51
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Abstract
AbstractHereditary stomatocytosis is a red cell membrane protein disorder, which results in hemolytic anemia. Some patients with hereditary stomatocytosis experience dyspnea, chest pain, and abdominal pain, particularly after splenectomy. These symptoms may represent vaso-occlusion secondary to adherence of an abnormal erythrocyte membrane to vascular endothelium. We studied three members of a family with varying clinical expression of hereditary stomatocytosis. Adherence of red cells to endothelium was quantified by measuring the shear force required to separate individual cells from endothelial monolayers using a micropipette technique. Two patients with symptoms of in situ thromboses had a higher percentage of adherent cells compared with their asymptomatic sibling and normal controls. Correlation between this in vitro phenomenon and the clinical course suggests that flow abnormalities in the microcirculation attributable to erythrocyte endothelial adherence may play an important pathogenetic role in the illness. When the proportion of adherent red cells was reduced by a chronic transfusion program in one patient and pentoxifyllin therapy in another, the vaso-occlusive complications were eliminated.
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52
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Abstract
Stomatin is a 31-kDa integral membrane protein, named after the rare human haemolytic anaemia hereditary stomatocytosis. In some cases of this anaemia, in which the red cells leak sodium and potassium ions, this protein is absent from the membrane, immediately suggesting that it has a role in the regulation of ion transport. The protein has a single hydrophobic domain, presumed to be membrane-associated, is phosphorylated, and is widely distributed in animal tissues. Mutations of a homologue in sensory nerve cells of the nematode Caenorhabditis elegans disrupt a neuronal transduction mechanism, in which mechanosensory information is relayed to an ion channel, whose opening initiates an action potential. It could be that this protein is a molecular link in a genetic stretch-sensitive system. Abnormalities of red cell ion transport are well known in human hypertension, but the molecular basis has never been elucidated: this protein and its functional associates, operating in a stretch- or pressure-sensitive complex, might be important.
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Affiliation(s)
- G W Stewart
- Department of Medicine, Rayne Institute, University College School of Medicine, London, U.K
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53
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Schlegel W, Unfried I, Prohaska R. Cloning and analysis of a cDNA encoding the BALB/c murine erythrocyte band 7 integral membrane protein. Gene 1996; 178:115-8. [PMID: 8921901 DOI: 10.1016/0378-1119(96)00347-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
cDNA clones encoding the BALB/c murine erythrocyte band 7 integral membrane protein (also termed protein 7.2b, or 'stomatin') were isolated by the screening of a corresponding bone-marrow lambda gt11 cDNA library with a human cDNA probe, and by 5'-RACE PCR cloning. Comparison of the murine, human and Caenorhabditis elegans protein 7.2b amino acid (aa) sequences revealed overall identities of 88% (human) and 61% (C. elegans), with the N-terminal domains showing only little similarity. The 7.2b protein sequences of the two mouse strains, BALB/c and C57BL/6J (B6), showed six rather conservative aa substitutions, three of them in the hydrophobic domain. The BALB/c murine mRNA, about 3.5 kb in size, is widely expressed in various tissues, most notably in spleen, lung and testis.
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Affiliation(s)
- W Schlegel
- Institute of Biochemistry, University of Vienna, Austria
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54
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Gallagher PG, Forget BG. Structure, organization, and expression of the human band 7.2b gene, a candidate gene for hereditary hydrocytosis. J Biol Chem 1995; 270:26358-63. [PMID: 7592848 DOI: 10.1074/jbc.270.44.26358] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Band 7.2b is an integral membrane phosphoprotein absent from the erythrocyte membranes of patients with hereditary hydrocytosis, a hemolytic anemia inherited in an autosomal dominant fashion and characterized by stomatocytic red blood cells with abnormal permeability to Na+ and K+. The precise role of band 7.2b is unknown, but it may interact with other proteins of the junctional complex of the membrane skeleton. To gain additional insight into the structure and function of this protein and to provide the necessary tools for further genetic studies of hydrocytosis patients, we determined the sequence of the full-length human band 7.2b cDNA, characterized the genomic structure of the band 7.2b gene, studied its pattern of expression in different tissues, and characterized the promoter of the gene. The composite band 7.2b gene cDNA was 3047 base pairs in length. Northern blot analysis revealed a wide tissue distribution of expression of the band 7.2b gene, with utilization of alternative polyadenylation signals generating transcripts of 2.2 and 3.1 kilobases. Cloning of the band 7.2b chromosomal gene revealed that it is composed of seven exons distributed over 40 kilobases of DNA. The band 7.2b gene promoter was identified as a TATA-less, (G+C)-rich promoter with a typical InR recognition sequence and a single transcription initiation site. It directed high level expression of a reporter gene in both erythroid and nonerythroid cells. An imperfect simple sequence repeat polymorphism was identified in the 5'-flanking DNA, and an assay was developed for its analysis by PCR.
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MESH Headings
- 3T3 Cells
- Amino Acid Sequence
- Anemia, Hemolytic/blood
- Anemia, Hemolytic/genetics
- Animals
- Base Sequence
- Blood Proteins/biosynthesis
- Blood Proteins/genetics
- Blotting, Northern
- Cell Line
- Consensus Sequence
- DNA Primers
- DNA, Complementary
- Exons
- Gene Expression
- Genetic Variation
- Hominidae/genetics
- Humans
- Introns
- Leukemia, Erythroblastic, Acute
- Membrane Proteins/genetics
- Mice
- Molecular Sequence Data
- Polymerase Chain Reaction
- Polymorphism, Genetic
- Promoter Regions, Genetic
- RNA, Messenger/analysis
- RNA, Messenger/biosynthesis
- Recombinant Fusion Proteins/biosynthesis
- Regulatory Sequences, Nucleic Acid
- Restriction Mapping
- Transfection
- Tumor Cells, Cultured
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Affiliation(s)
- P G Gallagher
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06520-8021, USA
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55
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MESH Headings
- Adaptation, Physiological
- Amino Acid Sequence
- Anemia, Dyserythropoietic, Congenital/genetics
- Anemia, Hemolytic, Congenital/blood
- Anemia, Hemolytic, Congenital/classification
- Anemia, Hemolytic, Congenital/genetics
- Animals
- Base Sequence
- Blood Group Antigens/genetics
- Blood Proteins/chemistry
- Blood Proteins/genetics
- Blood Proteins/metabolism
- Disease Models, Animal
- Elliptocytosis, Hereditary/genetics
- Erythrocyte Membrane/metabolism
- Erythrocyte Membrane/ultrastructure
- Erythrocytes, Abnormal/metabolism
- Hemoglobinuria, Paroxysmal/genetics
- Humans
- Immunity, Innate
- Malaria
- Membrane Lipids/blood
- Membrane Proteins/blood
- Membrane Proteins/chemistry
- Membrane Proteins/genetics
- Molecular Sequence Data
- Spherocytosis, Hereditary/genetics
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Affiliation(s)
- J Delaunay
- CNRS URA 1171, Institut Pasteur de Lyon, France
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56
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Stewart GW, Argent AC, Dash BC. Stomatin: a putative cation transport regulator in the red cell membrane. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1225:15-25. [PMID: 7694657 DOI: 10.1016/0925-4439(93)90116-i] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- G W Stewart
- Department of Pathology, Yale University School of Medicine, New Haven, CT 06510
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57
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Salzer U, Ahorn H, Prohaska R. Identification of the phosphorylation site on human erythrocyte band 7 integral membrane protein: implications for a monotopic protein structure. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1151:149-52. [PMID: 8373790 DOI: 10.1016/0005-2736(93)90098-k] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Band 7 membrane protein was metabolically labelled with [32P]phosphate in the presence of cAMP, isolated and digested, the labelled peptides were purified and sequenced. Ser-9 was identified as the only phosphorylation site. This proves that the N-terminal region is located at the cytoplasmic side of the membrane and implies a monotopic rather than the predicted bitopic structure.
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Affiliation(s)
- U Salzer
- Institute of Biochemistry, University of Vienna, Medical Faculty, Austria
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58
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Abstract
Hereditary stomatocytosis and allied conditions represent a series of diseases in which abnormal movements of univalent cations across the plasma membrane play an important part in cellular disease. The primary problem lies not in the active transporters but in the basal permeability of the membrane, which is always increased, and the extent of the increase correlates with the cellular dysfunction. A number of structural abnormalities have been described in these membranes, but the most consistent and convincing is the deficiency of a hitherto uncharacterized integral membrane protein of molecular weight 31 kDa in the severe, 'overhydrated' form of the disease. The true function of this protein remains enigmatic, but its deficiency in this condition indicates that it may have a role in the regulation of cation transport.
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MESH Headings
- Adult
- Anemia, Hemolytic, Congenital/blood
- Anemia, Hemolytic, Congenital/genetics
- Anemia, Hemolytic, Congenital/pathology
- Anemia, Hemolytic, Congenital/veterinary
- Animals
- Biological Transport
- Blood Proteins/chemistry
- Blood Proteins/deficiency
- Blood Proteins/metabolism
- Blood Proteins/physiology
- Carrier Proteins/blood
- Cations, Monovalent/blood
- Cell Membrane Permeability
- Child
- Dog Diseases/blood
- Dog Diseases/genetics
- Dogs
- Erythrocyte Membrane/metabolism
- Erythrocyte Membrane/ultrastructure
- Erythrocytes, Abnormal/ultrastructure
- Female
- Goat Diseases/blood
- Goat Diseases/genetics
- Goats
- Humans
- Membrane Proteins
- Potassium/blood
- Sheep
- Sheep Diseases/blood
- Sheep Diseases/genetics
- Sodium/blood
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Affiliation(s)
- G W Stewart
- Department of Medicine, University College and Middlesex School of Medicine, Rayne Institute, London, UK
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59
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Kanzaki A, Yawata Y. Hereditary stomatocytosis: phenotypical expression of sodium transport and band 7 peptides in 44 cases. Br J Haematol 1992; 82:133-41. [PMID: 1419788 DOI: 10.1111/j.1365-2141.1992.tb04605.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The clinical heterogeneity and the role of red cell membrane protein band 7 in membrane transport were studied in 44 patients with hereditary stomatocytosis with normal red cell membrane lipids. These patients were arbitrarily categorized into three phenotypes, based on the extent of sodium influx: hereditary stomatocytosis Type I: with markedly increased Na influx (8.90 +/- 3.39 mmol/lRBC/h); Type II: with moderately increased Na influx (2.10 +/- 0.79) and Type III with normal Na influx (1.31 +/- 0.13). The three groups of patients were compared with normal controls (1.29 +/- 0.14). The extent of anaemia and jaundice was almost identical in the three groups in the presence of nearly the same degree of stomatocytosis (I: 54.8 +/- 10.7%, II: 38.8 +/- 12.8, and III: 40.2 +/- 10.8). Approximately one third of the cases (14/44) with hereditary stomatocytosis showed no overt haemolysis even with marked stomatocytosis. Cell hydration was abnormal in Type I (MCV 119.6 +/- 8.5 fl, MCHC 29.3 +/- 1.8%) but normal in Types II and III (MCV 98.2 +/- 11.7, 94.1 +/- 8.5; MCHC 34.4 +/- 2.1, 34.5 +/- 2.2). These results indicate that there was no correlation between the extent of Na influx and either the degree of stomatocytosis or the extent of overt haemolysis. The role of band 7 in membrane transport was also studied. Three components (30 kD, 28 kD and 26 kD polypeptides) of band 7 were analysed by SDS-PAGE and NEPHGE/SDS-PAGE, and the content of these polypeptides were expressed as the ratio to band 5. The 30 kDa polypeptide in the three groups was nearly identical to that in normal controls (12.3 +/- 4.0), except for non-haemolysing patients in Type II. The 28 kD peptide was also decreased in five out of nine cases of Type II (25.7 +/- 5.6) as compared with normal controls (32.9 +/- 3.6) and cases of Type I (35.8 +/- 2.8) and Type III (32.7 +/- 2.9). No deficiency of this peptide was noted in Type I patients. No correlation was observed between the content of the 28 kD polypeptide and Na influx (r = 0.416), but the 26 kD polypeptide tended to be elevated in cases with overt haemolysis. These results suggest that band 7 may not be essentially involved in the formation of stomatocytic changes, although the presence of subtle defects in band 7 structure and function may not be ruled out. The present findings provide an important starting point to initiate further extensive investigations.
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Affiliation(s)
- A Kanzaki
- Department of Medicine, Kawasaki Medical School, Kurashiki, Japan
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60
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Abstract
Due to its fundamental importance, the movement of water across cell membranes has been an active area of research for more than 100 years. This subject is central to consideration of normal water metabolism by terrestrial animals, as well as derangements in overall water balance that are frequently encountered by nephrologists in the care of their patients. The objective of this review is to discuss the most basic aspects of cell membrane water permeability and provide a framework for these data in the context of the care of pediatric patients with renal disease. While the water permeability of most cell membranes can be accounted for by the diffusion of water across the lipid bilayer, other cells, including the red blood cell and certain epithelial cells that line the proximal and collecting tubules of the kidney and the urinary bladder of amphibians, possess specialized water channels. Water channels are composed of specialized proteins that create aqueous pores across cell membrane. Currently, there are active research efforts to isolate and characterize water channel proteins from these cell types. Data concerning the distribution, permeability and function of these various water channels will greatly enhance our knowledge of how water is transported across cell membranes.
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Affiliation(s)
- H W Harris
- Division of Nephrology, Children's Hospital, Boston, MA 02115
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61
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Wang D, Mentzer W, Cameron T, Johnson R. Purification of band 7.2b, a 31-kDa integral phosphoprotein absent in hereditary stomatocytosis. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)55202-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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62
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Huppi PS, Ott P, Amato M, Schneider H. Congenital haemolytic anaemia in a low birth weight infant due to congenital stomatocytosis. Eur J Haematol 1991; 47:1-9. [PMID: 1868910 DOI: 10.1111/j.1600-0609.1991.tb00554.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A baby girl born at 31 weeks gestation showed severe haemolytic anaemia and hyperbilirubinaemia which led to exchange transfusion within the first 12 hours of life. There was no blood group incompatibility between mother and child but there was a marked stomatocytosis of the baby's red blood cells. Family history revealed a congenital stomatocytosis in the mother. Biochemical characterization of the defect was performed. Phospholipid analysis of the erythrocyte membrane of mother and child showed an increase in phosphatidylserine with a compensatory decrease in phosphatidylcholine and phosphatidylethanolamine. SDS-electrophoresis showed multiple modifications of the protein pattern with a decrease in band 6, an increased content of band 4.1b, a slight decrease in band 7 and a clear change in the shape of the protein band 3 pattern. The results suggest that the basis of the observed abnormalities is a common defect in protein posttranslational modification, rather than multiple genetic defects in the synthesis of several proteins. Haematologic, biochemical and clinical course of the disease in this preterm infant are discussed.
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Affiliation(s)
- P S Huppi
- Department of Obstetrics and Gynaecology, University of Berne, Switzerland
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63
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Hiebl-Dirschmied CM, Adolf GR, Prohaska R. Isolation and partial characterization of the human erythrocyte band 7 integral membrane protein. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1065:195-202. [PMID: 1711899 DOI: 10.1016/0005-2736(91)90230-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Monoclonal antibodies to the Mr 31,000 major integral membrane protein of the human erythrocyte band 7 region were used to identify the corresponding polypeptide chain and epitope-carrying fragments on immunoblots. Analysis of the erythrocyte membrane, membrane fractions, and cytosol revealed that the Mr 31,000 band 7 integral membrane protein is unique and not related to any of the other water-soluble or membrane-bound band 7 components. Cross-reacting proteins were identified in the membranes of other mammalian erythrocytes and in cell lines of epithelial and lymphoid origin. Proteolytic digestion of intact human erythrocytes or erythrocyte membranes demonstrated that the band 7 integral membrane protein has an intracellular domain larger than Mr 12,000; it does not have an extracellular one. One of the monoclonal antibodies was employed for the isolation of band 7 integral membrane protein by immunoaffinity chromatography; subsequent Edman degradation revealed a blocked N-terminus.
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64
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Affiliation(s)
- S K Ballas
- Cardeza Foundation for Hematologic Research, Department of Medicine, Thomas Jefferson University, Philadelphia, PA 19107
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65
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Deuticke B, Grebe R, Haest CWM. Action of Drugs on the Erythrocyte Membrane. BLOOD CELL BIOCHEMISTRY 1990. [DOI: 10.1007/978-1-4757-9528-8_16] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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66
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Pristoupil TI, Marík T. On the hydrodynamic instability of hemoglobin solutions. BIOMATERIALS, ARTIFICIAL CELLS, AND ARTIFICIAL ORGANS 1990; 18:183-8. [PMID: 2369645 DOI: 10.3109/10731199009117300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The formation of heterogeneous fibers well observable under a magnifying glass in stirred "stroma-free" hemolysates of outdated banked erythrocytes was found to be predominantly due to random surface denaturation of both hemoglobin and non-heme proteins at the air-liquid interface. Electrophoretic analysis revealed that the precipitated and washed fibers contain residual membrane proteins as well as a certain amount of hemoglobin. The latter, however, largely remains in solution.
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Affiliation(s)
- T I Pristoupil
- Institute of Hematology and Blood Transfusion, Prague, Czechoslovakia
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67
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68
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Eber SW, Lande WM, Iarocci TA, Mentzer WC, Höhn P, Wiley JS, Schröter W. Hereditary stomatocytosis: consistent association with an integral membrane protein deficiency. Br J Haematol 1989; 72:452-5. [PMID: 2765409 DOI: 10.1111/j.1365-2141.1989.tb07731.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We studied the RBC membrane proteins of four patients, including a mother and daughter, with hereditary stomatocytosis. One- and two-dimensional gel electrophoresis revealed that a 28 kDa integral protein, present in normal RBC membranes, was absent in all four patients. This abnormality, reported once previously (Lande et al, 1982), appears to be a characteristic feature of hereditary stomatocytosis, and may be related to the underlying permeability defect in this disorder.
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Affiliation(s)
- S W Eber
- Kinderklinik und Poliklinik, Georg-August-Universität Göttingen, F.R.G
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69
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Morlé L, Pothier B, Alloisio N, Féo C, Garay R, Bost M, Delaunay J. Reduction of membrane band 7 and activation of volume stimulated (K+, Cl-)-cotransport in a case of congenital stomatocytosis. Br J Haematol 1989; 71:141-6. [PMID: 2917122 DOI: 10.1111/j.1365-2141.1989.tb06288.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We report on a case of congenital stomatocytosis in a French boy presenting with a haemolytic anaemia requiring splenectomy at the age of 6. The red cells included 15-20% stomatocytes and displayed a marked increase of volume. Their osmotic resistance and density were reduced; however, their deformability was unaltered in isotonicity. Erythrocyte Na+ was high (27 mEq/l) and K+ low (65 mEq/l). The newly described (K+, Cl-)-cotransporter normally triggered by hypo-osmotic stress, was activated to maximal capacity. Membrane band 7 was reduced by 72%. From anamnestic data, the condition appears to have been transmitted by the father. The mother proved to be strictly normal on clinical, morphological, osmotic and biochemical bases. We suggest that the partly missing band 7 may play an important role in the genesis of stomatocytosis.
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Affiliation(s)
- L Morlé
- CNRS UA1171, Génétique Moléculaire de la Membrane Erythrocytaire, Faculté de Médecine Grange-Blanche, Lyon, France
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70
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Affiliation(s)
- P Boivin
- Inserum U 160, Hôpital Beaujon, Clichy, France
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71
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Fisher KA, Yanagimoto KC. Topography of protein kinase C substrates analyzed by membrane splitting. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 970:39-50. [PMID: 3370227 DOI: 10.1016/0167-4889(88)90220-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have used the methods of planar cell and membrane monolayer formation and monolayer splitting to study structural details of the transmembrane signaling process mediated by protein kinase C. We analyzed human red cell membrane proteins phosphorylated by phorbol ester activation of protein kinase C. Planar single membrane preparations, extraction procedures, and gel electrophoresis coupled with silver staining and autoradiography confirmed that two bands in the 100 kDa region, and bands 4.1, and 4.9, were peripheral and phosphorylated by treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA). TPA also stimulated minor incorporation of [32 P]Pi into most integral membrane proteins, including band 3, glycophorin A, the band 4.5 region (glucose transporter) and band 7. Planar cell and membrane-splitting methods revealed that neither integral nor peripheral phosphorylated polypeptides were cleaved by freeze fracture, that all phosphorylated peripheral proteins partitioned intact with the cytoplasmic side of the membrane, and that the percentages of [32P]Pi-labeled peripheral proteins were the same in split membrane cytoplasmic leaflets as in intact membranes. As a unique approach to examining protein topographies membrane splitting provides strong evidence that the major phosphorylated products of the polyphosphatidylinositide pathway are topographically associated with the cytoplasmic leaflet of the human erythrocyte plasma membrane. We further conclude that TPA-induced phosphorylation of red cell peripheral proteins does not significantly alter their transbilayer partitioning patterns after membrane splitting.
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Affiliation(s)
- K A Fisher
- Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0130
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72
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Abstract
The lipid bilayer of the adult red cell is supported on its inner surface by a complex arrangement of proteins known as the membrane skeleton. This filamentous network, a major component of which is a multifunctional protein called spectrin, has an essential role in determining the shape, structural integrity, and deformability of the red cell. A significant achievement of modern biochemistry and hematology has been the elucidation of the organization of the components of the membrane skeleton and their relationship to other membrane proteins and lipids. This article reviews current concepts of membrane skeleton structure and function and emphasizes recent advances which have been made in characterizing and classifying molecular defects of the skeleton which manifest clinically with changes in the shape and stability of the red cell. The pathobiology of hereditary skeletal defects associated with hereditary spherocytosis (HS), hereditary elliptocytosis (HE), and hereditary pyropoikilocytosis (HPP) are comprehensively discussed. Secondary defects of the membrane skeleton occurring in glucose-6-phosphate dehydrogenase deficiency and sickle cell anemia are also briefly considered.
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73
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74
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75
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Lande WM, Thiemann PV, Fisher KA, Mentzer WC. Two-dimensional electrophoretic analysis of human erythrocyte cylindrin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1984; 778:105-11. [PMID: 6548644 DOI: 10.1016/0005-2736(84)90453-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cylindrin, a macromolecule isolated from the human erythrocyte, and the band 7 proteins of the erythrocyte membrane were analyzed by one- and two-dimensional electrophoresis. Cylindrin was recovered from both the cytosol and cell membranes of hypotonically lysed erythrocytes, and its identity was confirmed by electrophoresis and transmission electron microscopy. Cylindrin from either source produced eight bands on one-dimensional SDS gels, and seventeen spots on two-dimensional gels, revealing a more complex composition than previously reported. It is unlikely that this complexity was due to proteolysis, since preparations of cylindrin with various protease inhibitors gave the same electrophoretic patterns. Mixing experiments showed that the polypeptide subunits of the cylindrin complex are distinct from the band 7 proteins of the erythrocyte membrane. This finding failed to support a role for the cylindrin macromolecule in the permeability disorders of the erythrocyte membrane associated with a missing band 7 protein.
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