title: A tethered catalysis, two-hybrid system to identify protein-protein interactions requiring post-translational modifications.
abstract: We have modified the yeast two-hybrid system to enable the detection of protein-protein interactions that require a specific post-translational modification, using the acetylation of histones and the phosphorylation of the carboxyl terminal domain (CTD) of RNA polymerase II as test modifications. In this tethered catalysis assay, constitutive modification of the protein to be screened for interactions is achieved by fusing it to its cognate modifying enzyme, with the physical linkage resulting in efficient catalysis. This catalysis maintains substrate modification even in the presence of antagonizing enzyme activities. A catalytically inactive mutant of the enzyme is fused to the substrate as a control such that the modification does not occur; this construct enables the rapid identification of modification-independent interactions. We identified proteins with links to chromatin functions that interact with acetylated histones, and proteins that participate in RNA polymerase II functions and in CTD phosphorylation regulation that interact preferentially with the phosphorylated CTD.
authors.affiliation: Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA.
authors.forename: Dawei
authors.initials: D
authors.lastname: Guo
authors.forename: Tony R
authors.initials: TR
authors.lastname: Hazbun
authors.forename: Xin-Jing
authors.initials: XJ
authors.lastname: Xu
authors.forename: Sze-Ling
authors.initials: SL
authors.lastname: Ng
authors.forename: Stanley
authors.initials: S
authors.lastname: Fields
authors.forename: Min-Hao
authors.initials: MH
authors.lastname: Kuo
mesh_terms: D000107:Acetylation; D002384:Catalysis; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D004268:DNA-Binding Proteins; D006657:Histones; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; D012319:RNA Polymerase II