Tumor necrosis factor α receptor- and Fas-associated FLASH inhibit transcriptional activity of the glucocorticoid receptor by binding to and interfering with its interaction with p160 type nuclear receptor coactivators
Tumor necrosis factor α receptor- and Fas-associated FLASH inhibit transcriptional activity of the glucocorticoid receptor by binding to and interfering with its interaction with p160 type nuclear receptor coactivators
复制标题
DOI：
10.1074/jbc.m209234200
复制
发表时间：
2003-01-31
影响因子：
4.8
通讯作者：
Chrousos, GP
中科院分区：
文献类型：
--
作者：
Kino, T;Chrousos, GP
肿瘤坏死因子α(TNFpha)及其下游转录因子核因子kappaB(NF-kappaB)抑制糖皮质激素作用，在多种病理炎症状态下导致组织对糖皮质激素的抵抗。另一方面，P160核受体共激活子通过与糖皮质激素受体(GR)相互作用，通过其核受体结合域(NRB)中的LxxLL基序与其相互作用，从而对糖皮质激素受体(GR)的转录信号做出贡献。为了发现在辅激活子水平调节GR活性的TNFpha诱导因子，我们以糖皮质激素受体相互作用蛋白1(GRIP1)的NRB结构域为诱饵进行了酵母双杂交筛选。我们发现，FLICE相关的巨大蛋白(FLASH)负责传递TNFpha和Fas配体信号，它与GRIP1的NRB结构域结合在第二和第三个LxxLL基序之间的区域。Flash抑制糖皮质激素信号的GR反式激活和GRIP1增强，并抑制GR与GRIP1 NRB结构域的物理相互作用。转染型绿色荧光蛋白融合蛋白的Flash定位于胞浆和胞核，而内源性Flash在TNFpha作用下将其亚细胞定位从胞浆转移到胞核。Flash反义和超阻滞剂IkappaBalpha相互独立且相加地抑制TNFα的作用。这些发现表明，Flash参与了TNFpha诱导的GR反式激活的阻断，这种阻断是在核受体辅激活子水平上进行的，并且不依赖于NF-kappaB。
Tumor necrosis factor alpha (TNFalpha) and its downstream transcription factor nuclear factor kappaB (NF-kappaB) suppress glucocorticoid action, contributing to tissue resistance to glucocorticoids in several pathologic inflammatory states. p160 nuclear receptor coactivators on the other hand, contribute to the transcriptional signal of the glucocorticoid receptor (GR) through interaction with it via LXXLL motifs in their nuclear receptor-binding (NRB) domain. To discover TNFalpha-induced factors that regulate GR activity at the coactivator level, we performed yeast two-hybrid screening using the NRB domain of the glucocorticoid receptor-interacting protein 1 (GRIP1) as bait. We found that FLICE-associated huge protein (FLASH), which transduces, TNFalpha and Fas ligand signals, bound the NRB domain of GRIP1 at a region between the second and third LXXLL motifs. FLASH suppressed both GR transactivation and GRIP1 enhancement of the glucocorticoid signal and inhibited the physical interaction between GR and the GRIP1 NRB domain. Transfected green fluorescent protein-fused FLASH was located in both the cytoplasm and nucleus, while endogenous FLASH shifted its subcellular localization from the cytoplasm into the nucleus in response to TNFalpha. FLASH antisense and super-repressor IkappaBalpha inhibited the action of TNFalpha independently of each other and additively. These findings indicate that FLASH participates in TNFalpha-induced blockade of GR transactivation at the nuclear receptor coactivator level, upstream and independently of NF-kappaB.