DiDonato J A, Hayakawa M, Rothwarf D M, Zandi E, Karin M
Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California at San Diego, La Jolla 92093-0636, USA.
Nature. 1997 Aug 7;388(6642):548-54. doi: 10.1038/41493.
Nuclear transcription factors of the NF-kappaB/Rel family are inhibited by IkappaB proteins, which inactivate NF-kappaB by trapping it in the cell cytoplasm. Phosphorylation of IkappaBs marks them out for destruction, thereby relieving their inhibitory effect on NF-kappaB. A cytokine-activated protein kinase complex, IKK (for IkappaB kinase), has now been purified that phosphorylates IkappaBs on the sites that trigger their degradation. A component of IKK was molecularly cloned and identified as a serine kinase. IKK turns out to be the long-sought-after protein kinase that mediates the critical regulatory step in NF-kappaB activation.
NF-κB/Rel家族的核转录因子受到IκB蛋白的抑制，IκB蛋白通过将NF-κB困在细胞质中使其失活。IκB的磷酸化标志着它们将被降解，从而解除其对NF-κB的抑制作用。一种细胞因子激活的蛋白激酶复合物，即IκB激酶（IKK），现已被纯化，它能在触发IκB降解的位点上使其磷酸化。IKK的一个组分经分子克隆后被鉴定为一种丝氨酸激酶。结果表明，IKK就是长期以来寻找的介导NF-κB激活关键调控步骤的蛋白激酶。
