Clustering of plasma membrane-bound cytochrome b₅

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• 作者：Alej ; ro K. Samhan-Arias ; Miguel Angel Garcia-Bereguiain ; Francisco J. Martin-Romero ; Carlos Gutierrez-Merino
• 关键词：Cytochrome b₅ reductase ; Flavoproteins ; Cerebellar granule neurons ; Plasma membrane redox centres ; Lipid rafts ; FRET ; Imaging ; Cholera toxin B ; Caveolin ; Synaptic plasma membranes
• 刊名：Molecular and Cellular Neuroscience
• 出版年：2009
• 出版时间：5 January 2009
• 年：2009
• 卷：40
• 期：1
• 页码：14-26
• 全文大小：1599 K

文摘

Plasma membrane redox centres play a major role in neuronal defence against oxidative stress and survival. In cerebellar granule neurons in culture (CGN) a large pool of the flavoproteins are associated with the plasma membrane, and the intensity of CGN green/orange autofluorescence correlated with the levels of expression of cytochrome b₅ reductase. Regionalization of cytochrome b₅ reductase in the plasma membrane of CGN by fluorescence resonance energy transfer points out the close proximity between cytochrome b₅ reductase and the ‘lipid raft’ markers cholera toxin B and caveolin-2. This study unravels that membrane-bound cytochrome b₅ reductase is largely enriched at interneuronal contact sites in the neuronal soma and associated with ‘lipid rafts’ of the CGN plasma membrane. We also show that cytochrome b₅ reductase makes a large contribution to the NADH oxidase activity and to the red-shifted flavine fluorescence of purified rat brain synaptic plasma membranes. In conclusion, membrane-bound cytochrome b₅ reductase forms a large mesh of redox centres associated with the neuronal plasma membrane.