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Mariam I, Krikigianni E, Rantzos C, Bettiga M, Christakopoulos P, Rova U, Matsakas L, Patel A. Transcriptomics aids in uncovering the metabolic shifts and molecular machinery of Schizochytrium limacinum during biotransformation of hydrophobic substrates to docosahexaenoic acid. Microb Cell Fact 2024; 23:97. [PMID: 38561811 PMCID: PMC10983653 DOI: 10.1186/s12934-024-02381-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 03/23/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Biotransformation of waste oil into value-added nutraceuticals provides a sustainable strategy. Thraustochytrids are heterotrophic marine protists and promising producers of omega (ω) fatty acids. Although the metabolic routes for the assimilation of hydrophilic carbon substrates such as glucose are known for these microbes, the mechanisms employed for the conversion of hydrophobic substrates are not well established. Here, thraustochytrid Schizochytrium limacinum SR21 was investigated for its ability to convert oils (commercial oils with varying fatty acid composition and waste cooking oil) into ω-3 fatty acid; docosahexaenoic acid (DHA). RESULTS Within 72 h SR21 consumed ~ 90% of the oils resulting in enhanced biomass (7.5 g L- 1) which was 2-fold higher as compared to glucose. Statistical analysis highlights C16 fatty acids as important precursors of DHA biosynthesis. Transcriptomic data indicated the upregulation of multiple lipases, predicted to possess signal peptides for secretory, membrane-anchored and cytoplasmic localization. Additionally, transcripts encoding for mitochondrial and peroxisomal β-oxidation along with acyl-carnitine transporters were abundant for oil substrates that allowed complete degradation of fatty acids to acetyl CoA. Further, low levels of oxidative biomarkers (H2O2, malondialdehyde) and antioxidants were determined for hydrophobic substrates, suggesting that SR21 efficiently mitigates the metabolic load and diverts the acetyl CoA towards energy generation and DHA accumulation. CONCLUSIONS The findings of this study contribute to uncovering the route of assimilation of oil substrates by SR21. The thraustochytrid employs an intricate crosstalk among the extracellular and intracellular molecular machinery favoring energy generation. The conversion of hydrophobic substrates to DHA can be further improved using synthetic biology tools, thereby providing a unique platform for the sustainable recycling of waste oil substrates.
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Affiliation(s)
- Iqra Mariam
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, SE-971 87, Sweden
| | - Eleni Krikigianni
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, SE-971 87, Sweden
| | - Chloe Rantzos
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, SE-971 87, Sweden
| | - Maurizio Bettiga
- Department of Life Sciences - LIFE, Division of Industrial Biotechnology, Chalmers University of Technology, Gothenburg, SE-412 96, Sweden
- Innovation Unit, Italbiotec Srl Società Benefit, Milan, Italy
| | - Paul Christakopoulos
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, SE-971 87, Sweden
| | - Ulrika Rova
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, SE-971 87, Sweden
| | - Leonidas Matsakas
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, SE-971 87, Sweden
| | - Alok Patel
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, Luleå, SE-971 87, Sweden.
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2
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Kang H, Kang T, Jackson L, Murphy A, Nitta T. Evidence for Involvement of ADP-Ribosylation Factor 6 in Intracellular Trafficking and Release of Murine Leukemia Virus Gag. Cells 2024; 13:270. [PMID: 38334661 PMCID: PMC10854678 DOI: 10.3390/cells13030270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/29/2024] [Accepted: 01/29/2024] [Indexed: 02/10/2024] Open
Abstract
Murine leukemia viruses (MuLVs) are simple retroviruses that cause several diseases in mice. Retroviruses encode three basic genes: gag, pol, and env. Gag is translated as a polyprotein and moves to assembly sites where viral particles are shaped by cleavage of poly-Gag. Viral release depends on the intracellular trafficking of viral proteins, which is determined by both viral and cellular factors. ADP-ribosylation factor 6 (Arf6) is a small GTPase that regulates vesicular trafficking and recycling of different types of cargo in cells. Arf6 also activates phospholipase D (PLD) and phosphatidylinositol-4-phosphate 5-kinase (PIP5K) and produces phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2). We investigated how Arf6 affected MuLV release with a constitutively active form of Arf6, Arf6Q67L. Expression of Arf6Q67L impaired Gag release by accumulating Gag at PI(4,5)P2-enriched compartments in the cytoplasm. Treatment of the inhibitors for PLD and PIP5K impaired or recovered MuLV Gag release in the cells expressing GFP (control) and Arf6Q67L, implying that regulation of PI(4,5)P2 through PLD and PIP5K affected MuLV release. Interference with the phosphoinositide 3-kinases, mammalian target of rapamycin (mTOR) pathway, and vacuolar-type ATPase activities showed further impairment of Gag release from the cells expressing Arf6Q67L. In contrast, mTOR inhibition increased Gag release in the control cells. The proteasome inhibitors reduced viral release in the cells regardless of Arf6Q67L expression. These data outline the differences in MuLV release under the controlled and overactivated Arf6 conditions and provide new insight into pathways for MuLV release.
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Affiliation(s)
- Hyokyun Kang
- Department of Biology, Savannah State University, Savannah, GA 31404, USA; (H.K.); (T.K.); (L.J.); (A.M.)
| | - Taekwon Kang
- Department of Biology, Savannah State University, Savannah, GA 31404, USA; (H.K.); (T.K.); (L.J.); (A.M.)
| | - Lauryn Jackson
- Department of Biology, Savannah State University, Savannah, GA 31404, USA; (H.K.); (T.K.); (L.J.); (A.M.)
| | - Amaiya Murphy
- Department of Biology, Savannah State University, Savannah, GA 31404, USA; (H.K.); (T.K.); (L.J.); (A.M.)
| | - Takayuki Nitta
- Department of Biology, Savannah State University, Savannah, GA 31404, USA; (H.K.); (T.K.); (L.J.); (A.M.)
- Department of Molecular Biology and Biochemistry, Cancer Research Institute, University of California, Irvine, CA 92697, USA
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3
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Wang Y, Wakelam MJO, Bankaitis VA, McDermott MI. The wide world of non-mammalian phospholipase D enzymes. Adv Biol Regul 2024; 91:101000. [PMID: 38081756 DOI: 10.1016/j.jbior.2023.101000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 11/15/2023] [Indexed: 02/25/2024]
Abstract
Phospholipase D (PLD) hydrolyses phosphatidylcholine (PtdCho) to produce free choline and the critically important lipid signaling molecule phosphatidic acid (PtdOH). Since the initial discovery of PLD activities in plants and bacteria, PLDs have been identified in a diverse range of organisms spanning the taxa. While widespread interest in these proteins grew following the discovery of mammalian isoforms, research into the PLDs of non-mammalian organisms has revealed a fascinating array of functions ranging from roles in microbial pathogenesis, to the stress responses of plants and the developmental patterning of flies. Furthermore, studies in non-mammalian model systems have aided our understanding of the entire PLD superfamily, with translational relevance to human biology and health. Increasingly, the promise for utilization of non-mammalian PLDs in biotechnology is also being recognized, with widespread potential applications ranging from roles in lipid synthesis, to their exploitation for agricultural and pharmaceutical applications.
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Affiliation(s)
- Y Wang
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA; Department of Microbiology, University of Washington, Seattle, WA98109, USA
| | - M J O Wakelam
- Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, United Kingdom
| | - V A Bankaitis
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843, USA; Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - M I McDermott
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA.
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4
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Lv W, Sha Y, Liu X, He Y, Hu J, Wang J, Li S, Guo X, Shao P, Zhao F, Li M. Interaction between Rumen Epithelial miRNAs-Microbiota-Metabolites in Response to Cold-Season Nutritional Stress in Tibetan Sheep. Int J Mol Sci 2023; 24:14489. [PMID: 37833936 PMCID: PMC10572940 DOI: 10.3390/ijms241914489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/16/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
Tibetan sheep are already well adapted to cold season nutrient stress on the Tibetan Plateau. Rumen, an important nutrient for metabolism and as an absorption organ in ruminants, plays a vital role in the cold stress adaptations of Tibetan sheep. Ruminal microbiota also plays an indispensable role in rumen function. In this study, combined multiomics data were utilized to comprehensively analyze the interaction mechanism between rumen epithelial miRNAs and microbiota and their metabolites in Tibetan sheep under nutrient stress in the cold season. A total of 949 miRNAs were identified in the rumen epithelium of both cold and warm seasons. A total of 62 differentially expressed (DE) miRNAs were screened using FC > 1.5 and p value < 0.01, and a total of 20,206 targeted genes were predicted by DE miRNAs. KEGG enrichment analysis revealed that DE miRNA-targeted genes were mainly enriched in axon guidance(ko04360), tight junction(ko04530), inflammatory mediator regulation of TRP channels(ko04750) and metabolism-related pathways. Correlation analysis revealed that rumen microbiota, rumen VFAs and DE miRNAs were all correlated. Further study revealed that the targeted genes of cold and warm season rumen epithelial DE miRNAs were coenriched with differential metabolites of microbiota in glycerophospholipid metabolism (ko00564), apoptosis (ko04210), inflammatory mediator regulation of TRP channels (ko04750), small cell lung cancer (ko05222), and choline metabolism in cancer (ko05231) pathways. There are several interactions between Tibetan sheep rumen epithelial miRNAs, rumen microbiota, and microbial metabolites, mainly through maintaining rumen epithelial barrier function and host homeostasis of choline and cholesterol, improving host immunity, and promoting energy metabolism pathways, thus enabling Tibetan sheep to effectively respond to cold season nutrient stress. The results also suggest that rumen microbiota have coevolved with their hosts to improve the adaptive capacity of Tibetan sheep to cold season nutrient stress, providing a new perspective for the study of cold season nutritional stress adaptation in Tibetan sheep.
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Affiliation(s)
- Weibing Lv
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
- College of Animal and Veterinary Sciences, Southwest Minzu University, Chengdu 610041, China
| | - Yuzhu Sha
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
| | - Xiu Liu
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
| | - Yanyu He
- School of Fundamental Sciences, Massey University, Palmerston North 4410, New Zealand;
| | - Jiang Hu
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
| | - Jiqing Wang
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
| | - Shaobin Li
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
| | - Xinyu Guo
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
| | - Pengyang Shao
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
| | - Fangfang Zhao
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
| | - Mingna Li
- College of Animal Science and Technology/Gansu Key Laboratory of Herbivorous Animal Biotechnology, Gansu Agricultural University, Lanzhou 730070, China; (W.L.); (Y.S.); (J.H.); (J.W.); (S.L.); (X.G.); (P.S.); (F.Z.); (M.L.)
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5
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Nikolatou K, Sandilands E, Román‐Fernández A, Cumming EM, Freckmann E, Lilla S, Buetow L, McGarry L, Neilson M, Shaw R, Strachan D, Miller C, Huang DT, McNeish IA, Norman JC, Zanivan S, Bryant DM. PTEN deficiency exposes a requirement for an ARF GTPase module for integrin-dependent invasion in ovarian cancer. EMBO J 2023; 42:e113987. [PMID: 37577760 PMCID: PMC10505920 DOI: 10.15252/embj.2023113987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/13/2023] [Accepted: 07/19/2023] [Indexed: 08/15/2023] Open
Abstract
Dysregulation of the PI3K/AKT pathway is a common occurrence in high-grade serous ovarian carcinoma (HGSOC), with the loss of the tumour suppressor PTEN in HGSOC being associated with poor prognosis. The cellular mechanisms of how PTEN loss contributes to HGSOC are largely unknown. We here utilise time-lapse imaging of HGSOC spheroids coupled to a machine learning approach to classify the phenotype of PTEN loss. PTEN deficiency induces PI(3,4,5)P3 -rich and -dependent membrane protrusions into the extracellular matrix (ECM), resulting in a collective invasion phenotype. We identify the small GTPase ARF6 as a crucial vulnerability of HGSOC cells upon PTEN loss. Through a functional proteomic CRISPR screen of ARF6 interactors, we identify the ARF GTPase-activating protein (GAP) AGAP1 and the ECM receptor β1-integrin (ITGB1) as key ARF6 interactors in HGSOC regulating PTEN loss-associated invasion. ARF6 functions to promote invasion by controlling the recycling of internalised, active β1-integrin to maintain invasive activity into the ECM. The expression of the CYTH2-ARF6-AGAP1 complex in HGSOC patients is inversely associated with outcome, allowing the identification of patient groups with improved versus poor outcome. ARF6 may represent a therapeutic vulnerability in PTEN-depleted HGSOC.
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Affiliation(s)
- Konstantina Nikolatou
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
| | - Emma Sandilands
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
| | - Alvaro Román‐Fernández
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
| | - Erin M Cumming
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
| | - Eva Freckmann
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
| | | | | | | | | | | | | | | | - Danny T Huang
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
| | - Iain A McNeish
- Department of Surgery and Cancer, Ovarian Cancer Action Research CentreImperial College LondonLondonUK
| | - James C Norman
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
| | - Sara Zanivan
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
| | - David M Bryant
- School of Cancer SciencesUniversity of GlasgowGlasgowUK
- The CRUK Beatson InstituteGlasgowUK
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6
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Li FL, Guan KL. The Arf family GTPases: Regulation of vesicle biogenesis and beyond. Bioessays 2023; 45:e2200214. [PMID: 36998106 PMCID: PMC10282109 DOI: 10.1002/bies.202200214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 03/16/2023] [Accepted: 03/17/2023] [Indexed: 04/01/2023]
Abstract
The Arf family proteins are best known for their roles in the vesicle biogenesis. However, they also play fundamental roles in a wide range of cellular regulation besides vesicular trafficking, such as modulation of lipid metabolic enzymes, cytoskeleton remodeling, ciliogenesis, lysosomal, and mitochondrial morphology and functions. Growing studies continue to expand the downstream effector landscape of Arf proteins, especially for the less-studied members, revealing new biological functions, such as amino acid sensing. Experiments with cutting-edge technologies and in vivo functional studies in the last decade help to provide a more comprehensive view of Arf family functions. In this review, we summarize the cellular functions that are regulated by at least two different Arf members with an emphasis on those beyond vesicle biogenesis.
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Affiliation(s)
- Fu-Long Li
- College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
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7
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Singh SS, Mansuri MS, Naiyer S, Kaur D, Agrahari M, Srinivasan S, Jhingan GD, Bhattacharya A, Bhattacharya S. Multi-omics analysis to characterize molecular adaptation of Entamoeba histolytica during serum stress. Proteomics 2022; 22:e2200148. [PMID: 36066285 DOI: 10.1002/pmic.202200148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 08/07/2022] [Accepted: 08/19/2022] [Indexed: 12/29/2022]
Abstract
Entamoeba histolytica is responsible for dysentery and extraintestinal disease in humans. To establish successful infection, it must generate adaptive response against stress due to host defense mechanisms. We have developed a robust proteomics workflow by combining miniaturized sample preparation, low flow-rate chromatography, and ultra-high sensitivity mass spectrometry, achieving increased proteome coverage, and further integrated proteomics and RNA-seq data to decipher regulation at translational and transcriptional levels. Label-free quantitative proteomics led to identification of 2344 proteins, an improvement over the maximum number identified in E. histolytica proteomic studies. In serum-starved cells, 127 proteins were differentially abundant and were associated with functions including antioxidant activity, cytoskeleton, translation, catalysis, and transport. The virulence factor, Gal/GalNAc-inhibitable lectin subunits, was significantly altered. Integration of transcriptomic and proteomic data revealed that only 30% genes were coordinately regulated at both transcriptional and translational levels. Some highly expressed transcripts did not change in protein abundance. Conversely, genes with no transcriptional change showed enhanced protein abundance, indicating post-transcriptional regulation. This multi-omics approach enables more refined gene expression analysis to understand the adaptive response of E. histolytica during growth stress.
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Affiliation(s)
- Shashi Shekhar Singh
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.,Center for RNA Science and Therapeutics, Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | - Mohammad Shahid Mansuri
- Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sarah Naiyer
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.,Department of Immunology and Microbiology, University of Illinois Chicago, Chicago, Illinois, USA
| | - Devinder Kaur
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.,Central University of Punjab, Bathinda, Punjab, India
| | - Mridula Agrahari
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.,Vproteomics, Valerian Chem Private Limited, New Delhi, India
| | | | | | - Alok Bhattacharya
- Ashoka University, Rajiv Gandhi Education City, Sonipat, Haryana, India
| | - Sudha Bhattacharya
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.,Ashoka University, Rajiv Gandhi Education City, Sonipat, Haryana, India
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8
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Li F, Wu Z, Gao Y, Bowling FZ, Franklin JM, Hu C, Suhandynata RT, Frohman MA, Airola MV, Zhou H, Guan K. Defining the proximal interaction networks of Arf GTPases reveals a mechanism for the regulation of PLD1 and PI4KB. EMBO J 2022; 41:e110698. [PMID: 35844135 PMCID: PMC9433938 DOI: 10.15252/embj.2022110698] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/25/2022] [Accepted: 06/03/2022] [Indexed: 12/16/2022] Open
Abstract
The Arf GTPase family is involved in a wide range of cellular regulation including membrane trafficking and organelle-structure assembly. Here, we have generated a proximity interaction network for the Arf family using the miniTurboID approach combined with TMT-based quantitative mass spectrometry. Our interactome confirmed known interactions and identified many novel interactors that provide leads for defining Arf pathway cell biological functions. We explored the unexpected finding that phospholipase D1 (PLD1) preferentially interacts with two closely related but poorly studied Arf family GTPases, ARL11 and ARL14, showing that PLD1 is activated by ARL11/14 and may recruit these GTPases to membrane vesicles, and that PLD1 and ARL11 collaborate to promote macrophage phagocytosis. Moreover, ARL5A and ARL5B were found to interact with and recruit phosphatidylinositol 4-kinase beta (PI4KB) at trans-Golgi, thus promoting PI4KB's function in PI4P synthesis and protein secretion.
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Affiliation(s)
- Fu‐Long Li
- Department of Pharmacology and Moores Cancer CenterUniversity of California San DiegoLa JollaCAUSA
| | - Zhengming Wu
- Department of Pharmacology and Moores Cancer CenterUniversity of California San DiegoLa JollaCAUSA
| | - Yong‐Qi Gao
- Department of Cellular and Molecular MedicineUniversity of California San DiegoLa JollaCAUSA
| | - Forrest Z Bowling
- Department of Biochemistry and Cell BiologyStony Brook UniversityStony BrookNYUSA
| | - J Matthew Franklin
- Department of Pharmacology and Moores Cancer CenterUniversity of California San DiegoLa JollaCAUSA
| | - Chongze Hu
- Department of Nanoengineering, Program of Materials Science and EngineeringUniversity of California San DiegoLa JollaCAUSA
| | - Raymond T Suhandynata
- Department of Cellular and Molecular MedicineUniversity of California San DiegoLa JollaCAUSA
| | - Michael A Frohman
- Department of Pharmacological SciencesStony Brook UniversityStony BrookNYUSA
| | - Michael V Airola
- Department of Biochemistry and Cell BiologyStony Brook UniversityStony BrookNYUSA
| | - Huilin Zhou
- Department of Cellular and Molecular MedicineUniversity of California San DiegoLa JollaCAUSA
| | - Kun‐Liang Guan
- Department of Pharmacology and Moores Cancer CenterUniversity of California San DiegoLa JollaCAUSA
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9
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Wang Y, Dai M, Wu X, Zhang S, Shi Z, Cai D, Miao L. An ARF1-binding factor triggering programmed cell death and periderm development in pear russet fruit skin. HORTICULTURE RESEARCH 2022; 9:uhab061. [PMID: 35043172 PMCID: PMC8947239 DOI: 10.1093/hr/uhab061] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 10/28/2021] [Indexed: 06/14/2023]
Abstract
Plants have a cuticular membrane (CM) and periderm membrane (PM), which act as barriers to terrestrial stresses. The CM covers primary organs with a continuous hydrophobic layer of waxes embedded in cutin, while the PM stacks with suberized cells outermost to the secondary tissues. The formation of native periderm is regulated by a postembryonic meristem phellogen that produces suberized phellem (cork) outwardly. However, the mechanism controlling phellogen differentiation to phellem remains to be clarified. Here, map-based cloning in a pear F1 population with segregation for periderm development in fruit skin facilitated the identification of an aspartic acid repeat deletion in Pyrus Periderm Programmed Cell Death 1.1 (PyPPCD1.1) that triggers phellogen activity for cork formation in pear russet fruit skin. PyPPCD1.1 showed preferential expression in pear fruit skin, and the encoded protein shares a structural similarity to that of the viral capsid proteins. Asp deletion in PyPPCD1.1 weakened its nuclear localization but increased its accumulation in the chloroplast. Both PyPPCD1.1 and its recessive allele directly interact with ADP-ribosylation factor 1 (ARF1). PyPPCD1.1 triggered PCD in an ARF1-dependent manner. Thus, this study identified the switch gene for PCD and periderm development and provided a new molecular regulatory mechanism underlying the development of this trait.
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Affiliation(s)
- Yuezhi Wang
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Shiqiao Road No. 139, Hangzhou, Zhejiang Province, 310021, China
| | - Meisong Dai
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Shiqiao Road No. 139, Hangzhou, Zhejiang Province, 310021, China
| | - Xinyi Wu
- Institute of Vegetable, Zhejiang Academy of Agricultural Sciences, Desheng Middle Road No. 298, Hangzhou, Zhejiang Province, 310021, China
| | - Shujun Zhang
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Shiqiao Road No. 139, Hangzhou, Zhejiang Province, 310021, China
| | - Zebin Shi
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Shiqiao Road No. 139, Hangzhou, Zhejiang Province, 310021, China
| | - Danying Cai
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Shiqiao Road No. 139, Hangzhou, Zhejiang Province, 310021, China
| | - Lixiang Miao
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Shiqiao Road No. 139, Hangzhou, Zhejiang Province, 310021, China
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10
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Hussain SS, Tran TM, Ware TB, Luse MA, Prevost CT, Ferguson AN, Kashatus JA, Hsu KL, Kashatus DF. RalA and PLD1 promote lipid droplet growth in response to nutrient withdrawal. Cell Rep 2021; 36:109451. [PMID: 34320341 PMCID: PMC8344381 DOI: 10.1016/j.celrep.2021.109451] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 06/04/2021] [Accepted: 07/02/2021] [Indexed: 01/22/2023] Open
Abstract
Lipid droplets (LDs) are dynamic organelles that undergo dynamic changes in response to changing cellular conditions. During nutrient depletion, LD numbers increase to protect cells against toxic fatty acids generated through autophagy and provide fuel for beta-oxidation. However, the precise mechanisms through which these changes are regulated have remained unclear. Here, we show that the small GTPase RalA acts downstream of autophagy to directly facilitate LD growth during nutrient depletion. Mechanistically, RalA performs this function through phospholipase D1 (PLD1), an enzyme that converts phosphatidylcholine (PC) to phosphatidic acid (PA) and that is recruited to lysosomes during nutrient stress in a RalA-dependent fashion. RalA inhibition prevents recruitment of the LD-associated protein perilipin 3, which is required for LD growth. Our data support a model in which RalA recruits PLD1 to lysosomes during nutrient deprivation to promote the localized production of PA and the recruitment of perilipin 3 to expanding LDs.
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Affiliation(s)
- Syed S Hussain
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Tuyet-Minh Tran
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Timothy B Ware
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
| | - Melissa A Luse
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Christopher T Prevost
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Ashley N Ferguson
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Jennifer A Kashatus
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA
| | - Ku-Lung Hsu
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA; University of Virginia Cancer Center, University of Virginia Health System, Charlottesville, VA 22903, USA
| | - David F Kashatus
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, USA; University of Virginia Cancer Center, University of Virginia Health System, Charlottesville, VA 22903, USA.
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11
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The PKD-Dependent Biogenesis of TGN-to-Plasma Membrane Transport Carriers. Cells 2021; 10:cells10071618. [PMID: 34203456 PMCID: PMC8303525 DOI: 10.3390/cells10071618] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/14/2021] [Accepted: 06/24/2021] [Indexed: 01/30/2023] Open
Abstract
Membrane trafficking is essential for processing and transport of proteins and lipids and to establish cell compartmentation and tissue organization. Cells respond to their needs and control the quantity and quality of protein secretion accordingly. In this review, we focus on a particular membrane trafficking route from the trans-Golgi network (TGN) to the cell surface: protein kinase D (PKD)-dependent pathway for constitutive secretion mediated by carriers of the TGN to the cell surface (CARTS). Recent findings highlight the importance of lipid signaling by organelle membrane contact sites (MCSs) in this pathway. Finally, we discuss our current understanding of multiple signaling pathways for membrane trafficking regulation mediated by PKD, G protein-coupled receptors (GPCRs), growth factors, metabolites, and mechanosensors.
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12
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Emerging Prospects for Combating Fungal Infections by Targeting Phosphatidylinositol Transfer Proteins. Int J Mol Sci 2021; 22:ijms22136754. [PMID: 34201733 PMCID: PMC8269425 DOI: 10.3390/ijms22136754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 12/27/2022] Open
Abstract
The emergence of fungal “superbugs” resistant to the limited cohort of anti-fungal agents available to clinicians is eroding our ability to effectively treat infections by these virulent pathogens. As the threat of fungal infection is escalating worldwide, this dwindling response capacity is fueling concerns of impending global health emergencies. These developments underscore the urgent need for new classes of anti-fungal drugs and, therefore, the identification of new targets. Phosphoinositide signaling does not immediately appear to offer attractive targets due to its evolutionary conservation across the Eukaryota. However, recent evidence argues otherwise. Herein, we discuss the evidence identifying Sec14-like phosphatidylinositol transfer proteins (PITPs) as unexplored portals through which phosphoinositide signaling in virulent fungi can be chemically disrupted with exquisite selectivity. Recent identification of lead compounds that target fungal Sec14 proteins, derived from several distinct chemical scaffolds, reveals exciting inroads into the rational design of next generation Sec14 inhibitors. Development of appropriately refined next generation Sec14-directed inhibitors promises to expand the chemical weaponry available for deployment in the shifting field of engagement between fungal pathogens and their human hosts.
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13
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Khater M, Bryant CN, Wu G. Gβγ translocation to the Golgi apparatus activates ARF1 to spatiotemporally regulate G protein-coupled receptor signaling to MAPK. J Biol Chem 2021; 296:100805. [PMID: 34022220 PMCID: PMC8215300 DOI: 10.1016/j.jbc.2021.100805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/11/2021] [Accepted: 05/18/2021] [Indexed: 01/01/2023] Open
Abstract
After activation of G protein-coupled receptors, G protein βγ dimers may translocate from the plasma membrane to the Golgi apparatus (GA). We recently report that this translocation activates extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) via PI3Kγ; however, how Gβγ-PI3Kγ activates the ERK1/2 pathway is unclear. Here, we demonstrate that chemokine receptor CXCR4 activates ADP-ribosylation factor 1 (ARF1), a small GTPase important for vesicle-mediated membrane trafficking. This activation is blocked by CRISPR-Cas9-mediated knockout of the GA-translocating Gγ9 subunit. Inducible targeting of different Gβγ dimers to the GA can directly activate ARF1. CXCR4 activation and constitutive Gβγ recruitment to the GA also enhance ARF1 translocation to the GA. We further demonstrate that pharmacological inhibition and CRISPR-Cas9-mediated knockout of PI3Kγ markedly inhibit CXCR4-mediated and Gβγ translocation-mediated ARF1 activation. We also show that depletion of ARF1 by siRNA and CRISPR-Cas9 and inhibition of GA-localized ARF1 activation abolish ERK1/2 activation by CXCR4 and Gβγ translocation to the GA and suppress prostate cancer PC3 cell migration and invasion. Collectively, our data reveal a novel function for Gβγ translocation to the GA to activate ARF1 and identify GA-localized ARF1 as an effector acting downstream of Gβγ-PI3Kγ to spatiotemporally regulate G protein-coupled receptor signaling to mitogen-activated protein kinases.
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Affiliation(s)
- Mostafa Khater
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Christian N Bryant
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA.
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14
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Iyer DN, Faruq O, Zhang L, Rastgoo N, Liu A, Chang H. Pathophysiological roles of myristoylated alanine-rich C-kinase substrate (MARCKS) in hematological malignancies. Biomark Res 2021; 9:34. [PMID: 33958003 PMCID: PMC8101130 DOI: 10.1186/s40364-021-00286-9] [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: 01/05/2021] [Accepted: 04/16/2021] [Indexed: 12/17/2022] Open
Abstract
The myristoylated alanine-rich C-kinase substrate (MARCKS) protein has been at the crossroads of multiple signaling pathways that govern several critical operations in normal and malignant cellular physiology. Functioning as a target of protein kinase C, MARCKS shuttles between the phosphorylated cytosolic form and the unphosphorylated plasma membrane-bound states whilst regulating several molecular partners including, but not limited to calmodulin, actin, phosphatidylinositol-4,5-bisphosphate, and phosphoinositide-3-kinase. As a result of these interactions, MARCKS directly or indirectly modulates a host of cellular functions, primarily including cytoskeletal reorganization, membrane trafficking, cell secretion, inflammatory response, cell migration, and mitosis. Recent evidence indicates that dysregulated expression of MARCKS is associated with the development and progression of hematological cancers. While it is understood that MARCKS impacts the overall carcinogenesis as well as plays a part in determining the disease outcome in blood cancers, we are still at an early stage of interpreting the pathophysiological roles of MARCKS in neoplastic disease. The situation is further complicated by contradictory reports regarding the role of phosphorylated versus an unphosphorylated form of MARCKS as an oncogene versus tumor suppressor in blood cancers. In this review, we will investigate the current body of knowledge and evolving concepts of the physical properties, molecular network, functional attributes, and the likely pathogenic roles of MARCKS in hematological malignancies. Key emphasis will also be laid upon understanding the novel mechanisms by which MARCKS determines the overall disease prognosis by playing a vital role in the induction of therapeutic resistance. Additionally, we will highlight the importance of MARCKS as a valuable therapeutic target in blood cancers and will discuss the potential of existing strategies available to tackle MARCKS-driven blood cancers.
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Affiliation(s)
- Deepak Narayanan Iyer
- Laboratory medicine program, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Omar Faruq
- Laboratory medicine program, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Lun Zhang
- Laboratory medicine program, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Nasrin Rastgoo
- Laboratory medicine program, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada
| | - Aijun Liu
- Department of Hematology, Beijing Chaoyang Hospital, Capital University, Beijing, China.
| | - Hong Chang
- Laboratory medicine program, Toronto General Hospital, University Health Network, University of Toronto, Toronto, Canada.
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15
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Nacke M, Sandilands E, Nikolatou K, Román-Fernández Á, Mason S, Patel R, Lilla S, Yelland T, Galbraith LCA, Freckmann EC, McGarry L, Morton JP, Shanks E, Leung HY, Markert E, Ismail S, Zanivan S, Blyth K, Bryant DM. An ARF GTPase module promoting invasion and metastasis through regulating phosphoinositide metabolism. Nat Commun 2021; 12:1623. [PMID: 33712589 PMCID: PMC7955138 DOI: 10.1038/s41467-021-21847-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 02/12/2021] [Indexed: 12/21/2022] Open
Abstract
The signalling pathways underpinning cell growth and invasion use overlapping components, yet how mutually exclusive cellular responses occur is unclear. Here, we report development of 3-Dimensional culture analyses to separately quantify growth and invasion. We identify that alternate variants of IQSEC1, an ARF GTPase Exchange Factor, act as switches to promote invasion over growth by controlling phosphoinositide metabolism. All IQSEC1 variants activate ARF5- and ARF6-dependent PIP5-kinase to promote PI(3,4,5)P3-AKT signalling and growth. In contrast, select pro-invasive IQSEC1 variants promote PI(3,4,5)P3 production to form invasion-driving protrusions. Inhibition of IQSEC1 attenuates invasion in vitro and metastasis in vivo. Induction of pro-invasive IQSEC1 variants and elevated IQSEC1 expression occurs in a number of tumour types and is associated with higher-grade metastatic cancer, activation of PI(3,4,5)P3 signalling, and predicts long-term poor outcome across multiple cancers. IQSEC1-regulated phosphoinositide metabolism therefore is a switch to induce invasion over growth in response to the same external signal. Targeting IQSEC1 as the central regulator of this switch may represent a therapeutic vulnerability to stop metastasis.
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Affiliation(s)
- Marisa Nacke
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | - Emma Sandilands
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | - Konstantina Nikolatou
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | - Álvaro Román-Fernández
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | | | | | | | | | | | - Eva C Freckmann
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | | | - Jennifer P Morton
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | | | - Hing Y Leung
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | | | - Shehab Ismail
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
- Department of Chemistry, KU Leuven, Celestijnenlaan, Belgium
| | - Sara Zanivan
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | - Karen Blyth
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
- The CRUK Beatson Institute, Glasgow, UK
| | - David M Bryant
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
- The CRUK Beatson Institute, Glasgow, UK.
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16
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Bowling FZ, Frohman MA, Airola MV. Structure and regulation of human phospholipase D. Adv Biol Regul 2021; 79:100783. [PMID: 33495125 DOI: 10.1016/j.jbior.2020.100783] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/22/2020] [Accepted: 12/28/2020] [Indexed: 12/13/2022]
Abstract
Mammalian phospholipase D (PLD) generates phosphatidic acid, a dynamic lipid secondary messenger involved with a broad spectrum of cellular functions including but not limited to metabolism, migration, and exocytosis. As a promising pharmaceutical target, the biochemical properties of PLD have been well characterized. This has led to the recent crystal structures of human PLD1 and PLD2, the development of PLD specific pharmacological inhibitors, and the identification of cellular regulators of PLD. In this review, we discuss the PLD1 and PLD2 structures, PLD inhibition by small molecules, and the regulation of PLD activity by effector proteins and lipids.
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Affiliation(s)
- Forrest Z Bowling
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - Michael A Frohman
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Michael V Airola
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA.
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17
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Cross-Kingdom Activation of Vibrio Toxins by ADP-Ribosylation Factor Family GTPases. J Bacteriol 2020; 202:JB.00278-20. [PMID: 32900828 DOI: 10.1128/jb.00278-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pathogenic Vibrio species use many different approaches to subvert, attack, and undermine the host response. The toxins they produce are often responsible for the devastating effects associated with their diseases. These toxins target a variety of host proteins, which leads to deleterious effects, including dissolution of cell organelle integrity and inhibition of protein secretion. Becoming increasingly prevalent as cofactors for Vibrio toxins are proteins of the small GTPase families. ADP-ribosylation factor small GTPases (ARFs) in particular are emerging as a common host cofactor necessary for full activation of Vibrio toxins. While ARFs are not the direct target of Vibrio cholerae cholera toxin (CT), ARF binding is required for its optimal activity as an ADP-ribosyltransferase. The makes caterpillars floppy (MCF)-like and the domain X (DmX) effectors of the Vibrio vulnificus multifunctional autoprocessing repeats-in-toxin (MARTX) toxin also both require ARFs to initiate autoprocessing and activation as independent effectors. ARFs are ubiquitously expressed in eukaryotes and are key regulators of many cellular processes, and as such they are ideal cofactors for Vibrio pathogens that infect many host species. In this review, we cover in detail the known Vibrio toxins that use ARFs as cross-kingdom activators to both stimulate and optimize their activity. We further discuss how these contrast to toxins and effectors from other bacterial species that coactivate, stimulate, or directly modify host ARFs as their mechanisms of action.
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18
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Barisano D, Frohman MA. Roles for Phospholipase D1 in the Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1259:77-87. [PMID: 32578172 DOI: 10.1007/978-3-030-43093-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
The lipid-modifying signal transduction enzyme phospholipase D (PLD) has been proposed to have roles in oncogenic processes for well-on 30 years, with most of the early literature focused on potential functions for PLD in the biology of the tumor cells themselves. While such roles remain under investigation, evidence has also now been generated to support additional roles for PLD, in particular PLD1, in the tumor microenvironment, including effects on neoangiogenesis, the supply of nutrients, interactions of platelets with circulating cancer cells, the response of the immune system, and exosome biology. Here, we review these lines of investigation, accompanied by a discussion of the limitations of the existing studies and some cautionary notes regarding the study and interpretation of PLD function using model systems.
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Affiliation(s)
- Daniela Barisano
- Center for Developmental Genetics and the Department of Pharmacological Sciences, Stony Brook University School of Medicine, Stony Brook, NY, USA
| | - Michael A Frohman
- Center for Developmental Genetics and the Department of Pharmacological Sciences, Stony Brook University School of Medicine, Stony Brook, NY, USA.
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19
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Donaldson JG. Macropinosome formation, maturation and membrane recycling: lessons from clathrin-independent endosomal membrane systems. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180148. [PMID: 30967002 DOI: 10.1098/rstb.2018.0148] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Macropinocytosis is a form of endocytosis that brings large fluid-filled endosomes into the cell interior. Macrophages and dendritic cells are especially active in this process, but all cells can be stimulated to initiate this remarkable form of endocytosis. Although much is known about the membrane lipid and actin requirements for initiating macropinocytosis, less is known about the membrane that forms the macropinosome and the fate of that membrane once the macropinosome enters the cell interior. Since macropinocytosis is a specialized form of clathrin-independent endocytosis (CIE), studies of the constitutive internalization and trafficking of cargo proteins and membrane that enter cells independently of clathrin could reveal the types of membrane that form the macropinosome and the machinery that handles cargo sorting and recycling during the maturation of the macropinosome. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'.
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Affiliation(s)
- Julie G Donaldson
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health , Building 50, Room 2503, Bethesda, MD 20892 , USA
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20
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McDermott MI, Wang Y, Wakelam MJO, Bankaitis VA. Mammalian phospholipase D: Function, and therapeutics. Prog Lipid Res 2019; 78:101018. [PMID: 31830503 DOI: 10.1016/j.plipres.2019.101018] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/08/2019] [Accepted: 10/14/2019] [Indexed: 01/23/2023]
Abstract
Despite being discovered over 60 years ago, the precise role of phospholipase D (PLD) is still being elucidated. PLD enzymes catalyze the hydrolysis of the phosphodiester bond of glycerophospholipids producing phosphatidic acid and the free headgroup. PLD family members are found in organisms ranging from viruses, and bacteria to plants, and mammals. They display a range of substrate specificities, are regulated by a diverse range of molecules, and have been implicated in a broad range of cellular processes including receptor signaling, cytoskeletal regulation and membrane trafficking. Recent technological advances including: the development of PLD knockout mice, isoform-specific antibodies, and specific inhibitors are finally permitting a thorough analysis of the in vivo role of mammalian PLDs. These studies are facilitating increased recognition of PLD's role in disease states including cancers and Alzheimer's disease, offering potential as a target for therapeutic intervention.
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Affiliation(s)
- M I McDermott
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843-1114, United States of America.
| | - Y Wang
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843-1114, United States of America; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, United States of America
| | - M J O Wakelam
- Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - V A Bankaitis
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, TX 77843-1114, United States of America; Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, United States of America; Department of Chemistry, Texas A&M University, College Station, Texas 77840, United States of America
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21
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Thakur R, Naik A, Panda A, Raghu P. Regulation of Membrane Turnover by Phosphatidic Acid: Cellular Functions and Disease Implications. Front Cell Dev Biol 2019; 7:83. [PMID: 31231646 PMCID: PMC6559011 DOI: 10.3389/fcell.2019.00083] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 05/03/2019] [Indexed: 01/23/2023] Open
Abstract
Phosphatidic acid (PA) is a simple glycerophospholipid with a well-established role as an intermediate in phospholipid biosynthesis. In addition to its role in lipid biosynthesis, PA has been proposed to act as a signaling molecule that modulates several aspects of cell biology including membrane transport. PA can be generated in eukaryotic cells by several enzymes whose activity is regulated in the context of signal transduction and enzymes that can metabolize PA thus terminating its signaling activity have also been described. Further, several studies have identified PA binding proteins and changes in their activity are proposed to be mediators of the signaling activity of this lipid. Together these enzymes and proteins constitute a PA signaling toolkit that mediates the signaling functions of PA in cells. Recently, a number of novel genetic models for the analysis of PA function in vivo and analytical methods to quantify PA levels in cells have been developed and promise to enhance our understanding of PA functions. Studies of several elements of the PA signaling toolkit in a single cell type have been performed and are presented to provide a perspective on our understanding of the biochemical and functional organization of pools of PA in a eukaryotic cell. Finally, we also provide a perspective on the potential role of PA in human disease, synthesizing studies from model organisms, human disease genetics and analysis using recently developed PLD inhibitors.
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Affiliation(s)
- Rajan Thakur
- National Centre for Biological Sciences-TIFR, Bengaluru, India
| | - Amruta Naik
- National Centre for Biological Sciences-TIFR, Bengaluru, India
| | - Aniruddha Panda
- National Centre for Biological Sciences-TIFR, Bengaluru, India
| | - Padinjat Raghu
- National Centre for Biological Sciences-TIFR, Bengaluru, India
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22
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Wang H, Liu Y, Zhang L, Kundu JK, Liu W, Wang X. ADP ribosylation factor 1 facilitates spread of wheat dwarf virus in its insect vector. Cell Microbiol 2019; 21:e13047. [DOI: 10.1111/cmi.13047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/01/2019] [Accepted: 05/13/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Hui Wang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
| | - Yan Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
| | - Lu Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
| | - Jiban Kumar Kundu
- Division of Crop Protection and Plant HealthCrop Research Institute Praha 6 Czech Republic
| | - Wenwen Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
| | - Xifeng Wang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural Sciences Beijing China
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23
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Sztul E, Chen PW, Casanova JE, Cherfils J, Dacks JB, Lambright DG, Lee FJS, Randazzo PA, Santy LC, Schürmann A, Wilhelmi I, Yohe ME, Kahn RA. ARF GTPases and their GEFs and GAPs: concepts and challenges. Mol Biol Cell 2019; 30:1249-1271. [PMID: 31084567 PMCID: PMC6724607 DOI: 10.1091/mbc.e18-12-0820] [Citation(s) in RCA: 156] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 02/26/2019] [Accepted: 03/11/2019] [Indexed: 12/12/2022] Open
Abstract
Detailed structural, biochemical, cell biological, and genetic studies of any gene/protein are required to develop models of its actions in cells. Studying a protein family in the aggregate yields additional information, as one can include analyses of their coevolution, acquisition or loss of functionalities, structural pliability, and the emergence of shared or variations in molecular mechanisms. An even richer understanding of cell biology can be achieved through evaluating functionally linked protein families. In this review, we summarize current knowledge of three protein families: the ARF GTPases, the guanine nucleotide exchange factors (ARF GEFs) that activate them, and the GTPase-activating proteins (ARF GAPs) that have the ability to both propagate and terminate signaling. However, despite decades of scrutiny, our understanding of how these essential proteins function in cells remains fragmentary. We believe that the inherent complexity of ARF signaling and its regulation by GEFs and GAPs will require the concerted effort of many laboratories working together, ideally within a consortium to optimally pool information and resources. The collaborative study of these three functionally connected families (≥70 mammalian genes) will yield transformative insights into regulation of cell signaling.
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Affiliation(s)
- Elizabeth Sztul
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Pei-Wen Chen
- Department of Biology, Williams College, Williamstown, MA 01267
| | - James E. Casanova
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - Jacqueline Cherfils
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS and Ecole Normale Supérieure Paris-Saclay, 94235 Cachan, France
| | - Joel B. Dacks
- Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - David G. Lambright
- Program in Molecular Medicine and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Amherst, MA 01605
| | - Fang-Jen S. Lee
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
| | | | - Lorraine C. Santy
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802
| | - Annette Schürmann
- German Institute of Human Nutrition, 85764 Potsdam-Rehbrücke, Germany
| | - Ilka Wilhelmi
- German Institute of Human Nutrition, 85764 Potsdam-Rehbrücke, Germany
| | - Marielle E. Yohe
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892
| | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322-3050
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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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Phospholipase D and the Mitogen Phosphatidic Acid in Human Disease: Inhibitors of PLD at the Crossroads of Phospholipid Biology and Cancer. Handb Exp Pharmacol 2019; 259:89-113. [PMID: 31541319 DOI: 10.1007/164_2019_216] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Lipids are key building blocks of biological membranes and are involved in complex signaling processes such as metabolism, proliferation, migration, and apoptosis. Extracellular signaling by growth factors, stress, and nutrients is transmitted through receptors that activate lipid-modifying enzymes such as the phospholipases, sphingosine kinase, or phosphoinositide 3-kinase, which then modify phospholipids, sphingolipids, and phosphoinositides. One such important enzyme is phospholipase D (PLD), which cleaves phosphatidylcholine to yield phosphatidic acid and choline. PLD isoforms have dual role in cells. The first involves maintaining cell membrane integrity and cell signaling, including cell proliferation, migration, cytoskeletal alterations, and invasion through the PLD product PA, and the second involves protein-protein interactions with a variety of binding partners. Increased evidence of elevated PLD expression and activity linked to many pathological conditions, including cancer, neurological and inflammatory diseases, and infection, has motivated the development of dual- and isoform-specific PLD inhibitors. Many of these inhibitors are reported to be efficacious and safe in cells and mouse disease models, suggesting the potential for PLD inhibitors as therapeutics for cancer and other diseases. Current knowledge and ongoing research of PLD signaling networks will help to evolve inhibitors with increased efficacy and safety for clinical studies.
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Functional analysis of mammalian phospholipase D enzymes. Biosci Rep 2018; 38:BSR20181690. [PMID: 30369483 PMCID: PMC6435507 DOI: 10.1042/bsr20181690] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/11/2018] [Accepted: 10/17/2018] [Indexed: 12/15/2022] Open
Abstract
Phosphatidylcholine (PC)-specific phospholipase D (PLD) hydrolyzes the phosphodiester bond of the PC to generate phosphatidic acid (PA) and regulates several subcellular functions. Mammalian genomes contain two genes encoding distinct isoforms of PLD in contrast with invertebrate genomes that include a single PLD gene. However, the significance of two genes within a genome encoding the same biochemical activity remains unclear. Recently, loss of function in the only PLD gene in Drosophila was reported to result in reduced PA levels and a PA-dependent collapse of the photoreceptor plasma membrane due to defects in vesicular transport. Phylogenetic analysis reveals that human PLD1 (hPLD1) is evolutionarily closer to dPLD than human PLD2 (hPLD2). In the present study, we expressed hPLD1 and hPLD2 in Drosophila and found that while reconstitution of hPLD1 is able to completely rescue retinal degeneration in a loss of function dPLD mutant, hPLD2 was less effective in its ability to mediate a rescue. Using a newly developed analytical method, we determined the acyl chain composition of PA species produced by each enzyme. While dPLD was able to restore the levels of most PA species in dPLD3.1 cells, hPLD1 and hPLD2 each were unable to restore the levels of a subset of unique species of PA. Finally, we found that in contrast with hPLD2, dPLD and hPLD1 are uniquely distributed to the subplasma membrane region in photoreceptors. In summary, hPLD1 likely represents the ancestral PLD in mammalian genomes while hPLD2 represents neofunctionalization to generate PA at distinct subcellular membranes.
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Quartino PY, Fidelio GD, Manneville JB, Goud B, Ambroggio EE. Detecting phospholipase activity with the amphipathic lipid packing sensor motif of ArfGAP1. Biochem Biophys Res Commun 2018; 505:290-294. [DOI: 10.1016/j.bbrc.2018.09.116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 09/18/2018] [Indexed: 11/25/2022]
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Comparative Proteomic Study of the Antiproliferative Activity of Frog Host-Defence Peptide Caerin 1.9 and Its Additive Effect with Caerin 1.1 on TC-1 Cells Transformed with HPV16 E6 and E7. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7382351. [PMID: 29862288 PMCID: PMC5971270 DOI: 10.1155/2018/7382351] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Accepted: 03/27/2018] [Indexed: 12/26/2022]
Abstract
Caerin is a family of peptides isolated from the glandular secretion of Australian tree frogs, the genus Litoria, and has been previously shown to have anticancer activity against several cancer cells. In this work, we used two host-defence peptides, caerin 1.1 and caerin 1.9, to investigate their ability to inhibit a murine derived TC-1 cell transformed with human papillomavirus 16 E6 and E7 growth in vitro. Caerin 1.9 inhibits TC-1 cell proliferation, although inhibition is more pronounced when applied in conjunction with caerin 1.1. To gain further insights into the antiproliferative mechanisms of caerin 1.9 and its additive effect with caerin 1.1, we used a proteomics strategy to quantitatively examine (i) the changes in the protein profiles of TC-1 cells and (ii) the excretory-secretory products of TC-1 cells following caerin peptides treatment. Caerin 1.9 treatment significantly altered the abundance of several immune-related proteins and related pathways, such as the Tec kinase and ILK signalling pathways, as well as the levels of proinflammatory cytokines and chemokines. In conclusion, caerin peptides inhibit TC-1 cell proliferation, associated with modification in signalling pathways that would change the tumour microenvironment which is normally immune suppressive.
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Spatiotemporal Control of Lipid Conversion, Actin-Based Mechanical Forces, and Curvature Sensors during Clathrin/AP-1-Coated Vesicle Biogenesis. Cell Rep 2018; 20:2087-2099. [PMID: 28854360 DOI: 10.1016/j.celrep.2017.08.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/29/2017] [Accepted: 07/31/2017] [Indexed: 01/03/2023] Open
Abstract
Clathrin/adaptor protein-1-coated carriers connect the secretory and the endocytic pathways. Carrier biogenesis relies on distinct protein networks changing membrane shape at the trans-Golgi network, each regulating coat assembly, F-actin-based mechanical forces, or the biophysical properties of lipid bilayers. How these different hubs are spatiotemporally coordinated remains largely unknown. Using in vitro reconstitution systems, quantitative proteomics, and lipidomics, as well as in vivo cell-based assays, we characterize the protein networks controlling membrane lipid composition, membrane shape, and carrier scission. These include PIP5K1A and phospholipase C-beta 3 controlling the conversion of PI[4]P into diacylglycerol. PIP5K1A binding to RAC1 provides a link to F-actin-based mechanical forces needed to tubulate membranes. Tubular membranes then recruit the BAR-domain-containing arfaptin-1/2 guiding carrier scission. These findings provide a framework for synchronizing the chemical/biophysical properties of lipid bilayers, F-actin-based mechanical forces, and the activity of proteins sensing membrane shape during clathrin/adaptor protein-1-coated carrier biogenesis.
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Mendez-Gomez HR, Singh J, Meyers C, Chen W, Gorbatyuk OS, Muzyczka N. The Lipase Activity of Phospholipase D2 is Responsible for Nigral Neurodegeneration in a Rat Model of Parkinson's Disease. Neuroscience 2018. [PMID: 29526688 DOI: 10.1016/j.neuroscience.2018.02.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Phospholipase D2 (PLD2), an enzyme involved in vesicle trafficking and membrane signaling, interacts with α-synuclein, a protein known to contribute in the development of Parkinson disease (PD). We previously reported that PLD2 overexpression in rat substantia nigra pars compacta (SNc) causes a rapid neurodegeneration of dopamine neurons, and that α-synuclein suppresses PLD2-induced nigral degeneration (Gorbatyuk et al., 2010). Here, we report that PLD2 toxicity is due to its lipase activity. Overexpression of a catalytically inactive mutant (K758R) of PLD2 prevents the loss of dopaminergic neurons in the SNc and does not show signs of toxicity after 10 weeks of overexpression. Further, mutant K758R does not affect dopamine levels in the striatum. In contrast, mutants that prevent PLD2 interaction with dynamin or growth factor receptor bound protein 2 (Grb2) but retained lipase activity, continued to show rapid neurodegeneration. These findings suggest that neither the interaction of PLD2 with dynamin, which has a role in vesicle trafficking, nor the PLD2 interaction with Grb2, which has multiple roles in cell cycle control, chemotaxis and activation of tyrosine kinase complexes, are the primary cause of neurodegeneration. Instead, the synthesis of phosphatidic acid (the product of PLD2), which is a second messenger in multiple cellular pathways, appears to be the key to PLD2 induced neurodegeneration. The fact that α-synuclein is a regulator of PLD2 activity suggests that regulation of PLD2 activity could be important in the progression of PD.
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Affiliation(s)
- Hector R Mendez-Gomez
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA; UF Genetics Institute and Powell Gene Therapy Center, USA.
| | - Jasbir Singh
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA; UF Genetics Institute and Powell Gene Therapy Center, USA
| | - Craig Meyers
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA; UF Genetics Institute and Powell Gene Therapy Center, USA
| | - Weijun Chen
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA; UF Genetics Institute and Powell Gene Therapy Center, USA
| | - Oleg S Gorbatyuk
- Department of Vision Sciences, Center for Neurodegeneration and Experimental Therapy, University of Alabama at Birmingham, AL, USA
| | - Nicholas Muzyczka
- Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA; UF Genetics Institute and Powell Gene Therapy Center, USA
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ARF1 promotes prostate tumorigenesis via targeting oncogenic MAPK signaling. Oncotarget 2018; 7:39834-39845. [PMID: 27213581 PMCID: PMC5129974 DOI: 10.18632/oncotarget.9405] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 03/11/2016] [Indexed: 11/25/2022] Open
Abstract
ADP-ribosylation factor 1 (ARF1) is a crucial regulator in vesicle-mediated membrane trafficking and involved in the activation of signaling molecules. However, virtually nothing is known about its function in prostate cancer. Here we have demonstrated that ARF1 expression is significantly elevated in prostate cancer cells and human tissues and that the expression levels of ARF1 correlate with the activation of mitogen-activated protein kinases (MAPK) ERK1/2. Furthermore, we have shown that overexpression and knockdown of ARF1 produce opposing effects on prostate cancer cell proliferation, anchorage-independent growth and tumor growth in mouse xenograft models and that ARF1-mediated cell proliferation can be abolished by the Raf1 inhibitor GW5074 and the MEK inhibitors U0126 and PD98059. Moreover, inhibition of ARF1 activation achieved by mutating Thr48 abolishes ARF1's abilities to activate the ERK1/2 and to promote cell proliferation. These data demonstrate that the aberrant MAPK signaling in prostate cancer is, at least in part, under the control of ARF1 and that, similar to Ras, ARF1 is a critical regulator in prostate cancer progression. These data also suggest that ARF1 may represent a key molecular target for prostate cancer therapeutics and diagnosis.
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Song OR, Queval CJ, Iantomasi R, Delorme V, Marion S, Veyron-Churlet R, Werkmeister E, Popoff M, Ricard I, Jouny S, Deboosere N, Lafont F, Baulard A, Yeramian E, Marsollier L, Hoffmann E, Brodin P. ArfGAP1 restricts Mycobacterium tuberculosis entry by controlling the actin cytoskeleton. EMBO Rep 2017; 19:29-42. [PMID: 29141986 DOI: 10.15252/embr.201744371] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 10/03/2017] [Accepted: 10/23/2017] [Indexed: 11/09/2022] Open
Abstract
The interaction of Mycobacterium tuberculosis (Mtb) with pulmonary epithelial cells is critical for early stages of bacillus colonization and during the progression of tuberculosis. Entry of Mtb into epithelial cells has been shown to depend on F-actin polymerization, though the molecular mechanisms are still unclear. Here, we demonstrate that mycobacterial uptake into epithelial cells requires rearrangements of the actin cytoskeleton, which are regulated by ADP-ribosylation factor 1 (Arf1) and phospholipase D1 (PLD1), and is dependent on the M3 muscarinic receptor (M3R). We show that this pathway is controlled by Arf GTPase-activating protein 1 (ArfGAP1), as its silencing has an impact on actin cytoskeleton reorganization leading to uncontrolled uptake and replication of Mtb. Furthermore, we provide evidence that this pathway is critical for mycobacterial entry, while the cellular infection with other pathogens, such as Shigella flexneri and Yersinia pseudotuberculosis, is not affected. Altogether, these results reveal how cortical actin plays the role of a barrier to prevent mycobacterial entry into epithelial cells and indicate a novel role for ArfGAP1 as a restriction factor of host-pathogen interactions.
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Affiliation(s)
- Ok-Ryul Song
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France.,Equipe ATIP AVENIR, CRCINA, INSERM, Université de Nantes, Université d'Angers, Angers, France.,CRCINA, INSERM, Université de Nantes, Université d'Angers, Angers, France.,Institute Pasteur Korea, Seongnam-si Gyeonggi-do, South Korea
| | - Christophe J Queval
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Raffaella Iantomasi
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Vincent Delorme
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France.,Institute Pasteur Korea, Seongnam-si Gyeonggi-do, South Korea
| | - Sabrina Marion
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Romain Veyron-Churlet
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Elisabeth Werkmeister
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Michka Popoff
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France.,CNRS, UMR8520, Institut d'électronique, de microélectronique et de nanotechnologie, Villeneuve d'Ascq, France
| | - Isabelle Ricard
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Samuel Jouny
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Nathalie Deboosere
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Frank Lafont
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Alain Baulard
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Edouard Yeramian
- Unité de Microbiologie Structurale, CNRS UMR3528, Institut Pasteur, Paris, France
| | - Laurent Marsollier
- Equipe ATIP AVENIR, CRCINA, INSERM, Université de Nantes, Université d'Angers, Angers, France .,CRCINA, INSERM, Université de Nantes, Université d'Angers, Angers, France
| | - Eik Hoffmann
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France
| | - Priscille Brodin
- CNRS, Inserm, CHU Lille, U1019 - UMR8204 - CIIL - Centre d'Infection et d'Immunité de Lille, Institut Pasteur de Lille, Univ. Lille, Lille, France .,Institute Pasteur Korea, Seongnam-si Gyeonggi-do, South Korea
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Breitbart H, Finkelstein M. Actin cytoskeleton and sperm function. Biochem Biophys Res Commun 2017; 506:372-377. [PMID: 29102633 DOI: 10.1016/j.bbrc.2017.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 11/01/2017] [Indexed: 11/17/2022]
Abstract
For the acquisition of the ability to fertilize the egg, mammalian spermatozoa should undergo a series of biochemical transformations in the female reproductive tract, collectively called capacitation. The capacitated sperm can undergo the acrosomal exocytosis process near or on the oocyte, which allows the spermatozoon to penetrate and fertilize it. One of the main processes in capacitation involves dynamic cytoskeletal remodeling particularly of actin. Actin polymerization occurs during sperm capacitation and the produced F-actin should be depolymerized prior to the acrosomal exocytosis. In the present review, we describe the mechanisms that regulate F-actin formation during sperm capacitation and the F-actin dispersion prior to the acrosomal exocytosis. During sperm capacitation, the actin severing proteins gelsolin and cofilin are inactive and they undergo activation prior to the acrosomal exocytosis.
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Affiliation(s)
- Haim Breitbart
- The Mina & Everard Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 5290002, Israel.
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ARF6 mediates nephrin tyrosine phosphorylation-induced podocyte cellular dynamics. PLoS One 2017; 12:e0184575. [PMID: 28880939 PMCID: PMC5589247 DOI: 10.1371/journal.pone.0184575] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/26/2017] [Indexed: 01/10/2023] Open
Abstract
ADP-ribosylation factor 6 (ARF6) is a small GTPase necessary for regulating cellular structure, motility, and vesicle trafficking. In several cellular systems, ARF6 was shown to regulate actin dynamics in coordination with Rac1, a Rho small GTPase. We examined the function of ARF6 in the kidney podocyte because Rac1 was implicated in kidney diseases involving this cell. We found that ARF6 expression was enriched in human podocytes and that it modulated podocyte cytoskeletal dynamics through a functional interaction with nephrin, an intercellular junction protein necessary for podocyte injury-induced signaling requiring activation by tyrosine phosphorylation of its cytoplasmic domain. ARF6 was necessary for nephrin activation-induced ruffling and focal adhesion turnover, possibly by altering Rac1 activity. In podocyte-specific Arf6 (ARF6_PodKO) knockout mice, ARF6 deficiency did not result in a spontaneous kidney developmental phenotype or proteinuria after aging. However, ARF6_PodKO mice exhibited distinct phenotypes in two in vivo glomerular injury models. In the protamine sulfate perfusion model, which induced acute podocyte effacement, ARF6_PodKO mice were protected from podocyte effacement. In the nephrotoxic serum nephritis model, which induced immune-complex mediated injury, ARF6_PodKO mice exhibited aggravated proteinuria. Together, these observations suggest that while ARF6 is necessary for nephrin tyrosine phosphorylation-induced cytoskeletal dynamics in cultured podocytes, ARF6 has pleotropic podocyte roles in vivo, where glomerular injury-specific mechanisms might activate distinct signaling pathways that dictate whether ARF6 activity is beneficial or deleterious for maintaining the integrity of the glomerular filtration barrier.
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Yang C, Gao Q, Liu C, Wang L, Zhou Z, Gong C, Zhang A, Zhang H, Qiu L, Song L. The transcriptional response of the Pacific oyster Crassostrea gigas against acute heat stress. FISH & SHELLFISH IMMUNOLOGY 2017; 68:132-143. [PMID: 28698121 DOI: 10.1016/j.fsi.2017.07.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 07/05/2017] [Accepted: 07/08/2017] [Indexed: 06/07/2023]
Abstract
The Pacific oyster, Crassostrea gigas, has evolved sophisticated mechanisms to adapt the changing ambient conditions, and protect themselves from stress-induced injuries. In the present study, the expression profiles of mRNA transcripts in the haemocytes of oysters under heat stress were examined to reveal the possible mechanism of heat stress response. There were 23,315, 23,904, 23,123 and 23,672 transcripts identified in the haemocytes of oysters cultured at 25 °C for 0, 6, 12, and 24 h (designed as B, H6, H12, H24), respectively. And 22,330 differentially expressed transcripts (DTs) were yielded in the pairwise comparisons between the above four samples, which corresponded to 8074 genes. There were 9, 12 and 22 Gene Ontology (GO) terms identified in the DT pairwise comparison groups of H6_B, H12_H6 and H24_H12, respectively, and the richest GO terms in biological process category were cellular catabolic process, translational initiation and apoptotic process, respectively. There were 108, 102 and 102 KEGG pathways successfully retrieved from DTs comparison groups DTH6_B, DTH12_H6 and DTH24_H12, respectively, among which 93 pathways were shared by all three comparison groups, and most of them were related to metabolism of protein, carbohydrate and fat. The expression patterns of 12 representative heat stress response-relevant genes detected by quantitative real-time PCR (qRT-PCR) were similar to those obtained from transcriptome analysis. By flow cytometric analysis, the apoptosis rate of haemocytes increased significantly after oysters were treated at 25 °C for 24 h and recovered at 4 °C for 12 h (p < 0.05) and 36 h (p < 0.01), and it also increased significantly when the heat treatment lasted to 60 h (p < 0.01). The present results indicated that, when oysters encountered short term heat stress, the expression of genes related to energy metabolism, as well as unfolded protein response (UPR) and anti-apoptotic system, were firstly regulated to maintain basic life activities, and then a large number of genes involved in stabilizing protein conformation and facilitating further protein refolding were activated to repair the stress injury. However, the stress injury gradually became irreparable with the stress persisting, and apoptosis was activated when the heat treatment prolonged to 24 h. The information was useful to better understand the molecular mechanism of heat stress response and develop strategies for the improvement of oyster survival rate during summer high-temperature period.
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Affiliation(s)
- Chuanyan Yang
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Qiang Gao
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Chang Liu
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Lingling Wang
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
| | - Zhi Zhou
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Changhao Gong
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Anguo Zhang
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China
| | - Huan Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Limei Qiu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Linsheng Song
- Liaoning Key Laboratory of Marine Animal Immunology and Disease Control, Dalian Ocean University, Dalian 116023, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
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Abstract
Phospholipase D (PLD) enzymes are one source of receptor-generated phosphatidic acid (PtdOH),which may subsequently be metabolized to diacylglycerol (DAG) and lysophosphatidic acid. There are other pathways that lead to PtdOH generation, but differences in pathways and in the acyl composition of the products seem to provide some specificity. Both direct and indirect inhibitors of PLD activity have been identified despite a long-held suspicion that this pathway was undruggable. The identification of raloxifene and halopemide as direct inhibitors was followed by the systematic development of isoenzyme-preferring compounds that have been used to further differentiate the functions of PLD1 and PLD2. PLD2 in host cells has been associated with viral entry processes and innate immune response pathways such that inhibition blocks efficient infection. This PLD2 pathway has been linked to autophagy via AKT kinases. As a potential target in antiretroviral therapy, PLD1 works through the CAD enzyme (which contains carbamoyl aspartate synthase, aspartate transcarbamylase and dihydro-orotase domains) to modulate pyrimidine biosynthesis. PLD activity and expression have been shown to be upregulated in several types of human cancers, in which PLD enzymes function downstream of a variety of known oncogenes. Inhibition of PtdOH production has a marked effect on tumorigenesis and malignant invasion. PLD1, PLD2 and PLD3 have each been suggested to have a role in Alzheimer disease and other neurodegenerative conditions, but a mechanism has not yet emerged to explain the roles of these proteins in central nervous system pathophysiology.
Lipid second messengers such as phosphatidic acid (PtdOH) have a role in a wide range of pathological processes, and phospholipase D (PLD) enzymes are one of the major sources of signal-activated PtdOH generation. In this Review, Brown, Thomas and Lindsley discuss the development of PLD inhibitors, with a focus on isoform-specific inhibitors, and their potential applications in the treatment of cancer, neurodegeneration and infection. Lipid second messengers have essential roles in cellular function and contribute to the molecular mechanisms that underlie inflammation, malignant transformation, invasiveness, neurodegenerative disorders, and infectious and other pathophysiological processes. The phospholipase D (PLD) isoenzymes PLD1 and PLD2 are one of the major sources of signal-activated phosphatidic acid (PtdOH) generation downstream of a variety of cell-surface receptors, including G protein-coupled receptors (GPCRs), receptor tyrosine kinases (RTKs) and integrins. Recent advances in the development of isoenzyme-selective PLD inhibitors and in molecular genetics have suggested that PLD isoenzymes in mammalian cells and pathogenic organisms may be valuable targets for the treatment of several human diseases. Isoenzyme-selective inhibitors have revealed complex inter-relationships between PtdOH biosynthetic pathways and the role of PtdOH in pathophysiology. PLD enzymes were once thought to be undruggable owing to the ubiquitous nature of PtdOH in cell signalling and concerns that inhibitors would be too toxic for use in humans. However, recent promising discoveries suggest that small-molecule isoenzyme-selective inhibitors may provide novel compounds for a unique approach to the treatment of cancers, neurodegenerative disorders and other afflictions of the central nervous system, and potentially serve as broad-spectrum antiviral and antimicrobial therapeutics.
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RalF-Mediated Activation of Arf6 Controls Rickettsia typhi Invasion by Co-Opting Phosphoinositol Metabolism. Infect Immun 2016; 84:3496-3506. [PMID: 27698019 PMCID: PMC5116726 DOI: 10.1128/iai.00638-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 09/26/2016] [Indexed: 02/05/2023] Open
Abstract
Rickettsiae are obligate intracellular pathogens that induce their uptake into nonphagocytic cells; however, the events instigating this process are incompletely understood. Importantly, diverse Rickettsia species are predicted to utilize divergent mechanisms to colonize host cells, as nearly all adhesins and effectors involved in host cell entry are differentially encoded in diverse Rickettsia species. One particular effector, RalF, a Sec7 domain-containing protein that functions as a guanine nucleotide exchange factor of ADP-ribosylation factors (Arfs), is critical for Rickettsia typhi (typhus group rickettsiae) entry but pseudogenized or absent from spotted fever group rickettsiae. Secreted early during R. typhi infection, RalF localizes to the host plasma membrane and interacts with host ADP-ribosylation factor 6 (Arf6). Herein, we demonstrate that RalF activates Arf6, a process reliant on a conserved Glu within the RalF Sec7 domain. Furthermore, Arf6 is activated early during infection, with GTP-bound Arf6 localized to the R. typhi entry foci. The regulation of phosphatidylinositol 4-phosphate 5-kinase (PIP5K), which generates PI(4,5)P2, by activated Arf6 is instrumental for bacterial entry, corresponding to the requirement of PI(4,5)P2 for R. typhi entry. PI(3,4,5)P3 is then synthesized at the entry foci, followed by the accumulation of PI(3)P on the short-lived vacuole. Inhibition of phosphoinositide 3-kinases, responsible for the synthesis of PI(3,4,5)P3 and PI(3)P, negatively affects R. typhi infection. Collectively, these results identify RalF as the first bacterial effector to directly activate Arf6, a process that initiates alterations in phosphoinositol metabolism critical for a lineage-specific Rickettsia entry mechanism.
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Thakur R, Panda A, Coessens E, Raj N, Yadav S, Balakrishnan S, Zhang Q, Georgiev P, Basak B, Pasricha R, Wakelam MJ, Ktistakis NT, Raghu P. Phospholipase D activity couples plasma membrane endocytosis with retromer dependent recycling. eLife 2016; 5. [PMID: 27848911 PMCID: PMC5125754 DOI: 10.7554/elife.18515] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 11/14/2016] [Indexed: 01/11/2023] Open
Abstract
During illumination, the light-sensitive plasma membrane (rhabdomere) of Drosophila photoreceptors undergoes turnover with consequent changes in size and composition. However, the mechanism by which illumination is coupled to rhabdomere turnover remains unclear. We find that photoreceptors contain a light-dependent phospholipase D (PLD) activity. During illumination, loss of PLD resulted in an enhanced reduction in rhabdomere size, accumulation of Rab7 positive, rhodopsin1-containing vesicles (RLVs) in the cell body and reduced rhodopsin protein. These phenotypes were associated with reduced levels of phosphatidic acid, the product of PLD activity and were rescued by reconstitution with catalytically active PLD. In wild-type photoreceptors, during illumination, enhanced PLD activity was sufficient to clear RLVs from the cell body by a process dependent on Arf1-GTP levels and retromer complex function. Thus, during illumination, PLD activity couples endocytosis of RLVs with their recycling to the plasma membrane thus maintaining plasma membrane size and composition. DOI:http://dx.doi.org/10.7554/eLife.18515.001 Certain cells in the eye contain a receptor protein known as rhodopsin that enables them to detect light. Rhodopsin is found in distinct patches on the membrane surrounding each of these “photoreceptor” cells and the number of rhodopsin molecules present controls how sensitive the cell is to light. In humans, vitamin A deficiency or genetic defects can decrease the number of rhodopsin molecules on the membrane, leading to difficulty in seeing in dim light. Fruit fly eyes also contain rhodopsin. Exposure to normal levels of light triggers parts of the membranes of fly photoreceptor cells to detach and move into the interior of the cell. These internalized pieces of membrane have two possible fates: they can either be destroyed or recycled back to the cell surface. This membrane turnover adjusts the size of the membrane surrounding the cell and the number of rhodopsin molecules in it to regulate the cell’s sensitivity to light. It is crucial that turnover is tightly regulated in order to maintain the integrity of the cell membrane. However, it is not clear how the process is regulated during light exposure. Thakur et al. set out to address this question in fruit flies. The experiments show that an enzyme called phospholipase D is activated when photoreceptors are exposed to light. Active phospholipase D – which generates a molecule called phosphatidic acid – coordinates the internalization of pieces of membrane with the recycling of rhodopsin back to the cell surface. Thakur et al. generated fly mutants that lacked phospholipase D and in these animals the internalized rhodopsin was not transported back to the cell membrane. This caused the membrane to shrink in size and decreased the number of rhodopsin molecules in it. As a result, the photoreceptor cells became less sensitive to light. The findings of Thakur et al. show that in response to normal levels of light, phospholipase D balances membrane internalization and recycling to maintain the size and rhodopsin composition of the membrane. Future challenges will be to work out exactly how phospholipase D is activated and how phosphatidic acid tunes membrane internalization and recycling. DOI:http://dx.doi.org/10.7554/eLife.18515.002
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Affiliation(s)
- Rajan Thakur
- National Centre for Biological Sciences, Bangalore, India.,Shanmugha Arts, Science, Technology & Research Academy, Thanjavur, India
| | - Aniruddha Panda
- National Centre for Biological Sciences, Bangalore, India.,Manipal University, Karnataka, India
| | - Elise Coessens
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - Nikita Raj
- National Centre for Biological Sciences, Bangalore, India
| | - Shweta Yadav
- National Centre for Biological Sciences, Bangalore, India
| | | | - Qifeng Zhang
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - Plamen Georgiev
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - Bishal Basak
- National Centre for Biological Sciences, Bangalore, India
| | - Renu Pasricha
- National Centre for Biological Sciences, Bangalore, India
| | | | | | - Padinjat Raghu
- National Centre for Biological Sciences, Bangalore, India
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Breitbart H, Finkelstein M. Regulation of Sperm Capacitation and the Acrosome Reaction by PIP 2 and Actin Modulation. Asian J Androl 2016; 17:597-600. [PMID: 25966627 PMCID: PMC4492050 DOI: 10.4103/1008-682x.154305] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Actin polymerization and development of hyperactivated (HA) motility are two processes that take place during sperm capacitation. Actin polymerization occurs during capacitation and prior to the acrosome reaction, fast F-actin breakdown takes place. The increase in F-actin during capacitation depends upon inactivation of the actin severing protein, gelsolin, by its binding to phosphatydilinositol-4, 5-bisphosphate (PIP 2 ) and its phosphorylation on tyrosine-438 by Src. Activation of gelsolin following its release from PIP 2 is known to cause F-actin breakdown and inhibition of sperm motility, which can be restored by adding PIP 2 to the cells. Reduction of PIP 2 synthesis inhibits actin polymerization and motility, while increasing PIP 2 synthesis enhances these activities. Furthermore, sperm demonstrating low motility contained low levels of PIP 2 and F-actin. During capacitation there was an increase in PIP 2 and F-actin levels in the sperm head and a decrease in the tail. In spermatozoa with high motility, gelsolin was mainly localized to the sperm head before capacitation, whereas in low motility sperm, most of the gelsolin was localized to the tail before capacitation and translocated to the head during capacitation. We also showed that phosphorylation of gelsolin on tyrosine-438 depends upon its binding to PIP 2 . Stimulation of phospholipase C, by Ca 2 + -ionophore or by activating the epidermal-growth-factor-receptor, inhibits tyrosine phosphorylation of gelsolin and enhances enzyme activity. In conclusion, these data indicate that the increase of PIP 2 and/or F-actin in the head during capacitation enhances gelsolin translocation to the head. As a result, the decrease of gelsolin in the tail allows the maintenance of high levels of F-actin in this structure, which is essential for the development of HA motility.
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Affiliation(s)
- Haim Breitbart
- The Mina and Everard Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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40
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Xue Q, Jiang W, Wang L. Target-controlled gating liposome “off–on” cascade amplification for sensitive and accurate detection of phospholipase D in breast cancer cells with a low-background signal. Chem Commun (Camb) 2016; 52:10660-3. [DOI: 10.1039/c6cc05499d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Here we developed a simple, sensitive and accurate PLD detection method based on a target-controlled gating liposome (TCGL) “off–on” cascade amplified strategy and personal glucose meters (PGMs).
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Affiliation(s)
- Qingwang Xue
- School of Pharmacy
- Shandong University
- Jinan 250012
- P. R. China
- Department of Chemistry
| | - Wei Jiang
- School of Chemistry and Chemical Engineering
- Shandong University
- Jinan 250100
- P. R. China
| | - Lei Wang
- School of Pharmacy
- Shandong University
- Jinan 250012
- P. R. China
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41
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Rahier R, Noiriel A, Abousalham A. Development of a Direct and Continuous Phospholipase D Assay Based on the Chelation-Enhanced Fluorescence Property of 8-Hydroxyquinoline. Anal Chem 2015; 88:666-74. [DOI: 10.1021/acs.analchem.5b02332] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Renaud Rahier
- Institut
de Chimie et de Biochimie Moléculaires
et Supramoléculaires (ICBMS) UMR 5246 CNRS, Université Claude Bernard Lyon 1, Organisation
et Dynamique des Membranes Biologiques, Bâtiment Raulin, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
| | - Alexandre Noiriel
- Institut
de Chimie et de Biochimie Moléculaires
et Supramoléculaires (ICBMS) UMR 5246 CNRS, Université Claude Bernard Lyon 1, Organisation
et Dynamique des Membranes Biologiques, Bâtiment Raulin, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
| | - Abdelkarim Abousalham
- Institut
de Chimie et de Biochimie Moléculaires
et Supramoléculaires (ICBMS) UMR 5246 CNRS, Université Claude Bernard Lyon 1, Organisation
et Dynamique des Membranes Biologiques, Bâtiment Raulin, 43 Boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
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42
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Bruntz RC, Lindsley CW, Brown HA. Phospholipase D signaling pathways and phosphatidic acid as therapeutic targets in cancer. Pharmacol Rev 2015; 66:1033-79. [PMID: 25244928 DOI: 10.1124/pr.114.009217] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Phospholipase D is a ubiquitous class of enzymes that generates phosphatidic acid as an intracellular signaling species. The phospholipase D superfamily plays a central role in a variety of functions in prokaryotes, viruses, yeast, fungi, plants, and eukaryotic species. In mammalian cells, the pathways modulating catalytic activity involve a variety of cellular signaling components, including G protein-coupled receptors, receptor tyrosine kinases, polyphosphatidylinositol lipids, Ras/Rho/ADP-ribosylation factor GTPases, and conventional isoforms of protein kinase C, among others. Recent findings have shown that phosphatidic acid generated by phospholipase D plays roles in numerous essential cellular functions, such as vesicular trafficking, exocytosis, autophagy, regulation of cellular metabolism, and tumorigenesis. Many of these cellular events are modulated by the actions of phosphatidic acid, and identification of two targets (mammalian target of rapamycin and Akt kinase) has especially highlighted a role for phospholipase D in the regulation of cellular metabolism. Phospholipase D is a regulator of intercellular signaling and metabolic pathways, particularly in cells that are under stress conditions. This review provides a comprehensive overview of the regulation of phospholipase D activity and its modulation of cellular signaling pathways and functions.
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Affiliation(s)
- Ronald C Bruntz
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
| | - Craig W Lindsley
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
| | - H Alex Brown
- Department of Pharmacology (R.C.B., C.W.L., H.A.B.) and Vanderbilt Center for Neuroscience Drug Discovery (C.W.L.), Vanderbilt University Medical Center; Department of Chemistry, Vanderbilt Institute of Chemical Biology (C.W.L., H.A.B.); Vanderbilt Specialized Chemistry for Accelerated Probe Development (C.W.L.); and Department of Biochemistry, Vanderbilt-Ingram Cancer Center (H.A.B.), Vanderbilt University, Nashville, Tennessee
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Zhou F, Dong C, Davis JE, Wu WH, Surrao K, Wu G. The mechanism and function of mitogen-activated protein kinase activation by ARF1. Cell Signal 2015; 27:2035-2044. [PMID: 26169956 DOI: 10.1016/j.cellsig.2015.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 06/24/2015] [Indexed: 01/25/2023]
Abstract
Mitogen-activated protein kinases (MAPK) can be activated by a number of biochemical pathways through distinct signaling molecules. We have recently revealed a novel function for the Ras-like small GTPase ADP-ribosylation factor 1 (ARF1) in mediating the activation of Raf1-MEK-ERK1/2 pathway by G protein-coupled receptors [Dong C, Li C and Wu G (2011) J Biol Chem 286, 43,361-43,369]. Here, we have further defined the underlying mechanism and the possible function of ARF1-mediated MAPK pathway. We demonstrated that the blockage of ARF1 activation and the disruption of ARF1 localization to the Golgi by mutating Thr48, a highly conserved residue involved in the exchange of GDP for GTP, and the myristoylation site Gly2 abolished ARF1's ability to activate ERK1/2. In addition, treatment with Golgi structure disrupting agents markedly attenuated ARF1-mediated ERK1/2 activation. Furthermore, ARF1 significantly promoted cell proliferation. More interestingly, ARF1 activated 90kDa ribosomal S6 kinase 1 (RSK1) without influencing Elk-1 activation and ERK2 translocation to the nuclei. These data demonstrate that, once activated, ARF1 activates the MAPK pathway likely using the Golgi as a main platform, which in turn activates the cytoplasmic RSK1, leading to cell proliferation.
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Affiliation(s)
- Fuguo Zhou
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido St, New Orleans, LA 70112, United States
| | - Chunmin Dong
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido St, New Orleans, LA 70112, United States
| | - Jason E Davis
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta, GA 30912, United States
| | - William H Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta, GA 30912, United States
| | - Kristen Surrao
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta, GA 30912, United States
| | - Guangyu Wu
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, 1901 Perdido St, New Orleans, LA 70112, United States.,Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta, GA 30912, United States
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44
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Hyodo K, Taniguchi T, Manabe Y, Kaido M, Mise K, Sugawara T, Taniguchi H, Okuno T. Phosphatidic acid produced by phospholipase D promotes RNA replication of a plant RNA virus. PLoS Pathog 2015; 11:e1004909. [PMID: 26020241 PMCID: PMC4447390 DOI: 10.1371/journal.ppat.1004909] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 04/23/2015] [Indexed: 12/25/2022] Open
Abstract
Eukaryotic positive-strand RNA [(+)RNA] viruses are intracellular obligate parasites replicate using the membrane-bound replicase complexes that contain multiple viral and host components. To replicate, (+)RNA viruses exploit host resources and modify host metabolism and membrane organization. Phospholipase D (PLD) is a phosphatidylcholine- and phosphatidylethanolamine-hydrolyzing enzyme that catalyzes the production of phosphatidic acid (PA), a lipid second messenger that modulates diverse intracellular signaling in various organisms. PA is normally present in small amounts (less than 1% of total phospholipids), but rapidly and transiently accumulates in lipid bilayers in response to different environmental cues such as biotic and abiotic stresses in plants. However, the precise functions of PLD and PA remain unknown. Here, we report the roles of PLD and PA in genomic RNA replication of a plant (+)RNA virus, Red clover necrotic mosaic virus (RCNMV). We found that RCNMV RNA replication complexes formed in Nicotiana benthamiana contained PLDα and PLDβ. Gene-silencing and pharmacological inhibition approaches showed that PLDs and PLDs-derived PA are required for viral RNA replication. Consistent with this, exogenous application of PA enhanced viral RNA replication in plant cells and plant-derived cell-free extracts. We also found that a viral auxiliary replication protein bound to PA in vitro, and that the amount of PA increased in RCNMV-infected plant leaves. Together, our findings suggest that RCNMV hijacks host PA-producing enzymes to replicate.
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Affiliation(s)
- Kiwamu Hyodo
- Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Takako Taniguchi
- Institute for Enzyme Research, University of Tokushima, Tokushima, Japan
| | - Yuki Manabe
- Laboratory of Marine Bioproducts Technology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Masanori Kaido
- Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kazuyuki Mise
- Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Tatsuya Sugawara
- Laboratory of Marine Bioproducts Technology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Hisaaki Taniguchi
- Institute for Enzyme Research, University of Tokushima, Tokushima, Japan
| | - Tetsuro Okuno
- Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
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Spencer C, Brown HA. Biochemical characterization of a Pseudomonas aeruginosa phospholipase D. Biochemistry 2015; 54:1208-18. [PMID: 25565226 PMCID: PMC4337821 DOI: 10.1021/bi501291t] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phospholipase D is a ubiquitous protein in eukaryotes that hydrolyzes phospholipids to generate the signaling lipid phosphatidic acid (PtdOH). PldA, a Pseudomonas aeruginosa PLD, is a secreted protein that targets bacterial and eukaryotic cells. Here we have characterized the in vitro factors that modulate enzymatic activity of PldA, including divalent cations and phosphoinositides. We have identified several similarities between the eukaryotic-like PldA and the human PLD isoforms, as well as several properties in which the enzymes diverge. Notable differences include the substrate preference and transphosphatidylation efficiency for PldA. These findings offer new insights into potential regulatory mechanisms of PldA and its role in pathogenesis.
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Affiliation(s)
- Cierra Spencer
- Department of Pharmacology, and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - H. Alex Brown
- Department of Pharmacology, and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
- Department of Biochemistry, and Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
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46
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ARFGAP1 is dynamically associated with lipid droplets in hepatocytes. PLoS One 2014; 9:e111309. [PMID: 25397679 PMCID: PMC4232254 DOI: 10.1371/journal.pone.0111309] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 09/30/2014] [Indexed: 12/18/2022] Open
Abstract
The ARF GTPase Activating Protein 1 (ARFGAP1) associates mainly with the cytosolic side of Golgi cisternal membranes where it participates in the formation of both COPI and clathrin-coated vesicles. In this study, we show that ARFGAP1 associates transiently with lipid droplets upon addition of oleate in cultured cells. Also, that addition of cyclic AMP shifts ARFGAP1 from lipid droplets to the Golgi apparatus and that overexpression and knockdown of ARFGAP1 affect lipid droplet formation. Examination of human liver tissue reveals that ARFGAP1 is found associated with lipid droplets at steady state in some but not all hepatocytes.
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Caviston JP, Cohen LA, Donaldson JG. Arf1 and Arf6 promote ventral actin structures formed by acute activation of protein kinase C and Src. Cytoskeleton (Hoboken) 2014; 71:380-94. [PMID: 24916416 DOI: 10.1002/cm.21181] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 06/03/2014] [Accepted: 06/04/2014] [Indexed: 01/16/2023]
Abstract
Arf proteins regulate membrane traffic and organelle structure. Although Arf6 is known to initiate actin-based changes in cell surface architecture, Arf1 may also function at the plasma membrane. Here we show that acute activation of protein kinase C (PKC) induced by the phorbol ester PMA led to the formation of motile actin structures on the ventral surface of Beas-2b cells, a lung bronchial epithelial cell line. Ventral actin structures also formed in PMA-treated HeLa cells that had elevated levels of Arf activation. For both cell types, formation of the ventral actin structures was enhanced by expression of active forms of either Arf1 or Arf6 and by the expression of guanine nucleotide exchange factors that activate these Arfs. By contrast, formation of these structures was blocked by inhibitors of PKC and Src and required phosphatidylinositol 4, 5-bisphosphate, Rac, Arf6, and Arf1. Furthermore, expression of ASAP1, an Arf1 GTPase activating protein (GAP) was more effective at inhibiting the ventral actin structures than was ACAP1, an Arf6 GAP. This study adds to the expanding role for Arf1 in the periphery and identifies a requirement for Arf1, a "Golgi Arf," in the reorganization of the cortical actin cytoskeleton on ventral surfaces, against the substratum.
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48
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Arf6 exchange factor EFA6 and endophilin directly interact at the plasma membrane to control clathrin-mediated endocytosis. Proc Natl Acad Sci U S A 2014; 111:9473-8. [PMID: 24979773 DOI: 10.1073/pnas.1401186111] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Members of the Arf family of small G proteins are involved in membrane traffic and organelle structure. They control the recruitment of coat proteins, and modulate the structure of actin filaments and the lipid composition of membranes. The ADP-ribosylation factor 6 (Arf6) isoform and the exchange factor for Arf6 (EFA6) are known to regulate the endocytic pathway of many different receptors. To determine the molecular mechanism of the EFA6/Arf6 function in vesicular transport, we searched for new EFA6 partners. In a two-hybrid screening using the catalytic Sec7 domain as a bait, we identified endophilin as a new partner of EFA6. Endophilin contains a Bin/Amphiphysin/Rvs (BAR) domain responsible for membrane bending, and an SH3 domain responsible for the recruitment of dynamin and synaptojanin, two proteins involved, respectively, in the fission and uncoating of clathrin-coated vesicles. By using purified proteins, we confirmed the direct interaction, and identified the N-BAR domain as the binding motif to EFA6A. We showed that endophilin stimulates the catalytic activity of EFA6A on Arf6. In addition, we observed that the Sec7 domain competes with flat but not with highly curved lipid membranes to bind the N-BAR. In cells, expression of EFA6A recruits endophilin to EFA6A-positive plasma membrane ruffles, whereas expression of endophilin rescues the EFA6A-mediated inhibition of transferrin internalization. Overall, our results support a model whereby EFA6 recruits endophilin on flat areas of the plasma membrane to control Arf6 activation and clathrin-mediated endocytosis.
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Lo Vasco VR, Leopizzi M, Puggioni C, Della Rocca C, Businaro R. Neuropeptide Y reduces the expression of PLCB2, PLCD1 and selected PLC genes in cultured human endothelial cells. Mol Cell Biochem 2014; 394:43-52. [PMID: 24903829 DOI: 10.1007/s11010-014-2079-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 05/03/2014] [Indexed: 12/11/2022]
Abstract
Endothelial cells (EC) are the first elements exposed to mediators circulating in the bloodstream, and react to stimulation with finely tuned responses mediated by different signal transduction pathways, leading the endothelium to adapt. Neuropeptide Y (NPY), the most abundant peptide in heart and brain, is mainly involved in the neuroendocrine regulation of the stress response. The regulatory roles of NPY depend on many factors, including its enzymatic processing, receptor subtypes and related signal transduction systems, including the phosphoinositide (PI) pathway and related phospholipase C (PI-PLC) family of enzymes. The panel of expression of PI-PLC enzymes differs comparing quiescent versus differently stimulated human EC. Growing evidences indicate that the regulation of the expression of PLC genes, which codify for PI-PLC enzymes, might act as an additional mechanism of control of the PI signal transduction pathway. NPY was described to potentiate the activation of PI-PLC enzymes in different cell types, including EC. In the present experiments, we stimulated human umbilical vein EC using different doses of NPY in order to investigate a possible role upon the expression PLC genes. NPY reduced the overall transcription of PLC genes, excepting for PLCE. The most significant effects were observed for PLCB2 and PLCD1, both isoforms recruited by means of G-proteins and G-protein-coupled receptors. NPY behavior was comparable with other PI-PLC interacting molecules that, beside the stimulation of phospholipase activity, also affect the upcoming enzymes' production acting upon gene expression. That might represent a mode to regulate the activity of PI-PLC enzymes after activation.
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Affiliation(s)
- V R Lo Vasco
- Department Organi di Senso, Policlinico Umberto I, Faculty of Medicina e Odontoiatria, Sapienza University of Rome, viale del Policlinico 155, 00185, Rome, Italy,
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50
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Pu Z, Chen G, Wang J, Liu Y, Jiang Q, Li W, Lan X, Dai S, Wei Y, Zheng Y. Characterization and chromosome location of ADP-ribosylation factors (ARFs) in wheat. Pak J Biol Sci 2014; 17:792-801. [PMID: 26035952 DOI: 10.3923/pjbs.2014.792.801] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In this study, the ARF genes were cloned, sequenced and located on the chromosomes. The gene expression of various stress conditions were analyzed through RT-PCR. Two important features of ARF in wheat were found: (1) High sequences homology among species in mammalian and plant and (2) Four exons and three introns were conserved in Poaceae. In this study the coding genes of ADP-ribosylation Factors (ARF) were characterized and they were located on chromosomes 3AL and 2DL in common wheat and its diploid progenitors. Forty-seven candidate SNPs in ARF were detected which were located in exons (17 SNPs) and introns (30 SNPs), respectively. As expected, most of the SNPs (66.34%) in ARF were transitions and the rest (33.66%) were transversions. The expression difference of ARF under various environmental stresses (low-temperature, Abscisic Acid (ABA), Polyethylene Glycol (PEG), NaCl, stripe rust), in two stages (seedling and maturity) and in different tissues (root, stem, flag leaf and immature embryo) of 15 days post-flowering were investigated. The results revealed that the expression levels of ARF were affected by environmental stresses. PEG stress induced the highest level of ARF expression, followed by the stripe rust and ABA stresses.
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