Heterologous C-terminal sequences disrupt transcriptional activation and oncogenesis by p59v-rel.
Members of the NF-kappa B/rel family of transcription factors are regulated through a trans association with members of a family of inhibitor proteins, collectively known as I kappa B proteins, that contain five to eight copies of a 33-amino-acid repeat sequence (ankyrin repeat). Certain NF-kappa B/rel proteins are also regulated by cis-acting ankyrin repeat-containing domains. The C terminus of p105NF-kappa B, the precursor of the 50-kDa subunit of NF-kappa B, contains a series of ankyrin repeats; proteolytic removal of this ankyrin domain is necessary for the manifestation of sequence-specific DNA binding and nuclear translocation of the N-terminal product. To investigate the structural requirements important for regulation of different NF-kappa B/rel family members by polypeptides containing ankyrin repeat domains, we have constructed a p59v-rel:p105NF-kappa B chimeric protein (p110v-rel-ank). The presence of C-terminal p105NF-kappa B-derived sequences in p110v-rel-ank inhibited nuclear translocation, sequence-specific DNA binding, pp40I kappa B-alpha association, and oncogenic transformation. Sequential truncation of the C-terminal ankyrin domain of p110v-rel-ank resulted in the restoration of nuclear translocation, DNA binding, and pp40I kappa B-alpha association but did not restore the oncogenic properties of p59v-rel. The presence of 67 C-terminal p105NF-kappa B-derived amino acids was sufficient to inhibit both transcriptional activation and oncogenic transformation by p59v-rel. These results support a model in which activation of gene expression by p59v-rel is required for its ability to induce oncogenic transformation.
Diehl
J A
JA
Biochemistry Department, University of Missouri-Columbia 65212.
Hannink
M
M
D000818:Animals; D017487:Ankyrins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001692:Biological Transport; D002451:Cell Compartmentation; D002467:Cell Nucleus / Q000378:metabolism; D002471:Cell Transformation, Neoplastic; D002478:Cells, Cultured; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D020572:Oncogene Proteins v-rel; D011499:Protein Processing, Post-Translational; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics* / Q000378:metabolism; D013154:Spleen / Q000166:cytology; D014158:Transcription, Genetic
D017487:Ankyrins; D004268:DNA-Binding Proteins; D016328:NF-kappa B; D020572:Oncogene Proteins v-rel; D011993:Recombinant Fusion Proteins; D015682:Retroviridae Proteins, Oncogenic