摘要
IκB激酶(IKK复合体)是NF-κB信号转导途径成员之一,包括3个亚基:催化亚基IKKα、IKKβ和调节亚基IKKγ。无刺激时,NF-κB与抑制蛋白IκB家族的一个成员结合,或者与无活性前体(如p100)结合而以无活性形式存在。在外界信号如TNF-α或淋巴毒素β等刺激下,经过复杂的信号转导,IKK复合体被激活,导致IκB和(或)p100发生磷酸化,结果NF-κB被释放出来,进入细胞核内激活靶基因。最新研究发现在TNF-α刺激下,IKKα可直接进入细胞核内,通过催化组蛋白H3磷酸化进而激活特定NF-κB应答基因的表达。IKKα是首次发现的信号转导途径中直接进入细胞核内调节基因表达的上游成分,为NF-κB信号转导途径的研究开辟了新的道路。
IκB kinase or IKK complex, which is one important component of NF-κB signaling pathway, consists of three subunit： IKKα, IKKβ as catalytic subunits and IKKγ as modulator subunit. NF-κB proteins are dimmers, comprising a DNA-binding subunit （such as p50 or p52） and a transcription-activating subunit （such as p65 or RelB）. In cells that have not received appropriate external cues, NF-κB are kept inactive either by a member of the IκB family in the classical pathway, or by an inactive precursor （such as p100） in the alternative pathway. When stimulated by proteins such as TNF-α or lymphotoxin β, the IKK complex is activated. It phosphorylates IκB and/or p100, leading to degradation of IκB and the processing of p100 into a smaller, p52 form. NF-κB is then free to move into the nucleus and activates target genes. Recent studies reveals that IKKα can itself move into the nucleus where it regulates the expression of NF-κB-responsive genes rapidly via phosphorylating histone 3 on serine 10. It is the first discovery that IKKα being the upstream component of signaling pathway moves into the nucleus directly and regulates the expression of target genes, which open up a new avenue of research into the NF-κB signaling pathway.
出处
《细胞生物学杂志》
CSCD
2006年第3期392-394,共3页
Chinese Journal of Cell Biology
基金
曲阜师范大学科研基金资助项目(No.xj0510)~~
作者简介
通讯作者。Tel：0537-4458281，Fax：0537-4456887，E-mail：xudl1975@163．com
