A topoisomerase II-like protein is part of an inducible DNA-binding protein complex that binds 5' of an immunoglobulin promoter.
We previously identified a B cell-specific protein-DNA complex 5' of an immunoglobulin mu heavy chain promoter. The sequences to which this protein complex bound were required for induction of immunoglobulin mRNA levels with interleukin-5 + antigen. Further studies identified a second sequence 5' of these regulatory sequences that bound to both the nuclear matrix and to a similar interleukin-5 + antigen inducible protein complex. Therefore, we sought to identify the putative regulatory proteins that comprised this DNA-binding complex. In this study, we have used anti-topoisomerase II antibodies to demonstrate that one of the proteins found in the interleukin-5 + antigen inducible complexes is serologically related to topoisomerase II. To our knowledge, this is the first report where a topoisomerase II related protein participates in an inducible mobility shifted protein-DNA complex. These data suggest a model in which the enhanced immunoglobulin gene transcription observed after treatment with interleukin-5 + antigen might be explained by the induction of a protein complex that acts to relieve torsional stress along the gene.
Webb
C F
CF
Oklahoma Medical Research Foundation, Department of Immunobiology and Cancer, Oklahoma City 73104.
Eneff
K L
KL
Drake
F H
FH
D000595:Amino Acid Sequence; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity; D000941:Antigens / Q000276:immunology; D001402:B-Lymphocytes / Q000378:metabolism; D002460:Cell Line; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D007148:Immunoglobulin mu-Chains / Q000235:genetics*; D015848:Interleukin-5 / Q000494:pharmacology; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D059005:Topoisomerase II Inhibitors
D000906:Antibodies; D000941:Antigens; D004268:DNA-Binding Proteins; D007148:Immunoglobulin mu-Chains; D015848:Interleukin-5; D012333:RNA, Messenger; D059005:Topoisomerase II Inhibitors; D004250:DNA Topoisomerases, Type II