CD13/APN transcription is regulated by the proto-oncogene c-Maf via an atypical response element.
Angiogenic growth factors induce the transcription of the cell surface peptidase CD13/APN in activated endothelial cells of the tumor vasculature. Inhibition of CD13/APN abrogates endothelial invasion and morphogenesis in vitro and tumor growth in vivo suggesting a critical functional role for CD13 in angiogenesis. Experiments to identify the transcription factors responsible for this regulation demonstrated that exogenous expression of the proto-oncogene c-Maf, but not other bZip family members tested, potently activates transcription from a critical regulatory region of the CD13 proximal promoter between -115 and -70 bp which is highly conserved among mammalian species. Using promoter mutation, EMSA and ChIP analyses we established that both endogenous and recombinant c-Maf directly interact with an atypical Maf response element contained within this active promoter region via its basic DNA/leucine zipper domain. However full activity of c-Maf requires the amino-terminal transactivation domain, and site-directed mutation of putative phosphorylation sites within the transactivation domain (serines 15 and 70) shows that these sites behave in a dramatic cell type-specific manner. Therefore, this atypical response element predicts a broader range of c-Maf target genes than previously appreciated and thus impacts its regulation of multiple myeloma as well as endothelial cell function and angiogenesis.
Mahoney
Kathleen M M
KM
Center for Vascular Biology, Department of Cell Biology, University of Connecticut Health Center, Farmington, Connecticut, United States.
Petrovic
Nenad
N
Schacke
Wolfgang
W
Shapiro
Linda H
LH
D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D015153:Blotting, Western; D018826:CD13 Antigens / Q000235:genetics*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D024202:Electrophoretic Mobility Shift Assay; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D017930:Genes, Reporter; D005982:Glutathione Transferase / Q000378:metabolism; D006390:Hemangioendothelioma / Q000473:pathology; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D000090063:Proto-Oncogene Mas; D050787:Proto-Oncogene Protein c-ets-2 / Q000378:metabolism; D051257:Proto-Oncogene Proteins c-maf / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D020218:Response Elements / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012514:Sarcoma, Kaposi / Q000473:pathology; D014158:Transcription, Genetic; D014471:Umbilical Veins / Q000166:cytology
C494069:ETS2 protein, human; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D050787:Proto-Oncogene Protein c-ets-2; D051257:Proto-Oncogene Proteins c-maf; D011993:Recombinant Fusion Proteins; D008156:Luciferases; D005982:Glutathione Transferase; D018826:CD13 Antigens