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Chen R, Xie L, Fan Y, Hua X, Chung CY. Vesicular translocation of PARP-1 to cytoplasm causes ADP-ribosylation and disassembly of vimentin filaments during microglia activation induced by LPS. Front Cell Neurosci 2024; 18:1363154. [PMID: 38590714 PMCID: PMC10999663 DOI: 10.3389/fncel.2024.1363154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 03/04/2024] [Indexed: 04/10/2024] Open
Abstract
ADP-ribosylation plays a significant role in various biological processes including genomic stability maintenance, transcriptional regulation, energy metabolism, and cell death. Using macrodomain pull-down assay with microglia lysates and MALDI-TOF-MS analysis, we identified vimentin as a major protein highly ADP-ribosylated by the poly(ADP-ribose) polymerases-1 (PARP-1) in response to LPS. ABT-888, a potent inhibitor of PARP-1/2 blocks the disassembly and ADP-ribosylation of vimentin. PARP-1 is a highly abundant nuclear protein. Its nuclear functions in repairing DNA damages induced by various stress signals, such as inflammatory stresses, have been well studied. In contrast, limited studies have been done on the cytoplasmic role(s) of PARP-1. Our study focuses on the cytoplasmic role of PARP-1 during microglia activation. Using immunofluorescence microscopy and Western blotting, we showed that a significant amount of PARP-1 is present in the cytosol of microglia cells stimulated and activated by LPS. Live cell imaging showed the translocation of nuclear PARP-1-EGFP to the cytoplasm in vesicular structures upon LPS stimulation. ABT-888 and U0126 can block this translocation. Immunofluorescence staining with various organelle marker antibodies revealed that PARP-1 vesicles show colocalization with Lamin A/C, suggesting they might be derived from the nuclear envelope through nuclear envelope budding. In conclusion, we demonstrated that PARP-1 is translocated from the nucleus to cytoplasm via vesicles upon LPS stimulation and that cytoplasmic PARP-1 causes ADP-ribosylation and disassembly of vimentin filaments during microglia activation induced by LPS.
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Affiliation(s)
- Ruiqi Chen
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
| | - Lirui Xie
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
| | - Yang Fan
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
| | - Xiangmei Hua
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
| | - Chang Y. Chung
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
- Department of Biomedical Sciences, Mercer University School of Medicine, Columbus, GA, United States
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2
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Badoiu SC, Greabu M, Miricescu D, Stanescu-Spinu II, Ilinca R, Balan DG, Balcangiu-Stroescu AE, Mihai DA, Vacaroiu IA, Stefani C, Jinga V. PI3K/AKT/mTOR Dysregulation and Reprogramming Metabolic Pathways in Renal Cancer: Crosstalk with the VHL/HIF Axis. Int J Mol Sci 2023; 24:8391. [PMID: 37176098 PMCID: PMC10179314 DOI: 10.3390/ijms24098391] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/26/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023] Open
Abstract
Renal cell carcinoma (RCC) represents 85-95% of kidney cancers and is the most frequent type of renal cancer in adult patients. It accounts for 3% of all cancer cases and is in 7th place among the most frequent histological types of cancer. Clear cell renal cell carcinoma (ccRCC), accounts for 75% of RCCs and has the most kidney cancer-related deaths. One-third of the patients with ccRCC develop metastases. Renal cancer presents cellular alterations in sugars, lipids, amino acids, and nucleic acid metabolism. RCC is characterized by several metabolic dysregulations including oxygen sensing (VHL/HIF pathway), glucose transporters (GLUT 1 and GLUT 4) energy sensing, and energy nutrient sensing cascade. Metabolic reprogramming represents an important characteristic of the cancer cells to survive in nutrient and oxygen-deprived environments, to proliferate and metastasize in different body sites. The phosphoinositide 3-kinase-AKT-mammalian target of the rapamycin (PI3K/AKT/mTOR) signaling pathway is usually dysregulated in various cancer types including renal cancer. This molecular pathway is frequently correlated with tumor growth and survival. The main aim of this review is to present renal cancer types, dysregulation of PI3K/AKT/mTOR signaling pathway members, crosstalk with VHL/HIF axis, and carbohydrates, lipids, and amino acid alterations.
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Affiliation(s)
- Silviu Constantin Badoiu
- Department of Anatomy and Embryology, Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 8 Eroii Sanitari Blvd, 050474 Bucharest, Romania;
| | - Maria Greabu
- Department of Biochemistry, Faculty of Dentistry, Carol Davila University of Medicine and Pharmacy, 8 Eroii Sanitari Blvd, Sector 5, 050474 Bucharest, Romania;
| | - Daniela Miricescu
- Department of Biochemistry, Faculty of Dentistry, Carol Davila University of Medicine and Pharmacy, 8 Eroii Sanitari Blvd, Sector 5, 050474 Bucharest, Romania;
| | - Iulia-Ioana Stanescu-Spinu
- Department of Biochemistry, Faculty of Dentistry, Carol Davila University of Medicine and Pharmacy, 8 Eroii Sanitari Blvd, Sector 5, 050474 Bucharest, Romania;
| | - Radu Ilinca
- Department of Medical Informatics and Biostatistics, Faculty of Dentistry, Carol Davila University of Medicine and Pharmacy, 8 Eroii Sanitari Blvd, 050474 Bucharest, Romania;
| | - Daniela Gabriela Balan
- Department of Physiology, Faculty of Dentistry, Carol Davila University of Medicine and Pharmacy, 8 Eroii Sanitari Blvd, 050474 Bucharest, Romania; (D.G.B.); (A.-E.B.-S.)
| | - Andra-Elena Balcangiu-Stroescu
- Department of Physiology, Faculty of Dentistry, Carol Davila University of Medicine and Pharmacy, 8 Eroii Sanitari Blvd, 050474 Bucharest, Romania; (D.G.B.); (A.-E.B.-S.)
| | - Doina-Andrada Mihai
- Department of Diabetes, Nutrition and Metabolic Diseases, Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 8 Eroii Sanitari Blvd, 050474 Bucharest, Romania;
| | - Ileana Adela Vacaroiu
- Department of Nephrology, Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania;
| | - Constantin Stefani
- Department of Family Medicine and Clinical Base, Dr. Carol Davila Central Military Emergency University Hospital, 134 Calea Plevnei, 010825 Bucharest, Romania;
| | - Viorel Jinga
- Department of Urology, “Prof. Dr. Theodor Burghele” Hospital, 050653 Bucharest, Romania
- “Prof. Dr. Theodor Burghele” Clinical Hospital, University of Medicine and Pharmacy Carol Davila, 050474 Bucharest, Romania
- Medical Sciences Section, Academy of Romanian Scientists, 050085 Bucharest, Romania
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3
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Arabidopsis P4 ATPase-mediated cell detoxification confers resistance to Fusarium graminearum and Verticillium dahliae. Nat Commun 2021; 12:6426. [PMID: 34741039 PMCID: PMC8571369 DOI: 10.1038/s41467-021-26727-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 10/18/2021] [Indexed: 02/07/2023] Open
Abstract
Many toxic secondary metabolites produced by phytopathogens can subvert host immunity, and some of them are recognized as pathogenicity factors. Fusarium head blight and Verticillium wilt are destructive plant diseases worldwide. Using toxins produced by the causal fungi Fusarium graminearum and Verticillium dahliae as screening agents, here we show that the Arabidopsis P4 ATPases AtALA1 and AtALA7 are responsible for cellular detoxification of mycotoxins. Through AtALA1-/AtALA7-mediated vesicle transport, toxins are sequestered in vacuoles for degradation. Overexpression of AtALA1 and AtALA7 significantly increases the resistance of transgenic plants to F. graminearum and V. dahliae, respectively. Notably, the concentration of deoxynivalenol, a mycotoxin harmful to the health of humans and animals, was decreased in transgenic Arabidopsis siliques and maize seeds. This vesicle-mediated cell detoxification process provides a strategy to increase plant resistance against different toxin-associated diseases and to reduce the mycotoxin contamination in food and feed.
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Wu MY, Liu L, Wang EJ, Xiao HT, Cai CZ, Wang J, Su H, Wang Y, Tan J, Zhang Z, Wang J, Yao M, Ouyang DF, Yue Z, Li M, Chen Y, Bian ZX, Lu JH. PI3KC3 complex subunit NRBF2 is required for apoptotic cell clearance to restrict intestinal inflammation. Autophagy 2021; 17:1096-1111. [PMID: 32160108 PMCID: PMC8143223 DOI: 10.1080/15548627.2020.1741332] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 03/04/2020] [Accepted: 03/09/2020] [Indexed: 12/13/2022] Open
Abstract
NRBF2, a regulatory subunit of the ATG14-BECN1/Beclin 1-PIK3C3/VPS34 complex, positively regulates macroautophagy/autophagy. In this study, we report that NRBF2 is required for the clearance of apoptotic cells and alleviation of inflammation during colitis in mice. NRBF2-deficient mice displayed much more severe colitis symptoms after the administration of ulcerative colitis inducer, dextran sulfate sodium salt (DSS), accompanied by prominent intestinal inflammation and apoptotic cell accumulation. Interestingly, we found that nrbf2-/- mice and macrophages displayed impaired apoptotic cell clearance capability, while adoptive transfer of nrbf2+/+ macrophages to nrbf2-/- mice alleviated DSS-induced colitis lesions. Mechanistically, NRBF2 is required for the generation of the active form of RAB7 to promote the fusion between phagosomes containing engulfed apoptotic cells and lysosomes via interacting with the MON1-CCZ1 complex and regulating the guanine nucleotide exchange factor (GEF) activity of the complex. Evidence from clinical samples further reveals the physiological role of NRBF2 in maintaining intestinal homeostasis. In biopsies of UC patient colon, we observed upregulated NRBF2 in the colon macrophages and the engulfment of apoptotic cells by NRBF2-positive cells, suggesting a potential protective role for NRBF2 in UC. To confirm the relationship between apoptotic cell clearance and IBD development, we compared TUNEL-stained cell counts in the UC with UC severity (Mayo Score) and observed a strong correlation between the two indexes, indicating that apoptotic cell population in colon tissue correlates with UC severity. The findings of our study reveal a novel role for NRBF2 in regulating apoptotic cell clearance to restrict intestinal inflammation.Abbreviation: ANOVA: analysis of variance; ATG14: autophagy related 14; ATG16L1: autophagy related 16-like 1 (S. cerevisiae); BMDM: bone marrow-derived macrophage; BSA: bovine serum albumin; CD: Crohn disease; CD68: CD68 molecule; CFP: cyan fluorescent protein; CMFDA: 5-chloromethylfluorescein diacetate; Co-IP, co-immunoprecipitation; CPR: C-reactive protein; Cy7: cyanine 7 maleimide; DAB: diaminobezidine 3; DAI: disease activity indexes; DAPI: 4'6-diamidino-2-phenylindole; DMEM: dulbecco's modified eagle's medium; DMSO: dimethyl sulfoxide; DOC: sodium deoxycholate; DSS: dextran sulfate sodium; EDTA: ethylenediaminetetraacetic acid; EGTA: ethylenebis (oxyethylenenitrilo) tetraacetic acid; FBS: fetal bovine serum; FITC: fluorescein isothiocyanate; FRET: Förster resonance energy transfer; GDP: guanine dinucleotide phosphate; GEF: guanine nucleotide exchange factor; GFP: green fluorescent protein; GTP: guanine trinucleotide phosphate; GWAS: genome-wide association studies; HEK293: human embryonic kidney 293 cells; HRP: horseradish peroxidase; IBD: inflammatory bowel disease; IgG: immunoglobin G; IL1B/IL-1β: interleukin 1 beta; IL6: interleukin 6; IRGM: immunity related GTPase M; ITGAM/CD11b: integrin subunit alpha M; KO: knockout; LRRK2: leucine rich repeat kinase 2; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MOI: multiplicity of infection; MPO: myeloperoxidase; NaCl: sodium chloride; NEU: neutrophil; NOD2: nucleotide binding oligomerization domain containing 2; NP40: nonidet-P40; NRBF2: nuclear receptor binding factor 2; PBS: phosphate buffer saline; PCR: polymerase chain reaction; PE: P-phycoerythrin; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PtdIns3P: phosphatidylinositol-3-phosphate; PTPRC/CD45: protein tyrosine phosphatase receptor type C; SDS-PAGE: sodium dodecylsulphate-polyacrylamide gel electrophoresis; TBST: tris-buffered saline Tween-20; Tris-HCl: trihydroxymethyl aminomethane hydrochloride; TUNEL: TdT-mediated dUTP nick-end labeling; UC: ulcerative colitis; ULK1: unc-51 like autophagy activating kinase 1; WB: western blotting; WT: wild type; YFP: yellow fluorescent protein.
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Affiliation(s)
- Ming-Yue Wu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
| | - Le Liu
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Er-Jin Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
| | - Hai-Tao Xiao
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
- School of Pharmacy, Shenzhen University, Shenzhen, Guangdong, China
| | - Cui-Zan Cai
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
| | - Jing Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
| | - Huanxing Su
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
| | - Yitao Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
| | - Jieqiong Tan
- Center for Medical Genetics, School of Life Science, Central South University, Changsha, Hunan, China
| | - Zhuohua Zhang
- Institute of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Juan Wang
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Maojing Yao
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China
| | - De-Fang Ouyang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
| | - Zhenyu Yue
- Department of Neurology and Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Min Li
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Ye Chen
- Department of Gastroenterology, State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhao-Xiang Bian
- School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China
| | - Jia-Hong Lu
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR, China
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5
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Chen Y, Leng M, Gao Y, Zhan D, Choi JM, Song L, Li K, Xia X, Zhang C, Liu M, Ji S, Jain A, Saltzman AB, Malovannaya A, Qin J, Jung SY, Wang Y. A Cross-Linking-Aided Immunoprecipitation/Mass Spectrometry Workflow Reveals Extensive Intracellular Trafficking in Time-Resolved, Signal-Dependent Epidermal Growth Factor Receptor Proteome. J Proteome Res 2019; 18:3715-3730. [PMID: 31442056 DOI: 10.1021/acs.jproteome.9b00427] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Ligand binding to the cell surface receptors initiates signaling cascades that are commonly transduced through a protein-protein interaction (PPI) network to activate a plethora of response pathways. However, tools to capture the membrane PPI network are lacking. Here, we describe a cross-linking-aided mass spectrometry workflow for isolation and identification of signal-dependent epidermal growth factor receptor (EGFR) proteome. We performed protein cross-linking in cell culture at various time points following EGF treatment, followed by immunoprecipitation of endogenous EGFR and analysis of the associated proteins by quantitative mass spectrometry. We identified 140 proteins with high confidence during a 2 h time course by data-dependent acquisition and further validated the results by parallel reaction monitoring. A large proportion of proteins in the EGFR proteome function in endocytosis and intracellular protein transport. The EGFR proteome was highly dynamic with distinct temporal behavior; 10 proteins that appeared in all time points constitute the core proteome. Functional characterization showed that loss of the FYVE domain-containing proteins altered the EGFR intracellular distribution but had a minor effect on EGFR proteome or signaling. Thus, our results suggest that the EGFR proteome include functional regulators that influence EGFR signaling and bystanders that are captured as the components of endocytic vesicles. The high-resolution spatiotemporal information of these molecules facilitates the delineation of many pathways that could determine the strength and duration of the signaling, as well as the location and destination of the receptor.
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Affiliation(s)
- Yue Chen
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77003, United States
| | - Mei Leng
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77003, United States
| | - Yankun Gao
- State Key Laboratory of Proteomics, Beijing Proteome Research Center , National Center for Protein Sciences (The PHOENIX Center, Beijing), Institute of Lifeomics , Beijing 102206 , China
| | - Dongdong Zhan
- The Center for Bioinformatics and Computational Biology, Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences , East China Normal University , Shanghai 200241 , China
| | - Jong Min Choi
- Advanced Technology Core, Baylor College of Medicine, Houston, Texas77030, United States
| | - Lei Song
- State Key Laboratory of Proteomics, Beijing Proteome Research Center , National Center for Protein Sciences (The PHOENIX Center, Beijing), Institute of Lifeomics , Beijing 102206 , China
| | - Kai Li
- State Key Laboratory of Proteomics, Beijing Proteome Research Center , National Center for Protein Sciences (The PHOENIX Center, Beijing), Institute of Lifeomics , Beijing 102206 , China
| | - Xia Xia
- State Key Laboratory of Proteomics, Beijing Proteome Research Center , National Center for Protein Sciences (The PHOENIX Center, Beijing), Institute of Lifeomics , Beijing 102206 , China
| | - Chunchao Zhang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77003, United States
| | - Mingwei Liu
- State Key Laboratory of Proteomics, Beijing Proteome Research Center , National Center for Protein Sciences (The PHOENIX Center, Beijing), Institute of Lifeomics , Beijing 102206 , China
| | - Shuhui Ji
- State Key Laboratory of Proteomics, Beijing Proteome Research Center , National Center for Protein Sciences (The PHOENIX Center, Beijing), Institute of Lifeomics , Beijing 102206 , China
| | - Antrix Jain
- Advanced Technology Core, Baylor College of Medicine, Houston, Texas77030, United States
| | - Alexander B Saltzman
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77003, United States
| | - Anna Malovannaya
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77003, United States,Advanced Technology Core, Baylor College of Medicine, Houston, Texas77030, United States,Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, Texas77030, United States,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77003, United States
| | - Jun Qin
- State Key Laboratory of Proteomics, Beijing Proteome Research Center , National Center for Protein Sciences (The PHOENIX Center, Beijing), Institute of Lifeomics , Beijing 102206 , China.,The Center for Bioinformatics and Computational Biology, Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences and School of Life Sciences , East China Normal University , Shanghai 200241 , China.,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77003, United States,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77003, United States
| | - Sung Yun Jung
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77003, United States
| | - Yi Wang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center , National Center for Protein Sciences (The PHOENIX Center, Beijing), Institute of Lifeomics , Beijing 102206 , China.,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77003, United States,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77003, United States
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6
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Affiliation(s)
- Xiaolin Cheng
- Division of Medicinal Chemistry and Pharmacognosy, Biophysics Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United States
| | - Jeremy C. Smith
- UT/ORNL Center for Molecular Biophysics, Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
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7
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Ross JW, Hale BJ, Seibert JT, Romoser MR, Adur MK, Keating AF, Baumgard LH. Physiological mechanisms through which heat stress compromises reproduction in pigs. Mol Reprod Dev 2018; 84:934-945. [PMID: 28667793 DOI: 10.1002/mrd.22859] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 06/06/2017] [Indexed: 12/31/2022]
Abstract
Seasonal variations in environmental temperatures impose added stress on domestic species bred for economically important production traits. These heat-mediated stressors vary on a seasonal, daily, or spatial scale, and negatively impact behavior and reduce feed intake and growth rate, which inevitably lead to reduced herd productivity. The seasonal infertility observed in domestic swine is primarily characterized by depressed reproductive performance, which manifests as delayed puberty onset, reduced farrowing rates, and extended weaning-to-estrus intervals. Understanding the effects of heat stress at the organismal, cellular, and molecular level is a prerequisite to identifying mitigation strategies that should reduce the economic burden of compromised reproduction. In this review, we discuss the effect of heat stress on an animal's ability to maintain homeostasis in multiple systems via several hypothalamic-pituitary-end organ axes. Additionally, we discuss our understanding of epigenetic programming and how hyperthermia experienced in utero influences industry-relevant postnatal phenotypes. Further, we highlight the recent recognized mechanisms by which distant tissues and organs may molecularly communicate via extracellular vesicles, a potentially novel mechanism contributing to the heat-stress response.
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Affiliation(s)
- Jason W Ross
- Department of Animal Science, Iowa State University, Ames, Iowa
| | - Benjamin J Hale
- Department of Animal Science, Iowa State University, Ames, Iowa
| | - Jacob T Seibert
- Department of Animal Science, Iowa State University, Ames, Iowa
| | | | - Malavika K Adur
- Department of Animal Science, Iowa State University, Ames, Iowa
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8
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Zambrano S, Rodriguez PQ, Guo J, Möller-Hackbarth K, Schwarz A, Patrakka J. FYVE domain-containing protein ZFYVE28 regulates EGFR-signaling in podocytes but is not critical for the function of filtration barrier in mice. Sci Rep 2018; 8:4712. [PMID: 29549365 PMCID: PMC5856817 DOI: 10.1038/s41598-018-23104-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 03/06/2018] [Indexed: 12/27/2022] Open
Abstract
The kidney ultrafiltration barrier is formed of endothelial cells, the glomerular basement membrane and podocytes. Podocytes have a central role in normal physiology and disease pathogenesis of the glomerulus. Signaling through epidermal growth factor receptor (EGFR) in podocytes mediates development of many glomerular disease processes. In this work, we have identified zinc finger FYVE-type containing 28 (ZFYVE28) as a novel highly podocyte-enriched gene. We localize ZFYVE28 in podocyte foot processes in adult kidney. During glomerulogenesis, Zfyve28 is first expressed at the early capillary loop glomerulus. In cultured podocytes, we show that overexpression of ZFYVE28 promotes EGF-signaling, possibly by up-regulating EGFR expression and by modulating its localization. To study the role of ZFYVE28 in vivo, we generated both conventional and podocyte-specific knockout mouse lines. Kidneys developed normally in ZFYVE28-deficient mice. In adult mice, the absence of ZFYVE28 did not affect the maintenance of the filtration barrier. Moreover, ZFYVE28-deficiency did not affect the outcome of glomerular damage induced by injection of nephrotoxic serum. Taken together, we have identified Zfyve28 as a new molecular component of podocyte foot processes and show that it mediates EGF-signaling in podocytes. However, ZFYVE28 is not essential for the development or maintenance of the glomerulus filtration barrier.
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Affiliation(s)
- Sonia Zambrano
- KI/AZ Integrated CardioMetabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Patricia Q Rodriguez
- KI/AZ Integrated CardioMetabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Jing Guo
- KI/AZ Integrated CardioMetabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Katja Möller-Hackbarth
- KI/AZ Integrated CardioMetabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Angelina Schwarz
- KI/AZ Integrated CardioMetabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden
| | - Jaakko Patrakka
- KI/AZ Integrated CardioMetabolic Center, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Stockholm, Sweden.
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9
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MacFarlane PM, Di Fiore JM. Myo-inositol Effects on the Developing Respiratory Neural Control System. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1071:159-166. [PMID: 30357747 DOI: 10.1007/978-3-319-91137-3_20] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Myo-inositol is a highly abundant stereoisomer of the inositol family of sugar alcohols and forms the structural basis for a variety of polyphosphate derivatives including second messengers and membrane phospholipids. These derivatives regulate numerous cell processes including gene transcription, membrane excitability, vesicular trafficking, intracellular calcium signaling, and neuronal growth and development. Myo-inositol can be formed endogenously from the breakdown of glucose, is found in a variety of foods including breastmilk and is commercially available as a nutritional supplement. Abnormal myo-inositol metabolism has been shown to underlie the pathophysiology of a variety of clinical conditions including Down Syndrome, traumatic brain injury, bronchopulmonary dysplasia (BPD), and respiratory distress syndrome (RDS). Several animal studies have shown that myo-inositol may play a critical role in development of both the central and peripheral respiratory neural control system; a notable example is the neonatal apnea and respiratory insufficiency that manifests in a mouse model of myo-inositol depletion, an effect that is also postnatally lethal. This review focuses on myo-inositol (and some of its derivatives) and how it may play a role in respiratory neural control; we also discuss clinical evidence demonstrating a link between serum myo-inositol levels and the incidence of intermittent hypoxemia (IH) events (a surrogate measure of apnea of prematurity (AOP)) in preterm infants. Further, there are both animal and human infant studies that have demonstrated respiratory benefits following supplementation with myo-inositol, which highlights the prospects that nutritional requirements are important for appropriate development and maturation of the respiratory system.
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Affiliation(s)
- Peter M MacFarlane
- Case Western Reserve University, Rainbow Babies & Children's Hospital, Cleveland, OH, USA.
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10
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Gopi M, Arambakkam Janardhanam V. Asiaticoside: Attenuation of rotenone induced oxidative burden in a rat model of hemiparkinsonism by maintaining the phosphoinositide-mediated synaptic integrity. Pharmacol Biochem Behav 2017; 155:1-15. [PMID: 28238857 DOI: 10.1016/j.pbb.2017.02.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 02/14/2017] [Accepted: 02/20/2017] [Indexed: 02/06/2023]
Abstract
Asiaticoside (AS), a triterpenoid saponin isolated from the Indian medicinal herb Centella asiatica is known to exert a neuroprotective effect by attenuating the neurobehavioral, neurochemical and pathological changes in animal models. However, its potential neuroprotection in rotenone-induced hemiparkinsonism which implicates phospholipid-mediated neurotransmission remains unclear. Therefore, we have investigated the neuroprotective effects of AS in rat model of ROT-infused hemiparkinsonism with respect to phosphoinositides-assisted cytodynamics and synaptic function. Adult male Sprague-Dawley rats (250-300g) were distributed randomly into 6 groups, with 6 rats in each group: Sham control, Vehicle control (DMSO-0.1%), ROT-infused group (6μg/μl/kg), AS-treated group (50mg/kg/day), Drug (AS) control and Levodopa (l-DOPA)-treated group (6mg/kg/day). At the end of the experimental period, the rats were sacrificed after performing behavioral analyses and the striatum regions were dissected out. Phosphoinositides (PI) are involved in intrinsic membrane signals that regulate intracellular membrane trafficking vesicle and endocytosis. We have assessed mRNA and protein expressions of genes involved in PI-mediated signaling and also in synaptic function (PI3K, PDK 1, PEBP, Stx 1A and TH) in addition to the levels of neurotransmitters and the enzymatic antioxidant profile. AS caused an improved working memory and motor co-ordination in the ROT group. It alters the levels of neurotransmitters (p<0.01), the expression of mRNA and protein assessed which were significantly affected (P<0.001) by rotenone, thus exhibiting its intervention in the progression of neurodegeneration. We demonstrate that AS can mediate distinct function in PI-assisted vesicle endocytosis, cytoprotective signaling and in the synaptic function thereby mitigating the ROT-infused hemiparkinsonism, however, its specific regulatory role remains to be unraveled.
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Affiliation(s)
- Margabandhu Gopi
- Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, Tamilnadu, India.
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Li Z, Yao J, Xie Y, Geng X, Liu Z. Phosphoinositide 3-kinase family in channel catfish and their regulated expression after bacterial infection. FISH & SHELLFISH IMMUNOLOGY 2016; 49:364-373. [PMID: 26772478 DOI: 10.1016/j.fsi.2016.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/30/2015] [Accepted: 01/03/2016] [Indexed: 06/05/2023]
Abstract
The phosphoinositide-3-kinase (PI3Ks) family of lipid kinases is widely conserved from yeast to mammals. In this work, we identified a total of 14 members of the PI3Ks from the channel catfish genome and transcriptome and conducted phylogenetic and syntenic analyses of these genes. The expression profiles after infection with Edwardsiella ictaluri and Flavobacterium columnare were examined to determine the involvement of PI3Ks in immune responses after bacterial infection in catfish. The results indicated that PI3Ks genes including all of the catalytic subunit and several regulatory subunits genes were widely regulated after bacterial infection. The expression patterns were quite different when challenged with different bacteria. The PI3Ks were up-regulated rapidly at the early stage after ESC infection, but their induced expression was much slower, at the middle stage after columnaris infection. RNA-Seq datasets indicated that PI3K genes may be expressed at different levels in different catfish differing in their resistance levels against columnaris. Future studies are required to confirm and validate these observations. Taken together, this study indicated that PI3K genes may be involved as a part of the defense responses of catfish after infections, and they could be one of the determinants for disease resistance.
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Affiliation(s)
- Zhaoxia Li
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA; Marine Science and Engineering College, Qingdao Agricultural University, Qingdao 266109, PR China
| | - Jun Yao
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Yangjie Xie
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Xin Geng
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
| | - Zhanjiang Liu
- The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
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12
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Morphological characterization of Class III phosphoinositide 3-kinase during mouse brain development. Med Mol Morphol 2015; 49:28-33. [DOI: 10.1007/s00795-015-0116-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 07/28/2015] [Indexed: 10/23/2022]
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Ross JW, Hale BJ, Gabler NK, Rhoads RP, Keating AF, Baumgard LH. Physiological consequences of heat stress in pigs. ANIMAL PRODUCTION SCIENCE 2015. [DOI: 10.1071/an15267] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heat stress negatively influences the global pork industry and undermines genetic, nutritional, management and pharmaceutical advances in management, feed and reproductive efficiency. Specifically, heat stress-induced economic losses result from poor sow performance, reduced and inconsistent growth, decreased carcass quality, mortality, morbidity, and processing issues caused by less rigid adipose tissue (also known as flimsy fat). When environmental conditions exceed the pig’s thermal neutral zone, nutrients are diverted from product synthesis (meat, fetus, milk) to body temperature maintenance thereby compromising efficiency. Unfortunately, genetic selection for both increased litter size and leaner phenotypes decreases pigs’ tolerance to heat, as enhanced fetal development and protein accretion results in increased basal heat production. Additionally, research has demonstrated that in utero heat stress negatively and permanently alters post-natal body temperature and body composition and both variables represent an underappreciated consequence of heat stress. Advances in management (i.e. cooling systems) have partially alleviated the negative impacts of heat stress, but productivity continues to decline during the warm summer months. The detrimental effects of heat stress on animal welfare and production will likely become more of an issue in regions most affected by continued predictions for climate change, with some models forecasting extreme summer conditions in key animal-producing areas of the globe. Therefore, heat stress is likely one of the primary factors limiting profitable animal protein production and will certainly continue to compromise food security (especially in emerging countries) and regionalise pork production in developed countries. Thus, there is an urgent need to have a better understanding of how heat stress reduces animal productivity. Defining the biology of how heat stress jeopardises animal performance is critical in developing approaches (genetic, managerial, nutritional and pharmaceutical) to ameliorate current production issues and improve animal wellbeing and performance.
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Boularan C, Kamenyeva O, Cho H, Kehrl JH. Resistance to inhibitors of cholinesterase (Ric)-8A and Gαi contribute to cytokinesis abscission by controlling vacuolar protein-sorting (Vps)34 activity. PLoS One 2014; 9:e86680. [PMID: 24466196 PMCID: PMC3897744 DOI: 10.1371/journal.pone.0086680] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/12/2013] [Indexed: 11/18/2022] Open
Abstract
Resistance to inhibitors of cholinesterase (Ric)-8A is a guanine nucleotide exchange factor for Gαi, Gαq, and Gα12/13, which is implicated in cell signaling and as a molecular chaperone required for the initial association of nascent Gα subunits with cellular membranes. Ric-8A, Gαi subunits, and their regulators are localized at the midbody prior to abscission and linked to the final stages of cell division. Here, we identify a molecular mechanism by which Ric-8A affects cytokinesis and abscission by controlling Vps34 activity. We showed that Ric-8A protein expression is post-transcriptionally controlled during the cell cycle reaching its maximum levels at mitosis. A FRET biosensor created to measure conformational changes in Ric-8A by FLIM (Fluorescence Lifetime Imaging Microscopy) revealed that Ric-8A was in a close-state during mitosis and particularly so at cytokinesis. Lowering Ric-8A expression delayed the abscission time of dividing cells, which correlated with increased intercellular bridge length and multinucleation. During cytokinesis, Ric-8A co-localized with Vps34 at the midbody along with Gαi and LGN, where these proteins functioned to regulate Vps34 phosphatidylinositol 3-kinase activity.
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Affiliation(s)
- Cedric Boularan
- B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Olena Kamenyeva
- B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hyeseon Cho
- B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - John H. Kehrl
- B-cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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Wang H, Zhuang X, Cai Y, Cheung AY, Jiang L. Apical F-actin-regulated exocytic targeting of NtPPME1 is essential for construction and rigidity of the pollen tube cell wall. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 76:367-79. [PMID: 23906068 DOI: 10.1111/tpj.12300] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 07/15/2013] [Accepted: 07/18/2013] [Indexed: 05/03/2023]
Abstract
In tip-confined growing pollen tubes, delivery of newly synthesized cell wall materials to the rapidly expanding apical surface requires spatial organization and temporal regulation of the apical F-actin filament and exocytosis. In this study, we demonstrate that apical F-actin is essential for the rigidity and construction of the pollen tube cell wall by regulating exocytosis of Nicotiana tabacum pectin methylesterase (NtPPME1). Wortmannin disrupts the spatial organization of apical F-actin in the pollen tube tip and inhibits polar targeting of NtPPME1, which subsequently alters the rigidity and pectic composition of the pollen tube cell wall, finally causing growth arrest of the pollen tube. In addition to mechanistically linking cell wall construction and apical F-actin, wortmannin can be used as a useful tool for studying endomembrane trafficking and cytoskeletal organization in pollen tubes.
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Affiliation(s)
- Hao Wang
- School of Life Sciences, Centre for Cell and Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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Abstract
In recent years, several genetic and epigenetic alterations have been identified and linked with deregulated signaling pathways that promote growth and survival of lymphoma cells. These discoveries have raised hopes that a new era of targeted therapy will eventually improve treatment outcome of lymphoma. In this focused review, we summarize emerging preclinical and clinical data supporting the development of novel agents targeting B cell receptor signaling, phosphoinositol-3-kinase/AKT/mammalian target of rapamycin (PI3K/AKT/mTOR) and Janus kinase/signal transducer and activator of transcription (JAK/STAT) oncogenic pathways. Furthermore, we discuss new data on targeting chromatin modulating mechanisms.
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Affiliation(s)
- Lori A Leslie
- Division of Cancer Medicine, M. D. Anderson Cancer Center , Houston, TX , USA
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Giudice FS, Squarize CH. The determinants of head and neck cancer: Unmasking the PI3K pathway mutations. ACTA ACUST UNITED AC 2013; Suppl 5. [PMID: 25126449 DOI: 10.4172/2157-2518.s5-003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Studies attempting to identify and understand the function of mutated genes and deregulated molecular pathways in cancer have been ongoing for many years. The PI3K-PTEN-mTOR signaling pathway is one of the most frequently deregulated pathways in cancer. PIK3CA mutations are found 11%-33% of head and neck cancer (HNC). The hotspot mutation sites for PIK3CA are E542K, E545K and H1047R/L. The PTEN somatic mutations are in 9-23% of HNC, and they frequently cluster in the phosphatase domain of PTEN protein. PTEN loss of heterozygosity (LOH) ranges from 41%-71% and loss of PTEN protein expression occurs in 31.2% of the HNC samples. PIK3CA and PTEN are key molecules in the PI3K-PTEN-mTOR signaling pathway. In this review, we provided a comprehensive overview of mutations in the PI3K-PTEN-mTOR molecular circuitry in HNC, including PI3K family members, TSC1/TSC2, PTEN, AKT, and mTORC1 and mTORC2 complexes. We discussed how these genetic alterations may affect protein structure and function. We also highlight the latest discoveries in protein kinase and tumor suppressor families, emphasizing how mutations in these families interfere with PI3K signaling. A better understanding of the mechanisms underlying cancer formation, progression and resistance to therapy will inform selection of novel genomic-based personalized therapies for head and neck cancer patients.
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Affiliation(s)
- Fernanda S Giudice
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, 48109-1078, USA ; International Research Center, A. C. Camargo Cancer Center, São Paulo, SP, Brazil
| | - Cristiane H Squarize
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, Michigan, 48109-1078, USA
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Abstract
Autophagy is a self-degradation system of cellular components through an autophagosomal-lysosomal pathway. Over the last 15 yr, yeast genetic screens led to the identification of a number of genes involved in the autophagic pathway. Most of these autophagy genes are present in higher eukaryotes and regulate autophagy process for cell survival and homeostasis. Significant progress has recently been made to better understand the molecular mechanisms of the autophagy machinery. Especially, autophagy process, including the regulation of autophagy induction through mTOR and the nucleation and elongation in autophagosome formation through class III phosphatidylinositol 3-kinase complex and ubiquitin-like conjugation systems, became evident. While many unanswered questions remain to be answered, here, we summarize the recent process of autophagy with emphasis on molecules and their protein complexes along with advanced molecular mechanisms that regulate the autophagy machinery.
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Affiliation(s)
- Jong Ok Pyo
- School of Biological Science/Bio-MAX Institute, Seoul National University, Seoul 151-747, Korea
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Takeuchi H, Zhang Z, Gao J, Sugiyama G, Takeuchi T, Hirata M. Second basic pockets contribute to the localization of PX domains by binding to phosphatidic acid. Adv Biol Regul 2012; 52:183-194. [PMID: 21930145 DOI: 10.1016/j.advenzreg.2011.09.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 09/06/2011] [Indexed: 05/31/2023]
Affiliation(s)
- Hiroshi Takeuchi
- Laboratory of Molecular and Cellular Biochemistry, Faculty of Dental Science and Station for Collaborative Research, Kyushu University, Fukuoka 812-8582, Japan
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20
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Burroughs AM, Iyer LM, Aravind L. Functional diversification of the RING finger and other binuclear treble clef domains in prokaryotes and the early evolution of the ubiquitin system. MOLECULAR BIOSYSTEMS 2011; 7:2261-77. [PMID: 21547297 PMCID: PMC5938088 DOI: 10.1039/c1mb05061c] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent studies point to a diverse assemblage of prokaryotic cognates of the eukaryotic ubiquitin (Ub) system. These systems span an entire spectrum, ranging from those catalyzing cofactor and amino acid biosynthesis, with only adenylating E1-like enzymes and ubiquitin-like proteins (Ubls), to those that are closer to eukaryotic systems by virtue of possessing E2 enzymes. Until recently E3 enzymes were unknown in such prokaryotic systems. Using contextual information from comparative genomics, we uncover a diverse group of RING finger E3s in prokaryotes that are likely to function with E1s, E2s, JAB domain peptidases and Ubls. These E1s, E2s and RING fingers suggest that features hitherto believed to be unique to eukaryotic versions of these proteins emerged progressively in such prokaryotic systems. These include the specific configuration of residues associated with oxyanion-hole formation in E2s and the C-terminal UFD in the E1 enzyme, which presents the E2 to its active site. Our study suggests for the first time that YukD-like Ubls might be conjugated by some of these systems in a manner similar to eukaryotic Ubls. We also show that prokaryotic RING fingers possess considerable functional diversity and that not all of them are involved in Ub-related functions. In eukaryotes, other than RING fingers, a number of distinct binuclear (chelating two Zn atoms) and mononuclear (chelating one zinc atom) treble clef domains are involved in Ub-related functions. Through detailed structural analysis we delineated the higher order relationships and interaction modes of binuclear treble clef domains. This indicated that the FYVE domain acquired the binuclear state independently of the other binuclear forms and that different treble clef domains have convergently acquired Ub-related functions independently of the RING finger. Among these, we uncover evidence for notable prokaryotic radiations of the ZF-UBP, B-box, AN1 and LIM clades of treble clef domains and present contextual evidence to support their role in functions unrelated to the Ub-system in prokaryotes. In particular, we show that bacterial ZF-UBP domains are part of a novel cyclic nucleotide-dependent redox signaling system, whereas prokaryotic B-box, AN1 and LIM domains have related functions as partners of diverse membrane-associated peptidases in processing proteins. This information, in conjunction with structural analysis, suggests that these treble clef domains might have been independently recruited to the eukaryotic Ub-system due to an ancient conserved mode of interaction with peptides.
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Affiliation(s)
- A Maxwell Burroughs
- Omics Science Center, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama-shi, 230-0045 Kanagawa, Japan
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Yang SJ, Chen HM, Hsieh CH, Hsu JT, Yeh CN, Yeh TS, Hwang TL, Jan YY, Chen MF. Akt pathway is required for oestrogen-mediated attenuation of lung injury in a rodent model of cerulein-induced acute pancreatitis. Injury 2011; 42:638-42. [PMID: 20709317 DOI: 10.1016/j.injury.2010.07.242] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 07/01/2010] [Accepted: 07/12/2010] [Indexed: 02/08/2023]
Abstract
BACKGROUND The phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) is known to be an endogenous negative feedback or compensatory mechanism that serves to limit pro-inflammatory and chemotactic events in response to injury. The aim of this study is to elucidate whether Akt plays any role in 17β-estradiol (E2)-mediated attenuation of lung injury after acute pancreatitis (AP). MATERIALS AND METHODS Male Sprague-Dawley rats underwent cerulein-induced AP. Rats were treated with vehicle (cyclodextrin), E2 (1 mg/kg body weight [BW]), or E2 plus PI3K/Akt inhibitor Wortmannin (100 μg/kg BW) 1h after the onset of AP. At 8 h after sham operation or AP, various parameters were measured. RESULTS AP led to a significant decrease in lung Akt phosphorylation, which was associated with increased lung tissue myeloperoxidase (MPO) activity, wet-to-dry weight ratios, interleukin (IL)-6, tumor necrosis factor (TNF)-α, cytokine-induced neutrophil chemoattractant (CINC)-1, and CINC-3 levels. Administration of E2 after AP restored the AP-induced decrease in Akt phosphorylation and attenuated the increase in lung injury markers (MPO activity and wet-to dry weight ratios) and pro-inflammatory mediator production. The effects of E2 on the lung were abolished by co-administration of Wortmannin. CONCLUSIONS These results collectively suggest evidences that the Akt pathway seems to be required for E2-mediated protection of lung injury after AP.
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Affiliation(s)
- Shang-Ju Yang
- Department of Surgery, Chang Gung Memorial Hospital at Linkou, Chang Gung University College of Medicine, 5, Fushing Street, Kweishan Shiang, Taoyuan 333, Taiwan
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Sinha A, Mandal S, Banerjee S, Ghosh A, Ganguly S, Sil AK, Sarkar S. Identification and Characterization of a FYVE Domain from the Early Diverging Eukaryote Giardia lamblia. Curr Microbiol 2010; 62:1179-84. [DOI: 10.1007/s00284-010-9845-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 12/01/2010] [Indexed: 10/18/2022]
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Nazarewicz RR, Salazar G, Patrushev N, San Martin A, Hilenski L, Xiong S, Alexander RW. Early endosomal antigen 1 (EEA1) is an obligate scaffold for angiotensin II-induced, PKC-alpha-dependent Akt activation in endosomes. J Biol Chem 2010; 286:2886-95. [PMID: 21097843 DOI: 10.1074/jbc.m110.141499] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Akt/protein kinase B (PKB) activation/phosphorylation by angiotensin II (Ang II) is a critical signaling event in hypertrophy of vascular smooth muscle cells (VSMCs). Conventional wisdom asserts that Akt activation occurs mainly in plasma membrane domains. Recent evidence that Akt activation may take place within intracellular compartments challenges this dogma. The spatial identity and mechanistic features of these putative signaling domains have not been defined. Using cell fractionation and fluorescence methods, we demonstrate that the early endosomal antigen-1 (EEA1)-positive endosomes are a major site of Ang II-induced Akt activation. Akt moves to and is activated in EEA1 endosomes. The expression of EEA1 is required for phosphorylation of Akt at both Thr-308 and Ser-473 as well as for phosphorylation of its downstream targets mTOR and S6 kinase, but not for Erk1/2 activation. Both Akt and phosphorylated Akt (p-Akt) interact with EEA1. We also found that PKC-α is required for organizing Ang II-induced, EEA1-dependent Akt phosphorylation in VSMC early endosomes. EEA1 expression enables PKC-α phosphorylation, which in turn regulates Akt upstream signaling kinases, PDK1 and p38 MAPK. Our results indicate that PKC-α is a necessary regulator of EEA1-dependent Akt signaling in early endosomes. Finally, EEA1 down-regulation or expression of a dominant negative mutant of PKC-α blunts Ang II-induced leucine incorporation in VSMCs. Thus, EEA1 serves a novel function as an obligate scaffold for Ang II-induced Akt activation in early endosomes.
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Affiliation(s)
- Rafal Robert Nazarewicz
- Division of Cardiology, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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Kiefer S, Rogger J, Melone A, Mertz AC, Koryakina A, Hamburger M, Küenzi P. Separation and detection of all phosphoinositide isomers by ESI-MS. J Pharm Biomed Anal 2010; 53:552-8. [DOI: 10.1016/j.jpba.2010.03.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 03/22/2010] [Accepted: 03/23/2010] [Indexed: 01/15/2023]
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Wang L, Budolfson K, Wang F. Pik3c3 deletion in pyramidal neurons results in loss of synapses, extensive gliosis and progressive neurodegeneration. Neuroscience 2010; 172:427-42. [PMID: 20955765 DOI: 10.1016/j.neuroscience.2010.10.035] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 10/04/2010] [Accepted: 10/11/2010] [Indexed: 11/18/2022]
Abstract
The lipid kinase PIK3C3 (also known as VPS34) regulates multiple aspects of endo-membrane trafficking processes. PIK3C3 is widely expressed by neurons in the CNS, and its catalytic product PI3P is enriched in dendritic spines. Here we generated a line of conditional mutant mouse in which Pik3c3 is specifically deleted in hippocampal and in small subsets of cortical pyramidal neurons using the CaMKII-Cre transgene. We found that Pik3c3-deficiency initially causes loss of dendritic spines accompanied with reactive gliosis, which is followed by progressive neuronal degeneration over a period of several months. Layers III and IV cortical neurons are more susceptible to Pik3c3-deletion than hippocampal neurons. Furthermore, in aged conditional Pik3c3 mutant animals, there are extensive gliosis and severe secondary loss of wild type neurons. Our analyses show that Pik3c3 is essential for CNS neuronal homeostasis and Pik3c3flox/flox; CaMKII-Cre mouse is a useful model for studying pathological changes in progressive forebrain neurodegeneration.
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Affiliation(s)
- L Wang
- Department of Cell Biology, Duke University Medical Center, Box 3709, Durham, NC 27710, USA
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26
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Wywial E, Singh SM. Identification and structural characterization of FYVE domain-containing proteins of Arabidopsis thaliana. BMC PLANT BIOLOGY 2010; 10:157. [PMID: 20678208 PMCID: PMC3017826 DOI: 10.1186/1471-2229-10-157] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 08/02/2010] [Indexed: 05/02/2023]
Abstract
BACKGROUND FYVE domains have emerged as membrane-targeting domains highly specific for phosphatidylinositol 3-phosphate (PtdIns(3)P). They are predominantly found in proteins involved in various trafficking pathways. Although FYVE domains may function as individual modules, dimers or in partnership with other proteins, structurally, all FYVE domains share a fold comprising two small characteristic double-stranded beta-sheets, and a C-terminal alpha-helix, which houses eight conserved Zn2+ ion-binding cysteines. To date, the structural, biochemical, and biophysical mechanisms for subcellular targeting of FYVE domains for proteins from various model organisms have been worked out but plant FYVE domains remain noticeably under-investigated. RESULTS We carried out an extensive examination of all Arabidopsis FYVE domains, including their identification, classification, molecular modeling and biophysical characterization using computational approaches. Our classification of fifteen Arabidopsis FYVE proteins at the outset reveals unique domain architectures for FYVE containing proteins, which are not paralleled in other organisms. Detailed sequence analysis and biophysical characterization of the structural models are used to predict membrane interaction mechanisms previously described for other FYVE domains and their subtle variations as well as novel mechanisms that seem to be specific to plants. CONCLUSIONS Our study contributes to the understanding of the molecular basis of FYVE-based membrane targeting in plants on a genomic scale. The results show that FYVE domain containing proteins in plants have evolved to incorporate significant differences from those in other organisms implying that they play a unique role in plant signaling pathways and/or play similar/parallel roles in signaling to other organisms but use different protein players/signaling mechanisms.
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Affiliation(s)
- Ewa Wywial
- Department of Biology, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- Department of Biology, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
| | - Shaneen M Singh
- Department of Biology, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, NY 10016, USA
- Department of Biology, Brooklyn College, City University of New York, 2900 Bedford Avenue, Brooklyn, NY 11210, USA
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Activation of membrane-permeant caged PtdIns(3)P induces endosomal fusion in cells. Nat Chem Biol 2010; 6:324-6. [PMID: 20364126 DOI: 10.1038/nchembio.348] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 01/25/2010] [Indexed: 11/08/2022]
Abstract
Phosphatidylinositol 3-phosphate (PtdIns(3)P) is a phospholipid residing on early endosomes, where it is proposed to be involved in endosomal fusion. We synthesized membrane-permeant derivatives of PtdIns(3)P, including a caged version that is to our knowledge the first photoactivatable phosphoinositide derivative developed so far. In living cells, photoactivation of caged PtdIns(3)P induced rapid endosomal fusion in an EEA1-dependent fashion, thus providing in vivo evidence that PtdIns(3)P is a sufficient signal for driving this process.
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Regulation of Golgi function via phosphoinositide lipids. Semin Cell Dev Biol 2009; 20:793-800. [PMID: 19508852 DOI: 10.1016/j.semcdb.2009.03.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Revised: 03/24/2009] [Accepted: 03/25/2009] [Indexed: 12/22/2022]
Abstract
Phosphoinositides play important roles in Golgi traffic and structural integrity. Specific lipid kinases and phosphatases associate with the Golgi complex and regulate the multiplicity of trafficking routes from this organelle. Work in different model systems showed that the basic elements that regulate lipid signaling at the Golgi are conserved from yeast to humans. Many of the enzymes involved in Golgi phosphoinositide metabolism are essential for viability or cause severe human disease when malfunctioning. Phosphoinositide effectors at the Golgi control both non-vesicular transfer of lipids and sorting of secretory and membrane proteins. In addition, Golgi phosphoinositides were recently implicated in the metabolic and cell growth-dependent regulation of the secretory pathway.
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29
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Woodward HN, Anwar A, Riddle S, Taraseviciene-Stewart L, Fragoso M, Stenmark KR, Gerasimovskaya EV. PI3K, Rho, and ROCK play a key role in hypoxia-induced ATP release and ATP-stimulated angiogenic responses in pulmonary artery vasa vasorum endothelial cells. Am J Physiol Lung Cell Mol Physiol 2009; 297:L954-64. [PMID: 19684203 DOI: 10.1152/ajplung.00038.2009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We recently reported that vasa vasorum expansion occurs in the pulmonary artery (PA) adventitia of chronically hypoxic animals and that extracellular ATP is a pro-angiogenic factor for isolated vasa vasorum endothelial cells (VVEC). However, the sources of extracellular ATP in the PA vascular wall, as well as the molecular mechanisms underlying its release, remain elusive. Studies were undertaken to explore whether VVEC release ATP in response to hypoxia and to determine signaling pathways involved in this process. We found that hypoxia (1-3% O2) resulted in time- and O2-dependent ATP release from VVEC. Preincubation with the inhibitors of vesicular transport (monensin, brefeldin A, and N-ethylmaleimide) significantly decreased ATP accumulation in the VVEC conditioned media, suggesting that hypoxia-induced ATP release occurs through vesicular exocytosis. Additionally, both hypoxia and exogenously added ATP resulted in the activation of PI3K and accumulation of GTP-bound RhoA in a time-dependent manner. Pharmacological inhibition of PI3K and ROCK or knockout of RhoA by small interfering RNA significantly abolished hypoxia-induced ATP release from VVEC. Moreover, RhoA and ROCK play a critical role in ATP-induced increases in VVEC DNA synthesis, migration, and tube formation, indicating a functional contribution of PI3K, Rho, and ROCK to both the autocrine mechanism of ATP release and ATP-mediated angiogenic activation of VVEC. Taken together, our findings provide novel evidence for the signaling mechanisms that link hypoxia-induced increases in extracellular ATP and vasa vasorum expansion.
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Affiliation(s)
- Heather N Woodward
- Department of Pediatrics, 12700 E. 19th Ave., University of Colorado Denver, Research Complex 2, Box B131, Aurora, CO 80045, USA
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Sasaki T, Takasuga S, Sasaki J, Kofuji S, Eguchi S, Yamazaki M, Suzuki A. Mammalian phosphoinositide kinases and phosphatases. Prog Lipid Res 2009; 48:307-43. [PMID: 19580826 DOI: 10.1016/j.plipres.2009.06.001] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Phosphoinositides are lipids that are present in the cytoplasmic leaflet of a cell's plasma and internal membranes and play pivotal roles in the regulation of a wide variety of cellular processes. Phosphoinositides are molecularly diverse due to variable phosphorylation of the hydroxyl groups of their inositol rings. The rapid and reversible configuration of the seven known phosphoinositide species is controlled by a battery of phosphoinositide kinases and phosphoinositide phosphatases, which are thus critical for phosphoinositide isomer-specific localization and functions. Significantly, a given phosphoinositide generated by different isozymes of these phosphoinositide kinases and phosphatases can have different biological effects. In mammals, close to 50 genes encode the phosphoinositide kinases and phosphoinositide phosphatases that regulate phosphoinositide metabolism and thus allow cells to respond rapidly and effectively to ever-changing environmental cues. Understanding the distinct and overlapping functions of these phosphoinositide-metabolizing enzymes is important for our knowledge of both normal human physiology and the growing list of human diseases whose etiologies involve these proteins. This review summarizes the structural and biological properties of all the known mammalian phosphoinositide kinases and phosphoinositide phosphatases, as well as their associations with human disorders.
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Affiliation(s)
- Takehiko Sasaki
- Department of Pathology and Immunology, Akita University, Graduate School of Medicine, Akita 010-8543, Japan.
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31
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Wang J, Cai Y, Miao Y, Lam SK, Jiang L. Wortmannin induces homotypic fusion of plant prevacuolar compartments. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:3075-83. [PMID: 19436047 PMCID: PMC2718212 DOI: 10.1093/jxb/erp136] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2009] [Revised: 04/04/2009] [Accepted: 04/06/2009] [Indexed: 05/17/2023]
Abstract
Wortmannin, a specific inhibitor of phosphatidyl-inositol 3-kinase, is a useful tool for studying protein trafficking and identifying organelles in the plant secretory and endocytic pathways. It has recently been demonstrated that wortmannin at 16.5 microM or 33 microM caused the prevacuolar compartments (PVCs), identified as multivesicular bodies (MVBs) by their enrichment in vacuolar sorting receptor (VSRs) proteins and the BP-80 reporter, to form small vacuoles rapidly. However, the source(s) of the membrane needed for the rapid enlargement of PVCs/MVBs has been unclear. Using both confocal immunofluorescence and immunogold EM with high pressure freeze substitution of plant samples, it has been demonstrated here that wortmannin induces homotypic fusions of PVCs/MVBs thus providing an explanation for the demand for extra membrane. In addition, possible wortmannin-induced fusions between the trans-Golgi network (TGN) and PVC, as well as between the small internal vesicles and PVC membrane, were also observed and they may also contribute to the membranes needed for PVC enlargement. In contrast to mammalian cells and yeast, wortmannin-induced fusion of PVCs appears to be unique to plants.
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Affiliation(s)
| | | | | | | | - Liwen Jiang
- Department of Biology and Molecular Biotechnology Program, Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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Gozar MM, Goodchild A, Passioura T, King A, Lai A, Witherington C, Rivory L. Dz13, a DNAzyme targeting c-jun, induces off-target cytotoxicity in endothelial cells with features of nonapoptotic programmed cell death. Oligonucleotides 2009; 18:257-68. [PMID: 18699742 DOI: 10.1089/oli.2008.0139] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We have previously shown that Dz13, a catalytic DNA molecule (DNAzyme) designed against c-jun, is cytotoxic to nonquiescent cells by a mechanism independent of c-jun mRNA cleavage. In this report, we evaluated programmed cell death (PCD) pathways in order to gain further insight into the mechanism of action of Dz13. Using human dermal microvascular endothelial cells (HMEC-1), we found that Dz13-mediated cell death is characterized by mitochondrial depolarization, caspase-8 activation, lysosomal increase, and autophagosome formation. Classical DNA laddering and translocation of mitochondrial proteins were not observed. An array of inhibitors, including those targeting caspases, failed to abrogate cytotoxicity and mitochondrial depolarization. Cytotoxicity did not proceed from endoplasmic reticulum (ER) stress. The possible involvement of PARP-1 in Dz13-mediated cytotoxicity was indicated by its differential release as gauged by protein extraction data and its apparent binding to Dz13, as evidenced by protein pull-down experiments. This study on Dz13-mediated cytotoxicity presents a detailed investigation into the interplay of cell death effectors involved in apoptosis, autophagy, and necrosis, and demonstrates a novel form of oligonucleotide-mediated cytotoxicity with features of PCD.
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Affiliation(s)
- Mary Margaret Gozar
- Johnson and Johnson Research Pty Limited, Eveleigh, New South Wales, 1430, Australia.
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33
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Tamizhselvi R, Sun J, Koh YH, Bhatia M. Effect of hydrogen sulfide on the phosphatidylinositol 3-kinase-protein kinase B pathway and on caerulein-induced cytokine production in isolated mouse pancreatic acinar cells. J Pharmacol Exp Ther 2009; 329:1166-77. [PMID: 19258518 DOI: 10.1124/jpet.109.150532] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We have shown earlier that mouse pancreatic acinar cells produce hydrogen sulfide (H(2)S) and play a role in the pathogenesis of acute pancreatitis. It is noteworthy that recent evidence indicates that H(2)S has anti-inflammatory effects. To date, the mechanism by which H(2)S directly reduces inflammation has not been elucidated. In the present study, we hypothesized that H(2)S inhibits the production of proinflammatory cytokines by activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway. Pancreatic acinar cells were treated with the H(2)S donor, sodium hydrogen sulfide (NaHS) (5, 10, and 30 microM). To better understand the effect of H(2)S in inflammation, pancreatic acinar cells were stimulated with caerulein after the addition of NaHS (5, 10, and 30 microM). We observed that H(2)S at the 5 microM concentration down-regulates the activation of NF-kappaB and degradation of IkappaB alpha. However, H(2)S (5 microM) activates PI3K as reflected by AKT phosphorylation. We found that H(2)S-mediated activation of PI3K in caerulein-treated acinar cells correlated with the down-regulation of extracellular signal-regulated kinase 1/2 phosphorylation, whereas phosphorylation of p38 and c-Jun NH(2)-terminal kinase and mitogen-activated protein kinases was unchanged. The PI3K inhibitor LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride] abolished the H(2)S-mediated activation of AKT and increases tumor necrosis factor alpha and interleukin 1beta levels in caerulein-treated acinar cells. These findings indicate that the phosphatidylinositol 3-kinase plays a negative role in NaHS-treated pancreatic acinar cells and suggest a role for H(2)S in the PI3K/AKT pathway in acute pancreatitis.
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Intercellular transfer to signalling endosomes regulates an ex vivo bone marrow niche. Nat Cell Biol 2009; 11:303-11. [PMID: 19198600 PMCID: PMC2748410 DOI: 10.1038/ncb1838] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 11/18/2008] [Indexed: 12/14/2022]
Abstract
Hematopoietic stem-progenitor cells (HSPCs) reside in the bone marrow niche, where interactions with osteoblasts provide essential cues for their proliferation and survival. Here, we use live cell imaging to characterize both the site of contact between osteoblasts and hematopoietic progenitor cells (HPCs) and events at this site that result in downstream signaling responses important for niche maintenance. HPCs made prolonged contact with the osteoblast surface via a specialized membrane domain enriched in prominin 1, CD63 and rhodamine PE. At the contact site, portions of the specialized domain containing these molecules were taken up by the osteoblast and internalized into SARA-positive signaling endosomes. This caused osteoblasts to downregulate Smad signaling and increase production of stromal-derived factor-1 (SDF-1), a chemokine responsible for HSPC homing to bone marrow. These findings identify a mechanism involving intercellular transfer to signaling endosomes for targeted regulation of signaling and remodeling events within an ex vivo osteoblastic niche.
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Park SJ, Min KH, Lee YC. Phosphoinositide 3-kinase delta inhibitor as a novel therapeutic agent in asthma. Respirology 2009; 13:764-71. [PMID: 18811876 DOI: 10.1111/j.1440-1843.2008.01369.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Multiple signal transduction pathways are involved in airway inflammation with one of the key signalling pathways being phosphoinositide 3-kinase (PI3K). Numerous components of the PI3K pathway play an important role in the expression and activation of inflammatory mediators, inflammatory cell recruitment, immune cell function, airway remodelling and corticosteroid insensitivity in asthma. More recently studies exploring the specific roles of different PI3K catalytic subunit isoforms in asthma have been initiated. Several of these have highlighted the importance of p110delta isoform as a novel target for therapeutic intervention in asthma. In this review the biological role of PI3Ks, especially PI3Kdelta, are highlighted and the therapeutic potential of selective PI3Kdelta inhibitor in asthma discussed.
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Affiliation(s)
- Seoung J Park
- Department of Internal Medicine and Airway Remodeling Laboratory, Chonbuk National University Medical School, Jeonju, South Korea
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Blagoveshchenskaya A, Mayinger P. SAC1 lipid phosphatase and growth control of the secretory pathway. MOLECULAR BIOSYSTEMS 2008; 5:36-42. [PMID: 19081929 DOI: 10.1039/b810979f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Phosphoinositide lipids play a dual role in cell physiology. Specific sets of these molecules are short-lived downstream mediators of growth signals, regulating cell survival and differentiation. In addition, distinct classes of phosphoinositide lipids function as constitutive mediators of membrane traffic and organelle identity. Recent work has provided the first direct evidence that phosphoinositides also play a direct role in linking protein secretion with cell growth and proliferation. This review focuses on SAC1 lipid phosphatase and how this enzyme operates in an evolutionary conserved mechanism to coordinate the secretory capacity of ER and Golgi during cell growth.
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Affiliation(s)
- Anastasia Blagoveshchenskaya
- Division of Nephrology & Hypertension and Department of Cell & Developmental Biology, Oregon Health & Science University, Portland, Oregon, USA
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Pieters J. Mycobacterium tuberculosis and the macrophage: maintaining a balance. Cell Host Microbe 2008; 3:399-407. [PMID: 18541216 DOI: 10.1016/j.chom.2008.05.006] [Citation(s) in RCA: 341] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 05/19/2008] [Accepted: 05/19/2008] [Indexed: 01/03/2023]
Abstract
Mycobacterium tuberculosis is a highly efficient pathogen, killing millions of infected people annually. The capacity of M. tuberculosis to survive and cause disease is strongly correlated to their ability to escape immune defense mechanisms. In particular, M. tuberculosis has the remarkable capacity to survive within the hostile environment of the macrophage. Understanding M. tuberculosis virulence strategies will not only define novel targets for drug development but will also help to uncover previously unknown signaling pathways related to the host's response to M. tuberculosis infection.
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Affiliation(s)
- Jean Pieters
- Biozentrum, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland.
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Abstract
The Class III PI3K (phosphoinositide 3-kinase), Vps34 (vacuolar protein sorting 34), was first described as a component of the vacuolar sorting system in Saccharomyces cerevisiae and is the sole PI3K in yeast. The homologue in mammalian cells, hVps34, has been studied extensively in the context of endocytic sorting. However, hVps34 also plays an important role in the ability of cells to respond to changes in nutrient conditions. Recent studies have shown that mammalian hVps34 is required for the activation of the mTOR (mammalian target of rapamycin)/S6K1 (S6 kinase 1) pathway, which regulates protein synthesis in response to nutrient availability. In both yeast and mammalian cells, Class III PI3Ks are also required for the induction of autophagy during nutrient deprivation. Finally, mammalian hVps34 is itself regulated by nutrients. Thus Class III PI3Ks are implicated in the regulation of both autophagy and, through the mTOR pathway, protein synthesis, and thus contribute to the integration of cellular responses to changing nutritional status.
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39
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Morita M, Yoshizaki K, Nakane A, Kudo Y. Inhibitory effect of the phosphoinositide 3-kinase inhibitor LY294002 on muscarinic acetylcholine receptor-induced calcium entry in PC12h cells. J Pharmacol Sci 2007; 105:258-63. [PMID: 17965536 DOI: 10.1254/jphs.fp0070643] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Phosphoinositide-3 kinase (PI3K) and phospholipase C (PLC) utilize the same phosphoinositides as substrates to produce different signaling molecules. These enzymes are activated by a similar set of cell signaling mechanisms, i.e., tyrosine kinases and G proteins, and affect common cell functions, including proliferation, motility, and intracellular trafficking. Despite these similarities, the interplay between these enzymes is not well understood. To address this issue, the effects of the PI3K inhibitor LY294002 on carbachol-induced calcium increase in PC12h cells were examined. As carbachol stimulates both Gq- and Gi-coupled muscarinic acetylcholine receptors (mAChRs), PI3K and PLC are activated simultaneously in this protocol. LY294002 was found to reduce the carbachol-induced calcium increase, and the reduction was attributed to suppression of calcium entry. As LY294002 did not affect either carbachol-induced calcium release or calcium entry induced by calcium store depletion, this agent was found to suppress calcium entry directly activated by mAChRs. Although PI3K was supposed to compete for substrates with PLC, the PI3K inhibitor did not enhance PLC-dependent cellular responses. As LY294002 was still effective by treating cells after carbachol stimulation, it is likely that this agent blocks the calcium entry channels directly.
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Affiliation(s)
- Mitsuhiro Morita
- Laboratory of Cellular Neurobiology, School of Life Science, Tokyo University of Pharmacy and Life Science, 192-0392 Tokyo, Japan.
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40
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Sundaramurthy V, Pieters J. Interactions of pathogenic mycobacteria with host macrophages. Microbes Infect 2007; 9:1671-9. [PMID: 18023233 DOI: 10.1016/j.micinf.2007.09.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, is one of the most deadly infectious diseases across the globe. The success of M. tuberculosis is related to its capacity to survive and replicate in macrophages, cells of the host innate immune system that are designed to detect and eliminate pathogens [1,2]. In this review, we will focus on the mechanisms used by the innate system of the host to detect and eliminate mycobacteria and the strategies used by M. tuberculosis to overcome host responses to establish a successful infection.
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Drobic V, Cunnington RH, Bedosky KM, Raizman JE, Elimban VV, Rattan SG, Dixon IMC. Differential and combined effects of cardiotrophin-1 and TGF-β1 on cardiac myofibroblast proliferation and contraction. Am J Physiol Heart Circ Physiol 2007; 293:H1053-64. [PMID: 17483238 DOI: 10.1152/ajpheart.00935.2006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myofibroblasts respond to an array of signals from mitogens and cytokines during the course of wound healing following a myocardial infarction (MI), and these signals may coordinate ventricular myofibroblast proliferation. Furthermore, myofibroblasts are contractile and contribute to wound contraction by imparting mechanical tension on surrounding extracellular matrix. Although TGF-β1, CT-1, and PDGF-BB participate in various stages of post-MI wound healing, their combined net effect(s) on myofibroblast function is unknown. We investigated myofibroblast proliferation, expression of cell cycle proteins, and contractile function of cells treated with TGF-β1 and/or CT-1. We confirmed that TGF-β1 (10 ng/ml) suppresses proliferation of these cells, whereas CT-1 (10 ng/ml) and, for comparative purposes, PDGF-BB (1 ng/ml) treatments were associated with proliferation. Specific TGF-β1 treatment ablated CT-1-induced myofibroblast proliferation. TGF-β1 effects were specific, as they were suppressed by either TGF-β-neutralizing antibody or viral Smad7 overexpression. TGF-β1 treatment also increased expression of p27 and decreased expression of cyclin E and Cdk2 in primary cells. CT-1 (10 ng/ml) treatment of myofibroblasts had no effect on collagen gel deformation versus controls, whereas TGF-β1 (10 ng/ml) and PDGF (10 ng/ml) treatments were associated with significant cell contraction; again, TGF-β1-mediated contraction was unaffected by CT-1. Alone, CT-1 and TGF-β1 treatments exert opposing effects on myofibroblast function, whereas in combination TGF-β1-mediated effects supersede those of CT-1 (and PDGF-BB). Thus TGF-β1 and CT-1 exert differential effects on myofibroblast proliferation and contraction in vitro, and we suggest that a balance of these effects may be important for the execution of normal cardiac wound healing.
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Affiliation(s)
- Vanja Drobic
- Institute of Cardiovascular Science, St. Boniface General Hospital Research Centre, Department of Physiology, University of Manitoba, Winnipeg, MB, Canada
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Navarro-García F, Canizalez-Roman A, Burlingame KE, Teter K, Vidal JE. Pet, a non-AB toxin, is transported and translocated into epithelial cells by a retrograde trafficking pathway. Infect Immun 2007; 75:2101-9. [PMID: 17296748 PMCID: PMC1865752 DOI: 10.1128/iai.01515-06] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The plasmid-encoded toxin (Pet) of enteroaggregative Escherichia coli is a 104-kDa autotransporter protein that exhibits proteolytic activity against the actin-binding protein alpha-fodrin. Intracellular cleavage of epithelial fodrin by Pet disrupts the actin cytoskeleton, causing both cytotoxic and enterotoxic effects. Intoxication requires the serine protease activity of Pet and toxin endocytosis from clathrin-coated pits. The additional events in the intracellular trafficking of Pet are largely uncharacterized. Here, we determined by confocal microscopy that internalized Pet is transferred from the early endosomes to the Golgi apparatus and then travels to the endoplasmic reticulum (ER). Pet associates with the Sec61p translocon before it moves into the cytosol as an intact, 104-kDa protein. This translocation process contrasts with the export of other ER-translocating toxins, in which only the catalytic A subunit of the AB toxin enters the cytosol. However, like intoxication with these AB toxins, Pet intoxication was inhibited in a subset of mutant CHO cell lines with aberrant activity in the ER-associated degradation pathway of ER-to-cytosol translocation. This is the first report which documents the cell surface-to-ER and ER-to-cytosol trafficking of a bacterial non-AB toxin.
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Affiliation(s)
- Fernando Navarro-García
- Department of Cell Biology, Cinvestav-Zacatenco, Ap. Postal 14-740, 07000 México, DF, Mexico.
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Kuang PP, Zhang XH, Rich CB, Foster JA, Subramanian M, Goldstein RH. Activation of elastin transcription by transforming growth factor-beta in human lung fibroblasts. Am J Physiol Lung Cell Mol Physiol 2007; 292:L944-52. [PMID: 17209135 DOI: 10.1152/ajplung.00184.2006] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Elastin synthesis is essential for lung development and postnatal maturation as well as for repair following injury. Using human embryonic lung fibroblasts that express undetectable levels of elastin as assessed by Northern analyses, we found that treatment with exogenous transforming growth factor-beta (TGF-beta) induced rapid and transient increases in levels of elastin heterogeneous nuclear RNA (hnRNA) followed by increases of elastin mRNA and protein expression. In fibroblasts derived from transgenic mice, TGF-beta induced increases in the expression of a human elastin gene promoter fragment driving a chloramphenicol acetyl transferase reporter gene. The induction of elastin hnRNA and mRNA expression by TGF-beta was abolished by pretreatments with TGF-beta receptor I inhibitor, global transcription inhibitor actinomycin D, and partially blocked by addition of protein synthesis inhibitor cycloheximide, but was not affected by the p44/42 MAPK inhibitor U0126. Pretreatment with the p38 MAPK inhibitor SB-203580 also partially attenuated the levels of TGF-beta-induced elastin mRNA but not its hnRNA. Western analysis indicated that TGF-beta stimulated Akt phosphorylation. Inhibition of phosphatidylinositol 3-kinase and Akt phosphorylation by LY-294002 abolished TGF-beta-induced increases in elastin hnRNA and mRNA expression. Treatment of lung fibroblasts with interleukin-1beta or the histone deacetylase inhibitor trichostatin A inhibited TGF-beta-induced elastin mRNA and hnRNA expression by a mechanism that involved inhibition of Akt phosphorylation. Downregulation of Akt2 but not Akt1 expression employing small interfering RNA duplexes blocked TGF-beta-induced increases of elastin hnRNA and mRNA levels. Together, our results demonstrated that TGF-beta activates elastin transcription that is dependent on phosphatidylinositol 3-kinase/Akt activity.
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Affiliation(s)
- Ping-Ping Kuang
- Pulmonary Center, Boston University School of Medicine, 80 E. Concord St., Boston, MA 02118, USA.
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Zonia L, Munnik T. Cracking the green paradigm: functional coding of phosphoinositide signals in plant stress responses. Subcell Biochem 2006; 39:207-37. [PMID: 17121277 DOI: 10.1007/0-387-27600-9_9] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Laura Zonia
- Section of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Kruislaan 318, NL-1098 SM, Amsterdam, The Netherlands
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Dowd PE, Coursol S, Skirpan AL, Kao TH, Gilroy S. Petunia phospholipase c1 is involved in pollen tube growth. THE PLANT CELL 2006; 18:1438-53. [PMID: 16648366 PMCID: PMC1475500 DOI: 10.1105/tpc.106.041582] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 03/17/2006] [Accepted: 04/05/2006] [Indexed: 05/08/2023]
Abstract
Although pollen tube growth is essential for plant fertilization and reproductive success, the regulators of the actin-related growth machinery and the cytosolic Ca2+ gradient thought to determine how these cells elongate remain poorly defined. Phospholipases, their substrates, and their phospholipid turnover products have been proposed as such regulators; however, the relevant phospholipase(s) have not been characterized. Therefore, we cloned cDNA for a pollen-expressed phosphatidylinositol 4,5-bisphosphate (PtdInsP2)-cleaving phospholipase C (PLC) from Petunia inflata, named Pet PLC1. Expressing a catalytically inactive form of Pet PLC1 in pollen tubes caused expansion of the apical Ca2+ gradient, disruption of the organization of the actin cytoskeleton, and delocalization of growth at the tube tip. These phenotypes were suppressed by depolymerizing actin with low concentrations of latrunculin B, suggesting that a critical site of action of Pet PLC1 is in regulating actin structure at the growing tip. A green fluorescent protein (GFP) fusion to Pet PLC1 caused enrichment in regions of the apical plasma membrane not undergoing rapid expansion, whereas a GFP fusion to the PtdInsP2 binding domain of mammalian PLC delta1 caused enrichment in apical regions depleted in PLC. Thus, Pet PLC1 appears to be involved in the machinery that restricts growth to the very apex of the elongating pollen tube, likely through its regulatory action on PtdInsP2 distribution within the cell.
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Affiliation(s)
- Peter E Dowd
- Department of Biochemistry and Molecular Biology, Pensylvania State University, University Park, Pensylvania 16802, USA
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Holz RW. Analysis of the late steps of exocytosis: biochemical and total internal reflection fluorescence microscopy (TIRFM) studies. Cell Mol Neurobiol 2006; 26:439-47. [PMID: 16625428 DOI: 10.1007/s10571-006-9049-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2005] [Accepted: 03/08/2006] [Indexed: 10/24/2022]
Abstract
1. Time with Julie in his laboratory at the NIH in the early 1970s is remembered. The experience led to a life-long interest in the regulation of catecholamine secretion. Here are summarized aspects of this work. 2. The relationship between ATP-dependent priming of exocytosis and the polyphosphoinositides is reviewed. In addition, studies are summarized in which total internal reflection fluorescent microscopy (TIRFM) was used to visualize secretory granule behavior before exocytosis and individual exocytotic events. 3. Quantitative optical analysis indicates that chromaffin granule motion is highly restricted but regulated. Granules can undergo significant motion in the 100 ms prior to fusion and interactions with the plasma membrane leading to fusion can occur within this time. The small motions may permit granules adjacent to the plasma membrane to repetitively sample microdomains of the plasma membrane, thereby increasing the probability of fruitful interactions that lead to fusion.
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Affiliation(s)
- Ronald W Holz
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan 48109-0632, USA.
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Johnson EE, Overmeyer JH, Gunning WT, Maltese WA. Gene silencing reveals a specific function of hVps34 phosphatidylinositol 3-kinase in late versus early endosomes. J Cell Sci 2006; 119:1219-32. [PMID: 16522686 DOI: 10.1242/jcs.02833] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human type III phosphatidylinositol 3-kinase, hVps34, converts phosphatidylinositol (PtdIns) to phosphatidylinositol 3-phosphate [PtdIns(3)P]. Studies using inhibitors of phosphatidylinositide 3-kinases have indicated that production of PtdIns(3)P is important for a variety of vesicle-mediated trafficking events, including endocytosis, sorting of receptors in multivesicular endosomes, and transport of lysosomal enzymes from the trans-Golgi network (TGN) to the endosomes and lysosomes. This study utilizes small interfering (si)RNA-mediated gene silencing to define the specific trafficking pathways in which hVps34 functions in human U-251 glioblastoma cells. Suppression of hVps34 expression reduced the cellular growth rate and caused a striking accumulation of large acidic phase-lucent vacuoles that contain lysosomal membrane proteins LAMP1 and LGP85. Analysis of these structures by electron microscopy suggests that they represent swollen late endosomes that have lost the capacity for inward vesiculation but retain the capacity to fuse with lysosomes. Morphological perturbation of the late endosome compartment was accompanied by a reduced rate of processing of the endosomal intermediate form of cathepsin D to the mature lysosomal form. There was also a reduction in the rate of epidermal growth factor receptor (EGFR) dephosphorylation and degradation following ligand stimulation, consistent with the retention of the EGFR on the limiting membranes of the enlarged late endosomes. By contrast, the suppression of hVps34 expression did not block trafficking of cathepsin D between the TGN and late endosomes, or endocytic uptake of fluid-phase markers, or association of a PtdIns(3)P-binding protein, EEA1, with early endosomes. LAMP1-positive vacuoles were depleted of PtdIns(3)P in the hVps34-knockdown cells, as judged by their inability to bind the PtdIns(3)P probe GFP-2xFYVE. By contrast, LAMP1-negative vesicles continued to bind GFP-2xFYVE in the knockdown cells.
Overall, these findings indicate that hVps34 plays a major role in generating PtdIns(3)P for internal vesicle formation in multivesicular/late endosomes. The findings also unexpectedly suggest that other wortmannin-sensitive kinases and/or polyphosphoinositide phosphatases may be able to compensate for the loss of hVps34 and maintain PtdIns(3)P levels required for vesicular trafficking in the early endocytic pathway or the TGN.
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Affiliation(s)
- Erin E Johnson
- Department of Biochemistry and Cancer Biology, Medical University of Ohio, Toledo, OH 43614, USA
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Pendaries C, Tronchère H, Arbibe L, Mounier J, Gozani O, Cantley L, Fry MJ, Gaits-Iacovoni F, Sansonetti PJ, Payrastre B. PtdIns5P activates the host cell PI3-kinase/Akt pathway during Shigella flexneri infection. EMBO J 2006; 25:1024-34. [PMID: 16482216 PMCID: PMC1409730 DOI: 10.1038/sj.emboj.7601001] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Accepted: 01/23/2006] [Indexed: 12/18/2022] Open
Abstract
The virulence factor IpgD, delivered into nonphagocytic cells by the type III secretion system of the pathogen Shigella flexneri, is a phosphoinositide 4-phosphatase generating phosphatidylinositol 5 monophosphate (PtdIns5P). We show that PtdIns5P is rapidly produced and concentrated at the entry foci of the bacteria, where it colocalises with phosphorylated Akt during the first steps of infection. Moreover, S. flexneri-induced phosphorylation of host cell Akt and its targets specifically requires IpgD. Ectopic expression of IpgD in various cell types, but not of its inactive mutant, or addition of short-chain penetrating PtdIns5P is sufficient to induce Akt phosphorylation. Conversely, sequestration of PtdIns5P or reduction of its level strongly decreases Akt phosphorylation in infected cells or in IpgD-expressing cells. Accordingly, IpgD and PtdIns5P production specifically activates a class IA PI 3-kinase via a mechanism involving tyrosine phosphorylations. Thus, S. flexneri parasitism is shedding light onto a new mechanism of PI 3-kinase/Akt activation via PtdIns5P production that plays an important role in host cell responses such as survival.
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Affiliation(s)
- Caroline Pendaries
- INSERM Unité 563, CPTP, Département d'Oncogenèse et Signalisation dans les Cellules Hématopoiétiques, Hôpital Purpan, Toulouse, France
| | - Hélène Tronchère
- INSERM Unité 563, CPTP, Département d'Oncogenèse et Signalisation dans les Cellules Hématopoiétiques, Hôpital Purpan, Toulouse, France
| | - Laurence Arbibe
- INSERM Unité 389, Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
| | - Joelle Mounier
- INSERM Unité 389, Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
| | - Or Gozani
- Department of Biological Sciences, Stanford University, Stanford, CA, USA
| | - Lewis Cantley
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Michael J Fry
- School of Animal and Microbial Sciences, University of Reading, Whiteknights, Reading, UK
| | - Frédérique Gaits-Iacovoni
- INSERM Unité 563, CPTP, Département d'Oncogenèse et Signalisation dans les Cellules Hématopoiétiques, Hôpital Purpan, Toulouse, France
| | - Philippe J Sansonetti
- INSERM Unité 389, Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
| | - Bernard Payrastre
- INSERM Unité 563, CPTP, Département d'Oncogenèse et Signalisation dans les Cellules Hématopoiétiques, Hôpital Purpan, Toulouse, France
- INSERM U563, CPTP, CHU-Purpan, 31024, Toulouse Cedex 3, France. Tel.: +33 5 62 74 45 25; Fax: +33 5 61 74 45 57; E-mail:
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Wilkes MC, Mitchell H, Penheiter SG, Doré JJ, Suzuki K, Edens M, Sharma DK, Pagano RE, Leof EB. Transforming growth factor-beta activation of phosphatidylinositol 3-kinase is independent of Smad2 and Smad3 and regulates fibroblast responses via p21-activated kinase-2. Cancer Res 2006; 65:10431-40. [PMID: 16288034 DOI: 10.1158/0008-5472.can-05-1522] [Citation(s) in RCA: 165] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Transforming growth factor-beta (TGF-beta) stimulates cellular proliferation and transformation to a myofibroblast phenotype in vivo and in a subset of fibroblast cell lines. As the Smad pathway is activated by TGF-beta in essentially all cell types, it is unlikely to be the sole mediator of cell type-specific outcomes to TGF-beta stimulation. In the current study, we determined that TGF-beta receptor signaling activates phosphatidylinositol 3-kinase (PI3K) in several fibroblast but not epithelial cultures independently of Smad2 and Smad3. PI3K activation occurs in the presence of dominant-negative dynamin and is required for p21-activated kinase-2 kinase activity and the increased proliferation and morphologic change induced by TGF-beta in vitro.
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Affiliation(s)
- Mark C Wilkes
- Department of Biochemistry and Molecular Biology, Thoracic Diseases Research Unit, and Mayo Clinic Cancer Center, Mayo Clinic College of Medicine, Rochester, Minnesota 55905, USA
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Zeng X, Overmeyer JH, Maltese WA. Functional specificity of the mammalian Beclin-Vps34 PI 3-kinase complex in macroautophagy versus endocytosis and lysosomal enzyme trafficking. J Cell Sci 2006; 119:259-70. [PMID: 16390869 DOI: 10.1242/jcs.02735] [Citation(s) in RCA: 270] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Beclin 1 was originally identified as a novel Bcl-2-interacting protein, but co-immunoprecipitation studies suggest that the major physiological partner for Beclin 1 is the mammalian class III phosphatidylinositol 3-kinase (PI 3-kinase) Vps34. Beclin 1 has been proposed to function as a tumor suppressor by promoting cellular macroautophagy, a process that is known to depend on Vps34. However, an alternative role for Beclin 1 in modulating normal Vps34-dependent protein trafficking pathways has not been ruled out. This possibility was examined in U-251 glioblastoma cells. Immunoprecipitates of endogenous Beclin 1 contained human Vps34 (hVps34), but not Bcl-2. Suppression of Beclin 1 expression by short interfering (si)RNA-mediated gene silencing blunted the autophagic response of the cells to nutrient deprivation or C2-ceramide. However, other PI 3-kinase-dependent trafficking pathways, such as the post-endocytic sorting of the epidermal growth factor receptor (EGFR) or the proteolytic processing of procathepsin D en route from the trans-Golgi network (TGN) to lysosomes, were not affected. Depletion of Beclin 1 did not reduce endocytic internalization of a fluid phase marker (horseradish peroxidase, HRP) or cause swelling of late endosomal compartments typically seen in cells where the function of hVps34 is impaired. These findings argue against a role for Beclin 1 as an essential chaperone or adaptor for hVps34 in normal vesicular trafficking, and they support the hypothesis that Beclin 1 functions mainly to engage hVps34 in the autophagic pathway.
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Affiliation(s)
- Xuehuo Zeng
- Department of Biochemistry and Cancer Biology, Medical University of Ohio, Toledo, OH 43614, USA
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