An NF-κB-Like Transcription Factor in Axoplasm is Rapidly Inactivated after Nerve Injury inAplysia
Tóm tắt
We found a protein in Aplysia neurons that has many characteristics of the transcription factor NF-κB. Thus, the protein recognized a radiolabeled probe containing the κB sequence from the human interferon-β gene enhancer element (PRDII), and the binding was not affected by PRDIV, an ATF-2 enhancer sequence from the same gene. Binding was efficiently inhibited, however, by nonradioactive oligonucleotides containing H2, the κB site from the major histocompatibility complex I gene promotor. In addition, recombinant mammalian IκB-α, which associates specifically with the P65 subunit of NF-κB, inhibited the binding to the PRDII probe in a dose-dependent manner. The nuclear form of the Aplysia protein was constitutively active. Axoplasm, however, contained the constitutively active form as well as a latent form. The latter was activated by treatment with deoxycholate under the same conditions as mammalian NF-κB. Based on these findings, we believe the protein to be a homolog of NF-κB. To investigate the role of apNF-κB in the axon, we crushed the peripheral nerves to the body wall. Surprisingly, there was a rapid loss of apNF-κB binding at the crush site and, within 15 min, as far as 2.5 cm along the axon. In contrast, exposing either the intact animal or the nervous system
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Tài liệu tham khảo
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