A single regulator NrtR controls bacterial NAD+ homeostasis via its acetylation

Rongsui Gao, Wenhui Wei, Bachar H Hassan, Jun Li, Jiao-Yu Deng, Youjun Feng
2019 eLife  
Nicotinamide adenine dinucleotide (NAD+) is an indispensable cofactor in all domains of life, the homeostasis of which requires tight regulation. Here we report that a Nudix-related transcriptional factor, designated MsNrtR (MSMEG_3198), controls the de novo pathway of NAD+ biosynthesis in M. smegmatis, a non-tuberculosis Mycobacterium. The integrated evidence in vitro and in vivo confirms that MsNrtR is an auto-repressor, and negatively controls the de novo NAD+ biosynthetic pathway. Binding
more » ... MsNrtR cognate DNA is finely mapped, which can be disrupted by an ADP-ribose intermediate. Unexpectedly, we discover that the acetylation of MsNrtR at Lysine 134 participates in the homeostasis of intra-cellular NAD+ level in M. smegmatis. Furthermore, we demonstrate that NrtR acetylation proceeds via the non-enzymatic acetyl-phosphate (AcP) route rather than the enzymatic Pat/CobB pathway. In addition, the acetylation of NrtR also occurs in its paralogs of Gram-positive bacterium Streptococcus and Gram-negative bacterium Vibrio, suggesting a common mechanism of post-translational modification in the context of NAD+ homeostasis. Together, it represents a first paradigm for the recruitment of acetylated NrtR to regulate bacterial central NAD+ metabolism.
doi:10.7554/elife.51603 fatcat:szaoyjcewvhujpqjpzzmrpb6py