Is an ortholog of human SMAD6 (SMAD family member 6) and SMAD7 (SMAD family member 7). Exhibits RNA polymerase II transcription factor binding activity. Is involved in several processes, including dauer entry\; defense response to Gram-negative bacterium\; and regulation of cellular biosynthetic process. Localizes to the cytosol and nucleus. Is expressed in the excretory cell\; the gonad\; the intestine\; and the nervous system. Human ortholog(s) of this gene are implicated in aortic valve disease 2.