Figure 4

Chimeric β-catenin/Plakoglobin constructs identify regions of β-catenin and plakoglobin that account for the differential activity of the two proteins in transactivation assays. (a) Schematic representation of the chimeric constructs used in this study. The proteins are conceptually divided into three regions (as shown in Figure 1). A filled box denotes a portion of the chimeric protein derived from S37A β-catenin while an open box indicates that the region was derived from S28A plakoglobin. An example of the nomenclature used is as follows: P-B-B contains the amino terminus of S28A plakoglobin, the Arm repeats of β-catenin, and the carboxyl terminus of β-catenin. (b) Activity of the OT reporter in lysates of 293T cells after transient transfection with the indicated chimeric protein expression constructs. (c) Anti-β-catenin Western blot of cytoplasmic extracts of cell lysates derived from 293T cells transiently transfected with the denoted expression plasmid. The antibody used specifically recognizes the C terminus of β-catenin. (d) Anti-plakoglobin Western blot of cytoplasmic extracts of cell lysates derived from 293T cells transiently transfected with the denoted expression plasmid. The antibody used specifically recognizes the C terminus of plakoglobin. Note that in both (c) and (d) the origin of the C terminal domain correlates with detection of the hybrid protein