A plasmacytoma-specific factor binds the c-myc promoter region.
We used an electrophoretic mobility-shift assay to study proteins that bind to sequences in the 5' flanking region of the murine c-myc gene. By comparing the DNA-protein complexes formed with extracts from cells representing earlier stages of B-cell development with those from plasmacytomas, we identified a plasmacytoma-specific protein that binds to a region within the c-myc promoter. Five other regions of this promoter show extensive sequence-specific binding, but the binding is not clearly B-cell stage-specific. Methylation-interference and o-phenanthroline/copper-protection experiments identified a single plasmacytoma-specific protein binding site 290 base pairs 5' of the transcription start site P1. Homologues of a core sequence, d(AGAAAGGGAAAGGA), within the 25-base-pair binding site are found at three additional sites in the murine c-myc locus. The plasmacytoma-specific occurrence of this protein suggests that it may play a role in the transcriptional repression of the normal c-myc gene observed in plasmacytomas.
Kakkis
E
E
Department of Biological Chemistry, University of California, Los Angeles 90024.
Calame
K
K
D000818:Animals; D001402:B-Lymphocytes / Q000473:pathology; D001483:Base Sequence; D001665:Binding Sites; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D051379:Mice; D009363:Neoplasm Proteins / Q000302:isolation & purification / Q000378:metabolism*; D010954:Plasmacytoma / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D016271:Proto-Oncogene Proteins c-myc; D011519:Proto-Oncogenes; D012689:Sequence Homology, Nucleic Acid
D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc