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Restoration of IFNγR Subunit Assembly, IFNγ Signaling and Parasite Clearance in Infected Macrophages: Role of Membrane Cholesterol


Despite the presence of significant levels of systemic Interferon gamma (IFNγ), the host protective cytokine, Kala-azar patients display high parasite load with downregulated IFNγ signaling in Leishmania donovani (LD) infected macrophages (LD-MØs); the cause of such aberrant phenomenon is unknown. Here we reveal for the first time the mechanistic basis of impaired IFNγ signaling in parasitized murine macrophages. Our study clearly shows that in LD-MØs IFNγ receptor (IFNγR) expression and their ligand-affinity remained unaltered. The intracellular parasites did not pose any generalized defect in LD-MØs as IL-10 mediated signal transducer and activator of transcription 3 (STAT3) phosphorylation remained unaltered with respect to normal. Previously, we showed that LD-MØs are more fluid than normal MØs due to quenching of membrane cholesterol. The decreased rigidity in LD-MØs was not due to parasite derived lipophosphoglycan (LPG) because purified LPG failed to alter fluidity in normal MØs. IFNγR subunit 1 (IFNγR1) and subunit 2 (IFNγR2) colocalize in raft upon IFNγ stimulation of normal MØs, but this was absent in LD-MØs. Oddly enough, such association of IFNγR1 and IFNγR2 could be restored upon liposomal delivery of cholesterol as evident from the fluorescence resonance energy transfer (FRET) experiment and co-immunoprecipitation studies. Furthermore, liposomal cholesterol treatment together with IFNγ allowed reassociation of signaling assembly (phospho-JAK1, JAK2 and STAT1) in LD-MØs, appropriate signaling, and subsequent parasite killing. This effect was cholesterol specific because cholesterol analogue 4-cholestene-3-one failed to restore the response. The presence of cholesterol binding motifs [(L/V)-X1–5-Y-X1–5-(R/K)] in the transmembrane domain of IFNγR1 was also noted. The interaction of peptides representing this motif of IFNγR1 was studied with cholesterol-liposome and analogue-liposome with difference of two orders of magnitude in respective affinity (KD: 4.27×10−9 M versus 2.69×10−7 M). These observations reinforce the importance of cholesterol in the regulation of function of IFNγR1 proteins. This study clearly demonstrates that during its intracellular life-cycle LD perturbs IFNγR1 and IFNγR2 assembly and subsequent ligand driven signaling by quenching MØ membrane cholesterol.


Vyšlo v časopise: Restoration of IFNγR Subunit Assembly, IFNγ Signaling and Parasite Clearance in Infected Macrophages: Role of Membrane Cholesterol. PLoS Pathog 7(9): e32767. doi:10.1371/journal.ppat.1002229
Kategorie: Research Article
prolekare.web.journal.doi_sk: https://doi.org/10.1371/journal.ppat.1002229

Souhrn

Despite the presence of significant levels of systemic Interferon gamma (IFNγ), the host protective cytokine, Kala-azar patients display high parasite load with downregulated IFNγ signaling in Leishmania donovani (LD) infected macrophages (LD-MØs); the cause of such aberrant phenomenon is unknown. Here we reveal for the first time the mechanistic basis of impaired IFNγ signaling in parasitized murine macrophages. Our study clearly shows that in LD-MØs IFNγ receptor (IFNγR) expression and their ligand-affinity remained unaltered. The intracellular parasites did not pose any generalized defect in LD-MØs as IL-10 mediated signal transducer and activator of transcription 3 (STAT3) phosphorylation remained unaltered with respect to normal. Previously, we showed that LD-MØs are more fluid than normal MØs due to quenching of membrane cholesterol. The decreased rigidity in LD-MØs was not due to parasite derived lipophosphoglycan (LPG) because purified LPG failed to alter fluidity in normal MØs. IFNγR subunit 1 (IFNγR1) and subunit 2 (IFNγR2) colocalize in raft upon IFNγ stimulation of normal MØs, but this was absent in LD-MØs. Oddly enough, such association of IFNγR1 and IFNγR2 could be restored upon liposomal delivery of cholesterol as evident from the fluorescence resonance energy transfer (FRET) experiment and co-immunoprecipitation studies. Furthermore, liposomal cholesterol treatment together with IFNγ allowed reassociation of signaling assembly (phospho-JAK1, JAK2 and STAT1) in LD-MØs, appropriate signaling, and subsequent parasite killing. This effect was cholesterol specific because cholesterol analogue 4-cholestene-3-one failed to restore the response. The presence of cholesterol binding motifs [(L/V)-X1–5-Y-X1–5-(R/K)] in the transmembrane domain of IFNγR1 was also noted. The interaction of peptides representing this motif of IFNγR1 was studied with cholesterol-liposome and analogue-liposome with difference of two orders of magnitude in respective affinity (KD: 4.27×10−9 M versus 2.69×10−7 M). These observations reinforce the importance of cholesterol in the regulation of function of IFNγR1 proteins. This study clearly demonstrates that during its intracellular life-cycle LD perturbs IFNγR1 and IFNγR2 assembly and subsequent ligand driven signaling by quenching MØ membrane cholesterol.


Zdroje

1. MurrayHWMasurHKeithlyJS 1982 Cell-mediated immune response in experimental visceral Leishmaniasis. I. Correlation between resistance to Leishmania donovani and lymphokine-generating capacity. J Immunol 129 344 350

2. BelosevicMFinbloomDSVan der MeidePHSlayterMVNacyCA 1989 Administration of monoclonal anti–IFN-gamma antibodies in vivo abrogates natural resistance of C3H/HeN mice to infection with Leishmania major. J Immunol 143 266 274

3. NandanDReinerNE 1995 Attenuation of gamma interferon-induced tyrosine phosphorylation in mononuclear phagocytes infected with Leishmania donovani: selective inhibition of signaling through Janus kinases and Stat1. Infect Immun 63 4495 4500

4. HailuAVan der PollTBerheNKagerPA 2004 Elevated plasma levels of interferon (IFN)-gamma, IFN-gamma inducing cytokines, and IFN-gamma inducible CXC chemokines in visceral Leishmaniasis. Am J Trop Med Hyg 71 561 567

5. AnsariNASalujaSSalotraP 2006 Elevated levels of interferon-gamma, interleukin-10, and interleukin-6 during active disease in Indian kala azar. Clin Immunol 119 339 345

6. CaldasAFavaliCAquinoDVinhasVVan WeyenberghJ 2005 Balance of IL-10 and interferon-gamma plasma levels in human visceral Leishmaniasis: implications in the pathogenesis. BMC Infect Dis 5 113 121

7. De MedeirosIMCasteloASalomãoR 1998 Presence of circulating levels of interferon-gamma, interleukin-10 and tumor necrosis factor-alpha in patients with visceral Leishmaniasis. Rev Inst Med Trop Sao Paulo 40 31 34

8. KarpCLEl-SafiSHWynnTASattiMMKordofaniAM 1993 In vivo cytokine profiles in patients with kala-azar. Marked elevation of both interleukin-10 and interferon-gamma. J Clin Invest 91 1644 1648

9. NylénSMauryaREidsmoLManandharKDSundarS 2007 Splenic accumulation of IL-10 mRNA in T cells distinct from CD4+CD25+ (Foxp3) regulatory T cells in human visceral Leishmaniasis. J Exp Med 204 805 817

10. ReinerNENgWMaTMcMasterWR 1988 Kinetics of gamma interferon binding and induction of major histocompatibility complex class II mRNA in Leishmania-infected macrophages. Proc Natl Acad Sci U S A 85 4330 4334

11. RayMGamAABoykinsRAKenneyRT 2000 Inhibition of interferon-gamma signaling by Leishmania donovani. J Infect Dis 181 1121 1128

12. Darnell JEJr 1997 STATs and gene regulation. Science 277 1630 1635

13. KumarCSMarianoTMNoeMDeshpandeAKRosePM 1988 Expression of the murine interferon gamma receptor in Xenopus laevis oocytes. J Biol Chem 263 13493 13496

14. MarchettiMMonierMNFradagradaAMitchellKBaychelierF 2006 Stat-mediated signaling induced by type I and type II interferons (IFNs) is differentially controlled through lipid microdomain association and clathrin-dependent endocytosis of IFN receptors. Mol Biol Cell 17 2896 2909

15. SehgalPBGuoGGShahMKumarVPatelK 2002 Cytokine signaling: STATS in plasma membrane rafts. J Biol Chem 277 12067 12074

16. TakaokaAMitaniYSuemoriHSatoMYokochiT 2000 Cross talk between interferon-gamma and -alpha/beta signaling components in caveolar membrane domains. Science 288 2357 2360

17. DykstraMCherukuriASohnHWTzengSJPierceSK 2003 Location is everything: lipid rafts and immune cell signaling. Annu Rev Immunol 21 457 481

18. GimplG 2010 Cholesterol-protein interaction: methods and cholesterol reporter molecules. Subcell Biochem 51 1 45

19. BranniganGHéninJLawREckenhoffRKleinML 4423 2008 Embedded cholesterol in the nicotinic acetylcholine receptor. Proc Natl Acad Sci U S A 105 14418 14423

20. GimplGFahrenholzF 2002 Cholesterol as stabilizer of the oxytocin receptor. Biochim Biophys Acta 1564 384 392

21. PucadyilTJChattopadhyayA 2004 Cholesterol modulates ligand binding and G-protein coupling to serotonin1A receptors from bovine hippocampus. Biochim Biophys Acta 1663 188 200

22. ChakrabortyDBanerjeeSSenABanerjeeKKDasP 2005 Leishmania donovani affects antigen presentation of macrophage by disrupting lipid rafts. J Immunol 175 3214 3224

23. BanerjeeSGhoshJSenSGuhaRDharR 2009 Designing therapies against experimental visceral Leishmaniasis by modulating the membrane fluidity of antigen-presenting cells. Infect Immun 77 2330 2342

24. Perez-GuzmanCVargasMHQuinonezFBazavilvazoNAguilarA 2005 A cholesterol-rich diet accelerates bacteriological sterilization in pulmonary tuberculosis. Chest 127 643 651

25. EliasERIronsMBHurleyADTintGSSalenG 1997 Clinical effects of cholesterol supplementation in six patients with the Smith-Lemli-Opitz syndrome (SLOS). Am J Med Genet 68 305 310

26. GhoshJLalCSPandeyKDasVNRDasP 2011 Human visceral Leishmaniasis: decrease in serum cholesterol as a function of splenic parasite load Annals of Tropical Medicine & Parasitology 105 267 271

27. DograNWarburtonCMcMasterWR 2007 Leishmania major abrogates gamma interferon-induced gene expression in human macrophages from a global perspective. Infect Immun 75 3506 3515

28. ReinerNENgWWilsonCBMcMasterWRBurchettSK 1990 Modulation of in vitro monocyte cytokine responses to Leishmania donovani. Interferon-gamma prevents parasite-induced inhibition of interleukin 1 production and primes monocytes to respond to Leishmania by producing both tumor necrosis factor-alpha and interleukin. J Clin Invest 85 1914 1924

29. WilsonKCFinbloomDS 1992 Interferon gamma rapidly induces in human monocytes a DNA-binding factor that recognizes the gamma response region within the promoter of the gene for the high-affinity Fc gamma receptor. Proc Natl Acad Sci U S A 89 11964 11968

30. GreenlundACFarrarMAVivianoBLSchreiberRD 1994 Ligand-induced IFN gamma receptor tyrosine phosphorylation couples the receptor to its signal transduction system (p91). EMBO J 13 1591 1600

31. BachEATannerJWMarstersSAshkenaziAAguetM 1996 Ligand-induced assembly and activation of the gamma interferon receptor in intact cells. Mol Cell Biol 16 3214 3221

32. SakatsumeMIgarashiKWinestockKDGarottaGLarnerAC 1995 The Jak kinases differentially associate with the alpha and beta (accessory factor) chains of the interferon gamma receptor to form a functional receptor unit capable of activating STAT transcription factors. J Biol Chem 270 17528 17534

33. KotenkoSVIzotovaLSPollackBPMarianoTMDonnellyRJ 1995 Interaction between the components of the interferon gamma receptor complex. J Biol Chem 270 20915 20921

34. SchlessingerJ 2000 Cell signaling by receptor tyrosine kinases. Cell 103 211 225

35. YamaokaKSaharinenPPesuMHolt VE3rdSilvennoinenO 2004 The Janus kinases (Jaks). Genome Biol 5 253

36. MizuguchiRHatakeyamaM 1998 Conditional activation of Janus kinase (JAK) confers factor independence upon interleukin-3-dependent cells. Essential role of Ras in JAK-triggered mitogenesis. J Biol Chem 273 32297 32303

37. KossiakoffAADe VosAM 1998 Structural basis for cytokine hormone-receptor recognition and receptor activation. Adv Protein Chem 52 67 108

38. MüllerMBriscoeJLaxtonCGuschinDZiemieckiA 1993 The protein tyrosine kinase JAK1 complements defects in interferon-alpha/beta and -gamma signal transduction. Nature 366 129 135

39. WatlingDGuschinDMüllerMSilvennoinenOWitthuhnBA 1993 Complementation by the protein tyrosine kinase JAK2 of a mutant cell line defective in the interferon-gamma signal transduction pathway. Nature 366 166 170

40. WalterMRWindsorWTNagabhushanTLLundellDJLunnCA 1995 Crystal structure of a complex between interferon-gamma and its soluble high-affinity receptor. Nature 376 230 235

41. ThielDJle DuMHWalterRLD'ArcyAChèneC 2000 Observation of an unexpected third receptor molecule in the crystal structure of human interferon-gamma receptor complex. Structure 8 927 936

42. StryerL 1978 Fluorescence energy transfer as a spectroscopic ruler. Annu Rev Biochem 47 819 846

43. ChengPCDykstraMLMitchellRNPierceSK 1999 A role for lipid rafts in B cell antigen receptor signaling and antigen targeting. J Exp Med 190 1549 1560

44. MontixiCLangletCBernardAMThimonierJDuboisC 1998 Engagement of T cell receptor triggers its recruitment to low-density detergent-insoluble membrane domains. EMBO J 17 5334 5348

45. JanesPWLeySCMageeAIKabouridisPS 2000 The role of lipid rafts in T cell antigen receptor (TCR) signalling. Semin Immunol 12 23 34

46. HarderTScheiffelePVerkadePSimonsK 1998 Lipid domain structure of the plasma membrane revealed by patching of membrane components. J Cell Biol 141 929 942

47. SimonsKToomreD 2000 Lipid rafts and signal transduction. Nat Rev Mol Cell Biol 1 31 39

48. PetkovaDHMomchilova-PankovaABKoumanovKS 1987 Effect of liver plasma membrane fluidity on endogenous phospholipase A2 activity. Biochimie 69 1251 1255

49. Van der GootFGHarderT 2001 Raft membrane domains: from a liquid ordered membrane phase to a site of pathogen attack. Semin Immunol 13 89 97

50. KaneshiroESGottliebMDwyerDM 1982 Cell surface origin of antigens shed by Leishmania donovani during growth in axenic culture. Infect Immun 37 558 567

51. DennyPWFieldMCSmithDF 2001 GPI-anchored proteins and glycoconjugates segregate into lipid rafts in Kinetoplastida. FEBS Lett 491 148 153

52. WinbergMEHolmASärndahlEVinetAFDescoteauxA 2009 Leishmania donovani lipophosphoglycan inhibits phagosomal maturation via action on membrane rafts. Microbes Infect 2 215 222

53. DermineJFScianimanicoSPrivéCDescoteauxADesjardinsM 2000 Leishmania promastigotes require lipophosphoglycan to actively modulate the fusion properties of phagosomes at an early step of phagocytosis. Cell Microbiol 2 115 126

54. RasmussonBJFlanaganTDTurcoSJEpandRMPetersenNO 1998 Fusion of Sendai virus and individual host cells and inhibition of fusion by lipophosphoglycan measured with image correlation spectroscopy. Biochim Biophys Acta 1404 338 352

55. NandanDReinerNE 1995 Attenuation of gamma interferon-induced tyrosine phosphorylation in mononuclear phagocytes infected with Leishmania donovani: selective inhibition of signaling through Janus kinases and Stat1. Infect Immun 63 4495 4500

56. EpandRM 2006 Cholesterol and the interaction of proteins with membrane domains. Prog Lipid Res 45 279 294

57. LiHPapadopoulosV 1998 Peripheral-type benzodiazepine receptor function in cholesterol transport. Identification of a putative cholesterol recognition/interaction amino acid sequence and consensus pattern. Endocrinology 139 4991 4997

58. JaminNNeumannJMOstuniMAVuTKYaoZX 2005 Characterization of the cholesterol recognition amino acid consensus sequence of the peripheral-type benzodiazepine receptor. Mol Endocrinol 19 588 594

59. FountoulakisMZulaufMLustigAGarottaG 1992 Stoichiometry of interaction between interferon gamma and its receptor. Eur J Biochem 15 781 787

60. GreenlundACSchreiberRDGoeddelDVPennicaD 1993 Interferon-gamma induces receptor dimerization in solution and on cells. J. Biol Chem 268 18103 18110

61. BachEASzaboSJDigheASAshkenaziAAguetM 1995 Ligand-induced autoregulation of IFN-gamma receptor beta chain expression in T helper cell subsets. Science 270 1215 1218

62. MarstersSAPennicaDBachESchreiberRDAshkenaziA 1995 Interferon gamma signals via a high-affinity multisubunit receptor complex that contains two types of polypeptide chain. Proc Natl Acad Sci U S A 92 5401 5405

63. VrljicMNishimuraSYMoernerWEMcConnellHM 2005 Cholesterol depletion suppresses the translational diffusion of class II major histocompatibility complex proteins in the plasma membrane. Biophys J 88 334 347

64. BiKTanakaYCoudronniereNSugieKHongS 2001 Antigen-induced translocation of PKC-theta to membrane rafts is required for T cell activation. Nat Immunol Jun; 2 556 63

65. XuXLondonE 2000 The effect of sterol structure on membrane lipid domains reveals how cholesterol can induce lipid domain formation. Biochemistry 39 843 849

66. HarderTScheiffelePVerkadePSimonsK 1998 Lipid domain structure of the plasma membrane revealed by patching of membrane components. J Cell Biol 141 929 942

67. BograhACarpentierRTajmir-RiahiHA 1999 The effect of cholesterol on the solution structure of proteins of Photosystem II. Protein secondary structure and photosynthetic oxygen evolution. J Colloid Interface Sci 210 118 122

68. ForgetGGregoryDJOlivierM 2005 Proteasome-mediated degradation of STAT1alpha following infection of macrophages with Leishmania donovani. J Biol Chem 280 30542 30549

69. DasguptaBRoychoudhuryKGangulySKumar SinhaPVimalS 2003 AntiLeishmanial drugs cause up-regulation of interferon-gamma receptor 1, not only in the monocytes of visceral Leishmaniasis cases but also in cultured THP1 cells. Ann Trop Med Parasitol 97 245 257

70. BrownMSHoYKGoldsteinJL 1980 The cholesteryl ester cycle in macrophage foam cells. Continual hydrolysis and re-esterification of cytoplasmic cholesteryl esters. J Biol Chem 255 9344 9352

71. ChobanianAVHollanderW 1962 Body cholesterol metabolism in man. I. The equilibration of serum and tissue cholesterol. J Clin Invest 41 1732 7

72. RubADeyRJadhavMKamatRChakkaramakkilS 2009 Cholesterol depletion associated with Leishmania major infection alters macrophage CD40 signalosome composition and effector function. Nat Immunol 10 273 280

73. ShrivastavaSChattopadhyayA 2007 Influence of cholesterol and ergosterol on membrane dynamics using fluorescent probes. Biochem Biophys Res Commun 356 705 710

74. PucadyilTJTewaryPMadhubalaRChattopadhyayA 2004 Cholesterol is required for Leishmania donovani infection: implications in leishmaniasis. Mol Biochem Parasitol 133 145 52

75. GreenhalghCJHiltonDJ 2001 Negative regulation of cytokine signaling. J Leukocyte Biol 70 348 356

76. BlanchetteJRacetteNFaureRSiminovitchKAOlivierM 1999 Leishmania-induced increases in activation of macrophage SHP-1 tyrosine phosphatase are associated with impaired IFN-gamma-triggered JAK2 activation. Eur J Immunol 29 3737 3744

77. BousquetCSusiniCMelmedS 1999 Inhibitory roles for SHP-1 and SOCS-3 following pituitary proopiomelanocortin induction by leukemia inhibitory factor. J Clin Invest 104 1277 1285

78. GomezMAContrerasIHalléMTremblayMLMcMasterRW 2009 Leishmania GP63 alters host signaling through cleavage-activated protein tyrosine phosphatases. Sci Signal 2 ra58

79. SilvermanJMClosJde'OliveiraCCShirvaniOFangY 2010 An exosome-based secretion pathway is responsible for protein export from Leishmania and communication with macrophages. J Cell Sci 123 842 52

80. MelbyPCChandrasekarBZhaoWCoeJE 2001 The hamster as a model of human visceral leishmaniasis: progressive disease and impaired generation of nitric oxide in the face of a prominent Th1-like cytokine response. J Immunol 166 1912 1920

81. ItoSAnsariPSakatsumeMDickensheetsHVazquezN 1999 Interleukin-10 inhibits expression of both interferon alpha- and interferon gamma- induced genes by suppressing tyrosine phosphorylation of STAT1. Blood 93 1456 63

82. SahaBRoyHNPakrashiAChakrabartiRNRoyS 1991 Immunobiological studies on experimental visceral Leishmaniasis. I. Changes in lymphoid organs and their possible role in pathogenesis. Eur J Immunol 21 577 581

83. MukhopadhyaySSenPBhattacharyyaSMajumdarSRoyS 1999 Immunoprophylaxis and immunotherapy against experimental visceral Leishmaniasis. Vaccine 17 291 300

84. GreenLCWangerDAGlogowskiJSkipperPLWishnokJS 1982 Analysis of nitrate, nitrite, and [15N] nitrate in biological fluids. Anal Biochem 126 131 138

85. OlivierMRomero-GalloBJMatteCBlanchetteJPosnerBI 1998 Modulation of interferon-gamma-induced macrophage activation by phosphotyrosine phosphatases inhibition. Effect on murine Leishmaniasis progression. J Biol Chem 273 13944 13949

86. GreenMMLarkin J3rdSubramaniamPSSzenteBEJohnsonHM 1998 Human IFN gamma receptor cytoplasmic domain: expression and interaction with HuIFN gamma. Biochem Biophys Res Commun 243 170 176

87. SzenteBESubramaniamPSJohnsonHM 1995 Identification of IFN-gamma receptor binding sites for JAK2 and enhancement of binding by IFN-gamma and its C-terminal peptide IFN-gamma (95-133). J Immunol 155 5617 5622

88. ZöllnerCMousaSAFischerORittnerHLShaquraM 2008 Chronic morphine use does not induce peripheral tolerance in a rat model of inflammatory pain. J Clin Invest 118 1065 1073

89. GentJvan KerkhofPRozaMBuGStrousGJ 2002 Ligand-independent growth hormone receptor dimerization occurs in the endoplasmic reticulum and is required for ubiquitin system-dependent endocytosis. Proc Natl Acad Sci U S A 99 9858 9863

90. AndersonPYipYKVilcekJ 1983 Human interferon-gamma is internalized and degraded by cultured fibroblasts. J Biol Chem 258 6497 6502

91. LiuHRhodesMWiestDLVignaliDA 2000 On the dynamics of TCR:CD3 complex cell surface expression and downmodulation. Immunity 13 665 675

92. LacalleRAMiraEGomez-MoutonCJimenez-BarandaSMartinez-AC 2002 Specific SHP-2 partitioning in raft domains triggers integrin-mediated signaling via Rho activation. J Cell Biol 157 277 289

93. El KasmiKCHolstJCoffreMMielkeLde PauwA 2006 General nature of the STAT3-activated anti-inflammatory response. J Immunol 177 7880 7888

94. GaoJMorrisonDCParmelyTJRussellSWMurphyWJ 1997 An interferon-gamma-activated site (GAS) is necessary for full expression of the mouse iNOS gene in response to interferon-gamma and lipopolysaccharide. J Biol Chem 272 1226 1230

95. PlevySEGemberlingJHHsuSDornerAJSmaleST 1997 Multiple control elements mediate activation of the murine and human interleukin 12 p40 promoters: evidence of functional synergy between C/EBP and Rel proteins. Mol Cell Biol 17 4572 4588

96. GiraudMNMottaCRomeroJJBommelaerGLichtenbergerLM 1999 Interaction of Indomethacin and Naproxen with gastric surface-active phospholipids: A possible mechanism for the gastric toxicity of nonsteroidal anti-inflammatory drugs (NSAIDs) Biochemical Pharmacology 57 247 254

97. LeeBCZuckermannRNDillKA 2005 Folding a nonbiological polymer into a compact multihelical structure. J Am Chem Soc 127 10999 11009

98. RivenIKalmanzonESegevLReuvenyE 2003 Conformational rearrangements associated with the gating of the G protein-coupled potassium channel revealed by FRET microscopy. Neuron 38 225 235

99. NagamatsuSKornhauserJMBurantCFSeinoSMayoKE 1992 Glucose transporter expression in brain. cDNA sequence of mouse GLUT3, the brain facilitative glucose transporter isoform, and identification of sites of expression by in situ hybridization. J Biol Chem 267 467 472

100. OkadaSYamadaESaitoTOhshimaKHashimotoK 2008 CDK5-dependent phosphorylation of the Rho family GTPase TC10(alpha) regulates insulin-stimulated GLUT4 translocation. J Biol Chem 283 35455 35463

101. DemandolxDDavoustJ 1997 Multicolour analysis and local image correlation in confocal microscopy. J Microsc 185 21 36

102. MandersEMMVerbeekFJAtenJA 1993 Measurement of co-localization of objects in dual-colour confocal images. J Microsc 169 375 382

103. CunninghamOAndolfoASantovitoMLIuzzolinoLBlasiF 2003 Dimerization controls the lipid raft partitioning of uPAR/CD87 and regulates its biological functions. EMBO J 22 5994 6003

104. LeglerDFMicheauODouceyMATschoppJBronC 2003 Recruitment of TNF receptor 1 to lipid rafts is essential for TNFalpha-mediated NF-kappaB activation. Immunity 18 655 664

105. ShinitzkyMInbarM 1974 Difference in microviscosity induced by different cholesterol levels in the surface membrane lipid layer of normal lymphocytes and malignant lymphoma cells. J Mol Biol 85 603 615

106. ShinitzkyMBarenholzY 1978 Fluidity parameters of lipid regions determined by fluorescence polarization. Biochim Biophys Acta 515 367 394

107. ChenXReshMD 2002 Cholesterol depletion from the plasma membrane triggers ligand-independent activation of the epidermal growth factor receptor. J Biol Chem 277 49631 49637

108. MartinITurcoSJEpandRMRuysschaertJM 1998 Lipophosphoglycan of Leishmania donovani inhibits lipid vesicle fusion induced by the N-terminal extremity of viral fusogenic simian immunodeficiency virus protein. Eur J Biochem 258 150 156

109. FieldGBNobleRL 1990 Solid peptide synthesis utilizing 9-fluorenylmethoxycarbonyl amino acid. Int J Pept Protein Res 35 161 214

110. LiuZMasukoSSolakyildirimKPuDLinhardtRJ 2010 Glycosaminoglycans of the porcine central nervous system. Biochemistry 49 9839 9847

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