Abstract
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.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Cloning, Molecular
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Enzyme Activation
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HeLa Cells
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Humans
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I-kappa B Kinase
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Inflammation Mediators / metabolism
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Kinetics
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Molecular Sequence Data
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NF-kappa B / metabolism*
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Phosphoprotein Phosphatases / metabolism
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Phosphorylation
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Protein Serine-Threonine Kinases / genetics
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Protein Serine-Threonine Kinases / isolation & purification
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Protein Serine-Threonine Kinases / metabolism*
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Substrate Specificity
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Tumor Necrosis Factor-alpha / metabolism
Substances
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Inflammation Mediators
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NF-kappa B
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Tumor Necrosis Factor-alpha
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Protein Serine-Threonine Kinases
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CHUK protein, human
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I-kappa B Kinase
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IKBKB protein, human
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IKBKE protein, human
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Phosphoprotein Phosphatases