title: Identification of proteins interacting with the catalytic subunit of PP2A by proteomics.
abstract: The protein phosphatase 2A (PP2A) is a serine/threonine phosphatase involved in the regulation of multiple signaling pathways including the Wnt/beta-catenin and the ERK pathways. To understand the complex signaling networking associated with PP2A, we searched proteins interacting with the catalytic subunit of protein phosphatase 2A (PP2Ac) by a pull-down analysis followed by 2-D gel electrophoresis and proteomic analyses. The probability of identification of the proteins interacting with PP2Ac was increased by searching proteins differently interacting with PP2Ac according to stimulation of Wnt3a, which regulates both the Wnt/beta-catenin and the ERK pathways. Around 100 proteins, pulled-down by His-tagged PP2Ac, were identified in 2-D gels stained with CBB. By MALDI-TOF-MS analyses of 45 protein spots, we identified several proteins that were previously known to interact with PP2A, such as Axin and CaMK IV. In addition, we also identified many proteins that potentially interact with PP2Ac. The interactions of several candidate proteins, such as tuberous sclerosis complex 2, RhoB, R-Ras, and Nm23H2, with PP2Ac, were confirmed by in vitro binding analyses and/or coimmunoprecipitation experiments.
authors.affiliation: National Laboratory of Molecular Complex Control, Department of Biotechnology, College of Engineering and Protein Network Research Center, Yonsei University, Seoul, Korea.
authors.forename: Won-Jeong
authors.initials: WJ
authors.lastname: Lee
authors.forename: Dong-Uk
authors.initials: DU
authors.lastname: Kim
authors.forename: Mi-Young
authors.initials: MY
authors.lastname: Lee
authors.forename: Kang-Yell
authors.initials: KY
authors.lastname: Choi
mesh_terms: D000818:Animals; D020134:Catalytic Domain; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D025941:Protein Interaction Mapping; D054648:Protein Phosphatase 2; D021122:Protein Subunits / Q000378:metabolism*; D040901:Proteomics
chemical_list: D021122:Protein Subunits; C517189:PPP2CA protein, human; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2