Cytosolic NAD+ kinase (NADK) catalyses the transfer of a phosphate group from ATP to NAD+, forming NADP+. This is the only way to generate NADP+ in all living organisms. NADK is tetrameric and requires one divalent metal such as Zn2+ per subunit to function correctly (Lerner et al. 2004).
NAD+ kinase activity of NADK:Zn2+ tetramer [cytosol]