Abstract
α-Tocopherol (vitamin E) transfer protein (α-TTP) regulates the secretion of α-tocopherol from liver cells. Missense mutations of some arginine residues at the surface of α-TTP cause severe vitamin E deficiency in humans, but the role of these residues is unclear. Here, we found that wild-type α-TTP bound phosphatidylinositol phosphates (PIPs), whereas the arginine mutants did not. In addition, PIPs in the target membrane promoted the intermembrane transfer of α-tocopherol by α-TTP. The crystal structure of the α-TTP-PIPs complex revealed that the disease-related arginine residues interacted with phosphate groups of the PIPs and that the PIPs binding caused the lid of the α-tocopherol-binding pocket to open. Thus, PIPs have a role in promoting the release of a ligand from a lipid-transfer protein.
Original language | English |
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Pages (from-to) | 1106-1110 |
Number of pages | 5 |
Journal | Science |
Volume | 340 |
Issue number | 6136 |
DOIs | |
State | Published - 31 May 2013 |
Externally published | Yes |