Regulation of RelA (p65) function by the large subunit of replication factor C.
The RelA (p65) subunit of NF-kappaB is an important regulator of inflammation, proliferation, and apoptosis. We have discovered that the large subunit, p140, of replication factor C (RFC) can function as a regulator of RelA. RFC is a clamp loader, facilitating the addition and removal of proliferating-cell nuclear antigen from DNA during replication and repair but can also interact directly with the retinoblastoma tumor suppressor protein and the transcription factor C/EBPalpha. We find that RFC (p140) interacts with RelA both in vitro and in vivo and stimulates RelA transactivation. In contrast, coexpression of fragments of RFC (p140) that mediate the interaction with RelA results in transcriptional inhibition. The significance of this regulation was confirmed by using short interfering RNA oligonucleotides targeted to RFC (p140). Down regulation of endogenous RFC (p140) inhibits expression from a chromosomally integrated reporter plasmid induced by endogenous, TNF-alpha-activated NF-kappaB. Dominant negative fragments of RFC (p140) also cooperate with overexpressed RelA to induce cell death. Interestingly, RFC (p140) also interacts with the tumor suppressor p53. Taken together, these observations suggest that, in addition to its previously described function in DNA replication and repair, RFC (p140) has an important role as a regulator of transcription and NF-kappaB activity.
Anderson
Lisa A
LA
Division of Gene Expression and Regulation, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom.
Perkins
Neil D
ND
D020816:Amino Acid Motifs; D022763:CCAAT-Enhancer-Binding Protein-alpha / Q000378:metabolism; D016923:Cell Death; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002846:Chromatography, Affinity; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015536:Down-Regulation; D000939:Epitopes; D005982:Glutathione Transferase / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008025:Ligases / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D009841:Oligonucleotides / Q000494:pharmacology; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D051818:Replication Protein C; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D022763:CCAAT-Enhancer-Binding Protein-alpha; D004268:DNA-Binding Proteins; D000939:Epitopes; D009841:Oligonucleotides; D034741:RNA, Small Interfering; D016159:Tumor Suppressor Protein p53; D004247:DNA; D008156:Luciferases; D005982:Glutathione Transferase; D051818:Replication Protein C; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases