title: Mapping the interactions of adenoviral E1A proteins with the p160 nuclear receptor coactivator binding domain of CBP.
abstract: Many viruses deregulate the cell and force transcription of viral genes by competing with cellular proteins for binding to the transcriptional co-activators CREB-binding protein (CBP) and p300. Through its interactions with CBP/p300 and the retinoblastoma protein, the adenovirus (AdV) early region 1A (E1A) oncoprotein hijacks the cell cycle and, in rodents, transforms the cell; the mechanistic and structural basis for these effects remain unclear. In this study we compare the affinity of protein constructs from the E1A proteins from two adenovirus serotypes, non-oncogenic AdV5 and highly oncogenic AdV12, for binding to the nuclear receptor coactivator binding domain (NCBD) of CBP. NMR spectra show that the E1A constructs from both serotypes are intrinsically disordered in the free state and that each contains three homologous binding sites for the NCBD, one in the N-terminal region and two within conserved region 1 (CR1) of E1A. The binding sites in CR1 correspond to the motifs that bind the retinoblastoma protein and the TAZ2 domain of CBP/p300. The E1A and NCBD peptides fold synergistically upon complex formation. Binding affinities determined from NMR titrations show that, although the overall affinities for AdV5 and AdV12 E1A are comparable, there are significant differences between the two E1A serotypes in the relative strength with which their constituent interaction motifs bind to the NCBD. The individual E1A interaction motifs were unable to compete effectively with p53 for binding to the NCBD and both the N-terminal region and CR1 region of E1A are required for efficient competition with p53.
authors.affiliation: Department of Integrative Structural and Computational Biology and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, California.
authors.forename: Peter
authors.initials: P
authors.lastname: Haberz
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Tokyo, 153-8902, Japan.
authors.forename: Munehito
authors.initials: M
authors.lastname: Arai
authors.affiliation: Department of Integrative Structural and Computational Biology and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, California.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Martinez-Yamout
authors.affiliation: Department of Integrative Structural and Computational Biology and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, California.
authors.forename: H Jane
authors.initials: HJ
authors.lastname: Dyson
authors.affiliation: Department of Integrative Structural and Computational Biology and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, California.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Wright
mesh_terms: D000256:Adenoviridae / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017500:Adenovirus E1A Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020816:Amino Acid Motifs; D050882:CREB-Binding Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D050881:E1A-Associated p300 Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000072417:Protein Domains; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D017500:Adenovirus E1A Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D050882:CREB-Binding Protein; C494363:CREBBP protein, human; D050881:E1A-Associated p300 Protein
keywords: NMR; adenovirus; intrinsically disordered protein; oncogenic viral protein