Figure 2.

Functional analyses of NODAL. (A) Sequence chromatograms of NODAL in the family. (B) The conservation of alignment of the variant in the coding regions between species. Changes in amino acids are highlighted in red. The position of V341 is well-conserved between species. (C) Structure of the human NODAL protein. The position of the variant is indicated by an arrowhead. (D) Western blot analysis of the c-Myc-tagged wildtype NODAL and the variant NODAL (p.V341l) proteins. Glyceraldehyde-3-phosphate dehydrogenase, GAPDH, is used as an internal control. (E) Fold increase in relative luciferase activity in P19 cells transfected with green fluorescent protein (GFP) as control, wildtype NODAL or variant NODAL (p.V341l) expression construct, and p(SBE)₄-Luc (N = 5). All values are expressed as the mean ± SD. Significance was assessed using one-way ANOVA, followed by Tukey's post hoc test. **, p < 0.01; N.S., not significant.