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Human StAR-related lipid transfer protein 5

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PDB Code 2R55 Target Class Lipid signalling Target STARD5 Alias MGC10327, STARD5 Disease Area/Function cancer Date Deposited Sep 03 2007 Authors LEHTIO, L., BUSAM, R., ARROWSMITH, C., BERGLUND, H., COLLINS, R., DAHLGREN, L.G., HERMAN, M.D., EDWARDS, A., FLODIN, S., FLORES, A., GRASLUND, S., HAMMARSTROM, M., HALLBERG, B.M., JOHANSSON, I., KALLAS, A., KARLBERG, T., KOTENYOVA, T., MOCHE, M., NORDLUND, P., NYMAN, T., SAGEMARK, J., SUNDSTROM, M., THORSELL, A.G., TRESAUGUES, L., VAN DEN BERG, S., WEIGELT, J., WELIN, M., PERSSON, C.

About this structure

Human StAR-related lipid transfer protein 5 (STARD5) belongs to the STARD4 subfamily of the START domain containing superfamily of proteins that are involved in lipid related mechanisms such as lipid metabolism, lipid trafficking and cell signaling. The START domain is a ~210 amino acid globular domain that contains a hydrophobic cavity which determines the lipid ligand binding specificity. Unlike many other START domain proteins, the members of the STARD4 subfamily do not contain N-terminal targeting sequences or additional domains. Overexpression of STARD5 stimulates steroidogenesis by the mitochondrial P450scc enzyme and liver X receptor reporter gene activity. Furthermore STARD5 selectively binds to cholesterol and 25-hydroycholesterol, a potent inflammatory mediator and regulatory oxysterol, implicating that the protein has a role in maintaining cholesterol homeostasis. STARD5 is widely expressed with highest levels in the cytosolic fraction of human liver and inflammatory related cells. Increased gene expression has been demonstrated upon endoplasmic reticulum stress. Upregulation of STARD5 gene expression has also been shown in human lung carcinoma.

References

  1. Alpy F, Tomasetto C. (2005). Give lipids a START: the StAR-related lipid transfer (START) domain in mammals. J Cell Sci. 118(Pt 13), 2791-801
  2. Rodriguez-Agudo D, Ren S, Hylemon PB, Montaņez R, Redford K, Natarajan R, Medina MA, Gil G, Pandak WM. (2006). Localization of StarD5 cholesterol binding protein. J Lipid Res. 47(6), 1168-75.
  3. Soccio RE, Adams RM, Maxwell KN, Breslow JL. (2005). Differential gene regulation of StarD4 and StarD5 cholesterol transfer proteins. J Biol Chem. 280(19), 19410-8.
  4. Rodriguez-Agudo D, Ren S, Hylemon PB, Redford K, Natarajan R, Del Castillo A, Gil G, Pandak WM. (2005). Human StarD5, a cytosolic StAR-related lipid binding protein. J Lipid Res. 46(8), 1615-23.
  5. Romanowski MJ, Sehayek E, Burley SK, Breslow JL. (2002). The cholesterol-regulated StarD4 gene encodes a StAR-related lipid transfer protein with two closely related homologues, StarD5 and StarD6. Proc Natl Acad Sci U S A. 99(10), 6943-8.