Fig. 5.

Cardiogenic activity of GATA4 does not require residues which are essential for interaction with FOG2 or Tbx5. (A) E215D, V217G and G295S mutations do not affect cardiogenesis induced by GATA4 in animal pole explants, as assessed by expression of myh6 at st. 34. Bottom panel – Western blot analysis of rGATA4 variants in animal caps collected at st. 10. (B) Nuclear localisation of E215, V217G and G295S GATA4 mutants. (C) Ectopic myl7 expression (arrows) induced by indicated mutants in representative embryos (out of 50, 4–10 embryos showed ectopic myl7 expression). (D) In addition to being able to efficiently induce cardiac differentiation markers myh6 and myl7, V217G and G295S mutants are indistinguishable from the wt rGATA4 in their ability to induce liver (nr1h5; synonym-for1), endothelium (aplnr) and blood (hba3) markers. (E) Model of the C-terminal Zn finger of GATA4 with G295S mutation. The key side chains, Ser295 and Arg282, are indicated. The model shows the clash that would occur with the mutation in the absence of backbone or side chain adaptations to resolve it.