NAGK (N-acetyl-D-glucosamine kinase) belongs to the eukaryotic-type N-acetylglucosamine kinase family. NAGK converts endogenous N-acetylglucosamine (GlcNAc), a major component of complex carbohydrates, from lysosomal degradation or nutritional sources into GlcNAc 6-phosphate. It is a prominent salvage enzyme of amino sugar metabolism in mammals. NAGK has been shown to interact with STK16 and LNX1.