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Duewell BR, Faris KA, Hansen SD. Molecular basis of product recognition during PIP5K-mediated production of PI(4,5)P 2 with positive feedback. J Biol Chem 2024:107631. [PMID: 39098525 DOI: 10.1016/j.jbc.2024.107631] [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: 02/20/2024] [Revised: 07/20/2024] [Accepted: 07/26/2024] [Indexed: 08/06/2024] Open
Abstract
The ability for cells to localize and activate peripheral membrane binding proteins is critical for signal transduction. Ubiquitously important in these signaling processes are phosphatidylinositol phosphate (PIP) lipids, which are dynamically phosphorylated by PIP lipid kinases on intracellular membranes. Functioning primarily at the plasma membrane, phosphatidylinositol-4-phosphate 5-kinases (PIP5K) catalyzes the phosphorylation of PI(4)P to generate most of the PI(4,5)P2 lipids found in eukaryotic plasma membrane. Recently, we determined that PIP5K displays a positive feedback loop based on membrane-mediated dimerization and cooperative binding to its product, PI(4,5)P2. Here, we examine how two motifs contribute to PI(4,5)P2 recognition to control membrane association and catalysis of PIP5K. Using a combination of single molecule TIRF microscopy and kinetic analysis of PI(4)P lipid phosphorylation, we map the sequence of steps that allow PIP5K to cooperatively engage PI(4,5)P2. We find that the specificity loop regulates the rate of PIP5K membrane association and helps orient the kinase to more effectively bind PI(4,5)P2 lipids. After correctly orienting on the membrane, PIP5K transitions to binding PI(4,5)P2 lipids near the active site through a motif previously referred to as the substrate or PIP binding motif (PIPBM). The PIPBM has broad specificity for anionic lipids and serves a role in regulating membrane association in vitro and in vivo. Overall, our data supports a two-step membrane binding model where the specificity loop and PIPBM act in concert to help PIP5K orient and productively engage anionic lipids to drive the positive feedback during PI(4,5)P2 production.
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Affiliation(s)
- Benjamin R Duewell
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Katherine A Faris
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403
| | - Scott D Hansen
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403.
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2
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Griffiths G, Brügger B, Freund C. Lipid switches in the immunological synapse. J Biol Chem 2024; 300:107428. [PMID: 38823638 PMCID: PMC11259711 DOI: 10.1016/j.jbc.2024.107428] [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: 11/14/2023] [Revised: 05/07/2024] [Accepted: 05/26/2024] [Indexed: 06/03/2024] Open
Abstract
Adaptive immune responses comprise the activation of T cells by peptide antigens that are presented by proteins of the Major Histocompatibility Complex (MHC) on the surface of an antigen-presenting cell. As a consequence of the T cell receptor interacting productively with a certain peptide-MHC complex, a specialized cell-cell junction known as the immunological synapse forms and is accompanied by changes in the spatiotemporal patterning and function of intracellular signaling molecules. Key modifications occurring at the cytoplasmic leaflet of the plasma and internal membranes in activated T cells comprise lipid switches that affect the binding and distribution of proteins within or near the lipid bilayer. Here, we describe two major classes of lipid switches that act at this critical water/membrane interface. Phosphoinositides are derived from phosphatidylinositol, an amphiphilic molecule that contains two fatty acid chains and a phosphate group that bridges the glycerol backbone to the carbohydrate inositol. The inositol ring can be variably (de-)phosphorylated by dedicated kinases and phosphatases, thereby creating phosphoinositide signatures that define the composition and properties of signaling molecules, molecular complexes, or whole organelles. Palmitoylation refers to the reversible attachment of the fatty acid palmitate to a substrate protein's cysteine residue. DHHC enzymes, named after the four conserved amino acids in their active site, catalyze this post-translational modification and thereby change the distribution of proteins at, between, and within membranes. T cells utilize these two types of molecular switches to adjust their properties to an activation process that requires changes in motility, transport, secretion, and gene expression.
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Affiliation(s)
| | - Britta Brügger
- Heidelberg University Biochemistry Center (BZH), Heidelberg, Germany
| | - Christian Freund
- Laboratory of Protein Biochemistry, Institute of Chemistry & Biochemistry, Freie Universität Berlin, Berlin, Germany.
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3
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Li C, Yoon B, Stefani G, Slack FJ. Lipid kinase PIP5K1A regulates let-7 microRNA biogenesis through interacting with nuclear export protein XPO5. Nucleic Acids Res 2023; 51:9849-9862. [PMID: 37655623 PMCID: PMC10570020 DOI: 10.1093/nar/gkad709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/03/2023] [Accepted: 08/15/2023] [Indexed: 09/02/2023] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs first discovered in Caenorhabditis elegans. The let-7 miRNA is highly conserved in sequence, biogenesis and function from C. elegans to humans. During miRNA biogenesis, XPO5-mediated nuclear export of pre-miRNAs is a rate-limiting step and, therefore, might be critical for the quantitative control of miRNA levels, yet little is known about how this is regulated. Here we show a novel role for lipid kinase PPK-1/PIP5K1A (phosphatidylinositol-4-phosphate 5-kinase) in regulating miRNA levels. We found that C. elegans PPK-1 functions in the lin-28/let-7 heterochronic pathway, which regulates the strict developmental timing of seam cells. In C. elegans and human cells, PPK-1/PIP5K1A regulates let-7 miRNA levels. We investigated the mechanism further in human cells and show that PIP5K1A interacts with nuclear export protein XPO5 in the nucleus to regulate mature miRNA levels by blocking the binding of XPO5 to pre-let-7 miRNA. Furthermore, we demonstrate that this role for PIP5K1A is kinase-independent. Our study uncovers the novel finding of a direct connection between PIP5K1A and miRNA biogenesis. Given that miRNAs are implicated in multiple diseases, including cancer, this new finding might lead to a novel therapeutic opportunity.
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Affiliation(s)
- Chun Li
- Harvard Medical School Initiative for RNA Medicine, Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Bohyung Yoon
- Harvard Medical School Initiative for RNA Medicine, Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Giovanni Stefani
- Harvard Medical School Initiative for RNA Medicine, Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Frank J Slack
- Harvard Medical School Initiative for RNA Medicine, Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
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4
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Cabrera-Rodríguez R, Pérez-Yanes S, Lorenzo-Sánchez I, Trujillo-González R, Estévez-Herrera J, García-Luis J, Valenzuela-Fernández A. HIV Infection: Shaping the Complex, Dynamic, and Interconnected Network of the Cytoskeleton. Int J Mol Sci 2023; 24:13104. [PMID: 37685911 PMCID: PMC10487602 DOI: 10.3390/ijms241713104] [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: 08/08/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 09/10/2023] Open
Abstract
HIV-1 has evolved a plethora of strategies to overcome the cytoskeletal barrier (i.e., actin and intermediate filaments (AFs and IFs) and microtubules (MTs)) to achieve the viral cycle. HIV-1 modifies cytoskeletal organization and dynamics by acting on associated adaptors and molecular motors to productively fuse, enter, and infect cells and then traffic to the cell surface, where virions assemble and are released to spread infection. The HIV-1 envelope (Env) initiates the cycle by binding to and signaling through its main cell surface receptors (CD4/CCR5/CXCR4) to shape the cytoskeleton for fusion pore formation, which permits viral core entry. Then, the HIV-1 capsid is transported to the nucleus associated with cytoskeleton tracks under the control of specific adaptors/molecular motors, as well as HIV-1 accessory proteins. Furthermore, HIV-1 drives the late stages of the viral cycle by regulating cytoskeleton dynamics to assure viral Pr55Gag expression and transport to the cell surface, where it assembles and buds to mature infectious virions. In this review, we therefore analyze how HIV-1 generates a cell-permissive state to infection by regulating the cytoskeleton and associated factors. Likewise, we discuss the relevance of this knowledge to understand HIV-1 infection and pathogenesis in patients and to develop therapeutic strategies to battle HIV-1.
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Affiliation(s)
- Romina Cabrera-Rodríguez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Silvia Pérez-Yanes
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Iria Lorenzo-Sánchez
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Rodrigo Trujillo-González
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
- Analysis Department, Faculty of Mathematics, Universidad de La Laguna (ULL), 38200 La Laguna, Spain
| | - Judith Estévez-Herrera
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Jonay García-Luis
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
| | - Agustín Valenzuela-Fernández
- Laboratorio de Inmunología Celular y Viral, Unidad de Farmacología, Sección de Medicina, Facultad de Ciencias de la Salud, Universidad de La Laguna (ULL), 38200 La Laguna, Spain; (R.C.-R.); (S.P.-Y.); (I.L.-S.); (R.T.-G.); (J.E.-H.); (J.G.-L.)
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Le TPH, Nguyen NTT, Le DDT, Anwar MA, Lee SY. Lipid kinase PIP5Kα contributes to Hippo pathway activation via interaction with Merlin and by mediating plasma membrane targeting of LATS1. Cell Commun Signal 2023; 21:149. [PMID: 37337213 DOI: 10.1186/s12964-023-01161-w] [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: 03/22/2023] [Accepted: 05/07/2023] [Indexed: 06/21/2023] Open
Abstract
BACKGROUND The Hippo pathway plays a critical role in controlled cell proliferation. The tumor suppressor Merlin and large tumor suppressor kinase 1 (LATS1) mediate activation of Hippo pathway, consequently inhibiting the primary effectors, Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). Phosphatidylinositol 4,5-bisphosphate (PIP2), a lipid present in the plasma membrane (PM), binds to and activates Merlin. Phosphatidylinositol 4-phosphate 5-kinase α (PIP5Kα) is an enzyme responsible for PIP2 production. However, the functional role of PIP5Kα in regulation of Merlin and LATS1 under Hippo signaling conditions remains unclear. METHODS PIP5Kα, Merlin, or LATS1 knockout or knockdown cells and transfected cells with them were used. LATS1, YAP, and TAZ activities were measured using biochemical methods and PIP2 levels were evaluated using cell imaging. Low/high cell density and serum starvation/stimulation conditions were tested. Colocalization of PIP5Kα and PIP2 with Merlin and LATS1, and their protein interactions were examined using transfection, confocal imaging, immunoprecipitation, western blotting, and/or pull-down experiments. Colony formation and adipocyte differentiation assays were performed. RESULTS We found that PIP5Kα induced LATS1 activation and YAP/TAZ inhibition in a kinase activity-dependent manner. Consistent with these findings, PIP5Kα suppressed cell proliferation and enhanced adipocyte differentiation of mesenchymal stem cells. Moreover, PIP5Kα protein stability and PIP2 levels were elevated at high cell density compared with those at low cell density, and both PIP2 and YAP phosphorylation levels initially declined, then recovered upon serum stimulation. Under these conditions, YAP/TAZ activity was aberrantly regulated by PIP5Kα deficiency. Mechanistically, either Merlin deficiency or LATS1 deficiency abrogated PIP5Kα-mediated YAP/TAZ inactivation. Additionally, the catalytic domain of PIP5Kα directly interacted with the band 4.1/ezrin/radixin/moesin domain of Merlin, and this interaction reinforced interaction of Merlin with LATS1. In accordance with these findings, PIP5Kα and PIP2 colocalized with Merlin and LATS1 in the PM. In PIP5Kα-deficient cells, Merlin colocalization with PIP2 was reduced, and LATS1 solubility increased. CONCLUSIONS Collectively, our results support that PIP5Kα serves as an activator of the Hippo pathway through interaction and colocalization with Merlin, which promotes PIP2-dependent Merlin activation and induces local recruitment of LATS1 to the PIP2-rich PM and its activation, thereby negatively regulating YAP/TAZ activity. Video Abstract.
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Affiliation(s)
- Truc Phan Hoang Le
- Department of Biomedical Sciences, Ajou University Graduate School of Medicine, Suwon, Gyeonggi, 16499, Republic of Korea
| | - Nga Thi Thanh Nguyen
- Department of Biomedical Sciences, Ajou University Graduate School of Medicine, Suwon, Gyeonggi, 16499, Republic of Korea
| | - Duong Duy Thai Le
- Department of Biomedical Sciences, Ajou University Graduate School of Medicine, Suwon, Gyeonggi, 16499, Republic of Korea
| | - Muhammad Ayaz Anwar
- Department of Applied Chemistry, Kyung Hee University International Campus, Yongin, Gyeonggi, 17104, Republic of Korea
| | - Sang Yoon Lee
- Department of Biomedical Sciences, Ajou University Graduate School of Medicine, Suwon, Gyeonggi, 16499, Republic of Korea.
- Institute of Medical Science, Ajou University School of Medicine, Suwon, Gyeonggi, 16499, Republic of Korea.
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6
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Hipkaeo W, Kondo H. Localization of phospholipid-related signal molecules in salivary glands of rodents: A review. J Oral Biosci 2023; 65:146-155. [PMID: 37061129 DOI: 10.1016/j.job.2023.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/08/2023] [Accepted: 04/10/2023] [Indexed: 04/17/2023]
Abstract
BACKGROUND In the 1950s, Hokin conducted initial studies on phosphoinositide turnover/cycle in salivary glandular cells. From these studies, the idea emerged that receptor-mediated changes in intramembranous levels of phosphoinositides represent an early step in the stimulus-response pathway. Based on this idea and the general view that knowledge of the exact localization of a given endogenous molecule in cells in situ is important for understanding its functional significance, we have reviewed available information about the localization of several representative phosphoinositide-signaling molecules in the salivary glands in situ in mice. HIGHLIGHT We focused on phosphatidylinositol 4-kinase, phosphatidylinositol 4 phosphate 5-kinase α, β, γ, phospholipase Cβ, muscarinic cholinoceptors 1 and 3, diacylglycerol kinase ζ, phospholipase D1 and 2, ADP-ribosylation factor 6 and its exchange factors for Arf6, and cannabinoid receptors. These molecules individually exhibit differential localization in a spatiotemporal manner in the exocrine glands, making it possible to deduce their functional significance, such as their involvement in secretion and cell differentiation. CONCLUSION Although phosphoinositide-signaling molecules whose in situ localization in glandular cells has been clarified are still limited, the obtained information on their localization suggests that their functional significance is more valuable in glandular ducts than in acini. It thus suggests the necessity of greater attention to the ducts in their physio-pharmacological analyses. The purpose of this review is to encourage more in situ localization studies of phosphoinositide-signaling molecules with an aim to further understand their possible involvement in the pathogenesis of salivary gland diseases.
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Affiliation(s)
- Wiphawi Hipkaeo
- Electron Microscopy Laboratory, Division of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
| | - Hisatake Kondo
- Electron Microscopy Laboratory, Division of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Department of Anatomy, Graduate School of Medicine, Tohoku University, Sendai, JAPAN
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7
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Pakkarato S, Sakagami H, Watanabe M, Kondo H, Hipkaeo W, Chomphoo S. Discrete localization patterns of PIP5Kγ and PLCβ3 working sequentially in phosphoinositide-cycle within mouse sensory neuron somata. Microsc Res Tech 2023; 86:351-358. [PMID: 36579633 DOI: 10.1002/jemt.24276] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Revised: 11/11/2022] [Accepted: 12/11/2022] [Indexed: 12/30/2022]
Abstract
It is known that phosphatidylinositol phosphate 5 kinase (PIP5K) γ and phospholipase C (PLC) β3, working sequentially in the phosphoinositide cycle, are localized in dorsal root ganglion (DRG) somata and are involved in the regulation of pain and related sensations. However, the sites of their involvement have remained to be clarified. In the present study, immunoreactivity for PLCβ3 was distinct only in the central process of mouse DRG, but not in its peripheral process, in contrast to distinct PIP5Kγ-immunoreactivity in both peripheral and central DRG processes. No nerve terminals showing immunoreactivity for PLCβ3 were detected in any peripheral sensory fields, similar to PIP5Kγ-immunoreactivity. In DRG somata, PIP5Kγ-immunoreactivity was rather confined to the neurolemma in which dots and threads were discerned in 3D bright field light microscopy. This feature well corresponded to its discontinuous localization along the plasma membranes in immuno-electron microscopy. In contrast, PLCβ3-immunoreactivity occurred diffusely throughout the somata, but did not take distinct appearance of immunoreaction on neurolemma or plasma membranes, unlike PIP5Kγ-immunoreactivity. In addition, satellite glial cells were immunonegative for PLCβ3, but immunopositive for PIP5Kγ. The involvement of PLCβ3 in regulation of pain and related sensations is thus suggested to be mainly exerted at levels of the DRG soma and its upstream, but to be less significant in the peripheral sensory fields, similar to PIP5Kγ. The possibility is also suggested that PIP, PIP5Kγ-target, is localized heterogeneously, but PIP2, PLCβ3-target, is localized homogenously over the plane of the neuronal plasma membranes. RESEARCH HIGHLIGHTS: PIP5Kγ, different from PLCβ3, was localized heterogeneously on neuronal membranes, and this difference was demonstrated in 3D-bright field immuno-light and electron microscopy. Either PIP5Kγ or PLCβ3 was not detected in peripheral nerve terminals.
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Affiliation(s)
- Sawetree Pakkarato
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Department of Sports and Health Sciences, Faculty of Science and Arts, Rajamangala University of Technology Isan, Nakhon Ratchasima, Thailand
| | - Hiroyuki Sakagami
- Department of Anatomy, School of Medicine, Kitasato University, Sagamihara, Japan
| | - Masahiko Watanabe
- Department of Anatomy, School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hisatake Kondo
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.,Department of Anatomy, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Wiphawi Hipkaeo
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Surang Chomphoo
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
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Sirisin J, Kamnate A, Polsan Y, Somintara S, Chomphoo S, Sakagami H, Kondo H, Hipkaeo W. Localization of phosphatidylinositol 4-phosphate 5-kinase (PIP5K) α confined to the surface of lipid droplets and adjacent narrow cytoplasm in progesterone-producing cells of in situ ovaries of adult mice. Acta Histochem 2021; 123:151794. [PMID: 34624591 DOI: 10.1016/j.acthis.2021.151794] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 11/15/2022]
Abstract
Phosphatidylinositol(4,5)bisphosphate (PI(4,5)P2) produced by phosphatidylinositol phosphate 5 kinase (PIP5K) plays not only as a precursor of second messengers in the phosphoinositide signal transduction, but also multiple roles influencing a variety of cellular activities. From this viewpoint, the present study attempted to localize PIP5Kα in the ovaries in situ of adult mice. PIP5Kα-immunoreactivity was confined to the surfaces of lipid droplets (LDs) and their adjacent cytoplasm in progesterone-producing cells of the interstitial glands, corpora lutea and theca interna. The LDs often contained membranous tubules/lamellae along their surfaces and within their interior whose membranes were continuous with those delineating LDs composed of a monolayer of phospholipids and were partially PIP5Kα-immunoreactive. Although granulosa cells of healthy-looking follicles were immunonegative, as the atresia progressed, PIP5Kα-immunoreactivity first appeared in sparsely dispersed dot forms in mural cells of the follicular epithelia, and then were dominant in almost all mural cells that remained after desquamation of the antral cells. The present study provides evidence suggesting that PI(4,5)P2 locally synthesized by PIP5K in LDs is involved in the lipid transfer between lipid droplets (LDs) and the endoplasmic reticulum, which eventually regulates ovarian progesterone production through control of multiple dynamic activities of LDs. It is also suggested that PIP5Kα and PI(4,5)P2 are implicated in the modulation of programmed cell death and/or acquiring the ability of progesterone production in some follicular cells surviving atresia.
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Affiliation(s)
- Juthathip Sirisin
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Anussara Kamnate
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Yada Polsan
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Somsuda Somintara
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Surang Chomphoo
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
| | - Hiroyuki Sakagami
- Department of Anatomy, School of Medicine, Kitasato University, Sagamihara, Japan
| | - Hisatake Kondo
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand; Department of Anatomy, Graduate School of Medicine, Tohoku University, Sendai, Japan
| | - Wiphawi Hipkaeo
- Electron Microscopy Unit, Department of Anatomy, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
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Maxson ME, Sarantis H, Volchuk A, Brumell JH, Grinstein S. Rab5 regulates macropinocytosis by recruiting the inositol 5-phosphatases OCRL and Inpp5b that hydrolyse PtdIns(4,5)P2. J Cell Sci 2021; 134:237783. [PMID: 33722976 DOI: 10.1242/jcs.252411] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 02/25/2021] [Indexed: 01/09/2023] Open
Abstract
Rab5 is required for macropinosome formation, but its site and mode of action remain unknown. We report that Rab5 acts at the plasma membrane, downstream of ruffling, to promote macropinosome sealing and scission. Dominant-negative Rab5, which obliterates macropinocytosis, had no effect on the development of membrane ruffles. However, Rab5-containing vesicles were recruited to circular membrane ruffles, and soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-dependent endomembrane fusion was necessary for the completion of macropinocytosis. This fusion event coincided with the disappearance of PtdIns(4,5)P2 that accompanies macropinosome closure. Counteracting the depletion of PtdIns(4,5)P2 by expression of phosphatidylinositol-4-phosphate 5-kinase impaired macropinosome formation. Importantly, we found that the removal of PtdIns(4,5)P2 is dependent on Rab5, through the Rab5-mediated recruitment of the inositol 5-phosphatases OCRL and Inpp5b, via APPL1. Knockdown of OCRL and Inpp5b, or APPL1, prevented macropinosome closure without affecting ruffling. We therefore propose that Rab5 is essential for the clearance of PtdIns(4,5)P2 needed to complete the scission of macropinosomes or to prevent their back-fusion with the plasmalemma.
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Affiliation(s)
- Michelle E Maxson
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Helen Sarantis
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Allen Volchuk
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - John H Brumell
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,SickKids IBD Centre, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario M5S 1A1, Canada.,Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Keenan Research Centre for Biomedical Science, St. Michael's Hospital, Toronto, Ontario M5B 1W8, Canada
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10
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Ernest James Phillips T, Maguire E. Phosphoinositides: Roles in the Development of Microglial-Mediated Neuroinflammation and Neurodegeneration. Front Cell Neurosci 2021; 15:652593. [PMID: 33841102 PMCID: PMC8032904 DOI: 10.3389/fncel.2021.652593] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/08/2021] [Indexed: 12/11/2022] Open
Abstract
Microglia are increasingly recognized as vital players in the pathology of a variety of neurodegenerative conditions including Alzheimer’s (AD) and Parkinson’s (PD) disease. While microglia have a protective role in the brain, their dysfunction can lead to neuroinflammation and contributes to disease progression. Also, a growing body of literature highlights the seven phosphoinositides, or PIPs, as key players in the regulation of microglial-mediated neuroinflammation. These small signaling lipids are phosphorylated derivates of phosphatidylinositol, are enriched in the brain, and have well-established roles in both homeostasis and disease.Disrupted PIP levels and signaling has been detected in a variety of dementias. Moreover, many known AD disease modifiers identified via genetic studies are expressed in microglia and are involved in phospholipid metabolism. One of these, the enzyme PLCγ2 that hydrolyzes the PIP species PI(4,5)P2, displays altered expression in AD and PD and is currently being investigated as a potential therapeutic target.Perhaps unsurprisingly, neurodegenerative conditions exhibiting PIP dyshomeostasis also tend to show alterations in aspects of microglial function regulated by these lipids. In particular, phosphoinositides regulate the activities of proteins and enzymes required for endocytosis, toll-like receptor signaling, purinergic signaling, chemotaxis, and migration, all of which are affected in a variety of neurodegenerative conditions. These functions are crucial to allow microglia to adequately survey the brain and respond appropriately to invading pathogens and other abnormalities, including misfolded proteins. AD and PD therapies are being developed to target many of the above pathways, and although not yet investigated, simultaneous PIP manipulation might enhance the beneficial effects observed. Currently, only limited therapeutics are available for dementia, and although these show some benefits for symptom severity and progression, they are far from curative. Given the importance of microglia and PIPs in dementia development, this review summarizes current research and asks whether we can exploit this information to design more targeted, or perhaps combined, dementia therapeutics. More work is needed to fully characterize the pathways discussed in this review, but given the strength of the current literature, insights in this area could be invaluable for the future of neurodegenerative disease research.
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Affiliation(s)
| | - Emily Maguire
- UK Dementia Research Institute at Cardiff University, Cardiff, United Kingdom
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11
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Desale SE, Chinnathambi S. Phosphoinositides signaling modulates microglial actin remodeling and phagocytosis in Alzheimer's disease. Cell Commun Signal 2021; 19:28. [PMID: 33627135 PMCID: PMC7905611 DOI: 10.1186/s12964-021-00715-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/26/2021] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease is one of the neurodegenerative diseases, characterized by the accumulation of abnormal protein deposits, which disrupts signal transduction in neurons and other glia cells. The pathological protein in neurodegenerative diseases, Tau and amyloid-β contribute to the disrupted microglial signaling pathways, actin cytoskeleton, and cellular receptor expression. The important secondary messenger lipids i.e., phosphatidylinositols are largely affected by protein deposits of amyloid-β in Alzheimer's disease. Phosphatidylinositols are the product of different phosphatidylinositol kinases and the state of phosphorylation at D3, D4, and D5 positions of inositol ring. Phosphatidylinositol 3,4,5-triphosphate (PI 3, 4, 5-P3) involves in phagocytic cup formation, cell polarization, whereas Phosphatidylinositol 4,5-bisphosphate (PI 4, 5-P2)-mediates the process of phagosomes formation and further its fusion with early endosome.. The necessary activation of actin-binding proteins such as Rac, WAVE complex, and ARP2/3 complex for the actin polymerization in the process of phagocytosis, migration is regulated and maintained by PI 3, 4, 5-P3 and PI 4, 5-P2. The ratio and types of fatty acid intake can influence the intracellular secondary lipid messengers along with the cellular content of phaphatidylcholine and phosphatidylethanolamine. The Amyloid-β deposits and extracellular Tau seeds disrupt phosphatidylinositides level and actin cytoskeletal network that hamper microglial-signaling pathways in AD. We hypothesize that being a lipid species intracellular levels of phosphatidylinositol would be regulated by dietary fatty acids. Further we are interested to understand phosphoinositide-based signaling cascades in phagocytosis and actin remodeling. Video Abstract.
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Affiliation(s)
- Smita Eknath Desale
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008 India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002 India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008 India
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12
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Verma DK, Peruzza L, Trusch F, Yadav MK, Ravindra, Shubin SV, Morgan KL, Mohindra V, Hauton C, van West P, Pradhan PK, Sood N. Transcriptome analysis reveals immune pathways underlying resistance in the common carp Cyprinus carpio against the oomycete Aphanomyces invadans. Genomics 2020; 113:944-956. [PMID: 33127583 DOI: 10.1016/j.ygeno.2020.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/30/2020] [Accepted: 10/25/2020] [Indexed: 12/13/2022]
Abstract
Infection with Aphanomyces invadans is a serious fish disease with major global impacts. Despite affecting over 160 fish species, some of the species like the common carp Cyprinus carpio are resistant to A. invadans infection. In the present study, we investigated the transcriptomes of head kidney of common carp experimentally infected with A. invadans. In time course analysis, 5288 genes were found to be differentially expressed (DEGs), of which 731 were involved in 21 immune pathways. The analysis of immune-related DEGs suggested that efficient processing and presentation of A. invadans antigens, enhanced phagocytosis, recognition of pathogen-associated molecular patterns, and increased recruitment of leukocytes to the sites of infection contribute to resistance of common carp against A. invadans. Herein, we provide a systematic understanding of the disease resistance mechanisms in common carp at molecular level as a valuable resource for developing disease management strategies for this devastating fish-pathogenic oomycete.
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Affiliation(s)
- Dev Kumar Verma
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Luca Peruzza
- School of Ocean and Earth Science, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH, United Kingdom; Present address: Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro, Italy
| | - Franziska Trusch
- International Centre for Aquaculture Research and Development, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, Scotland, United Kingdom; Present address: University of Dundee, School of Life Sciences, Department of Plant Sciences (@ James Hutton Institute), Invergowrie, Dundee DD2 5DA, Scotland, United Kingdom
| | - Manoj Kumar Yadav
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Ravindra
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Sergei V Shubin
- College of Science, Swansea University, Singleton Park, Swansea SA2 8PP, United Kingdom
| | - Kenton L Morgan
- The Institute of Veterinary Science, University of Liverpool, Leahurst Campus, Neston, CH64 7TE, Liverpool, United Kingdom
| | - Vindhya Mohindra
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Chris Hauton
- School of Ocean and Earth Science, University of Southampton, Waterfront Campus, European Way, Southampton, SO14 3ZH, United Kingdom
| | - Pieter van West
- International Centre for Aquaculture Research and Development, University of Aberdeen, Institute of Medical Sciences, Foresterhill, Aberdeen AB25 2ZD, Scotland, United Kingdom
| | - P K Pradhan
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India
| | - Neeraj Sood
- ICAR-National Bureau of Fish Genetic Resources, Canal Ring Road, P.O. Dilkusha, Lucknow 226 002, Uttar Pradesh, India.
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Beziau A, Brand D, Piver E. The Role of Phosphatidylinositol Phosphate Kinases during Viral Infection. Viruses 2020; 12:v12101124. [PMID: 33022924 PMCID: PMC7599803 DOI: 10.3390/v12101124] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 09/27/2020] [Accepted: 09/29/2020] [Indexed: 12/11/2022] Open
Abstract
Phosphoinositides account for only a small proportion of cellular phospholipids, but have long been known to play an important role in diverse cellular processes, such as cell signaling, the establishment of organelle identity, and the regulation of cytoskeleton and membrane dynamics. As expected, given their pleiotropic regulatory functions, they have key functions in viral replication. The spatial restriction and steady-state levels of each phosphoinositide depend primarily on the concerted action of specific phosphoinositide kinases and phosphatases. This review focuses on a number of remarkable examples of viral strategies involving phosphoinositide kinases to ensure effective viral replication.
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Affiliation(s)
- Anne Beziau
- INSERM U1259, University of Tours, 37000 Tours, France
| | - Denys Brand
- INSERM U1259, University of Tours, 37000 Tours, France
- Virology Laboratory, Tours University Hospital, 3700 Tours, France
| | - Eric Piver
- INSERM U1259, University of Tours, 37000 Tours, France
- Biochemistry and Molecular Biology, Tours University Hospital, 3700 Tours, France
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14
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Nguyen TTN, Koerdt SN, Gerke V. Plasma membrane phosphatidylinositol (4,5)-bisphosphate promotes Weibel-Palade body exocytosis. Life Sci Alliance 2020; 3:3/11/e202000788. [PMID: 32826291 PMCID: PMC7442956 DOI: 10.26508/lsa.202000788] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/14/2020] [Accepted: 08/14/2020] [Indexed: 01/26/2023] Open
Abstract
Phosphatidylinositol (4,5)-bisphosphate transiently accumulates at sites of Weibel–Palade body–plasma membrane fusion and promotes agonist-evoked exocytosis of endothelial von-Willebrand factor. Weibel–Palade bodies (WPB) are specialized secretory organelles of endothelial cells that control vascular hemostasis by regulated, Ca2+-dependent exocytosis of the coagulation-promoting von-Willebrand factor. Some proteins of the WPB docking and fusion machinery have been identified but a role of membrane lipids in regulated WPB exocytosis has so far remained elusive. We show here that the plasma membrane phospholipid composition affects Ca2+-dependent WPB exocytosis and von-Willebrand factor release. Phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] becomes enriched at WPB–plasma membrane contact sites at the time of fusion, most likely downstream of phospholipase D1-mediated production of phosphatidic acid (PA) that activates phosphatidylinositol 4-phosphate (PI4P) 5-kinase γ. Depletion of plasma membrane PI(4,5)P2 or down-regulation of PI4P 5-kinase γ interferes with histamine-evoked and Ca2+-dependent WPB exocytosis and a mutant PI4P 5-kinase γ incapable of binding PA affects WPB exocytosis in a dominant-negative manner. This indicates that a unique PI(4,5)P2-rich environment in the plasma membrane governs WPB fusion possibly by providing interaction sites for WPB-associated docking factors.
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Affiliation(s)
- Tu Thi Ngoc Nguyen
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Sophia N Koerdt
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
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15
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Wu PF, Bhore N, Lee YL, Chou JY, Chen YW, Wu PY, Hsu WM, Lee H, Huang YS, Lu PJ, Liao YF. Phosphatidylinositol-4-phosphate 5-kinase type 1α attenuates Aβ production by promoting non-amyloidogenic processing of amyloid precursor protein. FASEB J 2020; 34:12127-12146. [PMID: 32686865 DOI: 10.1096/fj.202000113r] [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: 01/15/2020] [Revised: 06/17/2020] [Accepted: 06/29/2020] [Indexed: 11/11/2022]
Abstract
Alzheimer's disease (AD) is characterized by a chronic decline in cognitive function and is pathologically typified by cerebral deposition of amyloid-β peptide (Aβ). The production of Aβ is mediated by sequential proteolysis of amyloid precursor protein (APP) by β- and γ-secretases, and has been implicated as the essential determinant of AD pathology. Previous studies have demonstrated that the level of phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] in the membrane may potentially modulate Aβ production. Given that PI(4,5)P2 is produced by type 1 phosphatidylinositol-4-phosphate 5-kinases (PIP5Ks), we sought to determine whether the level of PIP5K type Iα (PIP5K1A) can affect production of Aβ by modulating the lipid composition of the membrane. Using a HEK-derived cell line that constitutively expresses yellow fluorescent protein-tagged APP (APP-YFP), we demonstrated that overexpression of PIP5K1A results in significant enhancement of non-amyloidogenic APP processing and a concomitant suppression of the amyloidogenic pathway, leading to a marked decrease in secreted Aβ. Consistently, cells overexpressing PIP5K1A exhibited a significant redistribution of APP-YFP from endosomal compartments to the cell surface. Our findings suggest that PIP5K1A may play a critical role in governing Aβ production by modulating membrane distribution of APP, and as such, the pathway may be a valuable therapeutic target for AD.
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Affiliation(s)
- Po-Fan Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.,TIGP in Interdisciplinary Neuroscience, National Cheng Kung University and Academia Sinica, Taipei, Taiwan
| | - Noopur Bhore
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.,TIGP in Interdisciplinary Neuroscience, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
| | - Yen-Lurk Lee
- TIGP in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ju-Yun Chou
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Yun-Wen Chen
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Pei-Yi Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Wen-Ming Hsu
- Department of Surgery, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Hsinyu Lee
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Yi-Shuian Huang
- TIGP in Interdisciplinary Neuroscience, National Cheng Kung University and Academia Sinica, Taipei, Taiwan.,TIGP in Interdisciplinary Neuroscience, National Yang-Ming University and Academia Sinica, Taipei, Taiwan.,TIGP in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Pei-Jung Lu
- TIGP in Interdisciplinary Neuroscience, National Cheng Kung University and Academia Sinica, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yung-Feng Liao
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.,TIGP in Interdisciplinary Neuroscience, National Cheng Kung University and Academia Sinica, Taipei, Taiwan.,TIGP in Interdisciplinary Neuroscience, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
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16
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Pimm ML, Hotaling J, Henty-Ridilla JL. Profilin choreographs actin and microtubules in cells and cancer. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 355:155-204. [PMID: 32859370 PMCID: PMC7461721 DOI: 10.1016/bs.ircmb.2020.05.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Actin and microtubules play essential roles in aberrant cell processes that define and converge in cancer including: signaling, morphology, motility, and division. Actin and microtubules do not directly interact, however shared regulators coordinate these polymers. While many of the individual proteins important for regulating and choreographing actin and microtubule behaviors have been identified, the way these molecules collaborate or fail in normal or disease contexts is not fully understood. Decades of research focus on Profilin as a signaling molecule, lipid-binding protein, and canonical regulator of actin assembly. Recent reports demonstrate that Profilin also regulates microtubule dynamics and polymerization. Thus, Profilin can coordinate both actin and microtubule polymer systems. Here we reconsider the biochemical and cellular roles for Profilin with a focus on the essential cytoskeletal-based cell processes that go awry in cancer. We also explore how the use of model organisms has helped to elucidate mechanisms that underlie the regulatory essence of Profilin in vivo and in the context of disease.
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Affiliation(s)
- Morgan L Pimm
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States
| | - Jessica Hotaling
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States
| | - Jessica L Henty-Ridilla
- Department of Cell and Developmental Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States; Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY, United States.
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17
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Walpole GFW, Grinstein S. Endocytosis and the internalization of pathogenic organisms: focus on phosphoinositides. F1000Res 2020; 9. [PMID: 32494357 PMCID: PMC7233180 DOI: 10.12688/f1000research.22393.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/07/2020] [Indexed: 12/18/2022] Open
Abstract
Despite their comparatively low abundance in biological membranes, phosphoinositides are key to the regulation of a diverse array of signaling pathways and direct membrane traffic. The role of phosphoinositides in the initiation and progression of endocytic pathways has been studied in considerable depth. Recent advances have revealed that distinct phosphoinositide species feature prominently in clathrin-dependent and -independent endocytosis as well as in phagocytosis and macropinocytosis. Moreover, a variety of intracellular and cell-associated pathogens have developed strategies to commandeer host cell phosphoinositide metabolism to gain entry and/or metabolic advantage, thereby promoting their survival and proliferation. Here, we briefly survey the current knowledge on the involvement of phosphoinositides in endocytosis, phagocytosis, and macropinocytosis and highlight several examples of molecular mimicry employed by pathogens to either “hitch a ride” on endocytic pathways endogenous to the host or create an entry path of their own.
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Affiliation(s)
- Glenn F W Walpole
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, ON, Canada
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18
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Abstract
Phagocytosis is a pivotal immunological process, and its discovery by Elia Metchnikoff in 1882 was a step toward the establishment of the innate immune system as a separate branch of immunology. Elia Metchnikoff received the Nobel Prize in physiology and medicine for this discovery in 1908. Since its discovery almost 140 years before, phagocytosis remains the hot topic of research in immunology. The phagocytosis research has seen a great advancement since its first discovery. Functionally, phagocytosis is a simple immunological process required to engulf and remove pathogens, dead cells and tumor cells to maintain the immune homeostasis. However, mechanistically, it is a very complex process involving different mechanisms, induced and regulated by several pattern recognition receptors, soluble pattern recognition molecules, scavenger receptors (SRs) and opsonins. These mechanisms involve the formation of phagosomes, their maturation into phagolysosomes causing pathogen destruction or antigen synthesis to present them to major histocompatibility complex molecules for activating an adaptive immune response. Any defect in this mechanism may predispose the host to certain infections and inflammatory diseases (autoinflammatory and autoimmune diseases) along with immunodeficiency. The article is designed to discuss its mechanistic complexity at each level, varying from phagocytosis induction to phagolysosome resolution.
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Affiliation(s)
- Vijay Kumar
- Faculty of Medicine, Children's Health Queensland Clinical Unit, School of Clinical Medicine, Mater Research, University of Queensland, ST Lucia, Brisbane, Queensland, Australia.,Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, Brisbane, Queensland, Australia
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19
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The Role of Membrane Surface Charge in Phagocytosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1246:43-54. [DOI: 10.1007/978-3-030-40406-2_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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20
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Sharma S, Agarwal S, Bharadwaj R, Somlata, Bhattacharya S, Bhattacharya A. Novel regulatory roles of PtdIns(4,5)P2generating enzyme EhPIPKI in actin dynamics and phagocytosis ofEntamoeba histolytica. Cell Microbiol 2019; 21:e13087. [DOI: 10.1111/cmi.13087] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 07/03/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Shalini Sharma
- School of Life SciencesJawaharlal Nehru University New Delhi India
| | - Shalini Agarwal
- School of Life SciencesJawaharlal Nehru University New Delhi India
| | - Ravi Bharadwaj
- School of MedicineUMASS Medical School Worcester Massachusetts USA
| | - Somlata
- Multidisciplinary Centre for Advance Research and StudiesJamia Milia Islamia New Delhi India
| | - Sudha Bhattacharya
- School of Environmental SciencesJawaharlal Nehru University New Delhi India
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21
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The Small GTPase Arf6: An Overview of Its Mechanisms of Action and of Its Role in Host⁻Pathogen Interactions and Innate Immunity. Int J Mol Sci 2019; 20:ijms20092209. [PMID: 31060328 PMCID: PMC6539230 DOI: 10.3390/ijms20092209] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/26/2019] [Accepted: 04/27/2019] [Indexed: 12/15/2022] Open
Abstract
The small GTase Arf6 has several important functions in intracellular vesicular trafficking and regulates the recycling of different types of cargo internalized via clathrin-dependent or -independent endocytosis. It activates the lipid modifying enzymes PIP 5-kinase and phospholipase D, promotes actin polymerization, and affects several functionally distinct processes in the cell. Arf6 is used for the phagocytosis of pathogens and can be directly or indirectly targeted by various pathogens to block phagocytosis or induce the uptake of intracellular pathogens. Arf6 is also used in the signaling of Toll-like receptors and in the activation of NADPH oxidases. In this review, we first give an overview of the different roles and mechanisms of action of Arf6 and then focus on its role in innate immunity and host–pathogen interactions.
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García-Fojeda B, González-Carnicero Z, de Lorenzo A, Minutti CM, de Tapia L, Euba B, Iglesias-Ceacero A, Castillo-Lluva S, Garmendia J, Casals C. Lung Surfactant Lipids Provide Immune Protection Against Haemophilus influenzae Respiratory Infection. Front Immunol 2019; 10:458. [PMID: 30936871 PMCID: PMC6431623 DOI: 10.3389/fimmu.2019.00458] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2018] [Accepted: 02/20/2019] [Indexed: 12/14/2022] Open
Abstract
Non-typeable Haemophilus influenzae (NTHi) causes persistent respiratory infections in patients with chronic obstructive pulmonary disease (COPD), probably linked to its capacity to invade and reside within pneumocytes. In the alveolar fluid, NTHi is in contact with pulmonary surfactant, a lipoprotein complex that protects the lung against alveolar collapse and constitutes the front line of defense against inhaled pathogens and toxins. Decreased levels of surfactant phospholipids have been reported in smokers and patients with COPD. The objective of this study was to investigate the effect of surfactant phospholipids on the host-pathogen interaction between NTHi and pneumocytes. For this purpose, we used two types of surfactant lipid vesicles present in the alveolar fluid: (i) multilamellar vesicles (MLVs, > 1 μm diameter), which constitute the tensioactive material of surfactant, and (ii) small unilamellar vesicles (SUVs, 0.1 μm diameter), which are generated after inspiration/expiration cycles, and are endocytosed by pneumocytes for their degradation and/or recycling. Results indicated that extracellular pulmonary surfactant binds to NTHi, preventing NTHi self-aggregation and inhibiting adhesion of NTHi to pneumocytes and, consequently, inhibiting NTHi invasion. In contrast, endocytosed surfactant lipids, mainly via the scavenger receptor SR-BI, did not affect NTHi adhesion but inhibited NTHi invasion by blocking bacterial uptake in pneumocytes. This blockade was made possible by inhibiting Akt phosphorylation and Rac1 GTPase activation, which are signaling pathways involved in NTHi internalization. Administration of the hydrophobic fraction of lung surfactant in vivo accelerated bacterial clearance in a mouse model of NTHi pulmonary infection, supporting the notion that the lipid component of lung surfactant protects against NTHi infection. These results suggest that alterations in surfactant lipid levels in COPD patients may increase susceptibility to infection by this pathogen.
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Affiliation(s)
- Belén García-Fojeda
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Zoe González-Carnicero
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, Madrid, Spain
| | - Alba de Lorenzo
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, Madrid, Spain
| | - Carlos M Minutti
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
| | - Lidia de Tapia
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, Madrid, Spain
| | - Begoña Euba
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.,Instituto de Agrobiotecnología, Mutilva, Spain
| | - Alba Iglesias-Ceacero
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, Madrid, Spain
| | - Sonia Castillo-Lluva
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, Madrid, Spain
| | - Junkal Garmendia
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain.,Instituto de Agrobiotecnología, Mutilva, Spain
| | - Cristina Casals
- Department of Biochemistry and Molecular Biology I, Complutense University of Madrid, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain
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23
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Freemerman AJ, Zhao L, Pingili AK, Teng B, Cozzo AJ, Fuller AM, Johnson AR, Milner JJ, Lim MF, Galanko JA, Beck MA, Bear JE, Rotty JD, Bezavada L, Smallwood HS, Puchowicz MA, Liu J, Locasale JW, Lee DP, Bennett BJ, Abel ED, Rathmell JC, Makowski L. Myeloid Slc2a1-Deficient Murine Model Revealed Macrophage Activation and Metabolic Phenotype Are Fueled by GLUT1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2019; 202:1265-1286. [PMID: 30659108 PMCID: PMC6360258 DOI: 10.4049/jimmunol.1800002] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 12/03/2018] [Indexed: 12/15/2022]
Abstract
Macrophages (MΦs) are heterogeneous and metabolically flexible, with metabolism strongly affecting immune activation. A classic response to proinflammatory activation is increased flux through glycolysis with a downregulation of oxidative metabolism, whereas alternative activation is primarily oxidative, which begs the question of whether targeting glucose metabolism is a viable approach to control MΦ activation. We created a murine model of myeloid-specific glucose transporter GLUT1 (Slc2a1) deletion. Bone marrow-derived MΦs (BMDM) from Slc2a1M-/- mice failed to uptake glucose and demonstrated reduced glycolysis and pentose phosphate pathway activity. Activated BMDMs displayed elevated metabolism of oleate and glutamine, yet maximal respiratory capacity was blunted in MΦ lacking GLUT1, demonstrating an incomplete metabolic reprogramming. Slc2a1M-/- BMDMs displayed a mixed inflammatory phenotype with reductions of the classically activated pro- and anti-inflammatory markers, yet less oxidative stress. Slc2a1M-/- BMDMs had reduced proinflammatory metabolites, whereas metabolites indicative of alternative activation-such as ornithine and polyamines-were greatly elevated in the absence of GLUT1. Adipose tissue MΦs of lean Slc2a1M-/- mice had increased alternative M2-like activation marker mannose receptor CD206, yet lack of GLUT1 was not a critical mediator in the development of obesity-associated metabolic dysregulation. However, Ldlr-/- mice lacking myeloid GLUT1 developed unstable atherosclerotic lesions. Defective phagocytic capacity in Slc2a1M-/- BMDMs may have contributed to unstable atheroma formation. Together, our findings suggest that although lack of GLUT1 blunted glycolysis and the pentose phosphate pathway, MΦ were metabolically flexible enough that inflammatory cytokine release was not dramatically regulated, yet phagocytic defects hindered MΦ function in chronic diseases.
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Affiliation(s)
- Alex J. Freemerman
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 25799
| | - Liyang Zhao
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 25799
| | - Ajeeth K. Pingili
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Bin Teng
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Alyssa J. Cozzo
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 25799
| | - Ashley M. Fuller
- Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Amy R. Johnson
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 25799
| | - J. Justin Milner
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 25799
| | - Maili F. Lim
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 25799
| | - Joseph A. Galanko
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Melinda A. Beck
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 25799
| | - James E. Bear
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Jeremy D. Rotty
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Lavanya Bezavada
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Heather S. Smallwood
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Michelle A. Puchowicz
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Juan Liu
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Duke University, Durham, NC 27710
| | - Jason W. Locasale
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Duke University, Durham, NC 27710
| | | | - Brian J. Bennett
- U.S. Department of Agriculture Western Human Nutrition Research Center, Davis, CA 95616
| | - E. Dale Abel
- Division of Endocrinology and Metabolism, University of Iowa Carver College of Medicine, Iowa City, IA 52242;,Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA 52242; and
| | - Jeff C. Rathmell
- Department of Pathology, Microbiology, and Immunology, Vanderbilt Center for Immunobiology, Vanderbilt University, Nashville, TN 37232
| | - Liza Makowski
- Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 25799; .,Department of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163
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Jouette J, Guichet A, Claret SB. Dynein-mediated transport and membrane trafficking control PAR3 polarised distribution. eLife 2019; 8:40212. [PMID: 30672465 PMCID: PMC6358217 DOI: 10.7554/elife.40212] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 01/03/2019] [Indexed: 12/14/2022] Open
Abstract
The scaffold protein PAR3 and the kinase PAR1 are essential proteins that control cell polarity. Their precise opposite localisations define plasma membrane domains with specific functions. PAR3 and PAR1 are mutually inhibited by direct or indirect phosphorylations, but their fates once phosphorylated are poorly known. Through precise spatiotemporal quantification of PAR3 localisation in the Drosophila oocyte, we identify several mechanisms responsible for its anterior cortex accumulation and its posterior exclusion. We show that PAR3 posterior plasma membrane exclusion depends on PAR1 and an endocytic mechanism relying on RAB5 and PI(4,5)P2. In a second phase, microtubules and the dynein motor, in connection with vesicular trafficking involving RAB11 and IKK-related kinase, IKKε, are required for PAR3 transport towards the anterior cortex. Altogether, our results point to a connection between membrane trafficking and dynein-mediated transport to sustain PAR3 asymmetry.
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Affiliation(s)
- Julie Jouette
- Institut Jacques Monod, CNRS, UMR 7592, Paris Diderot University, Sorbonne Paris Cité, Paris, France
| | - Antoine Guichet
- Institut Jacques Monod, CNRS, UMR 7592, Paris Diderot University, Sorbonne Paris Cité, Paris, France
| | - Sandra B Claret
- Institut Jacques Monod, CNRS, UMR 7592, Paris Diderot University, Sorbonne Paris Cité, Paris, France
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Morioka S, Nigorikawa K, Okada E, Tanaka Y, Kasuu Y, Yamada M, Kofuji S, Takasuga S, Nakanishi H, Sasaki T, Hazeki K. TMEM55a localizes to macrophage phagosomes to downregulate phagocytosis. J Cell Sci 2018; 131:jcs.213272. [PMID: 29378918 DOI: 10.1242/jcs.213272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/22/2018] [Indexed: 01/29/2023] Open
Abstract
TMEM55a (also known as PIP4P2) is an enzyme that dephosphorylates the phosphatidylinositol (PtdIns) PtdIns(4,5)P2 to form PtdIns(5)P in vitro However, the in vivo conversion of the polyphosphoinositide into PtdIns(5)P by the phosphatase has not yet been demonstrated, and the role of TMEM55a remains poorly understood. Here, we found that mouse macrophages (Raw264.7) deficient in TMEM55a showed an increased engulfment of large particles without affecting the phagocytosis of Escherichia coli Transfection of a bacterial phosphatase with similar substrate specificity to TMEM55a, namely IpgD, into Raw264.7 cells inhibited the engulfment of IgG-erythrocytes in a manner dependent on its phosphatase activity. In contrast, cells transfected with PIP4K2a, which catalyzes PtdIns(4,5)P2 production from PtdIns(5)P, increased phagocytosis. Fluorescent TMEM55a transfected into Raw264.7 cells was found to mostly localize to the phagosome. The accumulation of PtdIns(4,5)P2, PtdIns(3,4,5)P3 and F-actin on the phagocytic cup was increased in TMEM55a-deficient cells, as monitored by live-cell imaging. Phagosomal PtdIns(5)P was decreased in the knockdown cells, but the augmentation of phagocytosis in these cells was unaffected by the exogenous addition of PtdIns(5)P. Taken together, these results suggest that TMEM55a negatively regulates the phagocytosis of large particles by reducing phagosomal PtdIns(4,5)P2 accumulation during cup formation.
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Affiliation(s)
- Shin Morioka
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Kiyomi Nigorikawa
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Eri Okada
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Yoshimasa Tanaka
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Yoshihiro Kasuu
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Miho Yamada
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Satoshi Kofuji
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
| | - Shunsuke Takasuga
- Department of Pathology and Immunology, Akita University School of Medicine, Akita 010-8543, Japan
| | - Hiroki Nakanishi
- Research Center for Biosignal, Akita University School of Medicine, Akita 010-8543, Japan
| | - Takehiko Sasaki
- Department of Pathology and Immunology, Akita University School of Medicine, Akita 010-8543, Japan
| | - Kaoru Hazeki
- Graduate School of Biomedical & Health Sciences, Hiroshima University, Hiroshima 734-8553, Japan
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26
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Lee S, Cheung-See-Kit M, Williams TA, Yamout N, Zufferey R. The glycosomal alkyl-dihydroxyacetonephosphate synthase TbADS is essential for the synthesis of ether glycerophospholipids in procyclic trypanosomes. Exp Parasitol 2018; 185:71-78. [PMID: 29355496 DOI: 10.1016/j.exppara.2018.01.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 12/30/2017] [Accepted: 01/14/2018] [Indexed: 01/15/2023]
Abstract
Glycerophospholipids are the main constituents of the biological membranes in Trypanosoma brucei, which causes sleeping sickness in humans. The present work reports the characterization of the alkyl-dihydroxyacetonephosphate synthase TbADS that catalyzes the committed step in ether glycerophospholipid biosynthesis. TbADS localizes to the glycosomal lumen. TbADS complemented a null mutant of Leishmania major lacking alkyl-dihydroxyacetonephosphate synthase activity and restored the formation of normal form of the ether lipid based virulence factor lipophosphoglycan. Despite lacking alkyl-dihydroxyacetonephosphate synthase activity, a null mutant of TbADS in procyclic trypanosomes remained viable and exhibited normal growth. Comprehensive analysis of cellular glycerophospholipids showed that TbADS was involved in the biosynthesis of all ether glycerophospholipid species, primarily found in the PE and PC classes.
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Affiliation(s)
- Sungsu Lee
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Melanie Cheung-See-Kit
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Tyler A Williams
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Nader Yamout
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA
| | - Rachel Zufferey
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, NY 11439, USA.
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27
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Nguyen TTN, Seo E, Choi J, Le OTT, Kim JY, Jou I, Lee SY. Phosphatidylinositol 4-phosphate 5-kinase α contributes to Toll-like receptor 2-mediated immune responses in microglial cells stimulated with lipoteichoic acid. Cell Signal 2017; 38:159-170. [DOI: 10.1016/j.cellsig.2017.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 06/21/2017] [Accepted: 07/12/2017] [Indexed: 12/11/2022]
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28
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Zufferey R, Pirani K, Cheung-See-Kit M, Lee S, Williams TA, Chen DG, Hossain MF. The Trypanosoma brucei dihydroxyacetonephosphate acyltransferase TbDAT is dispensable for normal growth but important for synthesis of ether glycerophospholipids. PLoS One 2017; 12:e0181432. [PMID: 28715456 PMCID: PMC5513551 DOI: 10.1371/journal.pone.0181432] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 06/30/2017] [Indexed: 01/28/2023] Open
Abstract
Glycerophospholipids are the most abundant constituents of biological membranes in Trypanosoma brucei, which causes sleeping sickness in humans and nagana in cattle. They are essential cellular components that fulfill various important functions beyond their structural role in biological membranes such as in signal transduction, regulation of membrane trafficking or control of cell cycle progression. Our previous studies have established that the glycerol-3-phosphate acyltransferase TbGAT is dispensable for growth, viability, and ester lipid biosynthesis suggesting the existence of another initial acyltransferase(s). This work presents the characterization of the alternative, dihydroxyacetonephosphate acyltransferase TbDAT, which acylates primarily dihydroxyacetonephosphate and prefers palmitoyl-CoA as an acyl-CoA donor. TbDAT restores the viability of a yeast double null mutant that lacks glycerol-3-phosphate and dihydroxyacetonephosphate acyltransferase activities. A conditional null mutant of TbDAT in T. brucei procyclic form was created and characterized. TbDAT was important for survival during stationary phase and synthesis of ether lipids. In contrast, TbDAT was dispensable for normal growth. Our results show that in T. brucei procyclic forms i) TbDAT but not TbGAT is the physiologically relevant initial acyltransferase and ii) ether lipid precursors are primarily made by TbDAT.
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Affiliation(s)
- Rachel Zufferey
- Department of Biochemistry, Kansas State University, Manhattan, Kansas, United States of America.,Department of Biological Sciences, St. John's University, Queens, New York, United States of America
| | - Karim Pirani
- Department of Biochemistry, Kansas State University, Manhattan, Kansas, United States of America
| | - Melanie Cheung-See-Kit
- Department of Biological Sciences, St. John's University, Queens, New York, United States of America
| | - Sungsu Lee
- Department of Biological Sciences, St. John's University, Queens, New York, United States of America
| | - Tyler A Williams
- Department of Biological Sciences, St. John's University, Queens, New York, United States of America
| | - Daniel G Chen
- Department of Biological Sciences, St. John's University, Queens, New York, United States of America
| | - Md Faruk Hossain
- Department of Biological Sciences, St. John's University, Queens, New York, United States of America
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29
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Abstract
Phagocytosis refers to the active process that allows cells to take up large particulate material upon binding to surface receptors. The discovery of phagocytosis in 1883 by Elie Metchnikoff, leading to the concept that specialized cells are implicated in the defense against microbes, was one of the starting points of the field of immunology. After more than a century of research, phagocytosis is now appreciated to be a widely used process that enables the cellular uptake of a remarkable variety of particles, including bacteria, fungi, parasites, viruses, dead cells, and assorted debris and solid materials. Uptake of foreign particles is performed almost exclusively by specialized myeloid cells, commonly termed "professional phagocytes": neutrophils, monocytes, macrophages, and dendritic cells. Phagocytosis of microbes not only stops or at least restricts the spread of infection but also plays an important role in regulating the innate and adaptive immune responses. Activation of the myeloid cells upon phagocytosis leads to the secretion of cytokines and chemokines that convey signals to a variety of immune cells. Moreover, foreign antigens generated by the degradation of microbes following phagocytosis are loaded onto the major histocompatibility complex for presentation to specific T lymphocytes. However, phagocytosis is not restricted to professional myeloid phagocytes; an expanding diversity of cell types appear capable of engulfing apoptotic bodies and debris, playing a critical role in tissue remodeling and in the clearance of billions of effete cells every day.
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30
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Zwozdesky MA, Fei C, Lillico DME, Stafford JL. Imaging flow cytometry and GST pulldown assays provide new insights into channel catfish leukocyte immune-type receptor-mediated phagocytic pathways. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 67:126-138. [PMID: 27984101 DOI: 10.1016/j.dci.2016.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/26/2016] [Accepted: 10/26/2016] [Indexed: 06/06/2023]
Abstract
Channel catfish (Ictalurus punctatus) leukocyte immune-type receptors (IpLITRs) control various innate immune cell effector responses including the phagocytic process. This large immunoregulatory receptor family also consists of multiple receptor-types with variable signaling abilities that is dependent on their inherent or acquired tyrosine-containing cytoplasmic tail (CYT) regions. For example, IpLITR 2.6b associates with the immunoreceptor tyrosine-based activation motif (ITAM)-containing adaptor molecule IpFcRγ-L, and when expressed in mammalian cells it activates phagocytosis using a similar profile of intracellular signaling mediators that also regulate the prototypical mammalian Fc receptor (FcR) phagocytic pathway. Alternatively, IpLITR 1.1b contains a long tyrosine-containing CYT with multifunctional capabilities including both inhibitory and stimulatory actions. Recently, we demonstrated that IpLITR 1.1b activates a unique phagocytic pathway involving the generation of multiple plasma membrane extensions that rapidly capture extracellular targets and secure them on the cell surface in phagocytic cup-like structures. Occasionally, these captured targets are completely engulfed albeit at a significantly lower rate than what was observed for IpLITR 2.6b. While this novel IpLITR 1.1b phagocytic activity is insensitive to classical blockers of phagocytosis, its distinct target capture and engulfment actions depend on the engagement of the actin polymerization machinery. However, it is not known how this protein translates target recognition into intracellular signaling events during this atypical mode of phagocytosis. Using imaging flow cytometry and GST pulldown assays, the aims of this study were to specifically examine what regions of the IpLITR 1.1b CYT trigger phagocytosis and to establish what profile of intracellular signaling molecules likely participate in its actions. Our results show that in stably transfected AD293 cells, the membrane proximal and distal CYT segments of IpLITR 1.1b independently regulate its phagocytic activities. These CYT regions were also shown to differentially recruit various SH2 domain-containing intracellular mediators, which provides new information about the dynamic immunoregulatory abilities of IpLITR 1.1b. Overall, this work further advances our understanding of how certain immunoregulatory receptor-types link extracellular target binding events to the actin polymerization machinery during a non-classical mode of phagocytosis.
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Affiliation(s)
- Myron A Zwozdesky
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Chenjie Fei
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Dustin M E Lillico
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - James L Stafford
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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Abstract
Phagocytosis is the cellular internalization and sequestration of particulate matter into a `phagosome, which then matures into a phagolysosome. The phagolysosome then offers a specialized acidic and hydrolytic milieu that ultimately degrades the engulfed particle. In multicellular organisms, phagocytosis and phagosome maturation play two key physiological roles. First, phagocytic cells have an important function in tissue remodeling and homeostasis by eliminating apoptotic bodies, senescent cells and cell fragments. Second, phagocytosis is a critical weapon of the immune system, whereby cells like macrophages and neutrophils hunt and engulf a variety of pathogens and foreign particles. Not surprisingly, pathogens have evolved mechanisms to either block or alter phagocytosis and phagosome maturation, ultimately usurping the cellular machinery for their own survival. Here, we review past and recent discoveries that highlight how phagocytes recognize target particles, key signals that emanate after phagocyte-particle engagement, and how these signals help modulate actin-dependent remodeling of the plasma membrane that culminates in the release of the phagosome. We then explore processes related to early and late stages of phagosome maturation, which requires fusion with endosomes and lysosomes. We end this review by acknowledging that little is known about phagosome fission and even less is known about how phagosomes are resolved after particle digestion.
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32
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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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Yeligar SM, Mehta AJ, Harris FL, Brown LAS, Hart CM. Peroxisome Proliferator-Activated Receptor γ Regulates Chronic Alcohol-Induced Alveolar Macrophage Dysfunction. Am J Respir Cell Mol Biol 2016; 55:35-46. [PMID: 26677910 PMCID: PMC4942203 DOI: 10.1165/rcmb.2015-0077oc] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 12/15/2015] [Indexed: 12/13/2022] Open
Abstract
Peroxisome proliferator-activated receptor (PPAR) γ is critical for alveolar macrophage (AM) function. Chronic alcohol abuse causes AM phagocytic dysfunction and susceptibility to respiratory infections by stimulating nicotinamide adenine dinucleotide oxidases (Nox), transforming growth factor-β1, and oxidative stress in the AM. Because PPARγ inhibits Nox expression, we hypothesized that alcohol reduces PPARγ, stimulating AM dysfunction. AMs were examined from: (1) patients with alcoholism or control patients; (2) a mouse model of chronic ethanol consumption; (3) PPARγ knockout mice; or (4) MH-S cells exposed to ethanol in vitro. Alcohol reduced AM PPARγ levels and increased Nox1, -2, and -4, transforming growth factor-β1, oxidative stress, and phagocytic dysfunction. Genetic loss of PPARγ recapitulated, whereas stimulating PPARγ activity attenuated alcohol-mediated alterations in gene expression and phagocytic function, supporting the importance of PPARγ in alcohol-induced AM derangements. Similarly, PPARγ activation in vivo reduced alcohol-mediated impairments in lung bacterial clearance. Alcohol increased levels of microRNA-130a/-301a, which bind to the PPARγ 3' untranslated region to reduce PPARγ expression. MicroRNA-130a/-301a inhibition attenuated alcohol-mediated PPARγ reductions and derangements in AM gene expression and function. Alcohol-induced Toll-like receptor 4 endocytosis was reversed by PPARγ activation. These findings demonstrate that targeting PPARγ provides a novel therapeutic approach for mitigating alcohol-induced AM derangements and susceptibility to lung infection.
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Affiliation(s)
- Samantha M. Yeligar
- Emory University, Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Emory and Children’s Healthcare of Atlanta Center for Developmental Lung Biology, Atlanta, Georgia
- Emory University, Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Decatur, Georgia
| | - Ashish J. Mehta
- Emory University, Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Decatur, Georgia
| | - Frank L. Harris
- Emory University, Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Emory and Children’s Healthcare of Atlanta Center for Developmental Lung Biology, Atlanta, Georgia
| | - Lou Ann S. Brown
- Emory University, Department of Pediatrics, Division of Neonatal-Perinatal Medicine, Emory and Children’s Healthcare of Atlanta Center for Developmental Lung Biology, Atlanta, Georgia
| | - C. Michael Hart
- Emory University, Department of Medicine, Division of Pulmonary, Allergy, and Critical Care Medicine, Atlanta Veterans Affairs and Emory University Medical Centers, Decatur, Georgia
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34
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Patel N, Pirani KA, Zhu T, Cheung-See-Kit M, Lee S, Chen DG, Zufferey R. The Glycerol-3-Phosphate Acyltransferase TbGAT is Dispensable for Viability and the Synthesis of Glycerolipids in Trypanosoma brucei. J Eukaryot Microbiol 2016; 63:598-609. [PMID: 26909872 DOI: 10.1111/jeu.12309] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Revised: 01/30/2016] [Accepted: 02/16/2016] [Indexed: 01/09/2023]
Abstract
Glycerolipids are the main constituents of biological membranes in Trypanosoma brucei, which causes sleeping sickness in humans. Importantly, they occur as a structural component of the glycosylphosphatidylinositol lipid anchor of the abundant cell surface glycoproteins procyclin in procyclic forms and variant surface glycoprotein in bloodstream form, that play crucial roles for the development of the parasite in the insect vector and the mammalian host, respectively. The present work reports the characterization of the glycerol-3-phosphate acyltransferase TbGAT that initiates the biosynthesis of ester glycerolipids. TbGAT restored glycerol-3-phosphate acyltransferase activity when expressed in a Leishmania major deletion strain lacking this activity and exhibited preference for medium length, unsaturated fatty acyl-CoAs. TbGAT localized to the endoplasmic reticulum membrane with its N-terminal domain facing the cytosol. Despite that a TbGAT null mutant in T. brucei procyclic forms lacked glycerol-3-phosphate acyltransferase activity, it remained viable and exhibited similar growth rate as the wild type. TbGAT was dispensable for the biosynthesis of phosphatidylcholine, phosphatidylinositol, phosphatidylserine, and GPI-anchored protein procyclin. However, the null mutant exhibited a slight decrease in phosphatidylethanolamine biosynthesis that was compensated with a modest increase in production of ether phosphatidylcholine. Our data suggest that an alternative initial acyltransferase takes over TbGAT's function in its absence.
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Affiliation(s)
- Nipul Patel
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, New York, 11439
| | - Karim A Pirani
- Department of Biochemistry, Kansas State University, Manhattan, Kansas, 66506
| | - Tongtong Zhu
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, New York, 11439
| | - Melanie Cheung-See-Kit
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, New York, 11439
| | - Sungsu Lee
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, New York, 11439
| | - Daniel G Chen
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, New York, 11439
| | - Rachel Zufferey
- Department of Biological Sciences, St John's University, 8000 Utopia Parkway, Jamaica, New York, 11439.,Department of Biochemistry, Kansas State University, Manhattan, Kansas, 66506
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Tuosto L, Capuano C, Muscolini M, Santoni A, Galandrini R. The multifaceted role of PIP2 in leukocyte biology. Cell Mol Life Sci 2015; 72:4461-74. [PMID: 26265181 PMCID: PMC11113228 DOI: 10.1007/s00018-015-2013-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/31/2015] [Accepted: 08/06/2015] [Indexed: 10/23/2022]
Abstract
Phosphatidylinositol 4,5-bisphosphate (PIP2) represents about 1 % of plasma membrane phospholipids and behaves as a pleiotropic regulator of a striking number of fundamental cellular processes. In recent years, an increasing body of literature has highlighted an essential role of PIP2 in multiple aspects of leukocyte biology. In this emerging picture, PIP2 is envisaged as a signalling intermediate itself and as a membrane-bound regulator and a scaffold of proteins with specific PIP2 binding domains. Indeed PIP2 plays a key role in several functions. These include directional migration in neutrophils, integrin-dependent adhesion in T lymphocytes, phagocytosis in macrophages, lysosomes secretion and trafficking at immune synapse in cytolytic effectors and secretory cells, calcium signals and gene transcription in B lymphocytes, natural killer cells and mast cells. The coordination of these different aspects relies on the spatio-temporal organisation of distinct PIP2 pools, generated by the main PIP2 generating enzyme, phosphatidylinositol 4-phosphate 5-kinase (PIP5K). Three different isoforms of PIP5K, named α, β and γ, and different splice variants have been described in leukocyte populations. The isoform-specific coupling of specific isoforms of PIP5K to different families of activating receptors, including integrins, Fc receptors, toll-like receptors and chemokine receptors, is starting to be reported. Furthermore, PIP2 is turned over by multiple metabolising enzymes including phospholipase C (PLC) γ and phosphatidylinositol 3-kinase (PI3K) which, along with Rho family small G proteins, is widely involved in strategic functions within the immune system. The interplay between PIP2, lipid-modifying enzymes and small G protein-regulated signals is also discussed.
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Affiliation(s)
- Loretta Tuosto
- Department of Biology and Biotechnology "Charles Darwin", Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University, Via dei Sardi 70, 00185, Rome, Italy.
| | - Cristina Capuano
- Department of Experimental Medicine, Sapienza University, Viale Regina Elena 324, 00185, Rome, Italy
| | - Michela Muscolini
- Department of Biology and Biotechnology "Charles Darwin", Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University, Via dei Sardi 70, 00185, Rome, Italy
| | - Angela Santoni
- Department of Molecular Medicine, Istituto Pasteur-Fondazione Cenci Bolognetti, Sapienza University, Viale Regina Elena 291, 00185, Rome, Italy
| | - Ricciarda Galandrini
- Department of Experimental Medicine, Sapienza University, Viale Regina Elena 324, 00185, Rome, Italy.
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Ando H, Hirose M, Gainche L, Kawaai K, Bonneau B, Ijuin T, Itoh T, Takenawa T, Mikoshiba K. IRBIT Interacts with the Catalytic Core of Phosphatidylinositol Phosphate Kinase Type Iα and IIα through Conserved Catalytic Aspartate Residues. PLoS One 2015; 10:e0141569. [PMID: 26509711 PMCID: PMC4624786 DOI: 10.1371/journal.pone.0141569] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/10/2015] [Indexed: 11/18/2022] Open
Abstract
Phosphatidylinositol phosphate kinases (PIPKs) are lipid kinases that generate phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), a critical lipid signaling molecule that regulates diverse cellular functions, including the activities of membrane channels and transporters. IRBIT (IP3R-binding protein released with inositol 1,4,5-trisphosphate) is a multifunctional protein that regulates diverse target proteins. Here, we report that IRBIT forms signaling complexes with members of the PIPK family. IRBIT bound to all PIPK isoforms in heterologous expression systems and specifically interacted with PIPK type Iα (PIPKIα) and type IIα (PIPKIIα) in mouse cerebellum. Site-directed mutagenesis revealed that two conserved catalytic aspartate residues of PIPKIα and PIPKIIα are involved in the interaction with IRBIT. Furthermore, phosphatidylinositol 4-phosphate, Mg2+, and/or ATP interfered with the interaction, suggesting that IRBIT interacts with catalytic cores of PIPKs. Mutations of phosphorylation sites in the serine-rich region of IRBIT affected the selectivity of its interaction with PIPKIα and PIPKIIα. The structural flexibility of the serine-rich region, located in the intrinsically disordered protein region, is assumed to underlie the mechanism of this interaction. Furthermore, in vitro binding experiments and immunocytochemistry suggest that IRBIT and PIPKIα interact with the Na+/HCO3− cotransporter NBCe1-B. These results suggest that IRBIT forms signaling complexes with PIPKIα and NBCe1-B, whose activity is regulated by PI(4,5)P2.
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Affiliation(s)
- Hideaki Ando
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Saitama, Japan
- * E-mail: (HA); (KM)
| | - Matsumi Hirose
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Laura Gainche
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Katsuhiro Kawaai
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Benjamin Bonneau
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Saitama, Japan
| | - Takeshi Ijuin
- Division of Biochemistry, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan
| | - Toshiki Itoh
- Biosignal Research Center, Organization of Advanced Science and Technology, Kobe University, Kobe, Hyogo, Japan
| | - Tadaomi Takenawa
- Biosignal Research Center, Organization of Advanced Science and Technology, Kobe University, Kobe, Hyogo, Japan
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Saitama, Japan
- * E-mail: (HA); (KM)
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Tafesse FG, Rashidfarrokhi A, Schmidt FI, Freinkman E, Dougan S, Dougan M, Esteban A, Maruyama T, Strijbis K, Ploegh HL. Disruption of Sphingolipid Biosynthesis Blocks Phagocytosis of Candida albicans. PLoS Pathog 2015; 11:e1005188. [PMID: 26431038 PMCID: PMC4592247 DOI: 10.1371/journal.ppat.1005188] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 09/03/2015] [Indexed: 01/08/2023] Open
Abstract
The ability of phagocytes to clear pathogens is an essential attribute of the innate immune response. The role of signaling lipid molecules such as phosphoinositides is well established, but the role of membrane sphingolipids in phagocytosis is largely unknown. Using a genetic approach and small molecule inhibitors, we show that phagocytosis of Candida albicans requires an intact sphingolipid biosynthetic pathway. Blockade of serine-palmitoyltransferase (SPT) and ceramide synthase-enzymes involved in sphingolipid biosynthesis- by myriocin and fumonisin B1, respectively, impaired phagocytosis by phagocytes. We used CRISPR/Cas9-mediated genome editing to generate Sptlc2-deficient DC2.4 dendritic cells, which lack serine palmitoyl transferase activity. Sptlc2-/- DC2.4 cells exhibited a stark defect in phagocytosis, were unable to bind fungal particles and failed to form a normal phagocytic cup to engulf C. albicans. Supplementing the growth media with GM1, the major ganglioside present at the cell surface, restored phagocytic activity of Sptlc2-/- DC2.4 cells. While overall membrane trafficking and endocytic pathways remained functional, Sptlc2-/- DC2.4 cells express reduced levels of the pattern recognition receptors Dectin-1 and TLR2 at the cell surface. Consistent with the in vitro data, compromised sphingolipid biosynthesis in mice sensitizes the animal to C. albicans infection. Sphingolipid biosynthesis is therefore critical for phagocytosis and in vivo clearance of C. albicans. The fungus Candida albicans is not only a commensal of the digestive system, but also a common cause of human opportunistic infections. Macrophages and dendritic cells can eliminate C. albicans by phagocytosis, a complex process that involves extensive membrane reorganization at the cell surface. The extent to which membrane lipids, including sphingolipids, contribute to the proper execution of phagocytosis remains largely unknown. Pharmacological blockade of sphingolipid biosynthesis by the small molecule inhibitors myriocin and fumonisin B1 impairs phagocytosis of C. albicans. DC2.4 dendritic cells genetically deficient in Sptlc2, the enzyme that catalyzes the first and rate-limiting step in the sphingolipid biosynthetic pathway, are likewise defective in phagocytosis of C. albicans. Sptlc2-/- DC2.4 cells showed reduced binding of C. albicans, but overall membrane transport and protein secretion remained functional. Sptlc2-deficient cells express reduced levels of the receptors Dectin-1 and TLR2 at the cell surface, and are unable to form a normal phagocytic cup. Exogenous addition of the major ganglioside GM1 restored phagocytic ability of Sptlc2-/- DC2.4 cells. Mice with compromised sphingolipid production upon in vivo treatment with fumonisin B1 fail to eradicate C. albicans, consistent with the in vitro results. Sphingolipids are thus essential for clearance of fungal infection through phagocytosis, and hence indispensable for the proper functioning of the innate immune system.
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Affiliation(s)
- Fikadu G. Tafesse
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
- * E-mail: ,
| | - Ali Rashidfarrokhi
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Ragon Institute of MGH, MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Florian I. Schmidt
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Elizaveta Freinkman
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Stephanie Dougan
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Michael Dougan
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Alexandre Esteban
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Takeshi Maruyama
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Karin Strijbis
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Hidde L. Ploegh
- Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
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Chakrabarti R, Sanyal S, Ghosh A, Bhar K, Das C, Siddhanta A. Phosphatidylinositol-4-phosphate 5-Kinase 1α Modulates Ribosomal RNA Gene Silencing through Its Interaction with Histone H3 Lysine 9 Trimethylation and Heterochromatin Protein HP1-α. J Biol Chem 2015; 290:20893-20903. [PMID: 26157143 DOI: 10.1074/jbc.m114.633727] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Indexed: 11/06/2022] Open
Abstract
Phosphoinositide signaling has been implicated in the regulation of numerous cellular processes including cytoskeletal dynamics, cellular motility, vesicle trafficking, and gene transcription. Studies have also shown that nuclear phosphoinositide(s) regulates processes such as mRNA export, cell cycle progression, gene transcription, and DNA repair. We have shown previously that the nuclear form of phosphatidylinositol-4-phosphate 5-kinase 1α (PIP5K), the enzyme responsible for phosphatidylinositol 4,5-bisphosphate synthesis, is modified by small ubiquitin-like modifier (SUMO)-1. In this study, we have shown that due to the site-specific Lys to Ala mutations of PIP5K at Lys-244 and Lys-490, it is unable to localize in the nucleus and nucleolus, respectively. Furthermore, by using chromatin immunoprecipitation assays, we have observed that PIP5K associates with the chromatin silencing complex constituted of H3K9me3 and heterochromatin protein 1α at multiple ribosomal DNA (rDNA) loci. These interactions followed a definite cyclical pattern of occupancy (mostly G1) and release from the rDNA loci (G1/S) throughout the cell cycle. Moreover, the immunoprecipitation results clearly demonstrate that PIP5K SUMOylated at Lys-490 interacts with components of the chromatin silencing machinery, H3K9me3 and heterochromatin protein 1α. However, PIP5K does not interact with the gene activation signature protein H3K4me3. This study, for the first time, demonstrates that PIP5K, an enzyme actively associated with lipid modification pathway, has additional roles in rDNA silencing.
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Affiliation(s)
| | - Sulagna Sanyal
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - Amit Ghosh
- Department of Biochemistry, University of Calcutta, Kolkata 700019, India and
| | - Kaushik Bhar
- Department of Biochemistry, University of Calcutta, Kolkata 700019, India and
| | - Chandrima Das
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata 700064, India.
| | - Anirban Siddhanta
- Department of Biochemistry, University of Calcutta, Kolkata 700019, India and.
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Zhao J, Li H, Fu S, Chen B, Sun W, Zhang J, Zhang J. An iTRAQ-based proteomics approach to clarify the molecular physiology of somatic embryo development in Prince Rupprecht's larch (Larix principis-rupprechtii Mayr). PLoS One 2015; 10:e0119987. [PMID: 25781987 PMCID: PMC4363690 DOI: 10.1371/journal.pone.0119987] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Accepted: 01/18/2015] [Indexed: 12/27/2022] Open
Abstract
Prince Rupprecht's larch (Larix principis-rupprechtii Mayr) is a native high-value forest tree species in North China whose clonal propagation through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. To date, research has focused on clarifying the molecular mechanism of SE, but proteomic studies are still in the early stages. In this study, isobaric tags for relative and absolute quantitation (iTRAQ) analysis was performed on three developmental stages of SE in L. principis-rupprechtii in an attempt to identify a wide range of proteins that are regulated differentially during this process. Proteins were extracted and analyzed from the pro-embryogenic mass (PEM), globular embryo (GE), and cotyledon embryo (CE) stages of embryo development. We detected 503 proteins in total and identified 96 proteins expressed differentially during different developmental stages. The identified proteins were analyzed further to provide information about their expression patterns and functions during SE. Four clusters of proteins based on shared expression profiles were generated. Functional analysis showed that proteins involved in primary metabolism, phosphorylation, and oxidation reduction were upregulated during somatic embryo development. This work provides novel insights into the process of larch embryo development in vitro and a basis for further study of the biological process and opportunities for practical application of this knowledge.
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Affiliation(s)
- Jian Zhao
- National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of State Forestry Administration, College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Hui Li
- National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of State Forestry Administration, College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Shuangbin Fu
- National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of State Forestry Administration, College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Bo Chen
- National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of State Forestry Administration, College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Wenting Sun
- National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of State Forestry Administration, College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Junqi Zhang
- National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of State Forestry Administration, College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Jinfeng Zhang
- National Engineering Laboratory for Tree Breeding, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants, Ministry of Education, The Tree and Ornamental Plant Breeding and Biotechnology Laboratory of State Forestry Administration, College of Biological Science and Biotechnology, Beijing Forestry University, Beijing 100083, China
- * E-mail:
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40
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Bryant KL, Baird B, Holowka D. A novel fluorescence-based biosynthetic trafficking method provides pharmacologic evidence that PI4-kinase IIIα is important for protein trafficking from the endoplasmic reticulum to the plasma membrane. BMC Cell Biol 2015; 16:5. [PMID: 25886792 PMCID: PMC4355129 DOI: 10.1186/s12860-015-0049-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 01/21/2015] [Indexed: 02/07/2023] Open
Abstract
Background Biosynthetic trafficking of receptors and other membrane-associated proteins from the endoplasmic reticulum (ER) to the plasma membrane (PM) underlies the capacity of these proteins to participate in crucial cellular roles. Phosphoinositides have been shown to mediate distinct biological functions in cells, and phosphatidylinositol 4-phosphate (PI4P), in particular, has emerged as a key regulator of biosynthetic trafficking. Results To investigate the source of PI4P that orchestrates trafficking events, we developed a novel flow cytometry based method to monitor biosynthetic trafficking of transiently transfected proteins. We demonstrated that our method can be used to assess the trafficking of both type-1 transmembrane and GPI-linked proteins, and that it can accurately monitor the pharmacological disruption of biosynthetic trafficking with brefeldin A, a well-documented inhibitor of early biosynthetic trafficking. Furthermore, utilizing our newly developed method, we applied pharmacological inhibition of different isoforms of PI 4-kinase to reveal a role for a distinct pool of PI4P, synthesized by PI4KIIIα, in ER-to-PM trafficking. Conclusions Taken together, these findings provide evidence that a specific pool of PI4P plays a role in biosynthetic trafficking of two different classes of proteins from the ER to the Golgi complex. Furthermore, our simple, flow cytometry-based biosynthetic trafficking assay can be widely applied to the study of multiple classes of proteins and varied pharmacological and genetic perturbations.
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Affiliation(s)
- Kirsten L Bryant
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA. .,University of North Carolina, Chapel Hill, NC, 27514, USA.
| | - Barbara Baird
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
| | - David Holowka
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
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Muscolini M, Camperio C, Porciello N, Caristi S, Capuano C, Viola A, Galandrini R, Tuosto L. Phosphatidylinositol 4–Phosphate 5–Kinase α and Vav1 Mutual Cooperation in CD28-Mediated Actin Remodeling and Signaling Functions. THE JOURNAL OF IMMUNOLOGY 2015; 194:1323-1333. [DOI: 10.4049/jimmunol.1401643] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Abstract
Phosphatidylinositol 4,5–biphosphate (PIP2) is a cell membrane phosphoinositide crucial for cell signaling and activation. Indeed, PIP2 is a pivotal source for second messenger generation and controlling the activity of several proteins regulating cytoskeleton reorganization. Despite its critical role in T cell activation, the molecular mechanisms regulating PIP2 turnover remain largely unknown. In human primary CD4+ T lymphocytes, we have recently demonstrated that CD28 costimulatory receptor is crucial for regulating PIP2 turnover by allowing the recruitment and activation of the lipid kinase phosphatidylinositol 4–phosphate 5–kinase (PIP5Kα). We also identified PIP5Kα as a key modulator of CD28 costimulatory signals leading to the efficient T cell activation. In this study, we extend these data by demonstrating that PIP5Kα recruitment and activation is essential for CD28-mediated cytoskeleton rearrangement necessary for organizing a complete signaling compartment leading to downstream signaling functions. We also identified Vav1 as the linker molecule that couples the C-terminal proline-rich motif of CD28 to the recruitment and activation of PIP5Kα, which in turn cooperates with Vav1 in regulating actin polymerization and CD28 signaling functions.
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Affiliation(s)
- Michela Muscolini
- *Department of Biology and Biotechnology “Charles Darwin,” Pasteur Institute–Cenci Bolognetti Foundation, Sapienza University, 00185 Rome, Italy
| | - Cristina Camperio
- *Department of Biology and Biotechnology “Charles Darwin,” Pasteur Institute–Cenci Bolognetti Foundation, Sapienza University, 00185 Rome, Italy
| | - Nicla Porciello
- *Department of Biology and Biotechnology “Charles Darwin,” Pasteur Institute–Cenci Bolognetti Foundation, Sapienza University, 00185 Rome, Italy
| | - Silvana Caristi
- *Department of Biology and Biotechnology “Charles Darwin,” Pasteur Institute–Cenci Bolognetti Foundation, Sapienza University, 00185 Rome, Italy
| | - Cristina Capuano
- †Department of Experimental Medicine, Sapienza University, 00185 Rome, Italy
| | - Antonella Viola
- ‡The Venetian Institute of Molecular Medicine, Padova 35129, Italy; and
- §Department of Biomedical Sciences, University of Padova, Padova 35121, Italy
| | | | - Loretta Tuosto
- *Department of Biology and Biotechnology “Charles Darwin,” Pasteur Institute–Cenci Bolognetti Foundation, Sapienza University, 00185 Rome, Italy
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Chakrabarti P, Kolay S, Yadav S, Kumari K, Nair A, Trivedi D, Raghu P. A dPIP5K dependent pool of phosphatidylinositol 4,5 bisphosphate (PIP2) is required for G-protein coupled signal transduction in Drosophila photoreceptors. PLoS Genet 2015; 11:e1004948. [PMID: 25633995 PMCID: PMC4310717 DOI: 10.1371/journal.pgen.1004948] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 12/09/2014] [Indexed: 12/02/2022] Open
Abstract
Multiple PIP2 dependent molecular processes including receptor activated phospholipase C activity occur at the neuronal plasma membranes, yet levels of this lipid at the plasma membrane are remarkably stable. Although the existence of unique pools of PIP2 supporting these events has been proposed, the mechanism by which they are generated is unclear. In Drosophila photoreceptors, the hydrolysis of PIP2 by G-protein coupled phospholipase C activity is essential for sensory transduction of photons. We identify dPIP5K as an enzyme essential for PIP2 re-synthesis in photoreceptors. Loss of dPIP5K causes profound defects in the electrical response to light and light-induced PIP2 dynamics at the photoreceptor membrane. Overexpression of dPIP5K was able to accelerate the rate of PIP2 synthesis following light induced PIP2 depletion. Other PIP2 dependent processes such as endocytosis and cytoskeletal function were unaffected in photoreceptors lacking dPIP5K function. These results provide evidence for the existence of a unique dPIP5K dependent pool of PIP2 required for normal Drosophila phototransduction. Our results define the existence of multiple pools of PIP2 in photoreceptors generated by distinct lipid kinases and supporting specific molecular processes at neuronal membranes. PIP2 has been implicated in multiple functions at the plasma membrane. Some of these require its hydrolysis by receptor-activated phospholipase C, whereas others, such as membrane transport and cytoskeletal function, involve the interaction of the intact lipid with cellular proteins. The mechanistic basis underlying the segregation of these two classes of PIP2 dependent functions is unknown; it has been postulated that this might involve unique pools of PIP2 generated by distinct phosphoinsoitide kinases. We have studied this question in Drosophila photoreceptors, a model system where sensory transduction requires robust phospholipase C mediated PIP2 hydrolysis. We find that the activity of phosphatidylinositol-4-phosphate 5 kinase encoded by dPIP5K is required to support normal sensory transduction and PIP2 dynamics in photoreceptors. Remarkably, non-PLC dependent functions of PIP2, such as vesicular transport and the actin cytoskeleton, were unaffected in dPIP5K mutants. Thus, dPIP5K supports a pool of PIP2 that is readily available to PLC, but has no role in sustaining other non-PLC mediated PIP2 dependent processes. These findings support the existence of at least two non-overlapping pools of PIP2 at the plasma membrane, and provide a platform for future studies of PIP2 regulation at the plasma membrane.
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Affiliation(s)
| | - Sourav Kolay
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bangalore, India
- Manipal University, Madhav Nagar, Manipal, Karnataka, India
| | - Shweta Yadav
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bangalore, India
| | - Kamalesh Kumari
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bangalore, India
- Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Amit Nair
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - Deepti Trivedi
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - Padinjat Raghu
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
- National Centre for Biological Sciences, TIFR-GKVK Campus, Bangalore, India
- * E-mail:
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43
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Levin R, Grinstein S, Schlam D. Phosphoinositides in phagocytosis and macropinocytosis. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:805-23. [PMID: 25238964 DOI: 10.1016/j.bbalip.2014.09.005] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/23/2014] [Accepted: 09/08/2014] [Indexed: 01/08/2023]
Abstract
Professional phagocytes provide immunoprotection and aid in the maintenance of tissue homeostasis. They perform these tasks by recognizing, engulfing and eliminating pathogens and endogenous cell debris. Here, we examine the paramount role played by phosphoinositides in phagocytosis and macropinocytosis, two major endocytic routes that mediate the uptake of particulate and fluid matter, respectively. We analyze accumulating literature describing the molecular mechanisms whereby phosphoinositides translate environmental cues into the complex, sophisticated responses that underlie the phagocytic and macropinocytic responses. In addition, we exemplify virulence strategies involving modulation of host cell phosphoinositide signaling that are employed by bacteria to undermine immunity. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- Roni Levin
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada
| | - Sergio Grinstein
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada; Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, 209 Victoria St., Toronto M5C1N8, Canada.
| | - Daniel Schlam
- Division of Cell Biology, Hospital for Sick Children, 555 University Ave., Toronto M5G1X8, Canada
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44
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Swanson JA. Phosphoinositides and engulfment. Cell Microbiol 2014; 16:1473-83. [PMID: 25073505 DOI: 10.1111/cmi.12334] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2014] [Revised: 07/17/2014] [Accepted: 07/28/2014] [Indexed: 12/24/2022]
Abstract
Cellular engulfment of particles, cells or solutes displaces large domains of plasma membrane into intracellular membranous vacuoles. This transfer of membrane is accompanied by major transitions of the phosphoinositide (PI) species that comprise the cytoplasmic face of membrane bilayers. Mapping of membrane PIs during engulfment reveals distinct patterns of protein and PI distributions associated with each stage of engulfment, which correspond with activities that regulate the actin cytoskeleton, membrane movements and vesicle secretion. Experimental manipulation of PI chemistry during engulfment indicates that PIs integrate organelle identity and orient signal transduction cascades within confined subdomains of membrane. These pathways are exploited by microbial pathogens to direct or redirect the engulfment process.
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Affiliation(s)
- Joel A Swanson
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, 48109-5620, USA
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Rougerie P, Miskolci V, Cox D. Generation of membrane structures during phagocytosis and chemotaxis of macrophages: role and regulation of the actin cytoskeleton. Immunol Rev 2014; 256:222-39. [PMID: 24117824 DOI: 10.1111/imr.12118] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Macrophages are best known for their protective search and destroy functions against invading microorganisms. These processes are commonly known as chemotaxis and phagocytosis. Both of these processes require actin cytoskeletal remodeling to produce distinct F-actin-rich membrane structures called lamellipodia and phagocytic cups. This review will focus on the mechanisms by which macrophages regulate actin polymerization through initial receptor signaling and subsequent Arp2/3 activation by nucleation-promoting factors like the WASP/WAVE family, followed by remodeling of actin networks to produce these very distinct structures.
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Affiliation(s)
- Pablo Rougerie
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY, USA
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Abstract
Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease.
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Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Cubí R, Matas LA, Pou M, Aguilera J, Gil C. Differential sensitivity to detergents of actin cytoskeleton from nerve endings. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2385-93. [PMID: 23817010 DOI: 10.1016/j.bbamem.2013.06.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/13/2013] [Accepted: 06/17/2013] [Indexed: 01/13/2023]
Abstract
Detergent-resistant membranes (DRM), an experimental model used to study lipid rafts, are typically extracted from cells by means of detergent treatment and subsequent ultracentrifugation in density gradients, Triton X-100 being the detergent of choice in most of the works. Since lipid rafts are membrane microdomains rich in cholesterol, depletion of this component causes solubilization of DRM with detergent. In previous works from our group, the lack of effect of cholesterol depletion on DRM solubilization with Triton X-100 was detected in isolated rat brain synaptosomes. In consequence, the aim of the present work is to explore reasons for this observation, analyzing the possible role of the actin cytoskeleton, as well as the use of an alternative detergent, Brij 98, to overcome the insensitivity to Triton X-100 of cholesterol-depleted DRM. Brij 98 yields Brij-DRM that are highly dependent on cholesterol, since marker proteins (Flotillin-1 and Thy-1), as well as actin, appear solubilized after MCD treatment. Pretreatment with Latrunculin A results in a significant increase in Flotillin-1, Thy-1 and actin solubilization by Triton X-100 after cholesterol depletion. Studies with transmission electron microscopy show that combined treatment with MCD and Latrunculin A leads to a significant increase in solubilization of DRM with Triton X-100. Thus, Triton-DRM resistance to cholesterol depletion can be explained, at least partially, thanks to the scaffolding action of the actin cytoskeleton, without discarding differential effects of Brij 98 and Triton X-100 on specific membrane components. In conclusion, the detergent of choice is important when events that depend on the actin cytoskeleton are going to be studied.
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Affiliation(s)
- Roger Cubí
- Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra 08193, Catalunya, Spain; Institut de Neurociències, Universitat Autònoma de Barcelona, Spain
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Learning-related synaptic growth mediated by internalization of Aplysia cell adhesion molecule is controlled by membrane phosphatidylinositol 4,5-bisphosphate synthetic pathway. J Neurosci 2013; 32:16296-305. [PMID: 23152613 DOI: 10.1523/jneurosci.1872-12.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Long-term facilitation in Aplysia is accompanied by the growth of new synaptic connections between the sensory and motor neurons of the gill-withdrawal reflex. One of the initial steps leading to the growth of these synapses is the internalization, induced by 5-HT, of the transmembrane isoform of Aplysia cell-adhesion molecule (TM-apCAM) from the plasma membrane of sensory neurons (Bailey et al., 1992). However, the mechanisms that govern the internalization of TM-apCAM and how this internalization is coupled to the molecular events that initiate the structural changes are not fully understood. Here, we report that the synthesis of membrane phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)], which is known to be mediated by a signaling cascade through Aplysia Sec7 protein (ApSec7) and phosphatidylinositol-4-phosphate 5-kinase type I α (PIP5KIα) is required for both the internalization of TM-apCAM and the initiation of synaptic growth during 5-HT-induced long-term facilitation. Pharmacological blockade of PI(4,5)P(2) synthesis by the application of the inhibitor phenylarsine oxide blocked the internalization of apCAM. Furthermore, perturbation of the endogenous activation of ApSec7 and its downstream target PIP5KIα also blocked 5-HT-mediated internalization of TM-apCAM and synaptic growth. Finally, long-term facilitation was specifically impaired by blocking the ApSec7 signaling pathway at sensory-to-motor neuron synapses. These data indicate that the ApSec7/PIP5KIα signaling pathway is actively recruited during learning-related 5-HT signaling and acts as a key regulator of apCAM internalization associated with the formation of new synaptic connections during long-term facilitation.
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Nguyen TTN, Kim YM, Kim TD, Le OTT, Kim JJ, Kang HC, Hasegawa H, Kanaho Y, Jou I, Lee SY. Phosphatidylinositol 4-phosphate 5-kinase α facilitates Toll-like receptor 4-mediated microglial inflammation through regulation of the Toll/interleukin-1 receptor domain-containing adaptor protein (TIRAP) location. J Biol Chem 2013; 288:5645-59. [PMID: 23297396 DOI: 10.1074/jbc.m112.410126] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Phosphatidylinositol (PI) 4,5-bisphosphate (PIP(2)), generated by PI 4-phosphate 5-kinase (PIP5K), regulates many critical cellular events. PIP(2) is also known to mediate plasma membrane localization of the Toll/IL-1 receptor domain-containing adaptor protein (TIRAP), required for the MyD88-dependent Toll-like receptor (TLR) 4 signaling pathway. Microglia are the primary immune competent cells in brain tissue, and TLR4 is important for microglial activation. However, a functional role for PIP5K and PIP(2) in TLR4-dependent microglial activation remains unclear. Here, we knocked down PIP5Kα, a PIP5K isoform, in a BV2 microglial cell line using stable expression of lentiviral shRNA constructs or siRNA transfection. PIP5Kα knockdown significantly suppressed induction of inflammatory mediators, including IL-6, IL-1β, and nitric oxide, by lipopolysaccharide. PIP5Kα knockdown also attenuated signaling events downstream of TLR4 activation, including p38 MAPK and JNK phosphorylation, NF-κB p65 nuclear translocation, and IκB-α degradation. Complementation of the PIP5Kα knockdown cells with wild type but not kinase-dead PIP5Kα effectively restored the LPS-mediated inflammatory response. We found that PIP5Kα and TIRAP colocalized at the cell surface and interacted with each other, whereas kinase-dead PIP5Kα rendered TIRAP soluble. Furthermore, in LPS-stimulated control cells, plasma membrane PIP(2) increased and subsequently declined, and TIRAP underwent bi-directional translocation between the membrane and cytosol, which temporally correlated with the changes in PIP(2). In contrast, PIP5Kα knockdown that reduced PIP(2) levels disrupted TIRAP membrane targeting by LPS. Together, our results suggest that PIP5Kα promotes TLR4-associated microglial inflammation by mediating PIP(2)-dependent recruitment of TIRAP to the plasma membrane.
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Affiliation(s)
- Tu Thi Ngoc Nguyen
- Chronic Inflammatory Disease Research Center, Neuroscience Graduate Program, Graduate School of Interdisciplinary Programs, Ajou University, Suwon, Gyeonggi 443-721, South Korea
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Bohdanowicz M, Grinstein S. Role of Phospholipids in Endocytosis, Phagocytosis, and Macropinocytosis. Physiol Rev 2013; 93:69-106. [DOI: 10.1152/physrev.00002.2012] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Endocytosis, phagocytosis, and macropinocytosis are fundamental processes that enable cells to sample their environment, eliminate pathogens and apoptotic bodies, and regulate the expression of surface components. While a great deal of effort has been devoted over many years to understanding the proteins involved in these processes, the important contribution of phospholipids has only recently been appreciated. This review is an attempt to collate and analyze the rapidly emerging evidence documenting the role of phospholipids in clathrin-mediated endocytosis, phagocytosis, and macropinocytosis. A primer on phospholipid biosynthesis, catabolism, subcellular distribution, and transport is presented initially, for reference, together with general considerations of the effects of phospholipids on membrane curvature and charge. This is followed by a detailed analysis of the critical functions of phospholipids in the internalization processes and in the maturation of the resulting vesicles and vacuoles as they progress along the endo-lysosomal pathway.
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Affiliation(s)
- Michal Bohdanowicz
- Division of Cell Biology, Hospital for Sick Children, and Institute of Medical Sciences, University of Toronto, Toronto, Canada
| | - Sergio Grinstein
- Division of Cell Biology, Hospital for Sick Children, and Institute of Medical Sciences, University of Toronto, Toronto, Canada
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