A single regulator NrtR controls bacterial NAD+ homeostasis via its acetylation
Rongsui Gao,
Wenhui Wei,
Bachar H Hassan,
Jun Li,
Jiaoyu Deng,
Youjun Feng
Affiliations
Rongsui Gao
Department of Pathogen Biology & Microbiology, and Department General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
Wenhui Wei
Department of Pathogen Biology & Microbiology, and Department General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
Bachar H Hassan
Stony Brook University, Stony Brook, United States
Jun Li
Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
Jiaoyu Deng
Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
Department of Pathogen Biology & Microbiology, and Department General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; College of Animal Sciences, Zhejiang University, Hangzhou, China
Nicotinamide adenine dinucleotide (NAD+) is an indispensable cofactor in all domains of life, and its homeostasis must be regulated tightly. 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, which negatively controls the de novo NAD+biosynthetic pathway. Binding of MsNrtR cognate DNA is finely mapped, and 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 by the enzymatic Pat/CobB pathway. In addition, the acetylation also occurs on the paralogs of NrtR in the Gram-positive bacterium Streptococcus and the Gram-negative bacterium Vibrio, suggesting that these proteins have a common mechanism of post-translational modification in the context of NAD+ homeostasis. Together, these findings provide a first paradigm for the recruitment of acetylated NrtR to regulate bacterial central NAD+ metabolism.
