Kaltschmidt C, Kaltschmidt B, Baeuerle P A
Laboratory for Molecular Biology, Gene Center, Martinsried, Germany.
Mech Dev. 1993 Oct;43(2-3):135-47. doi: 10.1016/0925-4773(93)90031-r.
We investigated the rat brain for the presence and activation state of the inducible transcription factor NF-kappa B. Two forms of NF-kappa B containing the transactivating p65 subunit were found in all brain regions investigated. The majority of NF-kappa B was in an inducible cytoplasmic form by virtue of its association with the inhibitory subunit I kappa B. Significant amounts of inducible NF-kappa B forms were present in synaptosomes, as suggested by electrophoretic mobility shift assay and Western blot analysis of subcellular brain fractions. A synaptic localization of NF-kappa B was further evident from immunostaining of inner and outer plexiform layers of the retina with an antibody directed against the p50 subunit of NF-kappa B. In cerebral cortex and striatum, NF-kappa B-specific antibodies showed a punctate immunostaining partially overlapping with that for the synaptic marker protein synaptophysin. NF-kappa B is thus the first transcription factor found in synapses of neurons. With its unusual subneuronal localization, the inducible transcription factor has the potential to function as retrograde messenger mediating stimulus-response coupling and long-term changes in gene expression following presynaptic stimulation.
我们研究了大鼠大脑中诱导型转录因子核因子-κB（NF-κB）的存在情况及其激活状态。在所研究的所有脑区中均发现了两种含有反式激活p65亚基的NF-κB形式。大多数NF-κB因其与抑制性亚基IκB的结合而处于可诱导的细胞质形式。如通过电泳迁移率变动分析和脑亚细胞组分的蛋白质印迹分析所示，突触体中存在大量可诱导的NF-κB形式。用针对NF-κB p50亚基的抗体对视网膜内、外丛状层进行免疫染色，进一步证明了NF-κB的突触定位。在大脑皮层和纹状体中，NF-κB特异性抗体显示出点状免疫染色，部分与突触标记蛋白突触素的免疫染色重叠。因此，NF-κB是在神经元突触中发现的首个转录因子。凭借其不寻常的神经元内定位，这种诱导型转录因子有可能作为逆行信使，介导突触前刺激后的刺激-反应偶联以及基因表达的长期变化。
