scholarly journals Plasma Membrane-Located Purine Nucleotide Transport Proteins Are Key Components for Host Exploitation by Microsporidian Intracellular Parasites

2014 ◽  
Vol 10 (12) ◽  
pp. e1004547 ◽  
Author(s):  
Eva Heinz ◽  
Christian Hacker ◽  
Paul Dean ◽  
John Mifsud ◽  
Alina V. Goldberg ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Transport Proteins ◽  
Purine Nucleotide ◽  
Intracellular Parasites ◽  
Host Exploitation

scholarly journals A new family of cell surface located purine transporters in Microsporidia and related fungal endoparasites

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Peter Major ◽  
Kacper M Sendra ◽  
Paul Dean ◽  
Tom A Williams ◽  
Andrew K Watson ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Functional Data ◽  
Animal Species ◽  
Transport Proteins ◽  
Intracellular Growth ◽  
Substrate Specificities ◽  
Obligate Intracellular ◽  
New Family ◽  
Intracellular Parasites

Plasma membrane-located transport proteins are key adaptations for obligate intracellular Microsporidia parasites, because they can use them to steal host metabolites the parasites need to grow and replicate. However, despite their importance, the functions and substrate specificities of most Microsporidia transporters are unknown. Here, we provide functional data for a family of transporters conserved in all microsporidian genomes and also in the genomes of related endoparasites. The universal retention among otherwise highly reduced genomes indicates an important role for these transporters for intracellular parasites. Using Trachipleistophora hominis, a Microsporidia isolated from an HIV/AIDS patient, as our experimental model, we show that the proteins are ATP and GTP transporters located on the surface of parasites during their intracellular growth and replication. Our work identifies a new route for the acquisition of essential energy and nucleotides for a major group of intracellular parasites that infect most animal species including humans.

Elementary auxin response chains at the plasma membrane involve external abp1 and multiple electrogenic ion transport proteins

1996 ◽  
Vol 18 (1-2) ◽  
pp. 23-28 ◽  
Author(s):  
H�l�ne Barbier-Brygoo ◽  
Sabine Zimmermann ◽  
S�bastien Thomine ◽  
Ian R. White ◽  
Paul Millner ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Ion Transport ◽  
Transport Proteins ◽  
Auxin Response ◽  
Electrogenic Ion Transport ◽  
Response Chains

Role of membrane trafficking in plasma membrane solute transport

1994 ◽  
Vol 267 (1) ◽  
pp. C1-C24 ◽  
Author(s):  
N. A. Bradbury ◽  
R. J. Bridges
Keyword(s):  
Plasma Membrane ◽  
Solute Transport ◽  
Membrane Trafficking ◽  
Molecular Mechanisms ◽  
Glucose Transporter ◽  
Water Channel ◽  
Transport Proteins ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Regulated Trafficking

Cells can rapidly and reversibly alter solute transport rates by changing the kinetics of transport proteins resident within the plasma membrane. Most notably, this can be brought about by reversible phosphorylation of the transporter. An additional mechanism for acute regulation of plasma membrane transport rates is by the regulated exocytic insertion of transport proteins from intracellular vesicles into the plasma membrane and their subsequent regulated endocytic retrieval. Over the past few years, the number of transporters undergoing this regulated trafficking has increased dramatically, such that what was once an interesting translocation of a few transporters has now become a widespread modality for regulating plasma membrane solute permeabilities. The aim of this article is to review the models proposed for the regulated trafficking of transport proteins and what lines of evidence should be obtained to document regulated exocytic insertion and endocytic retrieval of transport proteins. We highlight four transporters, the insulin-responsive glucose transporter, the antidiuretic hormone-responsive water channel, the urinary bladder H(+)-ATPase, and the cystic fibrosis transmembrane conductance regulator Cl- channel, and discuss the various approaches taken to document their regulated trafficking. Finally, we discuss areas of uncertainty that remain to be investigated concerning the molecular mechanisms involved in regulating the trafficking of proteins.

Use of plasma membrane vesicles

1980 ◽  
Vol 238 (3) ◽  
pp. G151-G164 ◽  
Author(s):  
G. Sachs ◽  
R. J. Jackson ◽  
E. C. Rabon
Keyword(s):  
Plasma Membrane ◽  
Membrane Vesicles ◽  
Transport Proteins ◽  
Plasma Membrane Vesicles

A summary of current methodologies employed to obtain and characterize epithelial plasma membrane vesicles is presented. Particular emphasis is placed on techniques to evaluate such parameters as homogeneity, tightness, orientation, and the percentage of active vesicles in a given vesicular population. Examples of isotopic, osmotic, and various probe techniques useful for quantitation of transport events and associated electrical phenomena are illustrated. Finally, the unique problems intrinsic to purification and reconstitution of transport proteins are briefly discussed.

scholarly journals Localization of the ATP-binding cassette (ABC) transport proteins PfMRP1, PfMRP2, and PfMDR5 at the Plasmodium falciparum plasma membrane

2009 ◽  
Vol 8 (1) ◽  
pp. 205 ◽  
Author(s):  
Reginald A Kavishe ◽  
Jeroen MW van den Heuvel ◽  
Marga van de Vegte-Bolmer ◽  
Adrian JF Luty ◽  
Frans GM Russel ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Transport Proteins ◽  
Atp Binding ◽  
Abc Transport ◽  
Atp Binding Cassette

scholarly journals Ca2+ Content and Expression of an Acidocalcisomal Calcium Pump Are Elevated in Intracellular Forms ofTrypanosoma cruzi

1998 ◽  
Vol 18 (4) ◽  
pp. 2309-2323 ◽  
Author(s):  
Hong-Gang Lu ◽  
Li Zhong ◽  
Wanderley de Souza ◽  
Marlene Benchimol ◽  
Silvia Moreno ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Ionic Composition ◽  
Calcium Content ◽  
Protein Product ◽  
Calcium Pump ◽  
Calculated Molecular Mass ◽  
Transmission Electron ◽  
Intracellular Parasites ◽  
High Calcium ◽  
Microscopy Analysis

ABSTRACT The survival of a eukaryotic protozoan as an obligate parasite in the interior of a eukaryotic host cell implies its adaptation to an environment with a very different ionic composition from that of its extracellular habitat. This is particularly important in the case of Ca2+, the intracellular concentration of which is 3 orders of magnitude lower than the extracellular value. Ca2+entry across the plasma membrane is a widely recognized mechanism for Ca2+ signaling, needed for a number of intracellular processes, and obviously, it would be restricted in the case of intracellular parasites. Here we show that Trypanosoma cruzi amastigotes possess a higher Ca2+ content than the extracellular stages of the parasite. This correlates with the higher expression of a calcium pump, the gene for which was cloned and sequenced. The deduced protein product (Tca1) of this gene has a calculated molecular mass of 121,141 Da and exhibits 34 to 38% identity with vacuolar Ca2+-ATPases of Saccharomyces cerevisiae and Dictyostelium discoideum, respectively. The tca1 gene suppresses the Ca2+hypersensitivity of a mutant of S. cerevisiae that has a defect in vacuolar Ca2+ accumulation. Indirect immunofluorescence and immunoelectron microscopy analysis indicate that Tca1 colocalizes with the vacuolar H+-ATPase to the plasma membrane and to intracellular vacuoles of T. cruzi. These vacuoles were shown to have the same size and distribution as the calcium-containing vacuoles identified by the potassium pyroantimoniate-osmium technique and as the electron-dense vacuoles observed in whole unfixed parasites by transmission electron microscopy and identified in a previous work (D. A. Scott, R. Docampo, J. A. Dvorak, S. Shi, and R. D. Leapman, J. Biol. Chem. 272:28020–28029, 1997) as being acidic and possessing a high calcium content (i.e., acidocalcisomes). Together, these results suggest that acidocalcisomes are distinct from other previously recognized organelles present in these parasites and underscore the ability of intracellular parasites to adapt to the hostile environment of their hosts.

Topography of the 27-and 31-kDa Electron Transport Proteins in the Onion Root Plasma Membrane

1995 ◽  
Vol 216 (3) ◽  
pp. 1054-1059 ◽  
Author(s):  
M.C. Cordoba ◽  
A. Serrano ◽  
F. Cordoba ◽  
J.A. Gonzalezreyes ◽  
P. Navas ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Electron Transport ◽  
Transport Proteins ◽  
Onion Root ◽  
Electron Transport Proteins ◽  
Root Plasma Membrane

scholarly journals The Molecular Mechanism of Hepcidin-mediated Ferroportin Down-Regulation

2007 ◽  
Vol 18 (7) ◽  
pp. 2569-2578 ◽  
Author(s):  
Ivana De Domenico ◽  
Diane McVey Ward ◽  
Charles Langelier ◽  
Michael B. Vaughn ◽  
Elizabeta Nemeth ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Molecular Mechanism ◽  
Small Interfering Rna ◽  
Multivesicular Body ◽  
Transport Proteins ◽  
Late Endosome ◽  
Phosphorylation Sites ◽  
Down Regulation ◽  
Green Fluorescent ◽  
Interfering Rna

Ferroportin (Fpn) is the only known iron exporter in vertebrates. Hepcidin, a peptide secreted by the liver in response to iron or inflammation, binds to Fpn, inducing its internalization and degradation. We show that after binding of hepcidin, Fpn is tyrosine phosphorylated at the plasma membrane. Mutants of human Fpn that do not get internalized or that are internalized slowly show either absent or impaired phosphorylation. We identify adjacent tyrosines as the phosphorylation sites and show that mutation of both tyrosines prevents hepcidin-mediated Fpn internalization. Once internalized, Fpn is dephosphorylated and subsequently ubiquitinated. An inability to ubiquitinate Fpn does not prevent hepcidin-induced internalization, but it inhibits the degradation of Fpn. Ubiquitinated Fpn is trafficked through the multivesicular body pathway en route to degradation in the late endosome/lysosome. Depletion of proteins involved in multivesicular body trafficking (Endosome Sorting Complex Required for Transport proteins), by small-interfering RNA, reduces the trafficking of Fpn-green fluorescent to the lysosome.

Antigen recognition induces phosphatidylserine exposure on the cell surface of human CD8+ T cells

Blood ◽  
2006 ◽  
Vol 108 (13) ◽  
pp. 4094-4101 ◽  
Author(s):  
Karin Fischer ◽  
Simon Voelkl ◽  
Jana Berger ◽  
Reinhard Andreesen ◽  
Thomas Pomorski ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Microscopic Analysis ◽  
Annexin V ◽  
Membrane Lipid ◽  
Transport Proteins ◽  
Cell Contact ◽  
Immunologic Synapse

Abstract In eukaryotic cells the phospholipid phosphatidylserine (PS) is restricted to the inner plasma-membrane leaflet. This lipid asymmetry, which is maintained by the concerted action of phospholipid transport proteins, is mainly lost during apoptosis. Here, we demonstrate that primary human CD8+ cytotoxic T lymphocytes (CTLs) expose PS on T-cell receptor (TCR)–mediated antigen (Ag) recognition. In contrast to PS externalization on apoptotic cells, activation-induced PS exposure is less pronounced and reversible. Fluorescence microscopic analysis revealed that PS is distributed nonhomogenously over the plasma membrane and concentrated in membrane lipid raft domains at the immunologic synapse. By studying the activity of PS transport proteins using a fluorescence-labeled PS analogue, we found that activation of CTLs inhibited the flippase-mediated inward-directed PS transport without affecting the outward transport. Shielding of exposed PS by annexin V protein during Ag recognition diminished cytokine secretion, activation, and cell-to-cell clustering of Ag-specific CTLs. In summary, our data demonstrate for the first time that externalized PS on Ag-stimulated CTLs is linked to T-cell activation and probably involved in cell-to-cell contact formation at the immunologic synapse.

scholarly journals Oligomerization of the Mg2+-transport proteins Alr1p and Alr2p in yeast plasma membrane

FEBS Journal ◽  
2006 ◽  
Vol 273 (18) ◽  
pp. 4236-4249 ◽  
Author(s):  
Marcin Wachek ◽  
Michael C. Aichinger ◽  
Jochen A. Stadler ◽  
Rudolf J. Schweyen ◽  
Anton Graschopf
Keyword(s):  
Plasma Membrane ◽  
Transport Proteins ◽  
Yeast Plasma Membrane
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