Viallinen alfaTTP-PIP-kompleksi ja perinnällinen E-vitamiinivaje

Science. 2013 May 31;340(6136):1106-10. doi: 10.1126/science.1233508. Epub 2013 Apr 18.

Impaired α-TTP-PIPs interaction underlies familial vitamin E deficiency.

Kono N¹, Ohto U, Hiramatsu T, Urabe M, Uchida Y, Satow Y, Arai H.

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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.

Comment in

• Cell biology. Vitamin currency in a lipid exchange market. [Science. 2013]
• The lipid trade. [Nat Rev Mol Cell Biol. 2014]

PMID:

23599266

[PubMed - indexed for MEDLINE]

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