Transcriptional induction of collagenase-1 in differentiated monocyte-like (U937) cells is regulated by AP-1 and an upstream C/EBP-beta site.
In this report, we demonstrate that the AP-1 site and a distal promoter element regulate transcriptional induction of collagenase-1 during monocytic differentiation. Chloramphenicol acetyltransferase expression constructs containing regions of the human collagenase-1 promoter were stably or transiently transfected into U937 cells, and reporter activity was assessed at various times after the onset of phorbol 12-myristate 13-acetate (PMA)-mediated differentiation. Rapid and strong induction of promoter activity was lost in constructs with a mutant AP-1 element; however, at 16-96 h post-PMA, the mutant collagenase-1 promoter displayed AP-1 independent PMA-mediated transactivation. The AP-1 mutant constructs also showed delayed transcriptional activation in PMA-treated fibroblasts. Western and supershift analyses indicated that functional Jun and Fos proteins were present in nuclear extracts of PMA-differentiated U937 cells. Promoter deletion constructs demonstrated the potential role of distal promoter sequences in regulating collagenase-1 transcription. In particular, Western, supershift, and promoter deletion analyses suggested a role for CCAAT/enhancer-binding protein-beta (C/EBP-beta) binding site between -2010 and -1954 in regulating transcription of collagenase-1 in monocytic cells. Our findings suggest that distinct regulatory elements, acting somewhat independently of each other, control expression of collagenase-1. In addition, our data suggests that the rapid PMA-mediated induction of collagenase-1 transcription is controlled by a mechanism distinct from that regulating the sustained expression of this proteinase in activated macrophages.
Doyle
G A
GA
Dermatology Division, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA. doyle@oncology.wisc.edu
Pierce
R A
RA
Parks
W C
WC
D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins; D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D017364:Collagenases / Q000096:biosynthesis* / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004790:Enzyme Induction; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D009000:Monocytes; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D017384:Sequence Deletion; D012867:Skin / Q000201:enzymology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D011993:Recombinant Fusion Proteins; D018808:Transcription Factor AP-1; D014157:Transcription Factors; D017364:Collagenases; D013755:Tetradecanoylphorbol Acetate