Partitioning of myelin basic protein into membrane microdomains in a spontaneously demyelinating mouse model for multiple sclerosisThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.

2006 ◽  
Vol 84 (6) ◽  
pp. 993-1005 ◽  
Author(s):  
Lillian S. DeBruin ◽  
Jeffery D. Haines ◽  
Dorothee Bienzle ◽  
George Harauz
Keyword(s):  
Myelin Basic Protein ◽  
Lipid Rafts ◽  
Basic Protein ◽  
Membrane Microdomains ◽  
Special Issue ◽  
Splice Isoforms ◽  
Severity Of Disease ◽  
Health And Disease ◽  
Detergent Resistant Membranes ◽  
Selection Of

We have characterized the lipid rafts in myelin from a spontaneously demyelinating mouse line (ND4), and from control mice (CD1 background), as a function of age and severity of disease. Myelin was isolated from the brains of CD1 and ND4 mice at various ages, and cold lysed with 1.5% CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulphonate). The lysate was separated by low-speed centrifugation into supernatant and pellet fractions, which were characterized by Western blotting for myelin basic protein (MBP) isoforms and their post-translationally modified variants. We found that, with maturation and with disease progression, there was a specific redistribution of the 14–21.5 kDa MBP isoforms (classic exon-II-containing vs exon-II-lacking) and phosphorylated forms into the supernatant and pellet. Further fractionation of the supernatant to yield detergent-resistant membranes (DRMs), representing coalesced lipid rafts, showed these to be highly enriched in exon-II-lacking MBP isoforms, and deficient in methylated MBP variants, in mice of both genotypes. The DRMs from the ND4 mice appeared to be enriched in MBP phosphorylated by MAP kinase at Thr95 (murine 18.5 kDa numbering). These studies indicate that different splice isoforms and post-translationally modified charge variants of MBP are targeted to different microdomains in the myelin membrane, implying multifunctionality of this protein family in myelin maintenance.

Active 3ʹ–5ʹ cyclic nucleotide phosphodiesterases are present in detergent-resistant membranes of mural granulosa cells

2017 ◽  
Vol 29 (4) ◽  
pp. 778 ◽  
Author(s):  
Annick Bergeron ◽  
Christine Guillemette ◽  
Marc-André Sirard ◽  
François J. Richard
Keyword(s):  
Cell Membrane ◽  
Lipid Rafts ◽  
Granulosa Cell ◽  
Granulosa Cells ◽  
Cell Membranes ◽  
Soluble Fraction ◽  
Cell Signalling ◽  
Membrane Microdomains ◽  
Dot Blot ◽  
Detergent Resistant Membranes

Lipids rafts are specialised membrane microdomains involved in cell signalling that can be isolated as detergent-resistant membranes (DRMs). The second messenger cyclic AMP (cAMP) has a central role in cell signalling in the ovary and its degradation is carried out by the phosphodiesterase (PDE) enzyme family. We hypothesised that PDEs could be functionally present in the lipid rafts of porcine mural granulosa cell membranes. PDE6C, PDE8A and PDE11A were detected by dot blot in the DRMs and the Triton-soluble fraction of the mural granulosa cells membrane and the cytosol. As shown by immunocytochemistry, PDEs showed clear immunostaining in mural granulosa cell membranes and the cytosol. Interestingly, cAMP–PDE activity was 18 times higher in the DRMs than in the Triton-soluble fraction of cell membranes and was 7.7 times higher in the cytosol than in the DRMs. cAMP–PDE activity in mural granulosa cells was mainly contributed by the PDE8 and PDE11 families. This study shows that PDEs from the PDE8 and PDE11 families are present in mural granulosa cells and that the cAMP–PDE activity is mainly contributed by the cytosol. In the cell membrane, the cAMP–PDE activity is mainly contributed by the DRMs. In addition, receptors for prostaglandin E2 and LH, two G-protein-coupled receptors, are present in lipid rafts and absent from the non-raft fraction of the granulosa cell membrane. These results suggest that in these cells, the lipid rafts exist as a cell-signalling platform and PDEs are one of the key enzyme families present in the raft.

Stimulatory effect of insecticides on partially purified P-glycoprotein ATPase from the resistant pest Helicoverpa armigeraThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB — Membrane Proteins in Health and Disease.

2006 ◽  
Vol 84 (6) ◽  
pp. 1045-1050 ◽  
Author(s):  
Ravindra Aurade ◽  
Senigala K. Jayalakshmi ◽  
Kuruba Sreeramulu
Keyword(s):  
Atpase Activity ◽  
Potent Inhibitor ◽  
Special Issue ◽  
Binding Domains ◽  
P Glycoprotein ◽  
Sds Page ◽  
Health And Disease ◽  
And Function ◽  
Lepidoptera Noctuidae ◽  
Selection Of

A P-glycoprotein-like protein (Ha-Pgp) was detected in a membrane preparation from the insecticide-resistant pest Helicoverpa armigera (Lepidoptera: Noctüidae) using C219 antibodies that are directed towards an epitope in the nucleotide-binding domains. This protein was partially purified and found to be a glycoprotein displaying ATPase activity. SDS–PAGE confirmed that a high molecular mass glycoprotein (150 kDa) was overexpressed in resistant pests, but was not detected in susceptible pests. The partially purified Ha-Pgp ATPase was reconstituted into proteoliposomes and it was found that some insecticides, namely, monocrotophos, endosulfan, cypermethrin, fenvalerate, and methylparathion, stimulated the ATPase activity. The effect of various inhibitors on partially purified Ha-Pgp showed that orthovanadate is a potent inhibitor of its ATPase activity, inhibiting it by 90% at a concentration of 2 mmol/L. Other inhibitors, such as EDTA, sodium azide, and molybdate resulted in only a 20% decrease in activity. Details of the structure and function of Ha-Pgp will be important in the development of strategies to overcome insecticide resistance in this pest.

The role of sex in cardiac function and diseaseThis paper is one of a selection of papers published in this Special Issue, entitled Young Investigator's Forum.

2006 ◽  
Vol 84 (1) ◽  
pp. 93-109 ◽  
Author(s):  
Michael P. Czubryt ◽  
Leon Espira ◽  
Lise Lamoureux ◽  
Bernard Abrenica
Keyword(s):  
Disease Susceptibility ◽  
Heart Function ◽  
Cardiac Diseases ◽  
Special Issue ◽  
Isolated Cardiomyocytes ◽  
The Past ◽  
Health And Disease ◽  
Shed Light ◽  
Selection Of

In the past decade, increasing attention has been paid to the importance of sex in the etiology of cardiac dysfunction. While focus has been primarily on how sex modulates atherogenesis, it is becoming clear that sex is both a predictor of outcome and an independent risk factor for a number of other cardiac diseases. Animal models and human studies have begun to shed light on the mechanisms by which sex influences the function of cardiomyocytes in health and disease. This review will survey the current literature on cardiac diseases that are influenced by sex and discuss the intracellular mechanisms by which steroid sex hormones affect heart function. A theory on how sex may regulate myocardial energy metabolism to affect disease susceptibility and progression will be presented, as well as a discussion of how sex may influence outcomes of experiments on isolated cardiomyocytes by epigenetic marking.

Human T lymphocyte response to myelin basic protein: Selection of T lymphocyte lines from mbp-responsive donors

1989 ◽  
Vol 23 (1) ◽  
pp. 21-30 ◽  
Author(s):  
A. A. Vandenbark ◽  
Y. K. Chou ◽  
D. Bourdette ◽  
R. Whitham ◽  
J. Chilgren ◽  
...  
Keyword(s):  
Myelin Basic Protein ◽  
T Lymphocyte ◽  
Basic Protein ◽  
Lymphocyte Response ◽  
Human T Lymphocyte ◽  
Protein Selection ◽  
Selection Of

Methods for detecting autophagy and determining autophagy-induced cell deathThis review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease.

2010 ◽  
Vol 88 (3) ◽  
pp. 285-295 ◽  
Author(s):  
Yongqiang Chen ◽  
Meghan B. Azad ◽  
Spencer B. Gibson
Keyword(s):  
Cell Death ◽  
Degradation Process ◽  
Research Groups ◽  
Special Issue ◽  
Lysosomal Degradation ◽  
The Past ◽  
Promote Cell Survival ◽  
Health And Disease ◽  
New Research ◽  
Selection Of

Autophagy is an intracellular lysosomal degradation process, which in the case of macroautophagy, is characterized by the formation of double-membraned autophagosomes. Enhanced under stress conditions, autophagy can function to promote cell survival or cell death depending on the type of cellular stress. Interest in autophagy has increased substantially in the past several years as new research implicates this “self-eating” pathway in cell growth, development, and many human diseases. Various methods have been developed for detecting autophagy; however, the implementation of these methods and the interpretation of the results often vary between studies, and a more standardized approach is required. In this review, we summarize the current methods available for detecting autophagy and for determining its contribution to cell death. Furthermore, we discuss the critical points for the successful application of these methods based on experiences from our laboratory and from other research groups.

scholarly journals Editorial: Lipid Rafts and Amyloidogenesis

2010 ◽  
Vol 3 (1) ◽  
pp. 15-15
Author(s):  
Wataru Araki
Keyword(s):  
Biological Sciences ◽  
Lipid Rafts ◽  
Critical Issue ◽  
Amyloid Peptide ◽  
Membrane Microdomains ◽  
Special Issue ◽  
Cellular Processes ◽  
Main Culprit ◽  
Β Amyloid Peptide ◽  
Aβ Generation

Lipid Rafts and Amyloidogenesis Lipid rafts are the membrane microdomains enriched in cholesterol and sphingolipids, which play important roles in such cellular processes as protein sorting and signal transduction. Lipid rafts have recently received significant attention as they have been shown to be important regions for the generation and accumulation of β-amyloid peptide (Aβ), the main culprit in the pathogenesis of Alzheimer’s disease. For instance, the proteases responsible for the production of Aβ are localized to lipid rafts, and rafts appear to be involved in the pathological aggregation of Aβ. Thus, the relationship between lipid rafts and amyloidogenesis is considered a critical issue to be investigated. In addition, modulation of lipid rafts is an interesting issue in biological sciences. In this special issue, the first two articles by Wataru Araki and Madepalli K. Lakshmana focus on the relation between lipid rafts and the mechanisms of Aβ generation, and the third article by Gunter P. Eckert mainly deals with the manipulation of lipid rafts in neuronal cells. I hope that this special issue provides informative unique collection of minireviews which highlight the significance of lipid rafts in amyloidogenesis.

scholarly journals Endogenous Myelin Basic Protein Inactivates the High Avidity T Cell Repertoire

1998 ◽  
Vol 187 (12) ◽  
pp. 2055-2063 ◽  
Author(s):  
Oleg S. Targoni ◽  
Paul V. Lehmann
Keyword(s):  
T Cell ◽  
Myelin Basic Protein ◽  
Cell Response ◽  
Basic Protein ◽  
T Cell Response ◽  
High Avidity ◽  
T Cell Repertoire ◽  
Cell Repertoire ◽  
C3h Mice ◽  
Selection Of

To study the contribution of endogenous myelin basic protein (MBP) to the positive and/or negative selection of the MBP-specific T cell repertoire, we studied the T cell response to MBP in MBP-deficient shiverer and MBP-expressing congenic C3H mice. Immunization with MBP induced a vigorous T cell response in shiverer mice directed against a single I-Ak– restricted immunodominant determinant, the core of which is peptide MBP:79-87 (DENPVVHFF). Injection of this peptide induced a high avidity T cell repertoire in shiverer mice that primarily consisted of clones capable of recognizing the native MBP protein in addition to the peptide itself. These data show that endogenous MBP is not required for the positive selection of an MBP-specific T cell repertoire. C3H mice, in contrast, were selectively unresponsive to the MBP protein and injection of MBP:79-87 peptide induced a low avidity repertoire that could be stimulated only by the peptide, not by the protein. Therefore, endogenous MBP induced profound inactivation of high avidity clones specific for the immunodominant determinant making that determinant appear cryptic.

Developmental partitioning of myelin basic protein into membrane microdomains

2005 ◽  
Vol 80 (2) ◽  
pp. 211-225 ◽  
Author(s):  
L.S. DeBruin ◽  
J.D. Haines ◽  
L.A. Wellhauser ◽  
G. Radeva ◽  
V. Schonmann ◽  
...  
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Membrane Microdomains
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