title: Specificity of the stimulatory interaction between chromosomal HMGB proteins and the transcription factor Dof2 and its negative regulation by protein kinase CK2-mediated phosphorylation.
abstract: The high mobility group (HMG) proteins of the HMGB family are chromatin-associated proteins that can contribute to transcriptional control by interaction with certain transcription factors. Using the transcription factor Dof2 and five different maize HMGB proteins, we have examined the specificity of the HMGB-transcription factor interaction. The HMG-box DNA binding domain of HMGB1 is sufficient for the interaction with Dof2. Although all tested HMGB proteins can interact with Dof2, the various HMGB proteins stimulate the binding of Dof2 to its DNA target site with different efficiencies. The HMGB5 protein is clearly the most potent facilitator of Dof2 DNA binding. Maximal stimulation of the DNA binding by the HMGB proteins requires association of HMGB and Dof2 prior to DNA binding. HMGB5 and Dof2 form a ternary complex with the DNA, but within the protein-DNA complex the interaction of HMGB5 and Dof2 is different from that in solution, as in contrast to the proteins in solution, they cannot be cross-linked with glutaraldehyde when bound to DNA. Phosphorylation of HMGB1 by protein kinase CK2 abolishes the interaction with Dof2 and the stimulation of Dof2 DNA binding. These findings indicate that transcription factors may recruit certain members of the HMGB family as assistant factors.
authors.affiliation: Department of Biotechnology, Institute of Life Sciences, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Krohn
authors.forename: Shuichi
authors.initials: S
authors.lastname: Yanagisawa
authors.forename: Klaus D
authors.initials: KD
authors.lastname: Grasser
mesh_terms: D001665:Binding Sites; D047390:Casein Kinase II; D002843:Chromatin / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D024002:HMGB Proteins / Q000378:metabolism*; D024243:HMGB1 Protein / Q000378:metabolism*; D008957:Models, Genetic; D010766:Phosphorylation; D010940:Plant Proteins; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D013379:Substrate Specificity; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D003313:Zea mays / Q000235:genetics / Q000378:metabolism
chemical_list: D002843:Chromatin; D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D024002:HMGB Proteins; D024243:HMGB1 Protein; D010940:Plant Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D004247:DNA; D005982:Glutathione Transferase; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases