Cooperation and regulatory loops of multiple nodals are essential for mesendoderm patterning in early embryos. Essential for mesoderm formation and axial patterning during embryonic development. Activates the activin-like signaling pathway to induce dorsal and ventral mesoderm in animal cap ectoderm. In addition, also dorsalizes ventral marginal zone (VMZ) tissues during gastrulation. Induces muscle actin. Appears to act as both a short-range and long-range morphogen. The unprocessed protein inhibits bmp- and wnt-signaling (By similarity). Homodimer; disulfide-linked. Forms heterodimers with the TGF-beta family member derriere. Interacts with tsku; enhances nodal2 activity. By dorsal-mesoderm inducing signals including activin, vegt and other nodal-related proteins. Beta-catenin potentiates the response to activin and vegt. Not induced by wnt8 alone, but wnt8 potentiates the response to activin. The pro-region is necessary but not sufficient for wnt-inhibitory activity. The central region is required for muscle induction activity (By similarity). Belongs to the TGF-beta family.