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Grice BA, Barton KJ, Covert JD, Kreilach AM, Tackett L, Brozinick JT, Elmendorf JS. Excess membrane cholesterol is an early contributing reversible aspect of skeletal muscle insulin resistance in C57BL/6NJ mice fed a Western-style high-fat diet. Am J Physiol Endocrinol Metab 2019; 317:E362-E373. [PMID: 31237447 PMCID: PMC6732462 DOI: 10.1152/ajpendo.00396.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Skeletal muscle insulin resistance manifests shortly after high-fat feeding, yet mechanisms are not known. Here we set out to determine whether excess skeletal muscle membrane cholesterol and cytoskeletal derangement known to compromise glucose transporter (GLUT)4 regulation occurs early after high-fat feeding. We fed 6-wk-old male C57BL/6NJ mice either a low-fat (LF, 10% kcal) or a high-fat (HF, 45% kcal) diet for 1 wk. This HF feeding challenge was associated with an increase, albeit slight, in body mass, glucose intolerance, and hyperinsulinemia. Liver analyses did not reveal signs of hepatic insulin resistance; however, skeletal muscle immunoblots of triad-enriched regions containing transverse tubule membrane showed a marked loss of stimulated GLUT4 recruitment. An increase in cholesterol was also found in these fractions from HF-fed mice. These derangements were associated with a marked loss of cortical filamentous actin (F-actin) that is essential for GLUT4 regulation and known to be compromised by increases in membrane cholesterol. Both the withdrawal of the HF diet and two subcutaneous injections of the cholesterol-lowering agent methyl-β-cyclodextrin at 3 and 6 days during the 1-wk HF feeding intervention completely mitigated cholesterol accumulation, cortical F-actin loss, and GLUT4 dysregulation. Moreover, these beneficial membrane/cytoskeletal changes occurred concomitant with a full restoration of metabolic responses. These results identify skeletal muscle membrane cholesterol accumulation as an early, reversible, feature of insulin resistance and suggest cortical F-actin loss as an early derangement of skeletal muscle insulin resistance.
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Affiliation(s)
- Brian A Grice
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kelly J Barton
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jacob D Covert
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Alec M Kreilach
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Lixuan Tackett
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Joseph T Brozinick
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
- Eli Lilly and Company, Indianapolis, Indiana
| | - Jeffrey S Elmendorf
- Department of Anatomy, Cell Biology, and Physiology, Indiana University School of Medicine, Indianapolis, Indiana
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
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2
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Local membrane charge regulates β 2 adrenergic receptor coupling to G i3. Nat Commun 2019; 10:2234. [PMID: 31110175 PMCID: PMC6527575 DOI: 10.1038/s41467-019-10108-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 04/18/2019] [Indexed: 11/13/2022] Open
Abstract
The β2 adrenergic receptor (β2AR) signals through both Gs and Gi in cardiac myocytes, and the Gi pathway counteracts the Gs pathway. However, Gi coupling is much less efficient than Gs coupling in most cell-based and biochemical assays, making it difficult to study β2AR−Gi interactions. Here we investigate the role of phospholipid composition on Gs and Gi coupling. While negatively charged phospholipids are known to enhance agonist affinity and stabilize an active state of the β2AR, we find that they impair coupling to Gi3 and facilitate coupling to Gs. Positively charged Ca2+ and Mg2+, known to interact with the negative charge on phospholipids, facilitates Gi3 coupling. Mutational analysis suggests that Ca2+ coordinates an interaction between phospholipid and the negatively charged EDGE motif on the amino terminal helix of Gi3. Taken together, our observations suggest that local membrane charge modulates the interaction between β2AR and competing G protein subtypes. In the healthy heart, the β2 adrenergic receptor (β2AR) signals through Gs and Gi proteins but the mechanism underlying G protein selectivity is not fully understood. Here, the authors show that membrane charge and intracellular cations modulate the β2AR−Gi3 interaction.
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3
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Russell J, Du Toit EF, Peart JN, Patel HH, Headrick JP. Myocyte membrane and microdomain modifications in diabetes: determinants of ischemic tolerance and cardioprotection. Cardiovasc Diabetol 2017; 16:155. [PMID: 29202762 PMCID: PMC5716308 DOI: 10.1186/s12933-017-0638-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular disease, predominantly ischemic heart disease (IHD), is the leading cause of death in diabetes mellitus (DM). In addition to eliciting cardiomyopathy, DM induces a ‘wicked triumvirate’: (i) increasing the risk and incidence of IHD and myocardial ischemia; (ii) decreasing myocardial tolerance to ischemia–reperfusion (I–R) injury; and (iii) inhibiting or eliminating responses to cardioprotective stimuli. Changes in ischemic tolerance and cardioprotective signaling may contribute to substantially higher mortality and morbidity following ischemic insult in DM patients. Among the diverse mechanisms implicated in diabetic impairment of ischemic tolerance and cardioprotection, changes in sarcolemmal makeup may play an overarching role and are considered in detail in the current review. Observations predominantly in animal models reveal DM-dependent changes in membrane lipid composition (cholesterol and triglyceride accumulation, fatty acid saturation vs. reduced desaturation, phospholipid remodeling) that contribute to modulation of caveolar domains, gap junctions and T-tubules. These modifications influence sarcolemmal biophysical properties, receptor and phospholipid signaling, ion channel and transporter functions, contributing to contractile and electrophysiological dysfunction, cardiomyopathy, ischemic intolerance and suppression of protective signaling. A better understanding of these sarcolemmal abnormalities in types I and II DM (T1DM, T2DM) can inform approaches to limiting cardiomyopathy, associated IHD and their consequences. Key knowledge gaps include details of sarcolemmal changes in models of T2DM, temporal patterns of lipid, microdomain and T-tubule changes during disease development, and the precise impacts of these diverse sarcolemmal modifications. Importantly, exercise, dietary, pharmacological and gene approaches have potential for improving sarcolemmal makeup, and thus myocyte function and stress-resistance in this ubiquitous metabolic disorder.
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Affiliation(s)
- Jake Russell
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Eugene F Du Toit
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Jason N Peart
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Hemal H Patel
- VA San Diego Healthcare System and Department of Anesthesiology, University of California San Diego, San Diego, USA
| | - John P Headrick
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia. .,School of Medical Science, Griffith University, Southport, QLD, 4217, Australia.
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4
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Macias-Medri AE, Liendo JA, Silva RJ. An electrostatic and probabilistic simulation model to describe neurosecretion at the synaptic scale. NETWORK (BRISTOL, ENGLAND) 2017; 28:53-73. [PMID: 29120672 DOI: 10.1080/0954898x.2017.1386806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A hybrid simulation model (macro-molecular dynamics and Monte Carlo method) is proposed to reproduce neurosecretion and exocytosis. A theory has been developed for vesicular dynamics based on quasi-static electric interactions and a simple transition-state model for the vesicular fusion. Under the non-equilibrium electric conditions in an electrolytic fluid, it is considered that the motion of each synaptic vesicle is influenced by electrostatic forces exerted by the membranes of the synaptic bouton, other vesicles, the intracellular and intravesicular fluids, and external elements to the neuron. In addition, friction between each vesicle and its surrounding intracellular fluid is included in the theory, resulting in a drift type movement. To validate the vesicle equations of motion, a molecular dynamics method has been implemented, where the synaptic pool was replaced by a straight angle parallelepiped, the vesicles were represented by spheres and the fusion between each vesicle and the presynaptic membrane was simulated by a Monte Carlo type probabilistic change of state. Density profiles showing clusters of preferential activity as well as fusion distributions similar to the Poisson distributions associated with miniature end-plate potentials were obtained in the simulations.
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Affiliation(s)
- A E Macias-Medri
- a Departamento de Física , Universidade Federal do Paraná , Curitiba , Brazil
| | - Jacinto A Liendo
- b Physics Department , Simón Bolívar University , Baruta , Venezuela
| | - Ricardo J Silva
- c Instituto Montenegro para la Investigación y Desarrollo de las Neurociencias Cognitivas , Unidad Médica I de la Clínica San Francisco , Guayaquil , Ecuador
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5
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Demonbreun AR, McNally EM. Muscle cell communication in development and repair. Curr Opin Pharmacol 2017; 34:7-14. [PMID: 28419894 DOI: 10.1016/j.coph.2017.03.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Revised: 02/25/2017] [Accepted: 03/06/2017] [Indexed: 12/18/2022]
Abstract
Under basal conditions, postnatal skeletal muscle displays little cell turnover. With injury, muscle initiates a rapid repair response to reseal damaged membrane, reactivating many developmental pathways to facilitate muscle regeneration and prevent tissue loss. Muscle precursor cells become activated accompanied by differentiation and fusion during both muscle growth and regeneration; inter-cellular communication is required for successful completion of these processes. Cellular communication is mediated by lipids, fusogenic membrane proteins, and exosomes. Muscle-derived exosomes carry proteins and micro RNAs as cargo. Secreted factors such as IGF-1, TGFβ, and myostatin are also released by muscle cells providing local signaling cues to modulate muscle fusion and regeneration. Proteins that regulate myoblast fusion also participate in membrane repair and regeneration. Here we will review methods of muscle cell communication focusing on proteins that mediate membrane fusion, exosomes, and autocrine factors.
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Affiliation(s)
- Alexis R Demonbreun
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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Llanos P, Contreras-Ferrat A, Georgiev T, Osorio-Fuentealba C, Espinosa A, Hidalgo J, Hidalgo C, Jaimovich E. The cholesterol-lowering agent methyl-β-cyclodextrin promotes glucose uptake via GLUT4 in adult muscle fibers and reduces insulin resistance in obese mice. Am J Physiol Endocrinol Metab 2015; 308:E294-305. [PMID: 25491723 DOI: 10.1152/ajpendo.00189.2014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Insulin stimulates glucose uptake in adult skeletal muscle by promoting the translocation of GLUT4 glucose transporters to the transverse tubule (T-tubule) membranes, which have particularly high cholesterol levels. We investigated whether T-tubule cholesterol content affects insulin-induced glucose transport. Feeding mice a high-fat diet (HFD) for 8 wk increased by 30% the T-tubule cholesterol content of triad-enriched vesicular fractions from muscle tissue compared with triads from control mice. Additionally, isolated muscle fibers (flexor digitorum brevis) from HFD-fed mice showed a 40% decrease in insulin-stimulated glucose uptake rates compared with fibers from control mice. In HFD-fed mice, four subcutaneous injections of MβCD, an agent reported to extract membrane cholesterol, improved their defective glucose tolerance test and normalized their high fasting glucose levels. The preincubation of isolated muscle fibers with relatively low concentrations of MβCD increased both basal and insulin-induced glucose uptake in fibers from controls or HFD-fed mice and decreased Akt phosphorylation without altering AMPK-mediated signaling. In fibers from HFD-fed mice, MβCD improved insulin sensitivity even after Akt or CaMK II inhibition and increased membrane GLUT4 content. Indinavir, a GLUT4 antagonist, prevented the stimulatory effects of MβCD on glucose uptake. Addition of MβCD elicited ryanodine receptor-mediated calcium signals in isolated fibers, which were essential for glucose uptake. Our findings suggest that T-tubule cholesterol content exerts a critical regulatory role on insulin-stimulated GLUT4 translocation and glucose transport and that partial cholesterol removal from muscle fibers may represent a useful strategy to counteract insulin resistance.
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Affiliation(s)
- Paola Llanos
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Institute for Research in Dental Sciences, Facultad de Odontología, Universidad de Chile, Santiago, Chile;
| | - Ariel Contreras-Ferrat
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Institute for Research in Dental Sciences, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Tihomir Georgiev
- Medical Biophysics, Institute of Physiology und Pathophysiology, Ruprecht Karls Universität, Heidelberg, Germany
| | | | - Alejandra Espinosa
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Jorge Hidalgo
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Physiology and Biophysics Program, Institute of Biomedical Sciences (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Cecilia Hidalgo
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Physiology and Biophysics Program, Institute of Biomedical Sciences (ICBM), Facultad de Medicina, Universidad de Chile, Santiago, Chile; Biomedical Neuroscience Institute, Facultad de Medicina, Universidad de Chile, Santiago, Chile; and
| | - Enrique Jaimovich
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Cell and Molecular Biology Program, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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7
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8
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Peachey LD, Franzini‐Armstrong C. Structure and Function of Membrane Systems of Skeletal Muscle Cells. Compr Physiol 2011. [DOI: 10.1002/cphy.cp100102] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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9
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Kim H, Lee BJ, Lee MH, Hong SG, Ryu PD. Mechanisms of selective antimicrobial activity of gaegurin 4. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2009; 13:39-47. [PMID: 19885025 DOI: 10.4196/kjpp.2009.13.1.39] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Gaegurin 4 (GGN4), an antimicrobial peptide isolated from a Korean frog, is five times more potent against Gram-positive than Gram-negative bacteria, but has little hemolytic activity. To understand the mechanism of such cell selectivity, we examined GGN4-induced K(+) efflux from target cells, and membrane conductances in planar lipid bilayers. The K(+) efflux from Gram-positive M. luteus (2.5 microg/ml) was faster and larger than that from Gram-negative E. coli (75 microg/ml), while that from RBC was negligible even at higher concentration (100 microg/ml). GGN4 induced larger conductances in the planar bilayers which were formed with lipids extracted from Gram-positive B. subtilis than in those from E. coli (p<0.01), however, the effects of GGN4 were not selective in the bilayers formed with lipids from E. coli and red blood cells. Addition of an acidic phospholipid, phosphatidylserine to planar bilayers increased the GGN4-induced membrane conductance (p<0.05), but addition of phosphatidylcholine or cholesterol reduced it (p<0.05). Transmission electron microscopy revealed that GGN4 induced pore-like damages in M. luteus and dis-layering damages on the outer wall of E. coli. Taken together, the present results indicate that the selectivity of GGN4 toward Gram-positive over Gram-negative bacteria is due to negative surface charges, and interaction of GGN4 with outer walls. The selectivity toward bacteria over RBC is due to the presence of phosphatidylcholine and cholesterol, and the trans-bilayer lipid asymmetry in RBC. The results suggest that design of selective antimicrobial peptides should be based on the composition and topology of membrane lipids in the target cells.
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Affiliation(s)
- Heejeong Kim
- Laboratories of Veterinary Pharmacology and Biochemistry, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea
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10
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Berman MC. Slippage and uncoupling in P-type cation pumps; implications for energy transduction mechanisms and regulation of metabolism. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1513:95-121. [PMID: 11470083 DOI: 10.1016/s0005-2736(01)00356-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
P-type ATPases couple scalar and vectorial events under optimized states. A number of procedures and conditions lead to uncoupling or slippage. A key branching point in the catalytic cycle is at the cation-bound form of E(1)-P, where isomerization to E(2)-P leads to coupled transport, and hydrolysis leads to uncoupled release of cations to the cis membrane surface. The phenomenon of slippage supports a channel model for active transport. Ability to occlude cations within the channel is essential for coupling. Uncoupling and slippage appear to be inherent properties of P-type cation pumps, and are significant contributors to standard metabolic rate. Heat production is favored in the uncoupled state. A number of disease conditions, include ageing, ischemia and cardiac failure, result in uncoupling of either the Ca(2+)-ATPase or Na(+)/K(+)-ATPase.
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Affiliation(s)
- M C Berman
- Division of Chemical Pathology, Health Sciences Faculty, University of Cape Town, Observatory 7925, Cape Town, South Africa.
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11
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Brandt NR, Franklin G, Brunschwig JP, Caswell AH. The role of mitsugumin 29 in transverse tubules of rabbit skeletal muscle. Arch Biochem Biophys 2001; 385:406-9. [PMID: 11368024 DOI: 10.1006/abbi.2000.2148] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- N R Brandt
- Department of Molecular and Cellular Pharmacology, University of Miami School of Medicine, Florida 33126, USA.
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12
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Brandt NR, Caswell AH. Localization of mitsugumin 29 to transverse tubules in rabbit skeletal muscle. Arch Biochem Biophys 1999; 371:348-50. [PMID: 10545225 DOI: 10.1006/abbi.1999.1444] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- N R Brandt
- Department of Molecular & Cellular Pharmacology, University of Miami School of Medicine, Miami, Florida 33126, USA.
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13
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Borchman D, Tang D, Yappert MC. Lipid composition, membrane structure relationships in lens and muscle sarcoplasmic reticulum membranes. BIOSPECTROSCOPY 1999; 5:151-67. [PMID: 10380082 DOI: 10.1002/(sici)1520-6343(1999)5:3<151::aid-bspy5>3.0.co;2-d] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Membrane lipid composition varies in different tissues and species. Since a defined lipid composition is essential to the function of many membranes, the relationship between membrane lipid composition and structure was determined using infrared and Raman spectroscopy in four membranes containing a calcium pump: rabbit fast and slow twitch muscle sarcoplasmic reticulum and human and bovine lens fiber cell membranes. We found that membrane sphingolipid and phosphatidylcholine content were correlated to a decrease and increase, respectively, in the infrared lipid CH2 symmetric stretching band frequency. We interpret the change in frequency as a change in lipid hydrocarbon chain structural order. This was confirmed by Raman order parameters. The high degree of hydrocarbon chain saturation found in the variable amide chains of sphingolipids is likely to account for this correlation. Lipid phase transition temperature and cooperativity also correlated to sphingolipid and phosphatidylcholine content, and are the forces defining the order in at physiological temperature in the samples studied. Ca(2+)-ATPase caused an increase in the CH2 symmetric stretching frequency in fast twitch muscle sarcoplasmic reticulum (interpreted as an increase in hydrocarbon chain disorder), but had no effect on slow twitch muscle sarcoplasmic reticulum lipid hydrocarbon chain structure. In the natural systems studied, we find that it is the lipid hydrocarbon chain saturation that defines lipid hydrocarbon chain order.
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MESH Headings
- Animals
- Calcium-Transporting ATPases/metabolism
- Cattle
- Cell Membrane/chemistry
- Cell Membrane/ultrastructure
- Humans
- Hydrocarbons
- Lens, Crystalline/chemistry
- Lens, Crystalline/cytology
- Lipids/analysis
- Lipids/chemistry
- Male
- Muscle Fibers, Fast-Twitch/chemistry
- Muscle Fibers, Fast-Twitch/cytology
- Muscle Fibers, Slow-Twitch/chemistry
- Muscle Fibers, Slow-Twitch/cytology
- Muscle, Skeletal/chemistry
- Muscle, Skeletal/cytology
- Phosphatidylcholines/analysis
- Phosphatidylcholines/chemistry
- Rabbits
- Sarcoplasmic Reticulum/chemistry
- Spectrophotometry, Infrared
- Spectrum Analysis, Raman
- Sphingolipids/analysis
- Sphingolipids/chemistry
- Temperature
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Affiliation(s)
- D Borchman
- Department of Ophthalmology & Visual Sciences, Kentucky Lions Eye Research Institute, School of Medicine, University of Louisville, Kentucky 40202, USA
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14
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Milting H, Heilmeyer LM, Thieleczek R. Phosphoinositides in membranes that build up the triads of rabbit skeletal muscle. FEBS Lett 1994; 345:211-8. [PMID: 8200458 DOI: 10.1016/0014-5793(94)00440-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The total membrane concentrations of PtdIns, PtdIns4P, and PtdIns(4,5)P2 contribute to the functional capacity of the Ins(1,4,5)P3 signalling system which is operating in skeletal muscle but the function of which is still unknown. Total amounts of these phosphoinositides have been determined in purified membranes of transverse tubules (TT) and terminal cisternae (TC) of the sarcoplasmic reticulum (SR) of rabbit skeletal muscle. PtdIns and PtdIns4P have been detected in both membrane systems whereas PtdIns(4,5)P2 (290 mumol/mol phospholipid) is confined only to TT. A much greater pool of PtdIns(4,5)P2 seems, however, to be located in the sarcolemma away from the triadic junction.
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Affiliation(s)
- H Milting
- Institut für Physiologische Chemie, Ruhr-Universität, Bochum, Germany
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15
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Flucher BE. Structural analysis of muscle development: transverse tubules, sarcoplasmic reticulum, and the triad. Dev Biol 1992; 154:245-60. [PMID: 1426638 DOI: 10.1016/0012-1606(92)90065-o] [Citation(s) in RCA: 118] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Increased interest in the mechanism of excitation-contraction (E-C) coupling over the last few years has been accompanied by numerous investigations into the development of the underlying cellular structures. Areas of particular interest include: (1) the compartmentalization and specialization of an external and an internal membrane system, the T-tubules, and the sarcoplasmic reticulum, respectively; (2) interactions between the membrane proteins of both systems upon the formation of a junction, the triad; and (3) membrane-cytoskeletal interactions leading to the orderly arrangement of the triads with respect to the myofibrils. Structural studies using newly available specific molecular probes and a variety of in vivo and in vitro model systems have provided new insights into the cellular and molecular mechanisms involved in the development of the E-C coupling apparatus in skeletal muscle.
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Affiliation(s)
- B E Flucher
- Laboratory of Neurobiology, NINDS, National Institutes of Health, Bethesda, Maryland 20892
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16
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17
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Gaillard S, Rock E, Vignon X, Dufourc EJ, Renou JP. 31P NMR and freeze fracture studies of sarcoplasmic reticulum membranes from normal and malignant hyperthermic pigs: effect of halothane and dantrolene. Arch Biochem Biophys 1992; 294:154-9. [PMID: 1550341 DOI: 10.1016/0003-9861(92)90150-u] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effects of halothane and dantrolene on sarcoplasmic reticulum membranes isolated from normal and malignant hyperthermia pig muscle have been investigated using 31P NMR and freeze fracture electron microscopy. The dynamical and structural changes are estimated from the second moment, as calculated from 31P NMR spectra. For both membranes, addition of halothane induces a similar decrease in the spectral second moment. At high concentration of halothane, freeze fracture replicas show small unilamellar vesicles or mixed micelles, uniformly sprayed in the case of malignant hyperthermia membranes but mainly aggregated for the normal ones. The effect of halothane on both membranes is partially inhibited by adding dantrolene. These results suggest that (i) the malignant hyperthermia syndrome is not directly related to the polar heads of phospholipids and (ii) dantrolene counteracts unspecifically the disturbing effect of halothane at the lipid level.
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18
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Flucher BE, Terasaki M, Chin HM, Beeler TJ, Daniels MP. Biogenesis of transverse tubules in skeletal muscle in vitro. Dev Biol 1991; 145:77-90. [PMID: 2019326 DOI: 10.1016/0012-1606(91)90214-n] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The transverse (T) tubules of skeletal muscle are membrane tubules that are continuous with the plasma membrane and penetrate the mature muscle fiber radially to carry surface membrane depolarization to the sites of excitation-contraction coupling. We have studied the development of the T-tubule system in cultured amphibian and mammalian muscle cells using a fluorescent lipid probe and antibodies against T-tubules and plasma membranes. Both the lipid probe and the T-tubule antibody recognized an extensive tubular membrane system which subsequently differentiated into the T-system. At all developmental stages, the molecular composition of the T-system was distinct from that of the plasma membrane, suggesting that during myogenesis T-tubules and the plasma membrane form independently from each other and that exchange of membrane proteins between the two continuous compartments is restricted. In rat muscle cultures, T-tubule-specific antigens were first expressed in terminally differentiated myoblasts. Prior to myoblast fusion the antigens appeared as punctate label throughout the cytoplasm. Shortly after fusion the T-tubule-specific antibody labeled a tubular membrane system that extended from the perinuclear region and penetrated most parts of the cells. In contrast, the lipid probe, which labels the T-tubules by virtue of their direct continuity with the plasma membrane, only labeled short tubules extending from the plasma membrane into the periphery of the myotubes at the early stage in development. Thus, the assembly of the T-tubules appears to begin before their connections with the plasma membrane are established.
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Affiliation(s)
- B E Flucher
- Laboratory of Neurobiology, NINDS, National Institutes of Health, Bethesda, Maryland 20892
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19
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Abstract
Sarcolemmal vesicles of white and red skeletal muscles of the rabbit were prepared by consecutive density gradient centrifugations in sucrose and dextran according to Seiler and Fleischer (1982, J. Biol. Chem. 257, 13,862-13,871). White and red muscle membrane fractions enriched in sarcolemma were characterized by high ouabain-sensitive Na+, K(+)-ATPase, by high Mg2(+)-ATPase activity, and by a high cholesterol content. Ca2(+)-ATPase activity, a marker enzyme for sarcoplasmic reticulum, was not detectable in the highly purified white and red muscle sarcolemmal fractions. White and red muscle sarcolemmal fractions exhibited no significant differences with regard to Na+, K(+)-ATPase, Mg2(+)-ATPase, and cholesterol. Specific activity of carbonic anhydrase in white muscle sarcolemmal fractions was 38 U.ml/mg and was 17.6 U.ml/mg in red muscle sarcolemma. Inhibition properties of sarcolemmal carbonic anhydrase were analyzed for acetazolamide, chlorzolamide, and cyanate. White muscle sarcolemmal carbonic anhydrase is characterized by inhibition constants, KI, toward acetazolamide of 4.6 X 10(-8) M, toward chlorzolamide of 0.75 X 10(-8) M, and toward cyanate of 1.3 X 10(-4) M. Red muscle sarcolemmal carbonic anhydrase is characterized by KI values toward acetazolamide of 8.1 X 10(-8) M, toward chlorzolamide of 6.3 X 10(-8) M, and toward cyanate of 0.81 X 10(-4) M. In contrast to the high specific carbonic anhydrase activities in sarcolemma, carbonic anhydrase activity in sarcoplasmic reticulum from white muscle varied between values of only 0.7 and 3.3 U.ml/mg. Carbonic anhydrase of red muscle sarcoplasmic reticulum ranged from 2.4 to 3.7 U.ml/mg.
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Affiliation(s)
- P Wetzel
- Zentrum Physiologie, Medizinische Hochschule Hannover, West Germany
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20
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Lagos N, Vergara J. Phosphoinositides in frog skeletal muscle: a quantitative analysis. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1043:235-44. [PMID: 2157489 DOI: 10.1016/0005-2760(90)90022-p] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The contents of major phospholipids per g of wet wt. in frog skeletal muscle are: 5.3 mumol PC; 1.4 mumol PE; 1 mumol SM; 0.4 mumol PtdIns; 0.3 mumol CL; and 0.13 mumol PS. The quantities of polyphosphoinositides per g of wet wt. are: 181 nmol PtInsP; 28 nmol PtdInsP2; and 8 nmol lyso-PtdInsP2. The specific activity of labelling of the total muscle ATP attained by external incubation with [32P]Pi was found to be 57 dpm/nmol x g muscle wet wt. PtdInsP2, the highest labelled polyphosphoinositide, showed a specific activity of 64,000 dpm/nmol per g muscle wet wt., suggesting that high specific activity ATP may be compartmentalized in the local environment of the triads and used as a substrate by the PtdIns and PtInsP kinase in that region. PtdInsP2 which is the immediate precursor for the release of InsP3, is found at a significant concentration and strategically located for its postulated role as a substrate for the action of phosphoinositidase C. The presence of a novel endogenous polyphosphoinositide, lyso-PtdInsP2, in animal tissues is reported for the first time. Electrical stimulation leads towards a rapid catabolization of polyphosphoinositides revealed by reductions in the 3H- and 32P-labelling, suggesting that muscle excitation is associated with the activation of breaking down of polyphosphoinositides.
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Affiliation(s)
- N Lagos
- Department of Physiology, School of Medicine, University of California, Los Angeles 90024-1751
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21
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Megías A, Saborido A. Abnormal properties of Mg2(+)-ATPase in transverse tubule membranes from dystrophic chicken. Arch Biochem Biophys 1990; 278:113-9. [PMID: 2157357 DOI: 10.1016/0003-9861(90)90238-t] [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: 12/30/2022]
Abstract
Purified transverse tubule membranes from normal and dystrophic chicken skeletal muscle were isolated by a calcium-loading procedure. Normal and dystrophic T-tubules were similar in cholesterol content and (Na+,K+)-ATPase and 5'-nucleotidase activities but a significant decrease of Mg2(+)-ATPase activity was observed in dystrophic membranes. A comparative analysis of the enzyme properties revealed that the kinetic parameters were altered in dystrophic T-tubules and the ATP-hydrolyzing activity was differently affected by the ionic strength. However, the influence of temperature and the regulatory effect of concanavalin A were the same as in normal T-tubules. Membrane fluidity was similar in both preparations as estimated by fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene and trimethylammonium diphenylhexatriene. These results point to an impairment in the function of Mg2(+)-ATPase due to structural alterations of the enzyme.
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Affiliation(s)
- A Megías
- Departamento de Bioquímica y Biología Molecular, Facultade de Biología, Universidad Complutense, Madrid, Spain
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22
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Martonosi A. Calcium regulation in muscle diseases; the influence of innervation and activity. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 991:155-242. [PMID: 2655711 DOI: 10.1016/0304-4165(89)90110-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- A Martonosi
- Department of Biochemistry and Molecular Biology, State University of New York, Syracuse 13210
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23
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Thieleczek R, Mayr GW, Brandt NR. Inositol polyphosphate-mediated repartitioning of aldolase in skeletal muscle triads and myofibrils. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83240-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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24
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Abstract
Biochemical approaches toward understanding the mechanism of muscle excitation have in recent years been directed to identification and isolation of proteins of the triad junction. The principal protein described--the junctional foot protein (JFP)2--was initially identified by morphological criteria and isolated using antibody-affinity chromatography. Subsequently this protein was described as the ryanodine receptor. It has been isolated and incorporated into lipid bilayers as a cation channel. This in its turn has directed attention toward the transverse (T)-tubular junctional constituents. Three approaches employing the JFP as a probe toward identifying these moieties on the T-tubule are described here. The binding of the JFP to the dihydropyridine receptor, which has been hypothesized to be the voltage sensor in excitation-contraction coupling, is also discussed. The detailed architecture and function of T-tubular proteins remain to be resolved.
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Affiliation(s)
- A H Caswell
- University of Miami School of Medicine, Department of Pharmacology, Florida 33101
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25
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Sabbadini RA, Dahms AS. Biochemical properties of isolated transverse tubular membranes. J Bioenerg Biomembr 1989; 21:163-213. [PMID: 2473982 DOI: 10.1007/bf00812068] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This review addresses the major biochemical and structural characteristics of isolated transverse tubule (T-tubule) membranes, including methods of isolation and morphology of purified membranes, evaluation of attendant membrane activities, including ion pumps and channels, and structural and compositional analyses of functionally relevant components. Particular emphasis is placed on the Mg2+-ATPase, its localization in the T-system, its unusual kinetic properties, its possible functions, and its potential regulation by diacylglycerol and other biologically-relevant lipids. Conclusions are drawn with respect to the biochemical markers characteristic of T-tubule membranes and the criteria to be applied in the assessment of isolated T-tubule membrane purity.
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Affiliation(s)
- R A Sabbadini
- Department of Biology, San Diego State University, California 92182
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26
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Ervasti JM, Mickelson JR, Louis CF. Transverse tubule calcium regulation in malignant hyperthermia. Arch Biochem Biophys 1989; 269:497-506. [PMID: 2537601 DOI: 10.1016/0003-9861(89)90133-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Transverse tubule (TT) calcium transport and permeability were examined in the inherited skeletal muscle disorder malignant hyperthermia (MH). ATP-dependent calcium uptake by TT vesicles isolated from normal and MH-susceptible (MHS) pig muscle had a similar dependence on ionized Ca2+ concentration (K1/2 for Ca2+ of 0.21 +/- 0.04 and 0.25 +/- 0.05 microM for MHS and normal TT, respectively), as well as a similar Vmax (20.9 +/- 2.0 and 23.7 +/- 4.5 nmol Ca/mg protein/min for MHS and normal TT, respectively). Furthermore, the stimulation of calcium uptake by either calmodulin or cAMP-dependent protein kinase was similar in normal and MHS TT. Halothane concentrations greater than 2 mM inhibited calcium uptake by either normal or MHS TT to a similar extent (IC50 = 8 mM). Dantrolene (10 microM), nitrendipine (1 microM), and Bay K 8644 (1 microM) had no significant effect on either the initial rates of calcium uptake or maximal calcium accumulation of either MHS or normal TT vesicles. However, in the absence of any added agents, maximum calcium accumulation by MHS TT was significantly less than by normal TT (90 +/- 10 versus 130 +/- 9 nmol Ca/mg protein after 15 min of uptake). This difference was not due to an increased permeability of MHS TT to calcium, nor was it due to a difference in the sarcoplasmic reticulum contamination (less than 5%) of the MHS and normal preparations. Although our results indicate there is no significant defect in MHS TT calcium regulation, the diminished maximum calcium accumulation by MHS TT may contribute to the abnormal sarcoplasmic calcium homeostasis in skeletal muscle during an MH crisis.
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Affiliation(s)
- J M Ervasti
- Department of Biochemistry, University of Minnesota, St. Paul 55108
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27
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Ervasti JM, Claessens MT, Mickelson JR, Louis CF. Altered transverse tubule dihydropyridine receptor binding in malignant hyperthermia. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)81671-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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28
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Salvatori S, Damiani E, Zorzato F, Volpe P, Pierobon S, Quaglino D, Salviati G, Margreth A. Denervation-induced proliferative changes of triads in rabbit skeletal muscle. Muscle Nerve 1988; 11:1246-59. [PMID: 2976894 DOI: 10.1002/mus.880111209] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Protein compositional and functional differences exist between longitudinal and junctional sarcoplasmic reticulum (SR) in relation to Ca transport and to Ca release. In light of this knowledge, we have reinvestigated the effects of denervation on SR of rabbit gastrocnemius, a predominantly fast muscle. Electron microscopy of 2-weeks denervated muscle showed proliferation of transverse tubules (TT), forming junctional contacts with SR terminal cisternae (TC). At coincident periods, the yield of muscle microsomes was increased, and their fractionation by sucrose-density centrifugation demonstrated a relative increase of heavy vesicles. Thin-section electron microscopy of heavy SR from denervated muscle showed an increased number of vesicles containing calsequestrin (CS) as compared with control muscle. Electrophoretic analysis confirmed the relative decrease of Ca-ATPase protein and the striking increase of CS both in total microsomes and in heavy SR vesicles. Calcium loading and Ca-ATPase activity as well as the density of Ca-ATPase protein were decreased to a similar extent (20-30%) in denervated muscle microsomes. Stimulation of Ca-ATPase activity by Ca-ionophore A23187 showed that the vesicles were tightly sealed. When probed by competitive ELISA with antibody to SR Ca-ATPase from pure fast muscle, the Ca-ATPase of denervated microsomes was found to be highly cross reactive. Cleveland's peptide maps of the Ca-ATPase protein after partial digestion with S. aureus V8 protease also showed no significant change after denervation. Changes in cholesterol content and in the ratio of Mg-ATPase to Ca-ATPase activity of denervated muscle microsomes indicated a 4-fold increase of TT protein, i.e., from about 3% to not more than 12% of total protein, at 2 weeks after denervation. All these changes were totally reversed upon reinnervation of muscle fibers, and the consequent muscle recovery, as obtained by nerve crushing instead of nerve sectioning. From these results, we conclude that denervated adult fast muscle, similarly to immature fast muscle, contains more junctional SR. However, the molecular and catalytic properties of the Ca-ATPase are unaffected by denervation.
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Affiliation(s)
- S Salvatori
- Centro di Studio della Biologia e Fisiopatologia Muscolare del CNR, Istituto di Patologia generale dell'Universitá di Padova, Italy
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29
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Caswell AH, Brandt NR, Brunschwig JP, Kawamoto RM. Isolation of transverse tubule membranes from skeletal muscle: ion transport activity, reformation of triad junctions, and isolation of junctional spanning protein of triads. Methods Enzymol 1988; 157:68-84. [PMID: 2976472 DOI: 10.1016/0076-6879(88)57069-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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30
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Horgan DJ, Kuypers R. Biochemical properties of purified transverse tubules isolated from skeletal muscle triads. Arch Biochem Biophys 1988; 260:1-9. [PMID: 2829722 DOI: 10.1016/0003-9861(88)90417-1] [Citation(s) in RCA: 17] [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
Transverse tubules (t-tubules) were prepared from muscle by dissociation of intact triads during centrifugation in ion-free sucrose gradients. They were further purified by the removal of contaminating sarcoplasmic reticulum after loading with calcium phosphate. Purification was accompanied by enrichment in markers specific for t-tubules, e.g., nitrendipine binding sites. According to gel electrophoresis the purified t-tubules contained three major protein bands of 104, 70, and 30 kDa. When solubilized with detergents there was a two- to threefold increase in Mg2+-ATPase activity, and a corresponding increase in the 30-kDa protein band. The 104-kDa protein was shown to be a (Na+ + K+)-ATPase because of its phosphorylation by [gamma-32P]ATP in the presence of sodium ions. The orientation of the t-tubule membrane was predominantly inside-out.
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Affiliation(s)
- D J Horgan
- CSIRO Division of Food Research, Queensland, Australia
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31
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Affiliation(s)
- K J Kako
- Department of Physiology, School of Medicine, University of Ottawa, Ontario, Canada
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32
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Pediconi MF, Donoso P, Hidalgo C, Barrantes FJ. Lipid composition of purified transverse tubule membranes isolated from amphibian skeletal muscle. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 921:398-404. [PMID: 3115305 DOI: 10.1016/0005-2760(87)90042-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The level and proportion of lipids and their fatty acid composition were analyzed in highly purified transverse tubule membranes of amphibian skeletal muscle. Tubule membranes show (a) a higher content of lipids, (b) a higher phospholipid/cholesterol ratio and (c) a different phospholipid composition from other subcellular fractions, such as the light and heavy membranes from sarcoplasmic reticulum, which are similar in lipid profile. Transverse tubule membranes are characterized by a high percentage of phosphatidylserine and sphingomyelin and a low proportion of phosphatidylcholine compared with the other membranes. All three show a high proportion of ethanolamine plasmalogens (50% of the total ethanolamine glycerophospholipid). Transverse tubule membrane lipids contain a high proportion of 20- and 22-carbon polyunsaturated fatty acids, predominantly 20:4, 20:5, 22:5 and 22:6. Arachidonate predominates in phosphatidylinositol, eicosapentaenoate and docosahexaenoate in ethanolamine and serine glycerophospholipids.
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Affiliation(s)
- M F Pediconi
- Instituto de Investigaciones Bioquimicas, UNS-CONICET, Bahia Blanca, Argentina
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33
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Nakayama N, Kirley TL, Vaghy PL, McKenna E, Schwartz A. Purification of putative Ca2+ channel protein from rabbit skeletal muscle. Determination of the amino-terminal sequence. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)48279-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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34
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Horgan DJ, Kuypers R. Isolation of transverse tubules by fractionation of sarcoplasmic reticulum preparations in ion-free sucrose density gradients. Arch Biochem Biophys 1987; 253:377-87. [PMID: 2952065 DOI: 10.1016/0003-9861(87)90191-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A new method for the preparation of transverse tubules (T-tubules) from rabbit skeletal muscles is reported. When crude sarcoplasmic reticulum (SR) preparations were centrifuged on sucrose density gradients containing buffering ions (buffered gradients) 70-80% of the material sedimented as a single heavy band in the region of 43% sucrose. When this fraction (or crude SR) was recentrifuged on sucrose gradients prepared free of buffer or other ions (ion-free gradients) the heavy band dissociated into three fractions of different densities. The lightest fraction sedimented at 28% sucrose and was identified as T-tubules on the basis of its nitrendipine and ouabain binding properties. The enzymatic properties, cholesterol contents, and protein compositions of the fractions obtained when SR is centrifuged on buffered and ion-free sucrose density gradients were measured. The T-tubules were enriched in cholesterol and in marker enzymes for surface membranes while the other fractions were shown to be terminal cisternae and longitudinal cisternae on the basis of their (Ca2+,Mg2+)-ATPase activities and characteristic protein profiles.
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35
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Acetylcholinesterase in membrane fractions derived from sarcotubular system of skeletal muscle: presence of monomeric acetylcholinesterase in sarcoplasmic reticulum and transverse tubule membranes. Neurochem Int 1987; 10:329-38. [DOI: 10.1016/0197-0186(87)90107-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/1986] [Accepted: 11/03/1986] [Indexed: 11/20/2022]
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36
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Kawamoto RM, Baskin RJ. Isolation and characterization of sarcoplasmic reticulum from normal and dystrophic chicken. Muscle Nerve 1986; 9:248-56. [PMID: 3010101 DOI: 10.1002/mus.880090309] [Citation(s) in RCA: 11] [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
Purified sarcoplasmic reticulum vesicles from normal and dystrophic chicken skeletal muscle have been isolated by a procedure employing pressure disruption of a microsomal suspension. The dystrophic sarcoplasmic reticulum (SR) exhibited reduced Ca++ transport and phosphoenzyme formation, but the Ca++-ATPase activity was normal. Normal and dystrophic SR showed similar lipid profiles, except for a significant increase in free fatty acids in the dystrophic SR. Investigations involving the interaction of oleic acid with normal SR showed fatty acids can induce conditions similar to those found in dystrophic SR.
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37
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Hidalgo C, Parra C, Riquelme G, Jaimovich E. Transverse tubules from frog skeletal muscle. Purification and properties of vesicles sealed with the inside-out orientation. BIOCHIMICA ET BIOPHYSICA ACTA 1986; 855:79-88. [PMID: 3002474 DOI: 10.1016/0005-2736(86)90191-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Transverse tubule vesicles were isolated from frog skeletal muscle by a procedure initially described by Rosemblatt et al. (J. Biol. Chem. 256, 8140-8148 (1981)) and later modified by Hidalgo et al. (J. Biol. Chem. 258, 13937-13945 (1983]. A large fraction of the isolated vesicles (80-90%) were sealed, as indicated by the detergent induced increase in (Na+ + K+)-ATPase activity and ATP-dependent ouabain binding. To determine the orientation of the sealed vesicles binding of digoxin, a lipid soluble derivative of ouabain, was measured. The same values of ATP-dependent digoxin binding were found with or without detergents, indicating that all the vesicles that are sealed have the ATP site accessible, and hence are sealed with the cytoplasmic side-out (inside-out orientation). The transverse tubule preparation isolated from frog muscle is highly purified, as indicated by its cholesterol content and its (Na+ + K+)-ATPase activity; negligible contamination with sarcoplasmic reticulum was observed, as indicated by the protein composition and the lack of measurable Ca2+-ATPase activity of the isolated transverse tubules. High initial rates of Mg2+-ATPase activity were found, with the peculiar property of being inhibited during the course of the reaction. Addition of lysophosphatidylcholine or saponin partially prevented the inhibition of Mg2+-ATPase activity during the reaction.
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38
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Beeler T, Gable K. Effect of halothane on Ca2+-induced Ca2+ release from sarcoplasmic reticulum vesicles isolated from rat skeletal muscle. BIOCHIMICA ET BIOPHYSICA ACTA 1985; 821:142-52. [PMID: 4063356 DOI: 10.1016/0005-2736(85)90165-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Halothane induces the release of Ca2+ from a subpopulation of sarcoplasmic reticulum vesicles that are derived from the terminal cisternae of rat skeletal muscle. Halothane-induced Ca2+ release appears to be an enhancement of Ca2+-induced Ca2+ release. The low-density sarcoplasmic reticulum vesicles which are believed to be derived from nonjunctional sarcoplasmic reticulum lack the capability of both Ca2+-induced and halothane-induced Ca2+ release. Ca2+ release from terminal cisternae vesicles induced by halothane is inhibited by Ruthenium red and Mg2+, and require ATP (or an ATP analogue), KCl (or similar salt) and extravesicular Ca2+. Ca2+-induced Ca2+ release has similar characteristics.
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39
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Mollman JE, Furman RE, Wood DS, Scarpa A, Barchi RL. Transmembrane calcium movement in 20,25-diazacholesterol myotonia. Exp Neurol 1985; 90:287-99. [PMID: 2932344 DOI: 10.1016/0014-4886(85)90019-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
An abnormality in myoplasmic Ca2+ regulation has frequently been proposed in 20,25-diazacholesterol (20,25-D) myotonia. We report here the results of several studies of transmembrane Ca2+ movement in this animal model. (i) Physiologic Ca2+ release by intact sarcoplasmic reticulum (SR) was examined in chemically skinned single muscle fibers preloaded in EGTA-buffered Ca2+ solutions (pCa2+7.0 to 6.4). Isometric tension development and Ca2+ release thresholds in response to Cl- or caffeine showed no differences between control and 20,25-D fibers at any pCa2+. (ii) The kinetics of energy-dependent Ca2+ accumulation in purified SR vesicles were followed spectrophotometrically using Ca2+-sensitive dyes. The apparent rate for ATP-dependent Ca2+ uptake and Ca2+ sequestering capacity were unchanged in SR from 20,25-D animals vs. controls. (iii) Surface membrane Ca2+ATPase activity was measured in red blood cell ghosts and sarcolemma. Enzyme Vmax was decreased by 25 to 50% in both membranes in the 20,25-D-treated animals with a compensatory increase in the number of Ca2+ATPase molecules. In general, the SR handling of Ca2+ appears normal in 20,25-D myotonia, although the activity of Ca2+ATPase in membranes with high sterol content may be altered in response to changes in the lipid environment in this model.
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40
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Corbett AM, Caswell AH, Brandt NR, Brunschwig JP. Determinants of triad junction reformation: identification and isolation of an endogenous promotor for junction reformation in skeletal muscle. J Membr Biol 1985; 86:267-76. [PMID: 4046012 DOI: 10.1007/bf01870606] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The junction of isolated triads can be mechanically broken by passage through a French press and subsequently reformed by incubation of the isolated organelles with certain salts of weak acids (e.g., K cacodylate, K propionate, and K butyrate). In contrast, other salts (e.g., KCl, K phosphate, and K benzoate) are ineffective in promoting triad formation. An endogenous factor obtained from a muscle homogenate acts in the same manner as these artificial compounds. When rabbit skeletal muscle is homogenized in a KCl solution and centrifuged to remove large cellular components and membrane fractions, an endogenous factor is extracted into the high speed supernatant which promotes the reformation of mechanically broken triads. A three-stage purification of this factor has been achieved using: ammonium sulfate fractionation, adsorption chromatography, and molecular sieve chromatography. SDS-PAGE showed that the protein was purified to homogeneity and had a subunit Mr of 34,000 daltons. This protein has the following characteristics: it exists in 0.1 M KCl as a polymeric substance with an estimated Mr = 123,000 on molecular sieve chromatography and a Mr = 155,000 on sedimentation equilibrium; it promotes the formation of triadic vesicles from isolated organelles in a low ionic strength medium; Both this protein and cacodylate share the property of specifically catalyzing the association and aggregation of junctional proteins which had previously been dissolved by neutral detergent and salt; it appears to be identical to an extrinsic constituent of terminal cisternae, which has been described as a protein of Mr = 34K. It is not clear, however, whether this protein is a necessary and integral component of the junctional feet or whether it exerts predominantly a catalytic role in the formation of the triad junction.
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41
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Kraner SD, Tanaka JC, Barchi RL. Purification and functional reconstitution of the voltage-sensitive sodium channel from rabbit T-tubular membranes. J Biol Chem 1985. [DOI: 10.1016/s0021-9258(18)88977-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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42
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Okamoto VR, Moulton MP, Runte EM, Kent CD, Lebherz HG, Dahms AS, Sabbadini RA. Characterization of transverse tubule membrane proteins: tentative identification of the Mg-ATPase. Arch Biochem Biophys 1985; 237:43-54. [PMID: 3155929 DOI: 10.1016/0003-9861(85)90252-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Vesiculated fragments of chicken skeletal muscle transverse tubule (TT) membranes were analyzed for their content of loosely associated and integral membrane proteins. Of particular interest was the identification of the magnesium-stimulated ATPase (Mg-ATPase), which is characteristically located in native isolated TT vesicles of chicken skeletal muscle [R. A. Sabbadini and V. R. Okamoto (1983) Arch. Biochem. Biophys. 223, 107-119]. A number of the proteins found in vesicular TT preparations were found to be extractable by a mild Triton-X100 treatment and were identified as aldolase, enolase, creatine kinase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, and pyruvate kinase. Approximately 60% of TT-associated protein was extracted with Triton, resulting in a twofold enrichment of the Mg-ATPase. Concommitantly, one core integral membrane protein possessing a Mr of 102,000 was enriched, suggesting that it is responsible for the Mg-ATPase activity present in chicken skeletal muscle TT membranes.
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43
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Caillé J, Ildefonse M, Rougier O. Excitation-contraction coupling in skeletal muscle. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1985; 46:185-239. [PMID: 2418459 DOI: 10.1016/0079-6107(85)90009-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Mrak RE. Isolation and characterization of transverse tubule from normal and dystrophic mice. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 774:35-42. [PMID: 6234025 DOI: 10.1016/0005-2736(84)90271-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
I have recently reported the isolation and characterization of sarcoplasmic reticulum from normal and dystrophic mice. These sarcoplasmic reticulum fractions were similar in calcium pump function, calcium release properties, and lipid composition. In this report, I describe the isolation of mouse muscle transverse tubule membranes using a calcium phosphate-loading technique. When the relative purity of normal and dystrophic preparations was considered, transverse tubule from normal and dystrophic mice were similar in calcium-insensitive ATPase activity, cholesterol content, and membrane microviscosity (as estimated by fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene); transverse tubule yield from dystrophic muscle, however, was twice that from normal muscle, while sarcoplasmic reticulum yield from these same dystrophic muscles was only 60% that from normal muscle. This result may reflect a difference in the relative quantities of these membranes in situ.
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Baskin RJ, Kawamoto R. Stereological analysis of transverse tubules and sarcoplasmic reticulum isolated from normal and dystrophic skeletal muscle. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 771:109-18. [PMID: 6142727 DOI: 10.1016/0005-2736(84)90523-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Vesicles isolated from the transverse tubules and sarcoplasmic reticulum of normal and dystrophic chicken skeletal muscle were analyzed for enzymatic activity and examined following freeze-fracture. A stereological procedure was used to determine particle density distributions on the resulting membrane fracture faces. The particle densities measured in this investigation were compared with those of an earlier study on intact muscle. Isolated sarcoplasmic reticulum vesicles showed a characteristically high P-face (cytoplasmic leaflet) particle density (5108 +/- 169 particles/micron2) and a low E-face (luminal leaflet) particle density (505 +/- 57 particles/micron2). Transverse tubule fractions showed a high E-face particle density (2346 +/- 179 particles/mu2) as well as a substantial P-face particle density (1019 +/- 129 particles/micron2). The high transverse tubule E-face particle density represents a characteristic morphological feature in the same way that the very high P-face particle density is characteristic of sarcoplasmic reticulum membranes. The major morphological alteration in dystrophic membranes was a shift in the E-face particle density distribution of isolated transverse tubules to a lower average particle density. (The E-face particle density of sarcoplasmic reticulum fractions showed no differences.)
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Borhan M, Shewfelt RL, Hultin HO. Sarcoplasmic reticulum from flounder muscle having improved lipid peroxidative activity. Anal Biochem 1984; 137:58-65. [PMID: 6233915 DOI: 10.1016/0003-2697(84)90346-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A procedure for the isolation of sarcoplasmic reticulum from winter flounder (Pseudopleuronectes americanus) resulted in a fraction with a specific activity of lipid peroxidation two to three times that of previous preparations. In addition, good stability of the NADH-dependent lipid peroxidative activity was achieved. There appeared to be minimal contamination of the preparation with lysosomes and mitochondria. The flounder sarcoplasmic reticulum was highly active with respect to ATPase and calcium uptake. The membrane fraction contained 43% lipid and 57% protein; 60% of the lipids were phospholipids. Phosphatidylcholine was the major phospholipid present.
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Hidalgo C, Gonzalez ME, Lagos R. Characterization of the Ca2+- or Mg2+-ATPase of transverse tubule membranes isolated from rabbit skeletal muscle. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)44007-5] [Citation(s) in RCA: 102] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Kawamoto RM, Baskin RJ. Calcium transport, ATPase activity and lipid composition in sarcoplasmic reticulum isolated from isogenic lines of normal and dystrophic chickens. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 732:620-6. [PMID: 6223663 DOI: 10.1016/0005-2736(83)90239-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Two new lines of chickens with near identical genotypes (greater than 90% isogeneity), one demonstrating avian dystrophy, were used for isolation of sarcoplasmic reticulum vesicles. Vesicles from line 433 (dystrophic) displayed reduced Ca2+-ATPase activity, phosphoenzyme formation and steady-state calcium transport capabilities in comparison with vesicles from line 03 (normal). Lipid analyses show that dystrophic vesicles have greater amounts of cholesterol and lesser amounts of phosphatidylcholine. The results support the use of isogenic chickens in further studies of avian dystrophy. However, the results also suggest that current sarcoplasmic reticulum vesicle purification procedures dependent on differential calcium accumulation may not fully achieve the intended purpose.
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Moczydlowski EG, Latorre R. Saxitoxin and ouabain binding activity of isolated skeletal muscle membrane as indicators of surface origin and purity. BIOCHIMICA ET BIOPHYSICA ACTA 1983; 732:412-20. [PMID: 6307371 DOI: 10.1016/0005-2736(83)90058-5] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A simple biochemical method for identifying and distinguishing transverse tubule and sarcolemma membranes in preparations of skeletal muscle microsomes is proposed and evaluated. This method is based on the previous observation that the ratio of ouabain to saxitoxin binding sites is five-fold higher in the sarcolemma than the transverse tubule. We measured [3H]saxitoxin and [3H]ouabain binding to microsomes of frog, rat and rabbit muscle in the presence of detergents to expose latent sites. A high density fraction (30--40% sucrose) of the membranes was identified as transverse tubule on the basis of a low ouabain/saxitoxin ratio and its association with sarcoplasmic reticulum. A low density fraction (20--30% sucrose) was identified as transverse tubule containing variable amounts of sarcolemma as judged by a higher ratio of ouabain/saxitoxin sites. Our results suggest that this ratio can be used to determine the surface origin of muscle membrane preparations. Several different methods for purifying transverse tubules were compared by this technique.
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