Next Article in Journal / Special Issue
Conserved Glycines Control Disorder and Function in the Cold-Regulated Protein, COR15A
Previous Article in Journal
Structural Determinants of Isoform Selectivity in PI3K Inhibitors
Previous Article in Special Issue
Extreme Fuzziness: Direct Interactions between Two IDPs
Article Menu
Issue 3 (March) cover image

Export Article

Open AccessArticle

p53 Phosphomimetics Preserve Transient Secondary Structure but Reduce Binding to Mdm2 and MdmX

1
Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
2
Center for Drug Discovery and Innovation, University of South Florida, Tampa, FL 33612, USA
*
Author to whom correspondence should be addressed.
Academic Editors: Prakash Kulkarni and Vladimir N. Uversky
Biomolecules 2019, 9(3), 83; https://doi.org/10.3390/biom9030083
Received: 23 January 2019 / Revised: 27 February 2019 / Accepted: 28 February 2019 / Published: 2 March 2019
(This article belongs to the Special Issue Intrinsically Disordered Proteins and Chronic Diseases)
  |  
PDF [1299 KB, uploaded 2 March 2019]
  |  

Abstract

The disordered p53 transactivation domain (p53TAD) contains specific levels of transient helical secondary structure that are necessary for its binding to the negative regulators, mouse double minute 2 (Mdm2) and MdmX. The interactions of p53 with Mdm2 and MdmX are also modulated by posttranslational modifications (PTMs) of p53TAD including phosphorylation at S15, T18 and S20 that inhibits p53-Mdm2 binding. It is unclear whether the levels of transient secondary structure in p53TAD are changed by phosphorylation or other PTMs. We used phosphomimetic mutants to determine if adding a negative charge at positions 15 and 18 has any effect on the transient secondary structure of p53TAD and protein-protein binding. Using a combination of biophysical and structural methods, we investigated the effects of single and multisite phosphomimetics on the transient secondary structure of p53TAD and its interaction with Mdm2, MdmX, and the KIX domain. The phosphomimetics reduced Mdm2 and MdmX binding affinity by 3–5-fold, but resulted in minimal changes in transient secondary structure, suggesting that the destabilizing effect of phosphorylation on the p53TAD-Mdm2 interaction is primarily electrostatic. Phosphomimetics had no effect on the p53-KIX interaction, suggesting that increased binding of phosphorylated p53 to KIX may be influenced by decreased competition with its negative regulators. View Full-Text
Keywords: tumor protein p53; mouse double minute 2; mouse double minute 4; Kinase-inducible domain interacting domain; phosphorylation; phosphomimetics; nuclear magnetic resonance; intrinsically disordered proteins; transient secondary structure tumor protein p53; mouse double minute 2; mouse double minute 4; Kinase-inducible domain interacting domain; phosphorylation; phosphomimetics; nuclear magnetic resonance; intrinsically disordered proteins; transient secondary structure
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Supplementary material

SciFeed

Share & Cite This Article

MDPI and ACS Style

Levy, R.; Gregory, E.; Borcherds, W.; Daughdrill, G. p53 Phosphomimetics Preserve Transient Secondary Structure but Reduce Binding to Mdm2 and MdmX. Biomolecules 2019, 9, 83.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Biomolecules EISSN 2218-273X Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top