Structural highlights
Function
TTPA_MOUSE Binds alpha-tocopherol and enhances its transfer between separate membranes (By similarity).
Publication Abstract from PubMed
alpha-Tocopherol (vitamin E) transfer protein (alpha-TTP) regulates the secretion of alpha-tocopherol from liver cells. Missense mutations of some arginine residues at the surface of alpha-TTP cause severe vitamin E deficiency in humans, but the role of these residues is unclear. Here, we found that wild-type alpha-TTP bound phosphatidylinositol phosphates (PIPs), whereas the arginine mutants did not. In addition, PIPs in the target membrane promoted the intermembrane transfer of alpha-tocopherol by alpha-TTP. The crystal structure of the alpha-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 alpha-tocopherol-binding pocket to open. Thus, PIPs have a role in promoting the release of a ligand from a lipid-transfer protein.
Impaired alpha-TTP-PIPs Interaction Underlies Familial Vitamin E Deficiency.,Kono N, Ohto U, Hiramatsu T, Urabe M, Uchida Y, Satow Y, Arai H Science. 2013 Apr 18. PMID:23599266[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kono N, Ohto U, Hiramatsu T, Urabe M, Uchida Y, Satow Y, Arai H. Impaired alpha-TTP-PIPs Interaction Underlies Familial Vitamin E Deficiency. Science. 2013 Apr 18. PMID:23599266 doi:10.1126/science.1233508
