Role of Unphosphorylated, Newly Synthesized I (cid:107) B (cid:98) in Persistent Activation of NF- (cid:107) B
Role of Unphosphorylated, Newly Synthesized I (cid:107) B (cid:98) in Persistent Activation of NF- (cid:107) B
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未磷酸化的新合成 I (cid:107) B (cid:98) 在 NF- (cid:107) B 持续激活中的作用
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
Sankar Ghosh
中科院分区：
文献类型：
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作者：
H. Suyang;R. Phillips;I. Douglas;Sankar Ghosh
用引起NF-（cid：107）B持续活化的诱导剂刺激导致NF-（cid：107）B抑制剂I（cid：107）B（cid：97）和I（cid：107）B（cid：98）降解。尽管I（cid：107）B（cid：97）快速重新合成和积累，但在这些条件下NF-（cid：107）B仍然被诱导。我们现在报告说，I（cid：107）B（cid：98）也在刺激的细胞中重新合成，并表现为非磷酸化蛋白。未磷酸化的I（cid：107）B（cid：98）与胞质溶胶中的NF-（cid：107）B形成稳定的复合物;然而，这种结合未能掩盖NF-（cid：107）B上的核定位信号和DNA结合结构域，并且I（cid：107）B（cid：98）-NF-（cid：107）B复合物进入细胞核。因此，在长时间刺激期间，I（cid：107）B（cid：98）似乎充当NF-（cid：107）B的伴侣，保护其免受I（cid：107）B（cid：97）的侵害，并允许其转运至细胞核。转录因子NF-（cid：107）B是一种普遍表达的转录因子，在大量转录因子的诱导表达中发挥重要作用
Stimulation with inducers that cause persistent activation of NF- (cid:107) B results in the degradation of the NF- (cid:107) B inhibitors, I (cid:107) B (cid:97) and I (cid:107) B (cid:98) . Despite the rapid resynthesis and accumulation of I (cid:107) B (cid:97) , NF- (cid:107) B remains induced under these conditions. We now report that I (cid:107) B (cid:98) is also resynthesized in stimulated cells and appears as an unphosphorylated protein. The unphosphorylated I (cid:107) B (cid:98) forms a stable complex with NF- (cid:107) B in the cytosol; however, this binding fails to mask the nuclear localization signal and DNA binding domain on NF- (cid:107) B, and the I (cid:107) B (cid:98) –NF- (cid:107) B complex enters the nucleus. It appears therefore that during prolonged stimulation, I (cid:107) B (cid:98) functions as a chaperone for NF- (cid:107) B by protecting it from I (cid:107) B (cid:97) and allowing it to be transported to the nucleus. The transcription factor NF- (cid:107) B is a ubiquitously expressed transcription factor that plays an important role in the induc- ible expression of a large number of