Nucleocytoplasmic Shuttling of Steroid and Thyroid Hormone Receptors

我们已经开发了一种测定，允许体内监测类固醇受体蛋白核出口。在这个实验中，用聚乙二醇融合共培养的异源细胞，产生具有共享细胞质的多核异核体。由于用于产生异核子的两种细胞类型中只有一种在其细胞核（即供体细胞）内含有受体蛋白，因此在原始受体细胞类型（即受体细胞）的异源细胞核内检测到的任何受体必须来自从供体细胞核输出的蛋白质。该试验将用于确定糖皮质激素、黄体酮和甲状腺激素受体在与通常不具有这种能力的异源蛋白融合时是否具有分离输出的能力。我们预计这一分析系统将为调节蛋白质在核膜上的双向运动的机制提供新的见解。

We have developed an assay that permits the in vivo monitoring of steroid receptor protein nuclear export. In this assay co-cultured heterologous cells are fused using polyethylene glycol to generate multi-nucleated heterokaryon with shared cytoplasm. Since only one of the two cell types used to generate a heterokaryon will contain receptor protein within its nucleus (i.e. the donor cell), any receptor detected within the heterologous nucleus of the original receptor cell type (i.e. recipient cell) must derive from protein that exported from the donor cell nucleus. This assay will be used to determine whether the glucocorticoid, progesterone, and thyroid hormone receptors possess the capacity to export in isolation when fused to heterologous proteins that do not normally have this capacity. We anticipate that this system of analysis will provide novel insights into the mechanisms that regulate bi-directional movement of proteins across the nuclear envelope.