title: The Ca(2+)-dependent interaction of S100B(beta beta) with a peptide derived from p53.
abstract: S100B(beta beta) was found to interact with the tumor suppressor protein, p53, and inhibit its PKC-dependent phosphorylation and tetramer formation [Baudier, J., Delphin, C., Grunwald, D., Khochbin, S., and Lawrence, J. J. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 11627-11631]. Since PKC-dependent phosphorylation at the C-terminus of p53 is known to effect transcription and p53 tetramer formation [Sakaguchi, K., Sakamoto, H., Lewis, M. S., Anderson, C. W., Erickson, J. W., Appella, E., and Xie, D. (1997) Biochemistry 36, 10117-10124], we examined the interaction of S100B(beta beta) with a peptide derived from the C-terminal regulatory domain of p53 (residues 367-388). In this paper, we report that S100B(beta beta) binds to the p53 peptide (CaK3 < or = 23.5 +/- 6.6 microM) in a Ca(2+)-dependent manner, and that the presence of the p53 peptide was found to increase the binding affinity of Ca2+ to S100B(beta beta) by 3-fold using EPR and PRR methods, whereas the peptide had no effect on Zn2+ binding to S100B(beta beta). Fluorescence and NMR spectroscopy experiments show that the p53 peptide binds to a region of S100B(beta beta) that probably includes residues in the "hinge" (S41, L44, E45, E46, I47), C-terminal loop (A83, C84, H85, E86, F87, F88), and helix 3 (V52, V53, V56, T59). Together these data support the notion that S100B(beta beta) inhibits PKC-dependent phosphorylation by binding directly to the C-terminus of p53.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore 21201, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: Rustandi
authors.forename: A C
authors.initials: AC
authors.lastname: Drohat
authors.forename: D M
authors.initials: DM
authors.lastname: Baldisseri
authors.forename: P T
authors.initials: PT
authors.lastname: Wilder
authors.forename: D J
authors.initials: DJ
authors.lastname: Weber
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008345:Manganese / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D051381:Rats; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D013050:Spectrometry, Fluorescence; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D002135:Calcium-Binding Proteins; D009414:Nerve Growth Factors; D010455:Peptides; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579160:S100B protein, human; C579158:S100b protein, rat; D016159:Tumor Suppressor Protein p53; D008345:Manganese; D002118:Calcium