Uncoiling c-Jun coiled coils: inhibitory effects of truncated Fos peptides on Jun dimerization and DNA binding in vitro.
c-Jun is an oncoprotein that comprises a portion of the AP-1 transcription factor and belongs to the basic-leucine zipper (bZIP) DNA binding protein family. Using peptides derived from the leucine zipper region of Fos, we have developed agents that inhibit Jun's DNA binding in the low micromolar range. Fos peptides that were effective inhibitors in the DNA binding assay were also found to inhibit cellular Jun binding to an AP-1 site in a luciferase reporter plasmid in MCF-7 cells. Size exclusion studies confirmed that peptides that inhibit the DNA binding of Jun also inhibit its dimerization. These peptides were found to have a cytotoxic effect on the MCF-7 cell line when delivered with the transfecting agent Tfx-50, possibly due to their role as transcription factor regulators.
Yao
S
S
Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
Brickner
M
M
Pares-Matos
E I
EI
Chmielewski
J
J
D000595:Amino Acid Sequence; D001667:Binding, Competitive; D002470:Cell Survival / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry*; D019281:Dimerization; D005786:Gene Expression Regulation; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D016350:Leucine Zippers; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010446:Peptide Fragments / Q000737:chemistry* / Q000633:toxicity; D016760:Proto-Oncogene Proteins c-fos / Q000737:chemistry*; D016755:Proto-Oncogene Proteins c-jun / Q000737:chemistry*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014162:Transfection / Q000235:genetics; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D010446:Peptide Fragments; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors