The Transcription Factor, Nm23H2, Binds to and Activates the Translocated c-myc Allele in Burkitt's Lymphoma

• Published in: The Journal of biological chemistry 1995-06, Vol.270 (22), p.13392-13398
• Main Authors: Ji, Lin, Arcinas, Magdalena, Boxer, Linda M.
• Format: Article
• Language: English
• Subjects: Alleles; B-Lymphocytes - metabolism; Base Sequence; Binding Sites; Burkitt Lymphoma - genetics; Cell Line; DNA Primers; Genes, myc; Humans; Molecular Sequence Data; Monomeric GTP-Binding Proteins; NM23 Nucleoside Diphosphate Kinases; Nucleoside-Diphosphate Kinase; Transcription Factors - metabolism; Transcriptional Activation; Translocation, Genetic; Tumor Cells, Cultured
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.270.22.13392

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.