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Alves-Ferreira M, da Silva ECC, Ferreira-Pereira A, Scofano HM. Regulatory differences between Ca(2+)-ATPase in plasma membranes from chicken (nucleated) and pig (anucleated) erythrocytes. Comp Biochem Physiol C Toxicol Pharmacol 2002; 131:405-15. [PMID: 11976055 DOI: 10.1016/s1532-0456(02)00023-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Kinetic and regulatory properties of the plasma membrane Ca(2+)-ATPase activity from chicken (nucleated) erythrocytes were studied and compared to those from pig (anucleated) erythrocytes. In the absence of known activators: (1) Ca(2+) affinity for the Ca(2+)-ATPase activity from nucleated erythrocytes was 12-fold higher than that from pig erythrocytes, and thus the enzyme is sensitive to physiological Ca(2+) concentrations; (2) the enzyme from chicken erythrocytes showed two apparent Km values for ATP, as compared to one apparent Km value displayed by pig erythrocytes; (3) Ca(2+)-ATPase inserted in chicken erythrocyte membranes showed a low sensitivity to activation by phosphatidylinositol-4-phosphate; (4) when p-NPP was used as substrate, the activity of chicken erythrocytes was high, similar to that attained by pig erythrocytes, but barely sensitive to activation by dimethylsulfoxide and calmodulin. ATP hydrolysis was 10-fold lower than that displayed by pig erythrocytes and the maximal velocity was activated three-fold by calmodulin. The enzyme was insensitive to alkaline phosphatase treatment and showed a single phosphorylation band in electrophoresis, ruling out the possibility of previous modulation by endogenous kinases and/or by partial proteolysis. The differences may be attributed to some endogenous modulator, to distinct isoforms, or to a difference in the E(1)/E(2) states of the enzyme.
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Affiliation(s)
- Marcelo Alves-Ferreira
- Departamento de Bioquímica Médica, ICB/CCS, UFRJ, CEP 21941-590, Rio de Janeiro, RJ, Brazil
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2
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Hägerstrand H, Danieluk M, Bobrowska-Hägerstrand M, Iglic A, Wróbel A, Isomaa B, Nikinmaa M. Influence of band 3 protein absence and skeletal structures on amphiphile- and Ca(2+)-induced shape alterations in erythrocytes: a study with lamprey (Lampetra fluviatilis), trout (Onchorhynchus mykiss) and human erythrocytes. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1466:125-38. [PMID: 10825437 DOI: 10.1016/s0005-2736(00)00184-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Amphiphiles which induce either spiculated (echinocytic) or invaginated (stomatocytic) shapes in human erythrocytes, and ionophore A23187 plus Ca(2+), were studied for their capacity to induce shape alterations, vesiculation and hemolysis in the morphologically and structurally different lamprey and trout erythrocytes. Both qualitative and quantitative differences were found. Amphiphiles induced no gross morphological changes in the non-axisymmetric stomatocyte-like lamprey erythrocyte or in the flat ellipsoidal trout erythrocyte, besides a rounding up at higher amphiphile concentrations. No shapes with large broad spicula were seen. Nevertheless, some of the 'echinocytogenic' amphiphiles induced plasma membrane protrusions in lamprey and trout erythrocytes, from where exovesicles were shed. In trout erythrocytes, occurrence of corrugations at the cell rim preceded protrusion formation. Other 'echinocytogenic' amphiphiles induced invaginations in lamprey erythrocytes. The 'stomatocytogenic' amphiphiles induced invaginations in both lamprey and trout erythrocytes. Surprisingly, in trout erythrocytes, some protrusions also occurred. Some of the amphiphiles hemolyzed lamprey, trout and human erythrocytes at a significantly different concentration/membrane area. Ionophore A23187 plus Ca(2+) induced membrane protrusions and sphering in human and trout erythrocytes; however, the lamprey erythrocyte remained unperturbed. The shape alterations in lamprey erythrocytes, we suggest, are characterized by weak membrane skeleton-lipid bilayer interactions, due to band 3 protein and ankyrin deficiency. In trout erythrocyte, the marginal band of microtubules appears to strongly influence cell shape. Furthermore, the presence of intermediate filaments and nuclei, additionally affecting the cell membrane shear elasticity, apparently influences cell shape changes in lamprey and trout erythrocytes. The different types of shape alterations induced by certain amphiphiles in the cell types indicates that their plasma membrane phospholipid composition differs.
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Affiliation(s)
- H Hägerstrand
- Department of Biology, Abo Akademi University, Abo/Turku, Finland.
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3
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Hägerstrand H, Danieluk M, Bobrowska-Hägerstrand M, Holmström T, Kralj-Iglic V, Lindqvist C, Nikinmaa M. The lamprey (Lampetra fluviatilis) erythrocyte; morphology, ultrastructure, major plasma membrane proteins and phospholipids, and cytoskeletal organization. Mol Membr Biol 1999; 16:195-204. [PMID: 10417985 DOI: 10.1080/096876899294661] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The aim of this study was to characterize the erythrocyte of the lamprey (Lampetra fluviatilis), a primitive vertebrate. The lamprey erythrocyte predominantly has a non-axisymmetric stomatocytelike shape. It has a nucleus and a haemoglobin-filled cytosol with a few organelles and vesicular structures. Surprisingly, there is no marginal band of microtubules. Sodium dodecylsulphate polyacrylamide gel electrophoresis followed by Coomassie blue staining of isolated plasma membranes revealed a single band at the level of the human spectrin doublet. Major bands also occurred at approximately 175 kDa and comigrating with human erythrocyte actin (approximately 45 kDa). The presence of spectrin, actin and vimentin was shown by immunoblotting. Band 3 protein, the anion exchanger in higher vertebrates, seemed to be highly deficient or lacking, as was also the case with ankyrin. Confocal laser scanning microscopy combined with immunocytochemical methods showed spectrin, actin and vimentin mainly to be localized around the nucleus, from where actin- and vimentin-strands extended out into the cytoplasm. Actin also seemed to be present at the plasma membrane. Phospholipid analyses of plasma membrane preparations showed the presence of the same four major phospholipid groups as in the human erythrocyte, although with higher and lower amounts of phosphatidylcholine and sphingomyelin, respectively. The low fluorescein isothiocyanate conjugated annexin V binding, as monitored by flow cytometry, indicated that phosphatidylserine is mainly confined to the inner membrane leaflet in the lamprey erythrocyte plasma membrane.
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Affiliation(s)
- H Hägerstrand
- Department of Biology, Abo Akademi University, Abo-Turku, Finland.
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4
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Li HL, Feinstein SI, Liu L, Zimmerman UJ. An antisense oligodeoxyribonucleotide to m-calpain mRNA inhibits secretion from alveolar epithelial type II cells. Cell Signal 1998; 10:137-42. [PMID: 9481489 DOI: 10.1016/s0898-6568(97)00101-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We investigated the effect of translational suppression of m-calpain on [3H]-phosphatidylcholine (PC) secretion utilising an antisense oligodexoyribonucleotide (oligo) directed against mRNA encoding m-calpain catalytic subunit. Two types of oligo, sense (S) and antisense (AS), to a portion of exon 12 of rat m-calpain catalytic subunit mRNA were tested. Constitutive secretion was decreased by 23% by AS-oligo (1 microM) treatment, while S-oligo (1 microM) had no effect. TPA-stimulated secretion was inhibited about 50-60% by AS-oligo (1-3 microM) and the inhibition was concentration-dependent, while S-oligo (1 microM) only inhibited about 10% of TPA-stimulated secretion. Northern and Western blot analyses revealed that the AS-oligo treatment reduced m-calpain mRNA and protein levels by 32% and 78%, respectively. The data indicate that antisense strategy is effective in suppressing calpain expression and type II cell secretion.
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Affiliation(s)
- H L Li
- Institute for Environmental Medicine, University of Pennsylvania Medical Center, Philadelphia 19104, USA
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5
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Nixon RA, Saito KI, Grynspan F, Griffin WR, Katayama S, Honda T, Mohan PS, Shea TB, Beermann M. Calcium-activated neutral proteinase (calpain) system in aging and Alzheimer's disease. Ann N Y Acad Sci 1994; 747:77-91. [PMID: 7847693 DOI: 10.1111/j.1749-6632.1994.tb44402.x] [Citation(s) in RCA: 207] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Calpains (CANPs) are a family of calcium-dependent cysteine proteases under complex cellular regulation. By making selective limited proteolytic cleavages, they activate or alter the regulation of certain enzymes, including key protein kinases and phosphatases, and induce specific cytoskeletal rearrangements, accounting for their suspected involvement in intracellular signaling, vesicular trafficking, and structural stabilization. Calpain activity has been implicated in various aging phenomena, including cataract formation and erythrocyte senescence. Abnormal activation of the large stores of latent calpain in neurons induces cell injury and is believed to underlie neurodegeneration in excitotoxicity, Wallerian degeneration, and certain other neuropathologic states involving abnormal calcium influx. In Alzheimer's disease, we found the ratio of activated calpain I to its latent precursor isoform in neocortex to be threefold higher than that in normal individuals and those with Huntington's or Parkinson's disease. Immunoreactivity toward calpastatin, the endogenous inhibitor of calpain, was also markedly reduced in layers II-V of the neocortex in Alzheimer's disease. The excessive calpain system activation suggested by these findings represents a potential molecular basis for synaptic loss and neuronal cell death in the brain in Alzheimer's disease given the known destructive actions of calpain I and its preferential neuronal and synaptic localization. In surviving cells, persistent calpain activation may also contribute to neurofibrillary pathology and abnormal amyloid precursor protein trafficking/processing through its known actions on protein kinases and the membrane skeleton. The degree of abnormal calpain activation in the brain in Alzheimer's disease strongly correlated with the extent of decline in levels of secreted amyloid precursor protein in brain. Cytoskeletal proteins that are normally good calpain substrates become relatively calpain resistant when they are hyperphosphorylated, which may contribute to their accumulation in neurofibrillary tangles. As a major effector of calcium signals, calpain activity may mirror disturbances in calcium homeostasis and mediate important pathologic consequences of such disturbances.
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Affiliation(s)
- R A Nixon
- Laboratories for Molecular Neuroscience, McLean Hospital, Belmont, Massachusetts 02178
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6
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Baldwin JM, Lucy JA. Chemically induced fusion of erythrocyte membranes. Methods Enzymol 1993; 220:161-73. [PMID: 8350752 DOI: 10.1016/0076-6879(93)20081-d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- J M Baldwin
- Department of Biochemistry and Chemistry, Royal Free Hospital School of Medicine, University of London, England
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7
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Ilian MA, Forsberg NE. Gene expression of calpains and their specific endogenous inhibitor, calpastatin, in skeletal muscle of fed and fasted rabbits. Biochem J 1992; 287 ( Pt 1):163-71. [PMID: 1417770 PMCID: PMC1133139 DOI: 10.1042/bj2870163] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To investigate the role of calpains in myofibrillar protein degradation in skeletal muscle and the regulation of their activity in vivo, we studied the effects of fasting on gene expression of calpains and calpastatin in the skeletal muscle of rabbits. In response to fasting, myofibrillar protein degradation increased 2-fold and mRNA levels of calpain I, calpain II and calpastatin were also increased. However, calpain and calpastatin activities remained unchanged. To investigate this discrepancy, we analysed polysomal calpain mRNA. Results indicated that fasting caused a 2-fold increase in the loading of calpain I and II mRNAs on ribosomes. Thus transcription of genes encoding calpain may be increased during fasting to ensure adequate synthesis of the proteinases needed to mobilize muscle protein reserves. The effect of fasting on calpain and calpastatin mRNA expression is shared by cathepsin D and proteasome C2 but not by beta-actin, implying that fasting invokes control of several proteolytic systems in skeletal muscle and underscores the possibility that each proteolytic system plays a role in the adaptation of skeletal muscle to the fasted state.
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Affiliation(s)
- M A Ilian
- Department of Animal Sciences, Oregon State University, Corvallis 97331
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8
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Nixon RA. Calcium-activated neutral proteinases as regulators of cellular function. Implications for Alzheimer's disease pathogenesis. Ann N Y Acad Sci 1989; 568:198-208. [PMID: 2560900 DOI: 10.1111/j.1749-6632.1989.tb12509.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Evidence is emerging that calcium-activated neutral proteinases (CANPs) not only participate in intracellular protein turnover but help to regulate the functional reorganization of cytoskeletal proteins in response to calcium and second-messenger stimulation. The high concentration of CANPs in certain neurons has suggested prominent roles for this proteolytic system in neuronal and synaptic function. In addition to acting directly on specific constituents of the cytoplasmic and membrane-associated cytoskeletal networks, CANP may amplify its effects by modulating the activities of protein kinase C and possibly other kinases and phosphatases by limited proteolysis. Given its suspected involvement at the cytoskeleton-membrane interface, calcium-mediated proteolysis is an example of a metabolic process which, if impaired, could provide a unifying basis for the slow progressive development of diverse structural and functional abnormalities within neurons. The multiplicity of mechanisms regulating its activity makes the CANP system a vulnerable target for disruption from various sources. A working hypothesis is advanced that down-regulation (inhibition) of neuronal calcium-mediated proteolysis in Alzheimer's disease is one critical and early step in the development of neurofibrillary degeneration and altered membrane cytoskeleton dynamics, which leads to membrane injury, accumulation of abnormal proteins, and synaptic dysfunction.
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Affiliation(s)
- R A Nixon
- Ralph Lowell Laboratories, McLean Hospital, Belmont, Massachusetts 02178
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9
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Marttila O, Nikinmaa M. Effects of membrane-perturbing drugs and noradrenalin on cAMP accumulation and red cell water content in carp (Cyprinus carpio) red cells. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/0300-9629(89)90164-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Bütikofer P, Brodbeck U, Ott P. Modulation of red cell vesiculation by protease inhibitors. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 904:259-67. [PMID: 3663672 DOI: 10.1016/0005-2736(87)90375-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Release of vesicles from human red cell membranes was induced either by ATP-depletion or by incubation of the cells in presence of sonicated dimyristoylphosphatidylcholine (DMPC) vesicles. Vesicles released from ATP-depleted red cells but not the DMPC-induced vesicles contained degradation products of band 3 protein. Furthermore, in ATP-depleted erythrocytes proteolytic breakdown products could be demonstrated that were not detected in cells incubated with DMPC. Proteolysis was neither significantly affected by the protease inhibitor N-alpha-tosyl-L-lysine chloromethyl ketone (TLCK) nor by other protease inhibitors tested in this study (diisopropylfluorophosphate, N-ethylmaleimide and phenylmethylsulfonyl fluoride). Both vesiculation processes were inhibited in a concentration dependent way by TLCK while other protease inhibitors did not significantly influence membrane vesiculation. Phase contrast microscopy showed that TLCK diminished the DMPC-induced formation of echinocytes which is known to precede vesicle release. These results suggest that the influence of TLCK on membrane vesiculation is not primarily due to inhibition of proteolysis but to a direct interaction of the inhibitor with the intrinsic domain of the erythrocyte membrane.
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Affiliation(s)
- P Bütikofer
- Institut für Biochemie und Molekularbiologie, Universität Bern, Switzerland
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11
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Hayashi M, Kasai Y, Kawashima S. Preferential localization of calcium-activated neutral protease in epithelial tissues. Biochem Biophys Res Commun 1987; 148:567-74. [PMID: 2825664 DOI: 10.1016/0006-291x(87)90914-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Immunohistochemical localization of calcium-activated neutral protease (CANP) in rabbit organs was determined using a monoclonal antibody against CANP. In most organs, epithelial tissues reacted intensely: these tissues include great alveolar and squamous alveolar cells in lung; interlobular artery, vein, and bile duct in liver; small vessels in skeletal muscle; glomeruli, juxtanglomerular cells, distal and collecting tubules in kidney; mucous epithelium in gallbladder; interstitial cells in testis; and cuboidal epithelial cells in brain choroid plexus. On the other hand, hepatocytes, epithelial cells which have ill defined basal lamina, were stained very faintly. These observations suggest that the physiological function of CANP is involved with transport systems in epithelial tissues through basal lamina.
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Affiliation(s)
- M Hayashi
- Department of Biochemistry, Tokyo Metropolitan Institute of Gerontology, Japan
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12
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Allan D, Raval PJ. A sphingomyelinase-resistant pool of sphingomyelin in the nuclear membrane of hen erythrocytes. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 897:355-63. [PMID: 3028484 DOI: 10.1016/0005-2736(87)90433-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Experiments in which hen erythrocytes were exposed to the action of exogenous sphingomyelinase (Staphylococcus aureus) or to their endogenous plasma membrane sphingomyelinase showed that about 15% of the total sphingomyelin was resistant to breakdown either in intact or lysed cells. This resistant pool of sphingomyelin seems likely to reside in the nuclear membranes of the cells, so that essentially all the plasma membrane sphingomyelin can be broken down by exogenous sphingomyelinase acting on intact cells, suggesting that plasma membrane sphingomyelin is exclusively localised in the outer lipid leaflet. Paradoxically, introduction of Ca2+ into the intact cells using A23187 causes the breakdown of up to 30% of total cell sphingomyelin inside the cells but without apparently affecting the putative nuclear pool of sphingomyelin and this suggests that Ca2+ may alter the original disposition of sphingomyelin in the membrane so that originally outer leaflet sphingomyelin becomes accessible to the endogenous sphingomyelinase inside the cells. No differences were seen in the fatty acid compositions of sphingomyelin degradable by exogenous sphingomyelinase, sphingomyelin degradable in the presence of A23187/Ca2+ or the enzyme-resistant pool of sphingomyelin.
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Glaser T, Kosower NS. Calpain-calpastatin and fusion. Fusibility of erythrocytes is determined by a protease-protease inhibitor [calpain-calpastatin] balance. FEBS Lett 1986; 206:115-20. [PMID: 3019763 DOI: 10.1016/0014-5793(86)81351-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rat erythrocytes fuse when treated with the membrane mobility agent, 2-(2-methoxyethoxy)ethyl-cis-8-(2-octylcyclopropyl)octanoate (A2C) and Ca2+, whereas human cells do not. Membrane proteolysis promoted by calpain is required for rat cell fusion [(1986) Eur. J. Biochem., in press]. Human calpain induced a selective proteolysis in both the human and rat erythrocyte ghosts (mainly band 4.1 in the human, band 4.1 and band 3 in the rat cell) and rendered them fusible. Calpastatin (calpain inhibitor) prevented A2C-induced fusion in both ghosts, via inhibition of proteolysis. The human erythrocyte has excess calpastatin and resists A2C-promoted fusion. A regulatory role of calpastatin in membrane fusion is thus indicated.
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Glaser T, Kosower NS. Fusion of rat erythrocytes by membrane-mobility agent A2C depends on membrane proteolysis by a cytoplasmic calpain. EUROPEAN JOURNAL OF BIOCHEMISTRY 1986; 159:387-92. [PMID: 3019690 DOI: 10.1111/j.1432-1033.1986.tb09880.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The membrane-mobility agent 2-(2-methoxyethoxy)ethyl-cis-8-(2-octylcyclopropyl)octanoate (A2C) promotes fusion of rat, but not of human, erythrocytes. The difference in fusibility was shown to be correlated with membrane proteolysis, a process induced by Ca2+ in the rat erythrocytes or hemolysate-loaded ghosts, but not in the human cell. Membrane proteolysis is necessary but not sufficient for fusion. Fusion requires both Ca2+ and A2C [Kosower, N. S., Glaser, T. and Kosower, E. M. (1983) Proc. Natl Acad. Sci USA 80, 7542-7546]. Membrane proteolysis (Ca2+-dependent) and fusion (Ca2+ and A2C-dependent) requires a Ca2+-activated cytoplasmic thiol protease, as shown by the following observations. In intact rat erythrocytes, proteolysis and fusion are prevented by thiol alkylation and by inhibitors of Ca2+-dependent thiol proteases. Inhibitors to other proteases have no effect. Erythrocyte ghosts undergo proteolysis and fusion only when loaded with non-inhibited hemolysate, irrespective of membrane status (native or alkylated membrane). A partially purified cytosolic enzyme, identified as calpain I, promotes proteolysis in rat erythrocyte ghosts. A2C induces fusion only in such calpain-treated ghosts.
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Ahkong QF, Lucy JA. Osmotic forces in artificially induced cell fusion. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 858:206-16. [PMID: 3707962 DOI: 10.1016/0005-2736(86)90308-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The importance of cell swelling in the fusion of erythrocytes by three different chemical treatments has been investigated with cells that were cytoplasmically labelled with 6-carboxyfluorescein. Hen erythrocytes, which had been pre-incubated with ionophore A23187 and 5 mM Ca2+ to cause a proteolytic breakdown of the membrane skeleton, were induced to fuse by applying an osmotic shock. Human erythrocytes that had been incubated in an isotonic salt/buffer solution, which was progressively diluted and which contained 0.5 mM La3+ to minimise cell lysis, were also fused. In addition, the fusion of human erythrocytes by 40% poly(ethylene glycol) began only when the poly(ethylene glycol) was diluted, and it mostly occurred when the diluted polymer solution was subsequently replaced by isotonic buffer. In related experiments, the effect of an osmotic gradient on electrically induced cell fusion has been studied. Human erythrocytes in 150 mM erythritol fused more readily than less swollen cells in 200-400 mM erythritol when subjected to a 20 microseconds pulse of 3.5 kV X cm-1, indicating that the extent of cell fusion induced by the breakdown pulse is governed by the combined electrical-compressive and osmotic forces. Since osmotic phenomena are already known to be important in exocytosis, we suggest that these observations on cell fusion indicate that osmotic forces may provide the driving force for many membrane fusion reactions in biological systems.
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Guenet L, Gueble-Val F, Blayau M, Le Treut A, Le Gall JY. Partial purification and characterization of a serine endopeptidase from rat liver plasma membranes. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 881:258-67. [PMID: 3513845 DOI: 10.1016/0304-4165(86)90012-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A serine endopeptidase was partially purified from rat liver plasma membranes by using a four-step procedure: solubilization with N-lauroylsarcosine; Ultrogel AcA-34 chromatography; CM Affi-Gel blue chromatography; agarose-soybean trypsin inhibitor chromatography. This enzyme was found to hydrolyze casein and various chromogenic peptide substrates; highest activity occurred with H-D-Val-Leu-Arg-p-nitroanilide, reported to be a specific substrate for human glandular kallikreins. The enzyme was heat-sensitive, showed a pH optimum between 8.0 and 9.0 and was inhibited by D-Phe-L-Phe-L-Arg-CH2Cl, aprotinin, diisopropyl fluorophosphate (DFP), soybean trypsin inhibitor, phenylmethylsulphonyl fluoride, leupeptin, antipain and dithiothreitol. This liver plasma membrane proteinase has an apparent molecular weight of about 30 000 as determined by Ultrogel AcA-34 chromatography and by autoradiography of [3H]DFP-labelled protein electrophoresis.
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17
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Abstract
A molecular model for fusion-fission reactions in membranes is proposed that is based on data from studies on artificially induced cell fusion and on the behaviour of phospholipid bilayers: it is put forward as a framework for further investigations into this fundamental property of biological systems.
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18
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Abstract
The variable distribution of the 80-kD subunit of two calcium-activated proteases, calpain I and calpain II, has been examined in L8 and L6 myoblasts, and their non-fusing variants, fu-1 and M3A using non-cross-reacting monoclonal antibodies to both subunits. Immunofluorescence results have shown that while the 80-kD subunit of calpain I is localized in the cytoplasm of all the myoblasts, the 80-kD subunit of calpain II appears to be predominantly associated with the plasma membranes of L8 and L6 myoblasts. The distribution of the 80-kD subunit of calpain II in non-fusing myoblasts, fu-1 and M3A, is generally cytoplasmic and diffuse. Immunoblot analysis of membrane and cytosol fractions of all the myoblasts using the monoclonal antibodies described above essentially confirms the immunofluorescence findings. Because calpain II exhibits a peripheral distribution in cells which are fusion-competent, L6 and L8 myoblasts, but not in fu-1 and M3A myoblasts, we suggest that calpain II may play a role in the Ca2+-mediated fusion events of differentiating (prefusion) myoblasts.
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Rousseau A, Livni N, Gatt S. Utilization of membranous lipid substrates by membranous enzymes: activation of the latent sphingomyelinase of hen erythrocyte membrane. Arch Biochem Biophys 1986; 244:838-45. [PMID: 3004352 DOI: 10.1016/0003-9861(86)90653-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Previous studies demonstrated that hen erythrocytes have an inoperative, latent sphingomyelinase which is activated when the cells are hemolyzed in a hypotonic medium. Within minutes after hemolysis about 60-80% of the sphingomyelin (SPM) of the RBC "ghost" membrane was hydrolyzed. In this paper, expression of sphingomyelinase activity was further investigated. The percentage of total SPM hydrolyzed depended on the volume of the hypotonic hemolyzing buffer. Thus, suspending the erythrocytes in 4 vol of the buffer resulted in clumping of the hemolyzed "ghosts" and no hydrolysis of SPM. In comparison, suspension in 19 vol of the hypotonic buffer showed no clumping and sphingomyelinase activity was fully expressed. But centrifugation of the latter or, alternatively, addition of concanavalin A induced clumping and elimination of sphingomyelinase activity. Hen RBC could also be hemolyzed in an isotonic medium in the presence of Triton X-100, mellitin, halothane, and phospholipase C. Activation of the latent sphingomyelinase occurred at concentrations of these reagents which caused cell lysis. Hen RBC were dispersed in an isotonic medium containing glutaraldehyde (0.1%) or formaldehyde (10%). This rendered the cells resistant to hemolysis, even when subsequently dispersed in a hypotonic medium or water. But incubation of the "fixed" cells in a hypotonic or isotonic medium activated the enzyme, resulting in hydrolysis of 60% of the cellular SPM. In contrast, when glutaraldehyde was included in the hypotonic buffer, hemolysis occurred but sphingomyelinase activity was eliminated.
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20
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Fleming AD, Kosower NS, Yanagimachi R. Alteration of sperm thiol-disulfide status and capacitation in the guinea pig. ACTA ACUST UNITED AC 1986. [DOI: 10.1002/mrd.1120130202] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Vorgias CE, Traub P. Efficient degradation in vitro of all intermediate filament subunit proteins by the Ca2+-activated neutral thiol proteinase from Ehrlich ascites tumor cells and porcine kidney. Biosci Rep 1986; 6:57-64. [PMID: 3516236 DOI: 10.1007/bf01145179] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Vimentin, desmin, glial fibrillary acidic protein, neurofilament triplet proteins, and a mixture of cytokeratins were digested with Ca2+-activated neutral thiol proteinase isolated from Ehrlich ascites tumor (EAT) cells and porcine kidney. All intermediate filament proteins were degraded by the proteinase, although with different rates and Ca2+ optima. These results are in part at variance with our previous statement that the Ca2+-activated proteinase from EAT cells is specific for vimentin and desmin.
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Raval PJ, Allan D. The effects of phorbol ester, diacylglycerol, phospholipase C and Ca2+ ionophore on protein phosphorylation in human and sheep erythrocytes. Biochem J 1985; 232:43-7. [PMID: 4084238 PMCID: PMC1152836 DOI: 10.1042/bj2320043] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Treatment of human or sheep erythrocytes with PMA (phorbol myristate acetate) enhanced [32P]phosphate labelling of membrane polypeptides of approx. 100, 80 and 46 kDa. The 80 kDa and 46 kDa polypeptides coincided with bands 4.1 and 4.9 respectively on Coomassie-Blue-stained gels. Similar but smaller effects were obtained by treating human cells with 1-oleoyl-2-acetyl-rac-glycerol (OAG), exogenous bacterial phospholipase C or ionophore A23187 + Ca2+, each of which treatments would be expected to raise the concentration of membrane diacylglycerol. In contrast, sheep cells, which do not increase their content of diacylglycerol when treated with phospholipase C or A23187 + Ca2+, only showed enhanced phosphorylation with OAG. Neither human nor sheep cells showed any enhanced [32P]phosphate labelling of phosphoproteins when treated with 1-mono-oleoyl-rac-glycerol. It is concluded that diacylglycerol from a variety of sources can activate erythrocyte protein kinase C, but that the most effective diacylglycerol is that derived from endogenous polyphosphoinositides. In contrast with bacterial phospholipase C and A23187, which stimulate synthesis of phosphatidate by increasing the cell-membrane content of diacylglycerol in human erythrocytes, PMA, OAG or 1-mono-oleoyl-rac-glycerol caused no change in phospholipid metabolism.
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Raval PJ, Allan D. Ca2+-induced polyphosphoinositide breakdown due to phosphomonoesterase activity in chicken erythrocytes. Biochem J 1985; 231:179-83. [PMID: 2998339 PMCID: PMC1152719 DOI: 10.1042/bj2310179] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Treatment of chicken erythrocytes with ionophore A23187 and Ca2+ caused the breakdown of a large proportion of the cellular polyphosphoinositides. Since no diacylglycerol or phosphatidate was generated, but there was a small increase in the level of phosphatidylinositol, it was concluded that breakdown occurred as a result of phosphomonoesterase activation. Experiments with subcellular fractions showed that the phosphomonoesterase activity was present in the cytosolic fraction of the cells.
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Pearce RS, Willison JH. A freeze-etch study of the effects of extracellular freezing on cellular membranes of wheat. PLANTA 1985; 163:304-316. [PMID: 24249403 DOI: 10.1007/bf00395140] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/1983] [Accepted: 08/28/1984] [Indexed: 06/02/2023]
Abstract
Seedlings of Triticum aestivum L. cv. Lennox were grown in different environments to obtain different hardiness. Pieces of laminae and leaf bases were slowly cooled to sub-zero temperatures and the damage caused was assessed by an ion-leakage method. Comparable pieces of tissue were slowly cooled to temperatures between 2° and-14°C and were then freeze-fixed and freeze-etched. Membranes generally retained their lamellar structures indicated by the abundance of typical membrane fracture faces in all treatments, and some membrane fracture faces had patches which lacked the usual scattering of intramembranous particles (IMP). These IMP-free areas were present in the plasma membrane of tissues given a damaging freezing treatment, but were absent from the plasma membrane of room-temperature controls, of supercooled tissues, and of tissues given a non-damaging freezing treatment. The frequency of IMP-free areas and the proportion of the plasma membrane affected increased with increasing damage. In the most damaged tissue (79% damage; leaf bases exposed to-8°C), 20% of the plasma membrane was IMP-free. The frequencies of IMP at a distance from the IMP-free areas were unaffected by freezing treatments. There was a patchy distribution of IMP in other membranes (nuclear envelope, tonoplast, thylakoids, chloroplast envelope), but only in the nuclear envelope did it appear possible that their occurrence coincided with damage. The IMP-free areas of several membranes were sometimes associated together in stacks. Such membranes lay both to the outside and inside of the plasma membrane, indicating that at least some of the adjacent membrane fragments arose as a result of membrane reorganization induced by the damaging treatment. Occasional views of folded IMP-free plasma membrane tended to confirm this conclusion. The following hypothesis is advanced to explain the damage induced by extracellular freezing. Areas of plasma membrane become free of IMP, probably as a result of the freezing-induced cellular dehydration. The lipids in these IMP-free patches may be in the fluid rather than the gel phase. The formation of these IMP-free patches, especially in the plasma membrane, initiates or involves proliferation and possibly fusion of membranes, and during or following this process, the cells become leaky.
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Affiliation(s)
- R S Pearce
- Department of Agricultural Biology, University of Newcastle upon Tyne, NE1 7RU, Newcastle upon Tyne, UK
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Sasaki T, Kikuchi T, Yumoto N, Yoshimura N, Murachi T. Comparative specificity and kinetic studies on porcine calpain I and calpain II with naturally occurring peptides and synthetic fluorogenic substrates. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90773-8] [Citation(s) in RCA: 212] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Abstract
Goose erythrocytes were subjected to agents and treatments that produce echinocytosis in human erythrocytes. In the presence of the ionophore A23187 and calcium at greater than micromolar concentrations, goose red cells retained their normal ellipsoidal symmetry, but developed extensive semiregular membrane wrinkles or corrugations. Metabolic NTP (nucleoside triphosphate) depletion, induced either by iodoacetamide or by incubating the cells without a substrate, initially produced a similar cell corrugation, but after prolonged incubation most cells became spherical with the nucleus displaced to the cell periphery. The echinocytic agents indomethacin and dimyristoylphosphatidylcholine had no effect on the gross morphology of goose erythrocytes.
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Zimmerman UJ, Schlaepfer WW. Kinase activities associated with calcium-activated neutral proteases. Biochem Biophys Res Commun 1984; 120:767-74. [PMID: 6329183 DOI: 10.1016/s0006-291x(84)80173-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Studies on the phosphorylation of calcium-activated neutral protease (CANP) revealed the presence of kinase activities closely associated with purified CANP preparations. The kinase activity in uCANP (CANP with high affinity for calcium) was cAMP-independent whereas the kinase activity in mCANP (CANP with low affinity for calcium) was cAMP-dependent, inhibited by kinase specific inhibitor and abolished when the mCANP was preincubated in calcium. The CANP-associated kinase(s) phosphorylate uCANP and mCANP , causing modulation of their proteolytic activities.
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Zimmermann U, Vienken J, Pilwat G, Arnold WM. Electro-fusion of cells: principles and potential for the future. ACTA ACUST UNITED AC 1984; 103:60-85. [PMID: 6561138 DOI: 10.1002/9780470720844.ch5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Exposure of cells or liposomes to a brief pulse of a strong electrical field can result in a reversible breakdown of the outer membrane. Such breakdown results in an increase in permeability of the plasmalemma, which however re-seals after a short incubation (i.e. the original impermeability is restored). Two or more cells in contact can be made to fuse by this process, provided that the contact is close enough and that the pulse of the electrical field is short enough not to damage the cells. Methods of achieving this contact by electrical and magnetic fields are described. The magnetic method does not demand the use of the low conductivity media used earlier. Other possible modifications of this flexible technique are also described, and used to show how the technique can be modified in future, and how it may be applied to the fields of membrane research, medicine and plant breeding.
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Lucy JA. Do hydrophobic sequences cleaved from cellular polypeptides induce membrane fusion reactions in vivo? FEBS Lett 1984; 166:223-31. [PMID: 6363131 DOI: 10.1016/0014-5793(84)80085-x] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The concept that a direct interaction between Ca2+ and phospholipids is a major factor in membrane fusion reactions is questioned. Attention is drawn to a number of findings on associations between fusion and the proteolysis of membrane proteins. It is proposed that hydrophobic polypeptides, which are functionally comparable to the fusogenic proteins of certain viruses but which are produced in cells by the endogenous proteolysis of membrane and cellular proteins, may induce membrane fusion reactions in vivo.
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Zimmerman UJ, Schlaepfer WW. Calcium-activated neutral protease (CANP) in brain and other tissues. Prog Neurobiol 1984; 23:63-78. [PMID: 6097938 DOI: 10.1016/0301-0082(84)90012-1] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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