Functions as a redox-dependent negative regulator of the Wnt signaling pathway, possibly by preventing ubiquitination of DVL3 by the BCR(KLHL12) complex. May also function as a transcriptional regulator act as a regulator of protein phosphatase 2A (PP2A) (By similarity). [protein]-dithiol + NAD(+) = [protein]-disulfide + H(+) + NADH [protein]-dithiol + NADP(+) = [protein]-disulfide + H(+) + NADPH Associates with the phosphatase 2A holoenzyme. Interacts with PPP2CA; the interaction is direct. Interacts with DVL1 (via PDZ domain); the interaction is direct and regulated by oxidative stress (By similarity). Belongs to the nucleoredoxin family.