Fluorescence correlation spectroscopy reveals topological segregation of the two tumor necrosis factor membrane receptors
| Autor: | Margarita Gerken, C. Tietz, Peter Scheurich, Sylvia Willi, Andrea Zappe, Anja Krippner-Heidenreich, Felix Neugart, Steffen Steinert, Jörg Wrachtrup |
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| Rok vydání: | 2010 |
| Předmět: |
Receptor complex
Microdomains Green Fluorescent Proteins Biophysics Fluorescence correlation spectroscopy Tumor necrosis factor (TNF) Biology Topology Ligands Biochemistry Plasma membrane receptor Proinflammatory cytokine Mice Membrane Microdomains Cell surface receptor Animals Humans Receptors Tumor Necrosis Factor Type II Receptor TNF receptor associated factor (TRAF) Mice Knockout Tumor Necrosis Factor-alpha Cell Biology Cell biology Protein Structure Tertiary Membrane Spectrometry Fluorescence Cytoplasm Receptors Tumor Necrosis Factor Type I Mutation Tumor necrosis factor alpha HeLa Cells Signal Transduction |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. 1798(6):1081-1089 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/j.bbamem.2010.02.021 |
| Popis: | The proinflammatory cytokine tumor necrosis factor (TNF) binds two distinct plasma membrane receptors, TNFR1 and TNFR2. We have produced different receptor mutants fused with enhanced green fluorescent protein to study their membrane dynamics by fluorescence correlation spectroscopy (FCS). TNFR1 mutants show diffusion constants of approximately 1.2 × 10 − 9 cm 2 /s and a broad distribution of diffusion times, which is hardly affected by ligand binding. However, cholesterol depletion enhances their diffusion, suggesting a constitutive affinity to cholesterol rich membrane microdomains. In contrast, TNFR2 and mutants thereof diffuse rather fast ( D = 3.1 × 10 − 9 cm 2 /s) with a marked reduction after 30 min of TNF treatment ( D = 0.9 × 10 − 9 cm 2 /s). This reduction cannot be explained by the formation of higher ordered receptor clusters, since the fluorescence intensity of TNF treated receptors indicate the presence of a few receptor molecules per complex only. Together, these data point to a topological segregation of the two TNF receptors in different microcompartments of the plasma membrane independent of the cytoplasmic signaling domains of the receptors. |
| Databáze: | OpenAIRE |
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