Generation of p50 subunit of NF-kappa B by processing of p105 through an ATP-dependent pathway.
The transcription factor NF-kappa B is a heterodimer consisting of two proteins encoded by different members of the rel gene family (p50 and p65). The p50 subunit is unusual among DNA-binding proteins in that its functional form is encoded in an open reading frame of relative molecular mass 105,000 (p105; ref. 4). The N-terminal region of this open reading frame encodes p50, whereas the remaining C terminus contains ankyrin repeats. Although p50 binds to DNA, full-length p105 translated in vitro does not. The mechanism by which p50 is generated in vivo, and the fate of the C-terminal region of p105 have not been established. Here we show that functional p50 is produced by ATP-dependent proteolysis of p105. Moreover, we find that the C-terminal half of p105 is not required for processing in vivo, and is rapidly degraded on processing. We propose that the C-terminal region of p105 is involved in the cytoplasmic assembly of the complex between the p50/p65 heterodimer and the inhibitor I kappa B.
Fan
C M
CM
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Maniatis
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D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002522:Chlorocebus aethiops; D003593:Cytoplasm / Q000378:metabolism; D004247:DNA / Q000235:genetics; D004252:DNA Mutational Analysis; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D051379:Mice; D008970:Molecular Weight; D016328:NF-kappa B / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000378:metabolism
D046911:Macromolecular Substances; D016328:NF-kappa B; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D004247:DNA