β-Catenin binds FOXO3 transcription factor in human T-ALL cells. (A) Schematic representation of coimmunoprecipitation followed by liquid chromatography–mass spectrometry for the identification of interacting proteins of β-catenin. (B) Distribution of transcription regulators, subcellular component, molecular function, and biological processes of identified β-catenin interactors by liquid chromatography–mass spectrometry. Benjamini adjusted P values and protein counts were determined by the database for Annotation, Visualization and Integrated Discovery resource. Functional annotations were collected from DAVID’s “UP_Keywords,” “UP_SEQ_Feature,” and “COG_Ontology” categories. (C) List of the top 12 β-catenin-interacting transcription factors with >3 unique peptides identified by mass spectrometry and determined as transcription factors by Proteome Discoverer software. Coimmunoprecipitation between β-catenin and FOXO3 (D) and nonphospho (active) β-catenin and FOXO3 (E) in PF382 and RPMI-8402 T-ALL cell lines, followed by immunoblot analysis using the indicated antibodies. (F) Coimmunoprecipitation between β-catenin and FOXO3 in PF382 cell line after in vitro growth into L-Wnt3A–conditioned medium or control-conditioned medium for 48 hours. Protein lysate were immunoprecipitated with indicated antibodies followed by immunoblot analysis. ADP, adenosine diphosphate; IgG, immunoglobulin G; rRNA, ribosomal RNA; SDS-PAGE, sodium dodecyl sulfate–polyacrylamide gel electrophoresis; WCL, whole cell lysate.