Phosphorylation of NF-KB1-p50 is involved in NF-kappa B activation and stable DNA binding.
We have previously shown that NF-kappa B/Rel family members are physically associated phosphoproteins, and p105 and p50 are hyperphosphorylated after NF-kappa B activation. In this report, we further studied the phosphorylation involved in NF-kappa B activation in Jurkat T cells responding to phorbol 12-myristate 13-acetate and phytohemagglutinin. Immediately following stimulation, p50 is hyperphosphorylated, and a phosphorylated form of p50 (pp50) is translocated from the cytoplasm to the nucleus. The kinetics of this nuclear translocation paralleled that of the appearance of an active kappa B DNA-binding complex. An at least 30-fold higher level of kappa B DNA binding was detected in pp50 than p50. The enhanced binding could be attributed to a much greater stability detected in the complex consisting of kappa B DNA and pp50, but not p50. These results suggest that phosphorylation of p50, and perhaps other family members as well, may be involved in the activation of NF-kappa B/Rel family transcription factors.
Li
C C
CC
Biological Carcinogenesis and Development Program, Program Resources, Inc./Dyncorp, Frederick, Maryland.
Dai
R M
RM
Chen
E
E
Longo
D L
DL
D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000302:isolation & purification / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit; D015345:Oligonucleotide Probes; D010766:Phosphorylation; D010835:Phytohemagglutinins / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D046911:Macromolecular Substances; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D015345:Oligonucleotide Probes; D010835:Phytohemagglutinins; D004247:DNA; D013755:Tetradecanoylphorbol Acetate