dehydroergosterol and phosphatidylinositol-4-phosphate
dehydroergosterol has been researched along with phosphatidylinositol-4-phosphate* in 2 studies
Other Studies
2 other study(ies) available for dehydroergosterol and phosphatidylinositol-4-phosphate
Article | Year |
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Lipid traffic: Osh4p makes an unexpected exchange.
A new study in this issue (De Saint-Jean et al. 2011. J. Cell Biol. http://dx.doi.org/jcb.201104062) reveals that the sterol transfer protein Osh4p can also transport the signaling phospholipid phosphatidylinositol 4-phosphate (PI(4)P), which binds to the same site in Osh4p as sterol. This finding helps explain some previously published studies and also indicates that lipid/sterol exchange could contribute to establishing a sterol gradient in cells. Topics: Ergosterol; Lipid Bilayers; Membrane Proteins; Phosphatidylinositol Phosphates; Receptors, Steroid; Saccharomyces cerevisiae Proteins | 2011 |
Osh4p exchanges sterols for phosphatidylinositol 4-phosphate between lipid bilayers.
Osh/Orp proteins transport sterols between organelles and are involved in phosphoinositide metabolism. The link between these two aspects remains elusive. Using novel assays, we address the influence of membrane composition on the ability of Osh4p/Kes1p to extract, deliver, or transport dehydroergosterol (DHE). Surprisingly, phosphatidylinositol 4-phosphate (PI(4)P) specifically inhibited DHE extraction because PI(4)P was itself efficiently extracted by Osh4p. We solve the structure of the Osh4p-PI(4)P complex and reveal how Osh4p selectively substitutes PI(4)P for sterol. Last, we show that Osh4p quickly exchanges DHE for PI(4)P and, thereby, can transport these two lipids between membranes along opposite routes. These results suggest a model in which Osh4p transports sterol from the ER to late compartments pinpointed by PI(4)P and, in turn, transports PI(4)P backward. Coupled to PI(4)P metabolism, this transport cycle would create sterol gradients. Because the residues that recognize PI(4)P are conserved in Osh4p homologues, other Osh/Orp are potential sterol/phosphoinositol phosphate exchangers. Topics: Ergosterol; Lipid Bilayers; Liposomes; Membrane Proteins; Phosphatidylinositol Phosphates; Protein Structure, Tertiary; Receptors, Steroid; Saccharomyces cerevisiae Proteins | 2011 |