Abstract: GlnR is a global transcriptional regulator for nitrogen metabolism that can be found in most Gram-positive bacteria. The GlnR belongs to the OmpR family as well as MerR family. GlnR activates or represses expression of various genes involved in nitrogen metabolism in response to changes in nitrogen availability. It also plays a role in the regulation of phosphate metabolism，antibiotic biosynthesis and bacterial virulence. Here, the differences of GlnR-mediated nitrogen regulation in bacteria and the cross-regulation with other metabolic pathways are detailed. The researches on GlnR-mediated regulation provide further insight into central nitrogen metabolism in bacteria and have important implications for researches on signal transduction in regulation of nitrogen metabolism.

Key words: global regulatory protein, GlnR, regulation for nitrogen metabolism, cross-regulation