Co-expression of mDia1ΔN3 and Phb2 rescues MyoG promoter activity. C2C12 were transfected with various mDia1 and Phb2 mutants along with MyoG-promoter reporter construct and shifted to DM for 72 hours, followed by lysis and dual-luciferase assays. (a) Normalised MyoG promoter activity in MT transfected with mDia1ΔN3, mDia1H + P or Phb2 FL. *p < 0.05, n = 3. (b) Normalised MyoG promoter activity in MT transfected with mDia1ΔN3(HindIII), mDia1CC or Phb2 FL, n = 3. (c) Schematic illustrating FH2 motif (aa 946–1010)-mediated regulation of MyoG promoter by mDia1 mutants and Phb2. The squiggle represents the common domains not depicted. The FH2 motif is indicated by the stripped box within the dotted grey box representing the FH2 domain. (d) Normalised MyoG promoter activity in MT transfected with mDia1ΔN3, Phb2-Carboxy or Phb2-Amino. **p < 0.01, n = 3. For all Luciferase assays performed, Luciferase readings were normalised to Renilla Luciferase, empty pGL3 vector and basal DRR or MyoG promoter activity, to correct for background luminescence and transfection efficiency. Bar graphs represent normalised Luciferase values. Error bars represent ± s.e.m. FL-Full-length. UT-Untransfected.