TY - JOUR
T1 - A Redox Regulatory System Critical for Mycobacterial Survival in Macrophages and Biofilm Development
AU - Wolff, Kerstin A.
AU - de la Peña, Andres H.
AU - Nguyen, Hoa T.
AU - Pham, Thanh H.
AU - Amzel, L. Mario
AU - Gabelli, Sandra B.
AU - Nguyen, Liem
N1 - Publisher Copyright:
© 2015 Wolff et al.
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Survival of M. tuberculosis in host macrophages requires the eukaryotic-type protein kinase G, PknG, but the underlying mechanism has remained unknown. Here, we show that PknG is an integral component of a novel redox homeostatic system, RHOCS, which includes the ribosomal protein L13 and RenU, a Nudix hydrolase encoded by a gene adjacent to pknG. Studies in M. smegmatis showed that PknG expression is uniquely induced by NADH, which plays a key role in metabolism and redox homeostasis. In vitro, RenU hydrolyses FAD, ADP-ribose and NADH, but not NAD+. Absence of RHOCS activities in vivo causes NADH and FAD accumulation, and increased susceptibility to oxidative stress. We show that PknG phosphorylates L13 and promotes its cytoplasmic association with RenU, and the phosphorylated L13 accelerates the RenU-catalyzed NADH hydrolysis. Importantly, interruption of RHOCS leads to impaired mycobacterial biofilms and reduced survival of M. tuberculosis in macrophages. Thus, RHOCS represents a checkpoint in the developmental program required for mycobacterial growth in these environments.
AB - Survival of M. tuberculosis in host macrophages requires the eukaryotic-type protein kinase G, PknG, but the underlying mechanism has remained unknown. Here, we show that PknG is an integral component of a novel redox homeostatic system, RHOCS, which includes the ribosomal protein L13 and RenU, a Nudix hydrolase encoded by a gene adjacent to pknG. Studies in M. smegmatis showed that PknG expression is uniquely induced by NADH, which plays a key role in metabolism and redox homeostasis. In vitro, RenU hydrolyses FAD, ADP-ribose and NADH, but not NAD+. Absence of RHOCS activities in vivo causes NADH and FAD accumulation, and increased susceptibility to oxidative stress. We show that PknG phosphorylates L13 and promotes its cytoplasmic association with RenU, and the phosphorylated L13 accelerates the RenU-catalyzed NADH hydrolysis. Importantly, interruption of RHOCS leads to impaired mycobacterial biofilms and reduced survival of M. tuberculosis in macrophages. Thus, RHOCS represents a checkpoint in the developmental program required for mycobacterial growth in these environments.
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U2 - 10.1371/journal.ppat.1004839
DO - 10.1371/journal.ppat.1004839
M3 - Article
C2 - 25884716
AN - SCOPUS:84929501321
SN - 1553-7366
VL - 11
JO - PLoS pathogens
JF - PLoS pathogens
IS - 4
M1 - e1004839
ER -