Inhibition of p53‐dependent transcription by BOX‐I phospho‐peptide mimetics that bind to p300
Authors: T R Hupp
D Dornan
Journal: EMBO reports (2001)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: p53; phosphorylation; MDM2; p300; transcription
Affiliations: Department of Molecular & Cellular Pathology, University of Dundee, UK., The Cancer Research Campaign Laboratories, Department of Molecular &amp; Cellular Pathology, University of Dundee  Dundee DD1 9SY UK

Abstract:  The N-terminal BOX-I domain of p53 containing a docking site for the negative regulator MDM2 and the positive effector p300, harbours two recently identified phosphorylation sites at Thr18 or Ser20O whose affect on p300 is undefined. Biochemical assays demonstrate that although MDM2 binding is inhibited by these phosphorylations, p300 binding is strikingly stabilized by Thr18 or Ser20 phosphorylation. Introducing EGFP-BOX-I domain peptides with an aspartate substitution at Thr18 or Ser20 induced a significant inhibition of endogenous p53-dependent transcription in cycling cells, in irradiated cells, as well as in cells transiently co-transfected with p300 and p53. In contrast an EGFP-wild-type BOX-I domain peptide stimulated p53 activity via inhibition of MDM2 protein binding. These results suggest that phosphorylation of p53 at Thr18 or Ser20 can activate p53 by stabilizing the p300-p53 complex and also identify a class of small molecular weight ligands capable of selective discrimination between MDM2- and p300-dependent activities. 

Retracted: No

PubPeer comments:
 Figure 3C. p300 panel. Vertical splicing abrupt change in level of bands within dose responses. ![file] , 
 The authors feel that this abrupt change resulted from cropping of images from different immunoblot gel regions that were used at the time. Because this experiment was done over 20 years ago, the original data could not be retrieved. This cropped image does not affect the overall data interpretation or the conclusions from the study regarding interaction of p300 to phospho-Thr18 phosphorylated-p53 peptides, which was reproduced using biophysical studies by another laboratory (DOI: 10.1038 onc.2009.71). , 
 Journal editors may find this COPE flowchart useful when reviewing image concerns: https: publicationethics.org files COPE_FLOW_Image_Manip_SCREEN_AW2.pdf In the case of the original data no longer being available (understandable given the date of the publication), journal editors may find this case study on the COPE website to be useful: https: publicationethics.org case data-manipulation-and-institutes-internal-review , 
 #2  reproduced using biophysical studies by another laboratory (DOI: 10.1038 onc.2009.71). Data in this paper is under question, not data in a paper from another laboratory. , 
  The authors feel that this abrupt change resulted from cropping of images from different immunoblot gel regions that were used at the time. How can this result in different splicing points between the different proteins? , 
 #1 Figure 3C. Much more similar after horizontal compression than expected. ![file] , 
 Thank you for highlighting this data duplication query in fig 3C. The University of Dundee research integrity team is now analyzing the data and we will post a conclusion of the review, and possible additional actions, once the evaluation has been completed. ,