Fig. 2. Transactivation of the deletion mutants of the TGF-ß RII promoter by v-Src. A, schematic representation of TGF-ß RII promoter deletion is shown. Serial deletion mutants of the 5'-flanking region of the TGF-ß RII gene were ligated to luciferase gene (pGL2-basic vector) and cotransfected with v-Src expression vector (pMvsrc) into HepG2 cell. B, pTßRIIP-219/+2-CAT and pTßRIIP+2/+36-CAT, which contain v-src-responsive elements, were cotransfected with v-Src expression vector into the 32D-123 cell line, and cells were harvested after 48 h. The results show a representative CAT assay. C, a series of deletion mutants from the regions -219 to +36 of the RII gene were subcloned into the promoterless pGL3-basic vector and transiently cotransfected with v-Src expression vector into HepG2 cell. Numbers indicate the position relative to transcription start site. D, to characterize other v-Src-responsive elements except for the inverted CCAAT box, the inverted CCAAT region was deleted from pTßRIIP-219/+36 by PvuII restriction enzyme, generating pTßRIIP{Delta}-130/-8-luc. This construct was cotransfected with v-Src expression vector into HepG2 cell. Results from these experiments are averages of at least triplicate experiments of three independent transfections. Transfection efficiencies were normalized by ß-gal activity as described in "Materials and Methods."