May act as a transcriptional coregulator during muscle development through its interaction with SNW1. Has lost its ancestral function as a Na,K-ATPase beta-subunit (By similarity). Associates with a SMAD7-transcriptional complex. Interacts with SNW1 and TOR1AIP1. Does not associate with known Na,K-ATPase alpha-subunits (By similarity). Detected in nuclear envelops. Belongs to the X(+)/potassium ATPases subunit beta family.