STRUCTURE OF THE FCRN RECEPTOR

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 新生儿Fc受体（FcRn）将免疫球蛋白G（IgG）转运穿过上皮，将IgG结合到细胞顶面形成的酸性囊泡（pH< 6.5）中，并在pH 7.4时将IgG释放到血液中。这一过程的结构特征正在研究的EM层析成像。 特别地，我们已经将纳米金颗粒缀合至IgG的恒定片段（Fc），并且在低pH下将缀合物施用至MDCK细胞的培养单层，并将它们作为食物给予新生大鼠。 通过快速冷冻和冷冻置换制备相关细胞或组织后，我们在细胞顶侧和顶侧附近的囊泡隔室中寻找金内化的证据。 这些样品的初步断层图像显示了一些金的内化，但很难可视化。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The neonatal Fc receptor (FcRn) transports immunoglobulin G (IgG) across epithelia, binding IgG into acidic vesicles (pH< 6.5) that form on the apical surface of the cell and releasing IgG into the blood at pH7.4. Structural features of this process are being studied by EM tomography. In particular we have conjugated nanogold particles to the constant fragment (Fc) of IgG and have both administered the conjugates at low pH to cultured monolayers of MDCK cells and given them as food to neonatal rats. Following preparation of the relevant cells or tissues by rapid freezing and freeze substitution, we have looked for evidence of gold internalization in the vesicular compartments at and near the apical side of the cells. Preliminary tomograms of these samples show some internalization of gold, however it is difficult to visualize.