of SG tethering, docking, priming and fusion in acinar cells.
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Affiliation(s)
- Scott W Messenger
- Department of Nutritional Sciences, Graduate Program in Biochemical and Molecular Nutrition, University of Wisconsin, Madison, WI 53706, United States
| | - Michelle A Falkowski
- Department of Nutritional Sciences, Graduate Program in Biochemical and Molecular Nutrition, University of Wisconsin, Madison, WI 53706, United States
| | - Guy E Groblewski
- Department of Nutritional Sciences, Graduate Program in Biochemical and Molecular Nutrition, University of Wisconsin, Madison, WI 53706, United States.
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19
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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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20
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Hou Y, Chen X, Tolmachova T, Ernst SA, Williams JA. EPI64B acts as a GTPase-activating protein for Rab27B in pancreatic acinar cells. J Biol Chem 2013; 288:19548-57. [PMID: 23671284 DOI: 10.1074/jbc.m113.472134] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The small GTPase Rab27B localizes to the zymogen granule membranes and plays an important role in regulating protein secretion by pancreatic acinar cells, as does Rab3D. A common guanine nucleotide exchange factor (GEF) for Rab3 and Rab27 has been reported; however, the GTPase-activating protein (GAP) specific for Rab27B has not been identified. In this study, the expression in mouse pancreatic acini of two candidate Tre-2/Bub2/Cdc16 (TBC) domain-containing proteins, EPI64 (TBC1D10A) and EPI64B (TBC1D10B), was first demonstrated. Their GAP activity on digestive enzyme secretion was examined by adenovirus-mediated overexpression of EPI64 and EPI64B in isolated pancreatic acini. EPI64B almost completely abolished the GTP-bound form of Rab27B, without affecting GTP-Rab3D. Overexpression of EPI64B also enhanced amylase release. This enhanced release was independent of Rab27A, but dependent on Rab27B, as shown using acini from genetically modified mice. EPI64 had a mild effect on both GTP-Rab27B and amylase release. Co-overexpression of EPI64B with Rab27B can reverse the inhibitory effect of Rab27B on amylase release. Mutations that block the GAP activity decreased the inhibitory effect of EPI64B on the GTP-bound state of Rab27B and abolished the enhancing effect of EPI64B on the amylase release. These data suggest that EPI64B can serve as a potential physiological GAP for Rab27B and thereby participate in the regulation of exocytosis in pancreatic acinar cells.
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Affiliation(s)
- Yanan Hou
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
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21
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Xu S, Ma L, Evans E, Okamoto CT, Hamm-Alvarez SF. Polymeric immunoglobulin receptor traffics through two distinct apically targeted pathways in primary lacrimal gland acinar cells. J Cell Sci 2013; 126:2704-17. [PMID: 23606742 DOI: 10.1242/jcs.122242] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The polymeric immunoglobulin receptor (pIgR) mediates transcytosis of dimeric immunoglobulin A (dIgA) and its release into mucosal secretions. The present study reveals the complexity of the trafficking of pIgR to the apical plasma membrane in epithelial cells with exocrine secretory functions; in rabbit lacrimal gland acinar cells (LGACs), trafficking of pIgR involves both the transcytotic pathway and one arm of the regulated secretory pathway. By specifically tracking pIgR endocytosed from the basolateral membrane, we show here that the Rab11a-regulated transcytotic pathway mediates the basal-to-apical transport of pIgR, and that pIgR sorted into the transcytotic pathway does not access the regulated secretory pathway. However, previous work in LGACs expanded in the present study has shown that some pIgR is localized to Rab3D-enriched mature secretory vesicles (SVs). Myosin Vb and myosin Vc motors modulate release of proteins from the Rab11a-regulated transcytotic pathway and the Rab3D-enriched secretory pathway in LGACs, respectively. Confocal fluorescence microscopy and biochemical assays showed that inhibition of myosin Vb and myosin Vc activity by overexpression of their dominant-negative mutants each significantly but differentially impaired aspects of apically targeted pIgR trafficking and secretory component release, suggesting that these motors function to regulate pIgR trafficking in both the transcytotic and exocytotic pathways. Intriguingly, a second mature SV population enriched in Rab27b was devoid of pIgR cargo, suggesting the specialization of Rab3D-enriched mature SVs to carry a particular subset of cargo proteins from the trans-Golgi network to the apical plasma membrane.
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Affiliation(s)
- Shi Xu
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA
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22
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Catz SD. Regulation of vesicular trafficking and leukocyte function by Rab27 GTPases and their effectors. J Leukoc Biol 2013; 94:613-22. [PMID: 23378593 DOI: 10.1189/jlb.1112600] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Rab27 family of GTPases regulates the efficiency and specificity of exocytosis in hematopoietic cells, including neutrophils, CTLs, NK cells, and mast cells. However, the mechanisms regulated by Rab27 GTPases are cell-specific, as they depend on the differential expression and function of particular effector molecules that are recruited by the GTPases. In addition, Rab27 GTPases participate in multiple steps of the regulation of the secretory process, including priming, tethering, docking, and fusion through sequential interaction with multiple effector molecules. Finally, recent reports suggest that Rab27 GTPases and their effectors regulate vesicular trafficking mechanisms other than exocytosis, including endocytosis and phagocytosis. This review focuses on the latest discoveries on the function of Rab27 GTPases and their effectors Munc13-4 and Slp1 in neutrophil function comparatively to their functions in other leukocytes.
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Affiliation(s)
- Sergio Daniel Catz
- 1.The Scripps Research Institute, 10550 North Torrey Pines Rd., La Jolla, CA 92037, USA. ; Twitter: http://www.scripps.edu/catz/
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23
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Dong WW, Mou Q, Chen J, Cui JT, Li WM, Xiao WH. Differential expression of Rab27A/B correlates with clinical outcome in hepatocellular carcinoma. World J Gastroenterol 2012; 18:1806-13. [PMID: 22553406 PMCID: PMC3332295 DOI: 10.3748/wjg.v18.i15.1806] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 02/28/2012] [Accepted: 03/20/2012] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the association of Rab27A and Rab27B expression with clinicopathological characteristics and prognosis of hepatocellular carcinoma (HCC).
METHODS: We used reverse transcription polymerase chain reaction (RT-PCR), real-time PCR, and Western blotting to detect Rab27A and Rab27B mRNA and protein expression in 5 human HCC lines and the immortalized hepatic HL-7702 cell line. We further examined 148 primary HCC samples matched with adjacent normal tissue and 80 non-HCC specimens by immunohistochemistry to evaluate the correlation of Rab27A and Rab27B expression with clinicopathological features and prognosis.
RESULTS: Our data showed that Rab27A and Rab27B were differentially expressed in cell lines and primary HCC tumors. Rab27A mRNA and protein were detected in 67% (4/6) of human cell lines and 80% (4/5) of HCC cell lines, while Rab27B was found in 50% (3/6) of human lines and 40% (2/5) of HCC lines. Rab27A expression was higher in primary HCC (46.2%, 66/143) than in matched adjacent tissue (24.3%, 33/136, P < 0.001), whereas immunopositivity for Rab27B was lower in primary HCC (57.4%, 81/141) than in matched adjacent tissue (87.5%, 119/136, P < 0.001). Analysis of clinicopathological characteristics of 148 HCC specimens revealed significant correlations between Rab27A and Rab27B expression and tumor tumor-node-metastasis (TNM) classification (P = 0.046 and P = 0.027, respectively), and between strong Rab27A expression and tumor differentiation grade (P = 0.008). Survival analyses revealed that patients with Rab27A+ or Rab27B+ tumors had significantly reduced overall survival compared with that of patients with Rab27A- or Rab27B- tumors (P = 0.015 and P = 0.005, respectively). Risk analyses revealed that Rab27B+ and TNM III-IV were independent poor prognosis factors associated with a 3.36- and 3.37- fold higher relative risk of death, respectively.
CONCLUSION: Rab27A and Rab27B expression were closely correlated with tumor progression and can be valuable prognostic indicators for HCC patients.
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Rab3D regulates amylase levels, not agonist-induced amylase release, in AR42J cells. Cell Mol Biol Lett 2012; 17:258-73. [PMID: 22367855 PMCID: PMC6275755 DOI: 10.2478/s11658-012-0008-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 02/15/2012] [Indexed: 12/23/2022] Open
Abstract
Rab3D is a low molecular weight GTP-binding protein that associates with secretory granules in exocrine cells. AR42J cells are derived from rat pancreatic exocrine tumor cells and develop an acinar cell-like phenotype when treated with dexamethasone (Dex). In the present study, we examined the role of Rab3D in Dex-treated AR42J cells. Rab3D expression and localization were analyzed by subcellular fractionation and immunoblotting. The role of Rab3D was examined by overexpressing myc-labeled wild-type-Rab3D and a constitutively active form of Rab3D (Rab3D-Q81L) in AR42J cells. We found that Rab3D is predominantly membrane-associated in AR42J cells and co-localizes with zymogen granules (ZG). Following CCK-8-induced exocytosis, amylase-positive ZGs appeared to move towards the periphery of the cell and co-localization between Rab3D and amylase was less complete when compared to basal conditions. Overexpression of WT, but not mutant Rab3D, resulted in an increase in cellular amylase levels. Overexpression of mutant and WT Rab3D did not affect granule morphology, CCK-8-induced secretion, long-term (48 hr) basal amylase release or granule density. We conclude that Rab3D is not involved in agonist-induced exocytosis in AR42J cells. Instead, Rab3D may regulate amylase content in these cells.
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Direct imaging of RAB27B-enriched secretory vesicle biogenesis in lacrimal acinar cells reveals origins on a nascent vesicle budding site. PLoS One 2012; 7:e31789. [PMID: 22363735 PMCID: PMC3282733 DOI: 10.1371/journal.pone.0031789] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 01/16/2012] [Indexed: 12/20/2022] Open
Abstract
This study uses YFP-tagged Rab27b expression in rabbit lacrimal gland acinar cells, which are polarized secretory epithelial cells, to characterize early stages of secretory vesicle trafficking. Here we demonstrate the utility of YFP-Rab27b to delineate new perspectives on the mechanisms of early vesicle biogenesis in lacrimal gland acinar cells, where information is significantly limited. Protocols were developed to deplete the mature YFP-Rab27b-enriched secretory vesicle pool in the subapical region of the cell, and confocal fluorescence microscopy was used to track vesicle replenishment. This analysis revealed a basally-localized organelle, which we termed the "nascent vesicle site," from which nascent vesicles appeared to emerge. Subapical vesicular YFP-Rab27b was co-localized with p150(Glued), a component of the dynactin cofactor of cytoplasmic dynein. Treatment with the microtubule-targeted agent, nocodazole, did not affect release of mature secretory vesicles, although during vesicle repletion it significantly altered nascent YFP-Rab27b-enriched secretory vesicle localization. Instead of moving to the subapical region, these vesicles were trapped at the nascent vesicle site which was adjacent to, if not a sub-compartment of, the trans-Golgi network. Finally, YFP-Rab27b-enriched secretory vesicles which reached the subapical cytoplasm appeared to acquire the actin-based motor protein, Myosin 5C. Our findings show that Rab27b enrichment occurs early in secretory vesicle formation, that secretory vesicles bud from a visually discernable nascent vesicle site, and that transport from the nascent vesicle site to the subapical region requires intact microtubules.
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Xu S, Edman M, Kothawala MS, Sun G, Chiang L, Mircheff A, Zhu L, Okamoto C, Hamm-Alvarez S. A Rab11a-enriched subapical membrane compartment regulates a cytoskeleton-dependent transcytotic pathway in secretory epithelial cells of the lacrimal gland. J Cell Sci 2011; 124:3503-14. [PMID: 21984810 DOI: 10.1242/jcs.088906] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Despite observations that the lacrimal gland has been identified as the principal source of dimeric immunoglobulin A (dIgA) in tears, the mechanism used by lacrimal gland acinar cells (LGACs) to transcytose dIgA produced by interstitial plasma cells is not well-characterized. This study identifies a transcytotic pathway in LGACs regulated by Rab11a for polymeric immunoglobulin receptor (pIgR) and dIgA. EGFP-tagged Rab11a expressed in primary LGACs labeled a unique membrane compartment of comparable localization to endogenous Rab11a beneath the apical plasma membrane. This compartment was enriched in pIgR and clearly distinct from the regulated secretory pathway. Comparison of dIgA uptake in LGACs expressing wild type and dominant negative EGFP-Rab11a showed that the rapid exocytosis of dIgA was inhibited in acini expressing the dominant-negative protein, which additionally redistributed subapical pIgR. The trafficking of EGFP-Rab11a-enriched vesicles was regulated by microtubule-based and myosin Vb motors at distinct steps. Our data suggest that Rab11a is a crucial regulator of dIgA trafficking in primary acinar secretory epithelial cells and further support a role for microtubules, cytoplasmic dynein, actin filaments and myosin Vb in the maintenance of the Rab11a compartment in this primary secretory epithelial cell.
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Affiliation(s)
- Shi Xu
- Department of Pharmacology and Pharmaceutical Sciences, 1985 Zonal Avenue, USC School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA
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Chiang L, Ngo J, Schechter JE, Karvar S, Tolmachova T, Seabra MC, Hume AN, Hamm-Alvarez SF. Rab27b regulates exocytosis of secretory vesicles in acinar epithelial cells from the lacrimal gland. Am J Physiol Cell Physiol 2011; 301:C507-21. [PMID: 21525430 DOI: 10.1152/ajpcell.00355.2010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tear proteins are supplied by the regulated fusion of secretory vesicles at the apical surface of lacrimal gland acinar cells, utilizing trafficking mechanisms largely yet uncharacterized. We investigated the role of Rab27b in the terminal release of these secretory vesicles. Confocal fluorescence microscopy analysis of primary cultured rabbit lacrimal gland acinar cells revealed that Rab27b was enriched on the membrane of large subapical vesicles that were significantly colocalized with Rab3D and Myosin 5C. Stimulation of cultured acinar cells with the secretagogue carbachol resulted in apical fusion of these secretory vesicles with the plasma membrane. Evaluation of morphological changes by transmission electron microscopy of lacrimal glands from Rab27b(-/-) and Rab27(ash/ash)/Rab27b(-/-) mice, but not ashen mice deficient in Rab27a, showed changes in abundance and organization of secretory vesicles, further confirming a role for this protein in secretory vesicle exocytosis. Glands lacking Rab27b also showed increased lysosomes, damaged mitochondria, and autophagosome-like organelles. In vitro, expression of constitutively active Rab27b increased the average size but retained the subapical distribution of Rab27b-enriched secretory vesicles, whereas dominant-negative Rab27b redistributed this protein from membrane to the cytoplasm. Functional studies measuring release of a cotransduced secretory protein, syncollin-GFP, showed that constitutively active Rab27b enhanced, whereas dominant-negative Rab27b suppressed, stimulated release. Disruption of actin filaments inhibited vesicle fusion to the apical membrane but did not disrupt homotypic fusion. These data show that Rab27b participates in aspects of lacrimal gland acinar cell secretory vesicle formation and release.
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Affiliation(s)
- Lilian Chiang
- School of Pharmacy, University of Southern California, Los Angeles, CA 90033, USA
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Fernandez NA, Liang T, Gaisano HY. Live pancreatic acinar imaging of exocytosis using syncollin-pHluorin. Am J Physiol Cell Physiol 2011; 300:C1513-23. [PMID: 21307342 DOI: 10.1152/ajpcell.00433.2010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In this report, a novel live acinar exocytosis imaging technique is described. An adenovirus was engineered, encoding for an endogenous zymogen granule (ZG) protein (syncollin) fused to pHluorin, a pH-dependent green fluorescent protein (GFP). Short-term culture of mouse acini infected with this virus permits exogenous adenoviral protein expression while retaining acinar secretory competence and cell polarity. The syncollin-pHluorin fusion protein was shown to be correctly localized to ZGs, and the pH-dependent fluorescence of pHluorin was retained. Coupled with the use of a spinning disk confocal microscope, the syncollin-pHluorin fusion protein exploits the ZG luminal pH changes that occur during exocytosis to visualize exocytic events of live acinar cells in real-time with high spatial resolution in three dimensions. Apical and basolateral exocytic events were observed on stimulation of acinar cells with maximal and supramaximal cholecystokinin concentrations, respectively. Sequential exocytic events were also observed. Coupled with the use of transgenic mice and/or adenovirus-mediated protein expression, this syncollin-pHluorin imaging method offers a superior approach to studying pancreatic acinar exocytosis. This assay can also be applied to acinar disease models to elucidate the mechanisms implicated in pancreatitis.
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Affiliation(s)
- Nestor A Fernandez
- Dept. of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada
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Quantitative analysis of synaptic vesicle Rabs uncovers distinct yet overlapping roles for Rab3a and Rab27b in Ca2+-triggered exocytosis. J Neurosci 2010; 30:13441-53. [PMID: 20926670 DOI: 10.1523/jneurosci.0907-10.2010] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Rab GTPases are molecular switches that orchestrate protein complexes before membrane fusion reactions. In synapses, Rab3 and Rab5 proteins have been implicated in the exo-endocytic cycling of synaptic vesicles (SVs), but an involvement of additional Rabs cannot be excluded. Here, combining high-resolution mass spectrometry and chemical labeling (iTRAQ) together with quantitative immunoblotting and fluorescence microscopy, we have determined the exocytotic (Rab3a, Rab3b, Rab3c, and Rab27b) and endocytic (Rab4b, Rab5a/b, Rab10, Rab11b, and Rab14) Rab machinery of SVs. Analysis of two closely related proteins, Rab3a and Rab27b, revealed colocalization in synaptic nerve terminals, where they reside on distinct but overlapping SV pools. Moreover, whereas Rab3a readily dissociates from SVs during Ca(2+)-triggered exocytosis, and is susceptible to membrane extraction by Rab-GDI, Rab27b persists on SV membranes upon stimulation and is resistant to GDI-coupled Rab retrieval. Finally, we demonstrate that selective modulation of the GTP/GDP switch mechanism of Rab27b impairs SV recycling, suggesting that Rab27b, probably in concert with Rab3s, is involved in SV exocytosis.
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Johnson JL, Brzezinska AA, Tolmachova T, Munafo DB, Ellis BA, Seabra MC, Hong H, Catz SD. Rab27a and Rab27b regulate neutrophil azurophilic granule exocytosis and NADPH oxidase activity by independent mechanisms. Traffic 2009; 11:533-47. [PMID: 20028487 DOI: 10.1111/j.1600-0854.2009.01029.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neutrophils rely on exocytosis to mobilize receptors and adhesion molecules and to release microbicidal factors. This process should be strictly regulated because uncontrolled release of toxic proteins would be injurious to the host. In vivo studies showed that the small GTPase Rab27a regulates azurophilic granule exocytosis. Using mouse neutrophils deficient in Rab27a (Rab27a(ash/ash)), Rab27b [Rab27b knockout (KO)] or both [Rab27a/b double KO (DoKo)], we investigated the role of the Rab27 isoforms in neutrophils. We found that both Rab27a and Rab27b deficiencies impaired azurophilic granule exocytosis. Rab27a(ash/ash) neutrophils showed upregulation of Rab27b expression which did not compensate for the secretory defects observed in Rab27a-deficient cells, suggesting that Rab27 isoforms play independent roles in neutrophil exocytosis. Total internal reflection fluorescence microscopy analysis showed that Rab27a(ash/ash) and Rab27b KO neutrophils have a decreased number of azurophilic granules near the plasma membrane. The effect was exacerbated in Rab27a/b DoKo neutrophils. Rab27-deficient neutrophils showed impaired activation of the reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase at the plasma membrane although intraphagosomal reactive oxygen species (ROS) production was not affected. Exocytosis of secretory vesicles in Rab27-deficient neutrophils was functional, suggesting that Rab27 GTPases selectively control the exocytosis of neutrophil granules.
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Affiliation(s)
- Jennifer L Johnson
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Rab27a and Rab27b control different steps of the exosome secretion pathway. Nat Cell Biol 2009; 12:19-30; sup pp 1-13. [PMID: 19966785 DOI: 10.1038/ncb2000] [Citation(s) in RCA: 1773] [Impact Index Per Article: 118.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 11/10/2009] [Indexed: 11/08/2022]
Abstract
Exosomes are secreted membrane vesicles that share structural and biochemical characteristics with intraluminal vesicles of multivesicular endosomes (MVEs). Exosomes could be involved in intercellular communication and in the pathogenesis of infectious and degenerative diseases. The molecular mechanisms of exosome biogenesis and secretion are, however, poorly understood. Using an RNA interference (RNAi) screen, we identified five Rab GTPases that promote exosome secretion in HeLa cells. Among these, Rab27a and Rab27b were found to function in MVE docking at the plasma membrane. The size of MVEs was strongly increased by Rab27a silencing, whereas MVEs were redistributed towards the perinuclear region upon Rab27b silencing. Thus, the two Rab27 isoforms have different roles in the exosomal pathway. In addition, silencing two known Rab27 effectors, Slp4 (also known as SYTL4, synaptotagmin-like 4) and Slac2b (also known as EXPH5, exophilin 5), inhibited exosome secretion and phenocopied silencing of Rab27a and Rab27b, respectively. Our results therefore strengthen the link between MVEs and exosomes, and introduce ways of manipulating exosome secretion in vivo.
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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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Gage MC, Keen JN, Buxton AT, Bedi MK, Findlay JBC. Proteomic Analysis of IgE-Mediated Secretion by LAD2 Mast Cells. J Proteome Res 2009; 8:4116-25. [DOI: 10.1021/pr900108w] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Matthew C. Gage
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom, and Division of Cardiovascular and Diabetes Research, Faculty of Medicine and Health, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Jeffrey N. Keen
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom, and Division of Cardiovascular and Diabetes Research, Faculty of Medicine and Health, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Anthony T. Buxton
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom, and Division of Cardiovascular and Diabetes Research, Faculty of Medicine and Health, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Maninder K. Bedi
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom, and Division of Cardiovascular and Diabetes Research, Faculty of Medicine and Health, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - John B. C. Findlay
- Institute of Membrane and Systems Biology, Faculty of Biological Sciences, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom, and Division of Cardiovascular and Diabetes Research, Faculty of Medicine and Health, LIGHT Laboratories, University of Leeds, Leeds LS2 9JT, United Kingdom
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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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Sabbatini ME, Chen X, Ernst SA, Williams JA. Rap1 activation plays a regulatory role in pancreatic amylase secretion. J Biol Chem 2008; 283:23884-94. [PMID: 18577515 PMCID: PMC2527106 DOI: 10.1074/jbc.m800754200] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Revised: 06/02/2008] [Indexed: 11/06/2022] Open
Abstract
Rap1 is a member of the Ras superfamily of small GTP-binding proteins and is localized on pancreatic zymogen granules. The current study was designed to determine whether GTP-Rap1 is involved in the regulation of amylase secretion. Rap1A/B and the two Rap1 guanine nucleotide exchange factors, Epac1 and CalDAG-GEF III, were identified in mouse pancreatic acini. A fraction of both Rap1 and Epac1 colocalized with amylase in zymogen granules, but only Rap1 was integral to the zymogen granule membranes. Stimulation with cholecystokinin (CCK), carbachol, and vasoactive intestinal peptide all induced Rap1 activation, as did calcium ionophore A23187, phorbol ester, forskolin, 8-bromo-cyclic AMP, and the Epac-specific cAMP analog 8-pCPT-2'-O-Me-cAMP. The phospholipase C inhibitor U-73122 abolished carbachol- but not forskolin-induced Rap1 activation. Co-stimulation with carbachol and 8-pCPT-2'-O-Me-cAMP led to an additive effect on Rap1 activation, whereas a synergistic effect was seen on amylase release. Although the protein kinase A inhibitor H-89 abolished forskolin-stimulated CREB phosphorylation, it did not modify forskolin-induced GTP-Rap1 levels, excluding PKA participation. Overexpression of Rap1 GTPase-activating protein, which blocked Rap1 activation, reduced the effect of 8-bromo-cyclic AMP, 8-pCPT-2'-O-Me-cAMP, and vasoactive intestinal peptide on amylase release by 60% and reduced CCK- as well as carbachol-stimulated pancreatic amylase release by 40%. These findings indicate that GTP-Rap1 is required for pancreatic amylase release. Rap1 activation not only mediates the cAMP-evoked response via Epac1 but is also involved in CCK- and carbachol-induced amylase release, with their action most likely mediated by CalDAG-GEF III.
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Affiliation(s)
- Maria E Sabbatini
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109-0622, USA.
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Faust F, Gomez-Lazaro M, Borta H, Agricola B, Schrader M. Rab8 is Involved in Zymogen Granule Formation in Pancreatic Acinar AR42J Cells. Traffic 2008; 9:964-79. [DOI: 10.1111/j.1600-0854.2008.00739.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Saegusa C, Kanno E, Itohara S, Fukuda M. Expression of Rab27B-binding protein Slp1 in pancreatic acinar cells and its involvement in amylase secretion. Arch Biochem Biophys 2008; 475:87-92. [PMID: 18477466 DOI: 10.1016/j.abb.2008.04.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Accepted: 04/18/2008] [Indexed: 12/16/2022]
Abstract
Slp1 is a putative Rab27 effector protein and implicated in intracellular membrane transport; however, the precise tissue distribution and function of Slp1 protein remain largely unknown. In this study we investigated the tissue distribution of Slp1 in mice and found that Slp1 is abundantly expressed in the pancreas, especially in the apical region of pancreatic acinar cells. Slp1 interacted with Rab27B in vivo and both proteins were co-localized on zymogen granules. Morphological analysis of fasted Slp1 knockout mice showed an increased number of zymogen granules in the pancreatic acinar cells, indicating that Slp1 is part of the machinery of amylase secretion by the exocrine pancreas.
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Affiliation(s)
- Chika Saegusa
- Fukuda Initiative Research Unit, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Marchelletta RR, Jacobs DT, Schechter JE, Cheney RE, Hamm-Alvarez SF. The class V myosin motor, myosin 5c, localizes to mature secretory vesicles and facilitates exocytosis in lacrimal acini. Am J Physiol Cell Physiol 2008; 295:C13-28. [PMID: 18434623 DOI: 10.1152/ajpcell.00330.2007] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We investigated the role of the actin-based myosin motor, myosin 5c (Myo5c) in vesicle transport in exocrine secretion. Lacrimal gland acinar cells (LGAC) are the major source for the regulated secretion of proteins from the lacrimal gland into the tear film. Confocal fluorescence and immunogold electron microscopy revealed that Myo5c was associated with secretory vesicles in primary rabbit LGAC. Upon stimulation of secretion with the muscarinic agonist, carbachol, Myo5c was also detected in association with actin-coated fusion intermediates. Adenovirus-mediated expression of green fluorescent protein (GFP) fused to the tail domain of Myo5c (Ad-GFP-Myo5c-tail) showed that this protein was localized to secretory vesicles. Furthermore, its expression induced a significant (P < or = 0.05) decrease in carbachol-stimulated release of two secretory vesicle content markers, secretory component and syncollin-GFP. Adenovirus-mediated expression of GFP appended to the full-length Myo5c (Ad-GFP-Myo5c-full) was used in parallel with adenovirus-mediated expression of GFP-Myo5c-tail in LGAC to compare various parameters of secretory vesicles labeled with either GFP-labeled protein in resting and stimulated LGAC. These studies revealed that the carbachol-stimulated increase in secretory vesicle diameter associated with compound fusion of secretory vesicles that was also exhibited by vesicles labeled with GFP-Myo5c-full was impaired in vesicles labeled with GFP-Myo5c-tail. A significant decrease in GFP labeling of actin-coated fusion intermediates was also seen in carbachol-stimulated LGAC transduced with GFP-Myo5c-tail relative to LGAC transduced with GFP-Myo5c-full. These results suggest that Myo5c participates in apical exocytosis of secretory vesicles.
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Affiliation(s)
- Ronald R Marchelletta
- Department Pharmacology and Pharmaceutical Sciences, USC School of Pharmacy, Los Angeles, CA 90033, USA
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Gomi H, Mori K, Itohara S, Izumi T. Rab27b is expressed in a wide range of exocytic cells and involved in the delivery of secretory granules near the plasma membrane. Mol Biol Cell 2007; 18:4377-86. [PMID: 17761531 PMCID: PMC2043558 DOI: 10.1091/mbc.e07-05-0409] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Rab proteins regulate multiple, complex processes of membrane traffic. Among these proteins, Rab27a has been shown to function specifically in regulated exocytic pathways. However, the roles of Rab27b, another Rab27 subfamily member, have not been well characterized. We disrupted the Rab27b gene in mice. The targeting vector was designed to insert LacZ downstream of the initiation codon of the Rab27b gene so that the authentic promoter should drive this reporter gene. A comprehensive analysis of Rab27b expression using this mouse strain indicated that it is widely expressed not only in canonical secretory cells, but also in neurons and cells involved in surface protection and mechanical extension. To evaluate the function in pituitary endocrine cells where the isoform Rab27a is coexpressed, we generated Rab27a/Rab27b double knockout mice by crossing Rab27b knockout mice with Rab27a-mutated ashen mice. The polarized distribution of secretory granules close to the plasma membrane was markedly impaired in the pituitary of double knockout mice, indicating that the Rab27 subfamily is involved in the delivery of granules near the exocytic site. In conjunction with a phenotype having a pituitary devoid of the Rab27 effector granuphilin, we discuss the relationship between the residence and the releasable pool of granules.
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Affiliation(s)
- Hiroshi Gomi
- *Laboratory of Molecular Endocrinology and Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan; and
| | - Kenichi Mori
- *Laboratory of Molecular Endocrinology and Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan; and
| | - Shigeyoshi Itohara
- Laboratory for Behavioral Genetics, Brain Science Institute, Institute of Physical and Chemical Research, Wako 351-0198, Japan
| | - Tetsuro Izumi
- *Laboratory of Molecular Endocrinology and Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan; and
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42
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Mizuno K, Tolmachova T, Ushakov DS, Romao M, Åbrink M, Ferenczi MA, Raposo G, Seabra MC. Rab27b regulates mast cell granule dynamics and secretion. Traffic 2007; 8:883-92. [PMID: 17587407 PMCID: PMC2063611 DOI: 10.1111/j.1600-0854.2007.00571.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Rab GTPase family regulates membrane domain organization and vesicular transport pathways. Recent studies indicate that one member of the family, Rab27a, regulates transport of lysosome-related organelles in specialized cells, such as melanosomes and lytic granules. Very little is known about the related isoform, Rab27b. Here we used genetically modified mice to study the involvement of the Rab27 proteins in mast cells, which play key roles in allergic responses. Both Rab27a and Rab27b isoforms are expressed in bone marrow-derived mast cells (BMMC) and localize to secretory granules. Nevertheless, secretory defects as measured by β-hexosaminidase release in vitro and passive cutaneous anaphylaxis in vivo were found only in Rab27b and double Rab27 knockout (KO) mice. Immunofluorescence studies suggest that a subset of Rab27b and double Rab27-deficient BMMCs exhibit mild clustering of granules. Quantitative analysis of live-cell time-lapse imaging revealed that BMMCs derived from double Rab27 KO mice showed almost 10-fold increase in granules exhibiting fast movement (>1.5 μm/s), which could be disrupted by nocodazole. These results suggest that Rab27 proteins, particularly Rab27b, play a crucial role in mast cell degranulation and that their action regulates the transition from microtubule to actin-based motility.
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Affiliation(s)
- Kouichi Mizuno
- Molecular and Cellular Medicine, National Heart and Lung Institute, Imperial College London SW7 2AZUK
| | - Tanya Tolmachova
- Molecular and Cellular Medicine, National Heart and Lung Institute, Imperial College London SW7 2AZUK
| | - Dmitry S Ushakov
- Biological Nanoscience, National Heart and Lung Institute, Imperial College London SW7 2AZUK
| | - Maryse Romao
- Institut Curie, CNRS UMR144, Structure and Membrane Compartments, 75248 ParisFrance
| | - Magnus Åbrink
- Department of Medical Biochemistry and Microbiology, Uppsala University, 751 05 UppsalaSweden
| | - Michael A Ferenczi
- Biological Nanoscience, National Heart and Lung Institute, Imperial College London SW7 2AZUK
| | - Graça Raposo
- Institut Curie, CNRS UMR144, Structure and Membrane Compartments, 75248 ParisFrance
| | - Miguel C Seabra
- Molecular and Cellular Medicine, National Heart and Lung Institute, Imperial College London SW7 2AZUK
- * Corresponding author: Miguel C. Seabra,
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Rindler MJ, Xu CF, Gumper I, Smith NN, Neubert TA. Proteomic analysis of pancreatic zymogen granules: identification of new granule proteins. J Proteome Res 2007; 6:2978-92. [PMID: 17583932 PMCID: PMC2582026 DOI: 10.1021/pr0607029] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The composition of zymogen granules from rat pancreas was determined by LC-MS/MS. Enriched intragranular content, peripheral membrane, and integral membrane protein fractions were analyzed after one-dimensional SDS-PAGE and tryptic digestion of gel slices. A total of 371 proteins was identified with high confidence, including 84 previously identified granule proteins. The 287 remaining proteins included 37 GTP-binding proteins and effectors, 8 tetraspan membrane proteins, and 22 channels and transporters. Seven proteins, pantophysin, cyclic nucleotide phosphodiesterase, carboxypeptidase D, ecto-nucleotide phosphodiesterase 3, aminopeptidase N, ral, and the potassium channel TWIK-2, were confirmed by immunofluorescence microscopy or by immunoblotting to be new zymogen granule membrane proteins.
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Affiliation(s)
- Michael J Rindler
- Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA.
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Chung JW, Ng-Thow-Hing C, Budman LI, Gibbs BF, Nash JHE, Jacques M, Coulton JW. Outer membrane proteome ofActinobacillus pleuropneumoniae: LC-MS/MS analyses validatein silico predictions. Proteomics 2007; 7:1854-65. [PMID: 17476711 DOI: 10.1002/pmic.200600979] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Gram-negative bacterial pathogen Actinobacillus pleuropneumoniae causes porcine pneumonia, a highly infectious respiratory disease that contributes to major economic losses in the swine industry. Outer membrane (OM) proteins play key roles in infection and may be targets for drug and vaccine research. Exploiting the genome sequence of A. pleuropneumoniae serotype 5b, we scanned in silico for proteins predicted to be localized at the cell surface. Five genome scanning programs (Proteome Analyst, PSORT-b, BOMP, Lipo, and LipoP) were run to construct a consensus prediction list of 93 OM proteins in A. pleuropneumoniae. An inventory of predicted OM proteins was complemented by proteomic analyses utilizing gel- and solution-based methods, both coupled to LC-MS/MS. Different protocols were explored to enrich for OM proteins; the most rewarding required sucrose gradient centrifugation followed by membrane washes with sodium bromide and sodium carbonate. This protocol facilitated our identification of 47 OM proteins that represent 50% of the predicted OM proteome, most of which have not been characterized. Our study establishes the first OM proteome of A. pleuropneumoniae.
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Affiliation(s)
- Jacqueline W Chung
- Department of Microbiology and Immunology, McGill University, Montreal, QC, Canada
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45
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Lam PPL, Hyvärinen K, Kauppi M, Cosen-Binker L, Laitinen S, Keränen S, Gaisano HY, Olkkonen VM. A cytosolic splice variant of Cab45 interacts with Munc18b and impacts on amylase secretion by pancreatic acini. Mol Biol Cell 2007; 18:2473-80. [PMID: 17442889 PMCID: PMC1924827 DOI: 10.1091/mbc.e06-10-0950] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We identified in a yeast two-hybrid screen the EF-hand Ca(2+)-binding protein Cab45 as an interaction partner of Munc18b. Although the full-length Cab45 resides in Golgi lumen, we characterize a cytosolic splice variant, Cab45b, expressed in pancreatic acini. Cab45b is shown to bind (45)Ca(2+), and, of its three EF-hand motifs, EF-hand 2 is demonstrated to be crucial for the ion binding. Cab45b is shown to interact with Munc18b in an in vitro assay, and this interaction is enhanced in the presence of Ca(2+). In this assay, Cab45b also binds the Munc18a isoform in a Ca(2+)-dependent manner. The endogenous Cab45b in rat acini coimmunoprecipitates with Munc18b, syntaxin 2, and syntaxin 3, soluble N-ethylmaleimide-sensitive factor attachment protein receptors with key roles in the Ca(2+)-triggered zymogen secretion. Furthermore, we show that Munc18b bound to syntaxin 3 recruits Cab45b onto the plasma membrane. Importantly, antibodies against Cab45b are shown to inhibit in a specific and dose-dependent manner the Ca(2+)-induced amylase release from streptolysin-O-permeabilized acini. The present study identifies Cab45b as a novel protein factor involved in the exocytosis of zymogens by pancreatic acini.
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Affiliation(s)
- Patrick P L Lam
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
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46
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Tolmachova T, Åbrink M, Futter CE, Authi KS, Seabra MC. Rab27b regulates number and secretion of platelet dense granules. Proc Natl Acad Sci U S A 2007; 104:5872-7. [PMID: 17384153 PMCID: PMC1831675 DOI: 10.1073/pnas.0609879104] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Rab27 GTPase subfamily consists of two closely related homologs, Rab27a and Rab27b. Rab27a has been shown previously to regulate organelle movement and regulated exocytosis in a wide variety of secretory cells. However, the role of the more restrictedly expressed Rab27b remains unclear. Here we describe the creation of Rab27b knockout (KO) strain that was subsequently crossed with the naturally occurring Rab27a KO line, ashen, to produce double KO (Rab27a(ash/ash) Rab27b(-/-)) mice. Rab27b KO (and double KO) exhibit significant hemorrhagic disease in contrast to ashen mice. In vitro assays demonstrated impaired aggregation with collagen and U46619 and reduced secretion of dense granules in both Rab27b and double KO strains. Additionally, we detected a 50% reduction in the number of dense granules per platelet and diminished platelet serotonin content, possibly due to a dense granule packaging defect into proplatelets during megakaryocyte maturation. The presence of Rab27a partially compensated for the secretory defect but not the reduced granule number. The morphology and function of platelet alpha-granules were unaffected. Our data suggest that Rab27b is a key regulator of dense granule secretion in platelets and thus a candidate gene for delta-storage pool deficiency in humans.
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Affiliation(s)
- Tanya Tolmachova
- *Molecular and Cellular Medicine, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
| | - Magnus Åbrink
- Department of Medical Biochemistry and Microbiology, Uppsala University, 751 05 Uppsala, Sweden
| | - Clare E. Futter
- Institute of Ophthalmology, University College London, London EC1V 9EL, United Kingdom; and
| | - Kalwant S. Authi
- Cardiovascular Division, King's College London, London SE1 9NH, United Kingdom
| | - Miguel C. Seabra
- *Molecular and Cellular Medicine, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom
- To whom correspondence should be addressed at:
Molecular and Cellular Medicine, National Heart and Lung Institute, Faculty of Medicine, Imperial College London, London SW7 2AZ, United Kingdom. E-mail:
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47
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Affiliation(s)
- Stephen J Pandol
- Department of Medicine, Department of Veterans Affairs and University of California, Los Angeles, California, USA.
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48
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Saegusa C, Tanaka T, Tani S, Itohara S, Mikoshiba K, Fukuda M. Decreased basal mucus secretion by Slp2-a-deficient gastric surface mucous cells. Genes Cells 2006; 11:623-31. [PMID: 16716193 DOI: 10.1111/j.1365-2443.2006.00964.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Synaptotagmin-like protein (Slp) 2-a is a putative Rab27A/B-effector protein and is implicated in intracellular membrane transport. However, the precise tissue distribution of Slp2-a protein and its functions remain largely unknown. In this study we used a specific anti-Slp2-a antibody to investigate the tissue distribution of Slp2-a in mice and found that Slp2-a is most abundantly expressed in mouse stomach. Co-immunoprecipitation experiments indicated that Slp2-a interacts with Rab27A/B in vivo. We also discovered that Slp2-a and Rab27A/B are predominantly localized at the apical region of gastric-surface mucous cells, where mucus granules are accumulated. Analysis of Slp2-a mutant mice generated by homologous recombination showed a reduced number of mucus granules, a deficiency of granule docking with the apical plasma membrane in the gastric-surface mucous cells and reduction of mucus secretion by Slp2-a-deficient gastric primary cells. Based on these results, we propose that Slp2-a is part of the mucin secretory machinery in surface mucous cells of mouse stomach.
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Affiliation(s)
- Chika Saegusa
- Fukuda Initiative Research Unit, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Abstract
PURPOSE OF REVIEW Recent investigations into the regulation of pancreatic acinar cell function have led to a more detailed understanding of the mechanisms regulating digestive enzyme synthesis and secretion. This review identifies and puts into context those articles which further our understanding in this area. RECENT FINDINGS The secretagogue receptors present on acinar cells, especially muscarinic and cholecystokinin, have been better identified and characterized. The complex control of intracellular Ca by intracellular messengers such as inositol trisphosphate, cellular ion pumps and membrane channels has become more clearly understood, including the identification of organelles sequestering intracellular Ca. In the area of Ca driven exocytosis, progress has been made in understanding the proteins present on the zymogen granules, especially Rabs and SNARE proteins, and the dynamic changes in actin filaments. Secretagogues have also been shown to enhance the translation of new protein by activation of the mammalian target of rapamycin pathway. Finally, considerable progress has been made in understanding the mechanisms regulating pancreatic growth in response to nutrients and following pancreatectomy or pancreatitis. SUMMARY Understanding the mechanisms that regulate pancreatic acinar cell function is contributing to our knowledge of normal pancreatic function and alterations in diseases such as pancreatitis and pancreatic cancer.
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Affiliation(s)
- John A Williams
- Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA.
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50
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Boluyt MO, Brevick JL, Rogers DS, Randall MJ, Scalia AF, Li ZB. Changes in the rat heart proteome induced by exercise training: Increased abundance of heat shock protein hsp20. Proteomics 2006; 6:3154-69. [PMID: 16586429 DOI: 10.1002/pmic.200401356] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chronic exercise training elicits adaptations in the heart that improve pump function and confer cardioprotection. To identify molecular mechanisms by which exercise training stimulates this favorable phenotype, a proteomic approach was employed to detect rat cardiac proteins that were differentially expressed or modified after exercise training. Exercise-trained rats underwent six weeks of progressive treadmill training five days/week, 0% grade, using an interval training protocol. Sedentary control rats were age- and weight-matched to the exercise-trained rats. Hearts were harvested at various times (0-72 h) after the last bout of exercise and were used to generate 2-D electrophoretic proteome maps and immunoblots. Compared with hearts of sedentary rats, 26 protein spot intensities were significantly altered in hypertrophied hearts of exercise-trained rats (p <0.05), and 12 spots appeared exclusively on gels from hearts of exercise-trained rats. Immunoblotting confirmed that chronic exercise training, but not a single bout of exercise, elicited a 2.5-fold increase in the abundance of one of the candidate proteins in the heart, a 20 kDa heat shock protein (hsp20) that persisted for at least 72 h of detraining. Thus, exercise training alters the cardiac proteome of the rat heart; the changes include a marked increase in the expression of hsp20.
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Affiliation(s)
- Marvin O Boluyt
- Center for Exercise Research, Division of Kinesiology, The University of Michigan, Laboratory of Molecular Kinesiology, 401 Washtenaw Avenue, Ann Arbor, MI 48109, USA.
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