Pj variant, a new hybrid MNSs glycoprotein of the human red-cell membrane.
Ontology highlight
ABSTRACT:
SUBMITTER: Blanchard D
PROVIDER: S-EPMC1158246 | biostudies-other | 1982 May
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The remarkable deformability of the human red blood cell (RBC) results from the coupled dynamic response of the phospholipid bilayer and the spectrin molecular network. Here we present quantitative connections between spectrin morphology and membrane fluctuations of human RBCs by using dynamic full-field laser interferometry techniques. We present conclusive evidence that the presence of adenosine 5'-triphosphate (ATP) facilitates non-equilibrium dynamic fluctuations in the RBC membrane that are highly correlated with the biconcave shape of RBCs. Spatial analysis of the fluctuations reveals that these non-equilibrium membrane vibrations are enhanced at the scale of spectrin mesh size. Our results indicate that the dynamic remodeling of the coupled membranes powered by ATP results in non-equilibrium membrane fluctuations manifesting from both metabolic and thermal energies and also maintains the biconcave shape of RBCs.
| S-EPMC2802590 | biostudies-literature
Project description:1. RhD,c and E immune complexes isolated from 3H- and 125I-surface-radiolabelled and unlabelled intact human red cells were analysed by SDS/polyacrylamide-gel electrophoresis. 2. Apparent Mr values of 31,900 for RhD polypeptide and 33,100 for Rhc,E polypeptide were obtained under both reducing and non-reducing conditions. Glycosylation of RhD,c and E polypeptides was not detected. 3. RhD,c and E immune complexes also contain a glycoprotein component. RhD glycoprotein (apparent Mr 45,000-100,000) is distinct from Rhc,E glycoprotein(s) (apparent Mr 35,000-65,000). Rh (Rhesus) glycoprotein carbohydrate moieties are susceptible to endo-beta-galactosidase digestion and carry blood-group-ABH determinants. This suggests the presence of polylactosaminoglycan-type structures. 4. Rh glycoproteins are not present in Rh immune complexes as a result of non-specific adsorption of membrane glycoproteins during the membrane-solubilization phase of immune-complex isolation because RhD immune complexes isolated from a 1:1 (v/v) mixture of Acde/cde and OcDE/cDE red cells do not contain blood-group-A-active glycoprotein. 5. Blood-group-A immune complexes isolated from group-A red cells of the appropriate Rh phenotypes contain the 31,900- and 33,100-apparent-Mr Rh polypeptides. 6. It was concluded from the above evidence that non-covalent Rh-glycoprotein-Rh-polypeptide complexes exist in the native red-cell membrane. 7. The 31,900- and 33,100-apparent-Mr Rh polypeptides are absent from blood-group-A immune complexes isolated from regulator type Rhnull cells (donor A.L.), but are replaced by a 33,800-apparent-Mr Rhnull-specific polypeptide (Rhnull polypeptide). It is suggested that Rhnull polypeptide is an aberrant product of the Rh gene complex.
| S-EPMC1148057 | biostudies-other
Project description:1. A new human erythrocyte variant (Ph) is described. The variant contains an unusual sialic acid-rich glycoprotein in addition to the blood-group-MN([unk])- and blood-group-Ss(delta)-active sialoglycoproteins found in normal erythrocytes. 2. The unusual component Ph has an apparent mol.wt. of 32000 on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The Ph component is not degraded during trypsin treatment of intact erythrocytes. 3. The Ph component was labelled by lacto-peroxidase-mediated radioiodination of intact erythrocytes and was found to be present in amounts approximately equimolar to alpha-sialoglycoprotein in the variant erythrocytes. 4. The Ph component had receptors for the lectins from Maclura aurantiaca (osage orange) and Triticum vulgaris (wheat-germ), but lacked a receptor for the Phaseolus vulgaris (red kidney bean) lectin, suggesting that it carries only O-linked oligosaccharides. 5. The presence of the Ph component in these erythrocytes does not correspond to any of the known blood-group-MNSs-related antigens examined. 6. We suggest that this component may be a hybrid polypeptide containing the N-terminal portion derived from normal delta-sialoglycoprotein, and the C-terminal portion from normal alpha-sialoglycoprotein, in a manner similar to the anti-Lepore haemoglobin.
| S-EPMC1161815 | biostudies-other
Project description:Protein 4.1R plays an important role in maintaining the mechanical properties of the erythrocyte membrane. We analysed the expression of Kell blood group protein in erythrocytes from a patient with hereditary elliptocytosis associated with complete 4.1R deficiency (4.1(-) HE). Flow cytometry and Western blot analyses revealed a severe reduction of Kell. In vitro pull down and co-immunoprecipitation experiments from erythrocyte membranes showed a direct interaction between Kell and 4.1R. Using different recombinant domains of 4.1R and the cytoplasmic domain of Kell, we demonstrated that the R(46) R motif in the juxta-membrane region of Kell binds to lobe B of the 4.1R FERM domain. We also observed that 4.1R deficiency is associated with a reduction of XK and DARC (also termed ACKR1) proteins, the absence of the glycosylated form of the urea transporter B and a slight decrease of band 3. The functional alteration of the 4.1(-) HE erythrocyte membranes was also determined by measuring various transport activities. We documented a slower rate of HCO3 (-) /Cl(-) exchange, but normal water and ammonia transport across erythrocyte membrane in the absence of 4.1. These findings provide novel insights into the structural organization of blood group antigen proteins into the 4.1R complex of the human red cell membrane.
| S-EPMC4715498 | biostudies-literature
Project description:The clonally variant Plasmodium falciparum PfEMP1 adhesin is a virulence factor and a prime target of humoral immunity. It is encoded by a repertoire of functionally differentiated var genes, which display architectural diversity and allelic polymorphism. Their serological relationship is key to understanding the evolutionary constraints on this gene family and rational vaccine design. Here, we investigated the Palo Alto/VarO and IT4/R29 and 3D7/PF13_003 parasites lines. VarO and R29 form rosettes with uninfected erythrocytes, a phenotype associated with severe malaria. They express an allelic Cys2/group A NTS-DBL1?(1) PfEMP1 domain implicated in rosetting, whose 3D7 ortholog is encoded by PF13_0003. Using these three recombinant NTS-DBL1?(1) domains, we elicited antibodies in mice that were used to develop monovariant cultures by panning selection. The 3D7/PF13_0003 parasites formed rosettes, revealing a correlation between sequence identity and virulence phenotype. The antibodies cross-reacted with the allelic domains in ELISA but only minimally with the Cys4/group B/C PFL1955w NTS-DBL1?. By contrast, they were variant-specific in surface seroreactivity of the monovariant-infected red cells by FACS analysis and in rosette-disruption assays. Thus, while ELISA can differentiate serogroups, surface reactivity assays define the more restrictive serotypes. Irrespective of cumulated exposure to infection, antibodies acquired by humans living in a malaria-endemic area also displayed a variant-specific surface reactivity. Although seroprevalence exceeded 90% for each rosetting line, the kinetics of acquisition of surface-reactive antibodies differed in the younger age groups. These data indicate that humans acquire an antibody repertoire to non-overlapping serotypes within a serogroup, consistent with an antibody-driven diversification pressure at the population level. In addition, the data provide important information for vaccine design, as production of a vaccine targeting rosetting PfEMP1 adhesins will require engineering to induce variant-transcending responses or combining multiple serotypes to elicit a broad spectrum of immunity.
| S-EPMC3029348 | biostudies-literature
Project description:Trypanosoma brucei Lister 427 bloodstream forms were cultured in HMI-11 medium. Total RNA was prepared using Qiagen RNAeasy kits for single sample RNAseq to estimate VSG mRNA abundance (and not to reconstruct the transcriptome). The cDNA libraries were prepared and sequenced at the Beijing Genomics Institute (Shenzhen, China). Polyadenylated RNA was purified from total RNA, converted to cDNA using random hexamer primers sheared and size selected for fragments ~200 bp in length using the Illumina TruSeq RNA Sample Preparation Kit v2. RNAseq of the resulting libraries was used for the determination of transcript abundances. Sequencing was performed on an Illumina Hiseq 2000 (Illumina, CA) platform and 90 base paired end reads obtained. Four samples were analysed: 1. Trypanosoma brucei Lister 427 expressing VSG2 2. Trypanosoma brucei Lister 427 expressing VSG6 3. Trypanosoma brucei Lister 427 expressing VSG6 and a VSG2 transgender located in the active bloodstream expression site 28 days after electroporation 4. Trypanosoma brucei Lister 427 expressing VSG6 and a VSG2 transgender located in the active bloodstream expression site 44 days after electroporation.
2020-06-03 | E-MTAB-9122 | biostudies-arrayexpress
Project description:Cultured red blood cells from human induced pluripotent stem cells (cRBC_iPSCs) are a promising source for future concepts in transfusion medicine. Before cRBC_iPSCs will have entrance into clinical or laboratory use, their functional properties and safety have to be carefully validated. Due to the limitations of established culture systems, such studies are still missing. Improved erythropoiesis in a recently established culture system, closer simulating the physiological niche, enabled us to conduct functional characterization of enucleated cRBC_iPSCs with a focus on membrane properties. Morphology and maturation stage of cRBC_iPSCs were closer to native reticulocytes (nRETs) than to native red blood cells (nRBCs). Whereas osmotic resistance of cRBC_iPSCs was similar to nRETs, their deformability was slightly impaired. Since no obvious alterations in membrane morphology, lipid composition, and major membrane associated protein patterns were observed, reduced deformability might be caused by a more primitive nature of cRBC_iPSCs comparable to human embryonic- or fetal liver erythropoiesis. Blood group phenotyping of cRBC_iPSCs further confirmed the potency of cRBC_iPSCs as a prospective device in pre-transfusional routine diagnostics. Therefore, RBC membrane analyses obtained in this study underscore the overall prospects of cRBC_iPSCs for their future application in the field of transfusion medicine.
| S-EPMC9406338 | biostudies-literature
Project description:BACKGROUND:Healthy subjects whose red blood cells (RBCs) react variably with anti-KEL1, but strongly express other Kell blood group antigens, have been described and called KEL1 variant. A 53-year-old Caucasian blood donor was identified whose RBCs reacted with three monoclonal and two polyclonal anti-KEL1 and did not react with two monoclonal and one polyclonal anti-KEL1. The molecular basis of this phenotype was investigated. STUDY DESIGN AND METHODS:Genomic white blood cell DNA was analyzed for KEL*1/2 genotype by utilizing sequence-specific primers and polymerase chain reaction. In addition, the region of the KEL*1/2 polymorphism at position 578 of KEL was analyzed by DNA sequencing. RESULTS:Genotyping of the donor with the KEL1 variant phenotype revealed that he was KEL*2 homozygous. Sequencing revealed one typical KEL*2 allele and a KEL*2 allele with an adenosine (A) to thymidine (T) substitution at position 577 that predicted a threonine to serine change at position 193. CONCLUSION:It is not known if this phenotype is clinically relevant, but for at least some genotyping applications probes that identify this polymorphism should be used and anti-KEL1 should be tested for reactivity to this allele.
| S-EPMC2666546 | biostudies-literature
Project description:The mature red blood cell (RBC) lacks a nucleus and organelles characteristic of most cells, but it is elegantly structured to perform the essential function of delivering oxygen and removing carbon dioxide from all other cells while enduring the shear stress imposed by navigating small vessels and sinusoids. Over the past several decades, the efforts of biochemists, cell and molecular biologists, and hematologists have provided an appreciation of the complexity of RBC membrane structure, while studies of the RBC membrane disorders have offered valuable insights into structure-function relationships. Within the last decade, advances in genetic testing and its increased availability have made it possible to substantially build upon this foundational knowledge. Although disorders of the RBC membrane due to altered structural organization or altered transport function are heterogeneous, they often present with common clinical findings of hemolytic anemia. However, they may require substantially different management depending on the underlying pathophysiology. Accurate diagnosis is essential to avoid emergence of complications or inappropriate interventions. We propose an algorithm for laboratory evaluation of patients presenting with symptoms and signs of hemolytic anemia with a focus on RBC membrane disorders. Here, we review the genotypic and phenotypic variability of the RBC membrane disorders in order to raise the index of suspicion and highlight the need for correct and timely diagnosis.
| S-EPMC7483429 | biostudies-literature
Project description:UnlabelledBackgroundIn sickle cell disease (SCD), the mitogen-activated protein kinase (MAPK) ERK1/2 is constitutively active and can be inducible by agonist-stimulation only in sickle but not in normal human red blood cells (RBCs). ERK1/2 is involved in activation of ICAM-4-mediated sickle RBC adhesion to the endothelium. However, other effects of the ERK1/2 activation in sickle RBCs leading to the complex SCD pathophysiology, such as alteration of RBC hemorheology are unknown.ResultsTo further characterize global ERK1/2-induced changes in membrane protein phosphorylation within human RBCs, a label-free quantitative phosphoproteomic analysis was applied to sickle and normal RBC membrane ghosts pre-treated with U0126, a specific inhibitor of MEK1/2, the upstream kinase of ERK1/2, in the presence or absence of recombinant active ERK2. Across eight unique treatment groups, 375 phosphopeptides from 155 phosphoproteins were quantified with an average technical coefficient of variation in peak intensity of 19.8%. Sickle RBC treatment with U0126 decreased thirty-six phosphopeptides from twenty-one phosphoproteins involved in regulation of not only RBC shape, flexibility, cell morphology maintenance and adhesion, but also glucose and glutamate transport, cAMP production, degradation of misfolded proteins and receptor ubiquitination. Glycophorin A was the most affected protein in sickle RBCs by this ERK1/2 pathway, which contained 12 unique phosphorylated peptides, suggesting that in addition to its effect on sickle RBC adhesion, increased glycophorin A phosphorylation via the ERK1/2 pathway may also affect glycophorin A interactions with band 3, which could result in decreases in both anion transport by band 3 and band 3 trafficking. The abundance of twelve of the thirty-six phosphopeptides were subsequently increased in normal RBCs co-incubated with recombinant ERK2 and therefore represent specific MEK1/2 phospho-inhibitory targets mediated via ERK2.ConclusionsThese findings expand upon the current model for the involvement of ERK1/2 signaling in RBCs. These findings also identify additional protein targets of this pathway other than the RBC adhesion molecule ICAM-4 and enhance the understanding of the mechanism of small molecule inhibitors of MEK/1/2/ERK1/2, which could be effective in ameliorating RBC hemorheology and adhesion, the hallmarks of SCD.
| S-EPMC3558407 | biostudies-literature