Emphatic visualization of sphingomyelin-rich domains by inter-lipid FRET imaging using fluorescent sphingomyelins
| Autor: | Masanao Kinoshita, Kenta Shigetomi, Michio Murata, Nobuaki Matsumori, Hikaru Ano, Junichi Ikenouchi |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Membrane Fluidity Protein domain lcsh:Medicine Article Cell Line 03 medical and health sciences Membrane Lipids Mice Protein Domains Membrane fluidity Fluorescence Resonance Energy Transfer Animals lcsh:Science Unilamellar Liposomes Multidisciplinary Chemistry Vesicle lcsh:R Biological membrane Fluorescence Sphingomyelins 030104 developmental biology Membrane Förster resonance energy transfer Biophysics lcsh:Q Sphingomyelin |
| Zdroj: | Scientific Reports Scientific Reports, Vol 7, Iss 1, Pp 1-10 (2017) |
| ISSN: | 2045-2322 |
| Popis: | Imaging the distribution of sphingomyelin (SM) in membranes is an important issue in lipid-raft research. Recently we developed novel fluorescent SM analogs that exhibit partition and dynamic behaviors similar to native SM, and succeeded in visualizing lateral domain-segregation between SM-rich liquid-ordered (Lo) and SM-poor liquid-disordered (Ld) domains. However, because the fluorescent contrast between these two domains depends directly on their partition ratio for the fluorescent SMs, domain-separation becomes indeterminate when the distribution difference is not great enough. In this study, we propose the use of inter-lipid Förster resonance energy transfer (FRET) imaging between fluorescent SMs to enhance the contrast of the two domains in cases in which the inter-domain difference in SM distribution is inadequate for conventional monochromic imaging. Our results demonstrate that inter-lipid FRET intensity was significantly higher in the Lo domain than in the Ld domain, resulting in a clear and distinguishable contrast between the two domains even in poorly phase-separated giant unilamellar vesicles. In addition, we show that inter-lipid FRET imaging is useful for selective visualization of highly condensed assemblies and/or clusters of SM molecules in living cell membranes. Thus, the inter-lipid FRET imaging technique can selectively emphasize the SM-condensed domains in both artificial and biological membranes. |
| Databáze: | OpenAIRE |
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