title: Functional profiling of p53-binding sites in Hdm2 and Hdmx using a genetic selection system.
abstract: Upregulation of structurally homologous oncoproteins Hdm2 and Hdmx has been linked to the depletion or inactivation of their common regulation target the tumor suppressor p53 protein leading to the progression of cancer. The restoration of the p53 function, rendered suppressed or dormant by these negative regulators, establishes, therefore, a unique opportunity for a targeted induction of apoptosis in cancers that retain wild-type p53. While several small molecules have been reported to rescue the tumor suppressor by antagonizing the Hdm2-p53 interaction, these agents displayed limited application scope by being ineffective in tumors enriched with active Hdmx. Here, we describe the use of a genetic selection system and encoded library of conformationally pre-organized peptides to perform functional profiling of each regulator revealing specific recognition features that guide the antagonism of Hdm2-p53 and Hdmx-p53 interactions. Structure-activity relationship analysis of the most effective leads identified functional and structural elements mediating selective recognition of the two structurally related regulators, while providing convenient starting points for further activity optimization.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Shreya
authors.initials: S
authors.lastname: Datta
authors.forename: Megan E
authors.initials: ME
authors.lastname: Bucks
authors.forename: Dipankar
authors.initials: D
authors.lastname: Koley
authors.forename: Pei Xin
authors.initials: PX
authors.lastname: Lim
authors.forename: Sergey N
authors.initials: SN
authors.lastname: Savinov
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018797:Cell Cycle Proteins; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D008958:Models, Molecular; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D025941:Protein Interaction Mapping / Q000379:methods; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051736:Proto-Oncogene Proteins c-mdm2 / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; C482775:MDM4 protein, human; D009687:Nuclear Proteins; D010455:Peptides; D011518:Proto-Oncogene Proteins; D016159:Tumor Suppressor Protein p53; D051736:Proto-Oncogene Proteins c-mdm2