The transcription factor, Nm23H2, binds to and activates the translocated c-myc allele in Burkitt's lymphoma.
We have identified an in vivo footprint over the PuF site on the translocated c-myc allele in Burkitt's lymphoma cells. The PuF site on the silent normal c-myc allele was unoccupied. We demonstrated by electrophoretic mobility shift assay, electrophoretic mobility shift assay with antibody, UV cross-linking followed by SDS-gel electrophoresis, and Western analysis that Nm23H2 in B cell nuclear extracts bound to the c-myc PuF site. Transfection experiments with c-myc promoter constructs in both DHL-9 and Raji cells revealed that the PuF site functioned as a positive regulatory element in B cells with a drop in activity with mutation of this site. Access to this site is blocked in the normal silent c-myc allele; these data suggest that the Nm23H2 protein is involved in deregulation of the translocated c-myc allele in Burkitt's lymphoma cells.
Ji
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L
Center for Molecular Biology in Medicine, VAMC, Palo Alto, California 94304, USA.
Arcinas
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M
Boxer
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LM
D000483:Alleles; D001402:B-Lymphocytes / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D002051:Burkitt Lymphoma / Q000235:genetics*; D002460:Cell Line; D017931:DNA Primers; D016259:Genes, myc; D006801:Humans; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins; D054778:NM23 Nucleoside Diphosphate Kinases; D009701:Nucleoside-Diphosphate Kinase; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D054778:NM23 Nucleoside Diphosphate Kinases; D014157:Transcription Factors; D009701:Nucleoside-Diphosphate Kinase; D020559:Monomeric GTP-Binding Proteins