|Budget Amount *help
¥13,900,000 (Direct Cost: ¥13,900,000)
Fiscal Year 2006: ¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 2005: ¥7,600,000 (Direct Cost: ¥7,600,000)
1.Preparation and analysis of ERM protein knockout mice : Analysis of knockout mice clarified that radixin maintains the function of the bilirubin transporter, MRP2, by anchoring it to the luminal surface of capillary bile ducts in the liver. In knockout mice, MRP2 cannot function, and induces Dubin-Johnson syndrome-type hyperbilirubinemia. In this study, we showed the possibility of individual histological and hematological differences in this syndrome reflecting genetic background-associated differences in the basolateral surface MRP3 expression level.
2.Analysis of the composition of cell adhesion apparatus : We established a preparation method of a concentrated cell adhesion apparatus fraction from a capillary bile duct fraction prepared from the liver in 1989, and identified major proteins composing the apparatus. In this study, we identified many novel components of the cell adhesion apparatus, which was not possible using previous methods, by taking advantage of the marked progre
ss in mass spectrometry. Many of these tagged proteins were localized in the cell adhesion apparatus, as expected. We prepared antibodies against these proteins, and RNAi experiments in cultured cells are now underway. We are planning to investigate how these proteins coordinate in their roles in intercellular adhesion.
3.Analysis of centrosome component protein, Odf2, knockout mice : In Odf2 conditional knockout mice, cell division may not be affected, and only the primary cilium may organ-specifically disappear. Using these mice, the role of primary cilia may be analyzed in vivo, which has remained unclear for a long time. Odf2 is a component of outer dense fibers (ODF) of sperms, and its disappearance causes male infertility. Since only a slight decrease in the expression caused infertility, preparation of conditional knockout mice was difficult, but we finally established a heterozygote generation. Since an unexpected function of the primary cilium was suggested at the cell culture level, analysis of individual animals may provide significant information. Less