Flagellar membrane localization via association with lipid rafts
Autor: | Theodore L. Hazlett, Krista M. Toriello, Cheryl L. Olson, Alina Fridberg, Kevin M. Tyler, David M. Engman, John A. Cieslak |
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Rok vydání: | 2009 |
Předmět: |
Axoneme
Calcium-Binding Proteins Detergents Trypanosoma brucei brucei Protozoan Proteins Direct observation Cell Biology Biology Flagellum Cell biology Protein Transport Membrane Microdomains Membrane Flagella Intraflagellar transport Animals lipids (amino acids peptides and proteins) Flagellar membrane Flagellar axoneme Laurdan fluorescence Lipid raft Research Article |
Zdroj: | Journal of Cell Science. 122:859-866 |
ISSN: | 1477-9137 0021-9533 |
DOI: | 10.1242/jcs.037721 |
Popis: | The eukaryotic flagellar membrane has a distinct composition from other domains of the plasmalemma. Our work shows that the specialized composition of the trypanosome flagellar membrane reflects increased concentrations of sterols and saturated fatty acids, correlating with direct observation of high liquid order by laurdan fluorescence microscopy. These findings indicate that the trypanosome flagellar membrane possesses high concentrations of lipid rafts: discrete regions of lateral heterogeneity in plasma membranes that serve to sequester and organize specialized protein complexes. Consistent with this, a dually acylated Ca2+ sensor that is concentrated in the flagellum is found in detergent-resistant membranes and mislocalizes if the lipid rafts are disrupted. Detergent-extracted cells have discrete membrane patches localized on the surface of the flagellar axoneme, suggestive of intraflagellar transport particles. Together, these results provide biophysical and biochemical evidence to indicate that lipid rafts are enriched in the trypanosome flagellar membrane, providing a unique mechanism for flagellar protein localization and illustrating a novel means by which specialized cellular functions may be partitioned to discrete membrane domains. |
Databáze: | OpenAIRE |
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