IkappaB kinase-alpha and -beta genes are coexpressed in adult and embryonic tissues but localized to different human chromosomes.
Activation of the transcription factor nuclear factor kappa B (NF-kappaB) is regulated by phosphorylation, ubiquitination, and degradation of its inhibitory factor IkappaB. Very recently, two closely related serine/threonine kinases have been identified as IkappaB kinases which are essential for IkappaB phosphorylation and NF-kappaB activation. Here, we isolated the full-length human cDNA clones encoding these two IkappaB kinases, IKK-alpha and IKK-beta. Both polypeptides contain a conserved amino-terminal kinase domain, a leucine zipper motif and a helix-loop-helix domain at their carboxyl terminus. We showed that IKK-alpha and IKK-beta were coexpressed in most human adult tissues as well as in different developmental stages of mouse embryos, suggesting that they may cooperate in the cells. The IKK-alpha and IKK-beta genes are distinct but evolutionarily conserved. Moreover, the IKK-alpha gene locus was mapped to human chromosome 10q24, whereas the IKK-beta gene locus was localized to human chromosome 8p11.2. These results indicated that both genes are not clustered on the same chromosome; nevertheless, both genes may be still regulated similarly during development and in adult tissues.
Hu
M C
MC
Department of Cell Biology and Functional Genomics, Amgen, Inc., Thousand Oaks, CA 91320, USA. mhu@amgen.com
Wang
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002879:Chromosomes, Human, Pair 10; D002898:Chromosomes, Human, Pair 8; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics; D004622:Embryo, Mammalian / Q000201:enzymology; D019143:Evolution, Molecular; D015870:Gene Expression; D006801:Humans; D051550:I-kappa B Kinase; D017404:In Situ Hybridization, Fluorescence; D007527:Isoenzymes / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014018:Tissue Distribution
D018076:DNA, Complementary; D007527:Isoenzymes; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; C496564:Chuk protein, mouse; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; C496562:Ikbkb protein, mouse; C496566:Ikbke protein, mouse