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Nature Structural & Molecular Biology Jul 2022The stability and shape of the erythrocyte membrane is provided by the ankyrin-1 complex, but how it tethers the spectrin-actin cytoskeleton to the lipid bilayer and the...
The stability and shape of the erythrocyte membrane is provided by the ankyrin-1 complex, but how it tethers the spectrin-actin cytoskeleton to the lipid bilayer and the nature of its association with the band 3 anion exchanger and the Rhesus glycoproteins remains unknown. Here we present structures of ankyrin-1 complexes purified from human erythrocytes. We reveal the architecture of a core complex of ankyrin-1, the Rhesus proteins RhAG and RhCE, the band 3 anion exchanger, protein 4.2, glycophorin A and glycophorin B. The distinct T-shaped conformation of membrane-bound ankyrin-1 facilitates recognition of RhCE and, unexpectedly, the water channel aquaporin-1. Together, our results uncover the molecular details of ankyrin-1 association with the erythrocyte membrane, and illustrate the mechanism of ankyrin-mediated membrane protein clustering.
Topics: Anion Exchange Protein 1, Erythrocyte; Ankyrins; Cytoskeletal Proteins; Erythrocyte Membrane; Erythrocytes; Humans; Spectrin
PubMed: 35835865
DOI: 10.1038/s41594-022-00792-w -
Biomolecules Jul 2020Red blood cell (RBC) deformability is altered in inherited RBC disorders but the mechanism behind this is poorly understood. Here, we explored the molecular,...
Red blood cell (RBC) deformability is altered in inherited RBC disorders but the mechanism behind this is poorly understood. Here, we explored the molecular, biophysical, morphological, and functional consequences of α-spectrin mutations in a patient with hereditary elliptocytosis (pEl) almost exclusively expressing the Pro260 variant of SPTA1 and her mother (pElm), heterozygous for this mutation. At the molecular level, the pEI RBC proteome was globally preserved but spectrin density at cell edges was increased. Decreased phosphatidylserine vs. increased lysophosphatidylserine species, and enhanced lipid peroxidation, methemoglobin, and plasma acid sphingomyelinase (aSMase) activity were observed. At the biophysical level, although membrane transversal asymmetry was preserved, curvature at RBC edges and rigidity were increased. Lipid domains were altered for membrane:cytoskeleton anchorage, cholesterol content and response to Ca exchange stimulation. At the morphological and functional levels, pEl RBCs exhibited reduced size and circularity, increased fragility and impaired membrane Ca exchanges. The contribution of increased membrane curvature to the pEl phenotype was shown by mechanistic experiments in healthy RBCs upon lysophosphatidylserine membrane insertion. The role of lipid domain defects was proved by cholesterol depletion and aSMase inhibition in pEl. The data indicate that aberrant membrane content and biophysical properties alter pEl RBC morphology and functionality.
Topics: Cholesterol; Elliptocytosis, Hereditary; Erythrocyte Membrane; Erythrocytes; Humans; Lysophospholipids; Membrane Fluidity; Membrane Microdomains; Oxidative Stress
PubMed: 32751168
DOI: 10.3390/biom10081120 -
Cellular Physiology and Biochemistry :... 2016Erythrocytes (RBCs) are extremely sensitive cells, and although they do not have nuclei and mitochondria, are important health indicators. This is particularly true... (Review)
Review
Erythrocytes (RBCs) are extremely sensitive cells, and although they do not have nuclei and mitochondria, are important health indicators. This is particularly true because, during inflammation, whether it is systemic or chronic, the haematological system is constantly exposed to circulating inflammatory mediators. RBCs have a highly specialized and organized membrane structure, which interacts and reacts to inflammatory molecule insults, and undergo programmed cell death, similar to apoptosis, known as eryptosis. Over the past years, eryptosis studies have focussed on determining if membrane changes have occurred, particularly whether a phosphatidylserine (PS) flip, Ca2+ leakage into the cell, changes to ceramide and cell shrinkage have occurred. Mostly, flow cytometry is used, but confocal microscopy and ultrastructural studies also confirm eryptosis. Here, we provide a comprehensive overview of eryptosis, where we revisit the biochemical process of the process, review all literature in PUBMED, that is shown under the search word, "eryptosis", and also discuss current methodologies to determine the presence of eryptosis; included in the discussion of the methodologies, we discuss a pitfalls section for each method. This paper is therefore a comprehensive synopsis of current knowledge of eryptosis and discusses how RBCs may provide an essential in vivo cell model system to study not only inflammation in disease, but also track disease progression and treatment regimes.
Topics: Biological Products; Calcium; Cell Size; Cells, Cultured; Ceramides; Eryptosis; Erythrocyte Membrane; Flow Cytometry; Humans; Oxidative Stress; Phosphatidylserines; Prescription Drugs; Reactive Oxygen Species; Small Molecule Libraries
PubMed: 27771701
DOI: 10.1159/000447895 -
American Journal of Hematology Aug 2013
Topics: Adult; Erythrocyte Membrane; Humans; Male; Neuroacanthocytosis; Vesicular Transport Proteins
PubMed: 23674404
DOI: 10.1002/ajh.23481 -
Blood Jan 2016The red cell membrane skeleton is a pseudohexagonal meshwork of spectrin, actin, protein 4.1R, ankyrin, and actin-associated proteins that laminates the inner membrane... (Review)
Review
The red cell membrane skeleton is a pseudohexagonal meshwork of spectrin, actin, protein 4.1R, ankyrin, and actin-associated proteins that laminates the inner membrane surface and attaches to the overlying lipid bilayer via band 3-containing multiprotein complexes at the ankyrin- and actin-binding ends of spectrin. The membrane skeleton strengthens the lipid bilayer and endows the membrane with the durability and flexibility to survive in the circulation. In the 36 years since the first primitive model of the red cell skeleton was proposed, many additional proteins have been discovered, and their structures and interactions have been defined. However, almost nothing is known of the skeleton's physiology, and myriad questions about its structure remain, including questions concerning the structure of spectrin in situ, the way spectrin and other proteins bind to actin, how the membrane is assembled, the dynamics of the skeleton when the membrane is deformed or perturbed by parasites, the role lipids play, and variations in membrane structure in unique regions like lipid rafts. This knowledge is important because the red cell membrane skeleton is the model for spectrin-based membrane skeletons in all cells, and because defects in the red cell membrane skeleton underlie multiple hemolytic anemias.
Topics: Actin Cytoskeleton; Animals; Cytoskeleton; Erythrocyte Membrane; Humans; Models, Molecular; Protein Structure, Secondary; Protein Structure, Tertiary; Spectrin; Tropomyosin
PubMed: 26537302
DOI: 10.1182/blood-2014-12-512772 -
Communications Biology Dec 2021Cholesterol-rich microdomains are membrane compartments characterized by specific lipid and protein composition. These dynamic assemblies are involved in several...
Cholesterol-rich microdomains are membrane compartments characterized by specific lipid and protein composition. These dynamic assemblies are involved in several biological processes, including infection by intracellular pathogens. This work provides a comprehensive analysis of the composition of human erythrocyte membrane microdomains. Based on their floating properties, we also categorized the microdomain-associated proteins into clusters. Interestingly, erythrocyte microdomains include the vast majority of the proteins known to be involved in invasion by the malaria parasite Plasmodium falciparum. We show here that the Ecto-ADP-ribosyltransferase 4 (ART4) and Aquaporin 1 (AQP1), found within one specific cluster, containing the essential host determinant CD55, are recruited to the site of parasite entry and then internalized to the newly formed parasitophorous vacuole membrane. By generating null erythroid cell lines, we showed that one of these proteins, ART4, plays a role in P. falciparum invasion. We also found that genetic variants in both ART4 and AQP1 are associated with susceptibility to the disease in a malaria-endemic population.
Topics: Erythrocyte Membrane; Erythrocytes; Humans; Malaria; Malaria, Falciparum; Membrane Microdomains; Plasmodium falciparum
PubMed: 34880413
DOI: 10.1038/s42003-021-02900-w -
Basic & Clinical Pharmacology &... Feb 2016The ionophore antibiotic nonactin permeabilizes cell membranes to NH4+ and K(+) . Treatment of erythrocytes with nonactin is expected to trigger cellular K(+) loss with...
The ionophore antibiotic nonactin permeabilizes cell membranes to NH4+ and K(+) . Treatment of erythrocytes with nonactin is expected to trigger cellular K(+) loss with subsequent cell shrinkage, which in turn is known to trigger suicidal death of a wide variety of cells including erythrocytes. This study explored whether nonactin exposure induces eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and translocation of cell membrane phosphatidylserine to the erythrocyte surface. Signalling of eryptosis includes increase in cytosolic Ca(2+) activity [(Ca(2+) )i ] and stimulation of protein kinase C (PKC) as well as p38 mitogen-activated protein kinase. Phosphatidylserine abundance at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter (FSC) and (Ca(2+) )i from Fluo3-fluorescence. A 48-hr treatment of human erythrocytes with nonactin significantly decreased FSC (≥10 ng/ml) and significantly increased the percentage of annexin-V-binding cells (≥10 ng/ml), effects paralleled by increase in (Ca(2+) )i (≥50 ng/ml) and virtually abrogated by increase in extracellular K(+) concentration to 120 mM at the expense of Na(+) . The up-regulation of annexin-V-binding after nonactin treatment was significantly blunted but not abolished by the removal of extracellular Ca(2+) and by addition of either PKC inhibitor staurosporine (0.4 μM) or p38 kinase inhibitor SB203580 (2 μM). In conclusion, exposure of erythrocytes to the K(+) ionophore nonactin induces erythrocyte shrinkage and subsequent erythrocyte membrane scrambling, effects involving cellular K(+) loss, Ca(2+) entry and activation of staurosporine as well as SB203580-sensitive kinases.
Topics: Anti-Bacterial Agents; Apoptosis; Cell Membrane Permeability; Cell Size; Erythrocyte Membrane; Humans; Ionophores; Macrolides; Phosphatidylserines; Signal Transduction
PubMed: 26280658
DOI: 10.1111/bcpt.12455 -
Cellular & Molecular Biology Letters Mar 2014The spectrin-based membrane skeleton is crucial for the mechanical stability and resilience of erythrocytes. It mainly contributes to membrane integrity, protein... (Review)
Review
The spectrin-based membrane skeleton is crucial for the mechanical stability and resilience of erythrocytes. It mainly contributes to membrane integrity, protein organization and trafficking. Two transmembrane protein macro-complexes that are linked together by spectrin tetramers play a crucial role in attaching the membrane skeleton to the cell membrane, but they are not exclusive. Considerable experimental data have shown that direct interactions between spectrin and membrane lipids are important for cell membrane cohesion. Spectrin is a multidomain, multifunctional protein with several distinctive structural regions, including lipid-binding sites within CH tandem domains, a PH domain, and triple helical segments, which are excellent examples of ligand specificity hidden in a regular repetitive structure, as recently shown for the ankyrin-sensitive lipid-binding domain of beta spectrin. In this review, we summarize the state of knowledge about interactions between spectrin and membrane lipids.
Topics: Actin Cytoskeleton; Ankyrins; Binding Sites; Erythrocyte Membrane; Humans; Membrane Lipids; Phospholipids; Protein Binding; Protein Structure, Tertiary; Spectrin
PubMed: 24569979
DOI: 10.2478/s11658-014-0185-5 -
Theranostics 2020Biomineralization of enzymes for diagnosis and treatment of diseases remain a considerable challenge, due to their severe reaction conditions and complicated...
Biomineralization of enzymes for diagnosis and treatment of diseases remain a considerable challenge, due to their severe reaction conditions and complicated physiological environment. Herein, we reported a biomimetic enzyme cascade delivery nanosystem, tumor-targeted erythrocyte membrane (EM)-cloaked iron-mineralized glucose oxidases (GOx-Fe@EM-A) for enhancing anticancer efficacy by self-activated cascade to generate sufficient high toxic •OH at tumor site. : An ultra-small Fe nanoparticle (FeNP) was anchored in the inner cavity of glucose oxidase (GOx) to form iron-mineralized glucose oxidase (GOx-Fe) as a potential tumor therapeutic nanocatalyst. Moreover, erythrocyte membrane cloaking delivery of GOx-Fe was designed to effectively accumulate ultra-small GOx-Fe at tumor site. : GOx-Fe@EM-A had satisfactory biocompatibility and light-trigged release efficiency. Erythrocyte membrane cloaking of GOx-Fe@EM-A not only prolongs blood circulation but also protects enzyme activity of GOx-Fe; Tumor targeting of GOx-Fe@EM-A endowed preferential accumulation at tumor site. After NIR light irradiation at tumor site, erythrocyte membrane of GOx-Fe@EM-A was ruptured to achieve light-driven release and tumor deep penetration of ultra-small nanosize GOx-Fe by the photothermal effect of ICG. Then, GOx-Fe occurred self-activated cascade to effectively eradicate tumor by producing the highly cumulative and deeply penetrating •OH at tumor site. : Tumor-targeted erythrocyte membrane-cloaked iron-mineralized glucose oxidase (GOx-Fe0@EM-A) exhibits a promising strategy for striking antitumor efficacy by light-driven tumor deep penetration and self-activated therapeutic cascade.
Topics: Animals; Biomimetics; Biomineralization; Cell Line, Tumor; Disease Models, Animal; Erythrocyte Membrane; Female; Glucose Oxidase; Humans; Iron; Metal-Organic Frameworks; Mice; Mice, Inbred BALB C; Nanoparticles; Trace Elements; Xenograft Model Antitumor Assays
PubMed: 32104504
DOI: 10.7150/thno.39621 -
Ultrasonics Sonochemistry Apr 2021In this communication, we report an ultrasound-assisted method, utilising human red blood cell (RBC) or erythrocyte membranes, to produce acoustically active "bubbles",...
In this communication, we report an ultrasound-assisted method, utilising human red blood cell (RBC) or erythrocyte membranes, to produce acoustically active "bubbles", intended for vasculature imaging. The resulting RBC membrane bubbles have an average size of 1.5 μm with a generally spherical morphology, altered internal aqueous compartment contents, and small gas-containing protrusions or "pockets" in between the membrane bilayer. We also found that this method produced some nanobubbles (200-400 nm diameter), due to the shedding of lipid components from the RBC membranes to compensate for the membrane structural changes. In vitro ultrasound imaging showed that RBC membrane bubbles had comparable ultrasound contrast enhancement as the standard DEFINTY microbubble preparation (~13% v/v) and lower concentrations of this standard contrast agent. This current technology demonstrate a new and important application of ultrasound and of RBC membranes, having inherent biocompatibility, as potential material for the development of new types of ultrasound imaging agents, without the use of additional lipid components and pre-made microbubbles.
Topics: Acoustics; Erythrocyte Membrane; Humans; Ultrasonic Waves
PubMed: 33383541
DOI: 10.1016/j.ultsonch.2020.105429