Related ArticlesProton NMR visible mobile lipid signals in sensitive and multidrug-resistant K562 cells are modulated by rafts.
Cancer Cell Int. 2005 Feb 9;5(1):2
Authors: Mannechez A, Reungpatthanaphong P, de Certaines JD, Leray G, Le Moyec L
BACKGROUND: Most cancer cells are characterized by mobile lipids visible on proton NMR (1H-NMR), these being comprised mainly of methyl and methylene signals from lipid acyl chains. Erythroleukemia K562 cells show narrow signals at 1.3 and 0.9 ppm, corresponding to mobile lipids (methylene and methyl, respectively), which are reduced when K562 cells are multidrug resistant (MDR). While the significance of the mobile lipids is unknown, their subcellular localization is still a matter of debate and may lie in the membrane or the cytoplasm. In this study, we investigate the role of cholesterol in the generation of mobile lipid signals. RESULTS: The proportion of esterified cholesterol was found to be higher in K562-sensitive cells than in resistant cells, while the total cholesterol content was identical in both cell lines. Cholesterol extraction in the K562 wild type (K562wt) cell line and its MDR counterpart (K562adr), using methyl-beta-cyclodextrin, was accompanied by a rise of mobile lipids in K562wt cells only. The absence of caveolae was checked by searching for the caveolin-1 protein in K562wt and K562adr cells. However, cholesterol was enriched in another membrane microdomain designated as "detergent-insoluble glycosphingomyelin complexes" or rafts. These microdomains were studied after extraction with triton X-100, a mild non-ionic detergent, revealing mobile lipid signals preserved only in the K562wt spectra. Moreover, following perturbation/disruption of these microdomains using sphingomyelinase, mobile lipids increased only in K562wt cells. CONCLUSION: These results suggest that cholesterol and sphingomyelin are involved in mobile lipid generation via microdomains of detergent-insoluble glycosphingomyelin complexes such as rafts. Increasing our knowledge of membrane microdomains in sensitive and resistant cell lines may open up new possibilities in resistance reversion.
PMID: 15703065 [PubMed - as supplied by publisher]
[NMR paper] Detergent-resistant membrane fractions contribute to the total 1H NMR-visible lipid s
Detergent-resistant membrane fractions contribute to the total 1H NMR-visible lipid signal in cells.
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Eur J Biochem. 2003 May;270(9):2091-100
Authors: Wright LC, Djordjevic JT, Schibeci SD, Himmelreich U, Muljadi N, Williamson P, Lynch GW
Leukocytes and other cells show an enhanced intensity of mobile lipid in their 1H NMR spectra under a variety of conditions. Such conditions include stimulation, which has recently been shown...
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[NMR paper] Assignment of amide proton signals by combined evaluation of HN, NN and HNCA MAS-NMR
Assignment of amide proton signals by combined evaluation of HN, NN and HNCA MAS-NMR correlation spectra.
Related Articles Assignment of amide proton signals by combined evaluation of HN, NN and HNCA MAS-NMR correlation spectra.
J Biomol NMR. 2003 Mar;25(3):217-23
Authors: van Rossum BJ, Castellani F, Pauli J, Rehbein K, Hollander J, de Groot HJ, Oschkinat H
In this paper, we present a strategy for the (1)H(N) resonance assignment in solid-state magic-angle spinning (MAS) NMR, using the alpha-spectrin SH3 domain as an example. A novel 3D...
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[NMR paper] Differentiation of the P-gp and MRP1 multidrug resistance systems by mobile lipid 1H-
Differentiation of the P-gp and MRP1 multidrug resistance systems by mobile lipid 1H-NMR spectroscopy and phosphatidylserine externalization.
Related Articles Differentiation of the P-gp and MRP1 multidrug resistance systems by mobile lipid 1H-NMR spectroscopy and phosphatidylserine externalization.
Anticancer Res. 2001 Nov-Dec;21(6A):3915-9
Authors: Mannechez A, Collet B, Payen L, Lecureur V, Fardel O, Le Moyec L, de Certaines JD, Leray G
We have previously demonstrated that proton NMR spectra of fatty acid chains in erythroleukemia K562...
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11-19-2010 08:44 PM
Solution NMR structure of the V27A drug resistant mutant of influenza A M2 channel.
Solution NMR structure of the V27A drug resistant mutant of influenza A M2 channel.
Solution NMR structure of the V27A drug resistant mutant of influenza A M2 channel.
Biochem Biophys Res Commun. 2010 Sep 9;
Authors: Pielak RM, Chou JJ
The M2 protein of influenza A virus forms a proton-selective channel that is required for viral replication; it is also the target of the anti-influenza drugs, amantadine and rimantadine. Widespread drug-resistant mutants, however, has greatly compromised the effectiveness of these drugs. Here, we report the...
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[NMR paper] 31P and 13C NMR spectroscopic study of wild type and multidrug resistant Ehrlich asci
31P and 13C NMR spectroscopic study of wild type and multidrug resistant Ehrlich ascites tumor cells.
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Oncol Res. 1993;5(3):119-26
Authors: Rasmussen J, Hansen LL, Friche E, Jaroszewski JW
Steady-state 31P NMR spectra of wild type EHR2 Ehrlich ascites tumor cells and multidrug resistant EHR2/DNR+ cells, immobilized in agarose threads, and continuously perfused with medium, showed temperature-dependent differences in the levels...
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[NMR paper] The mobile loop region of the NAD(H) binding component (dI) of proton-translocating n
The mobile loop region of the NAD(H) binding component (dI) of proton-translocating nicotinamide nucleotide transhydrogenase from Rhodospirillum rubrum: complete NMR assignment and effects of bound nucleotides.
http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-PubMedLink.gif Related Articles The mobile loop region of the NAD(H) binding component (dI) of proton-translocating nicotinamide nucleotide transhydrogenase from Rhodospirillum rubrum: complete NMR assignment and effects of bound nucleotides.
Biochim Biophys Acta. 1999...
Proton NMR visible mobile lipid signals in sensitive and multidrug-resistant K562 cel
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