This is the non-catalytic component of the active enzyme, which catalyzes the hydrolysis of ATP coupled with the exchange of Na(+) and K(+) ions across the plasma membrane. The beta subunit regulates, through assembly of alpha/beta heterodimers, the number of sodium pumps transported to the plasma membrane (PubMed:19694409). Plays a role in innate immunity by enhancing virus-triggered induction of interferons (IFNs) and interferon stimulated genes (ISGs). Mechanistically, enhances the ubiquitination of TRAF3 and TRAF6 as well as the phosphorylation of TAK1 and TBK1 (PubMed:34011520). ; Involved in cell adhesion and establishing epithelial cell polarity.