Cytokinin signaling inMycobacterium tuberculosis

Abstract

SummaryIt was reported the human-exclusive pathogen Mycobacterium (M.) tuberculosis secretes cytokinins, which previously had only been known as plant hormones. Cytokinins are adenine-based signaling molecules in plants that have never been shown to participate in signal transduction in other kingdoms of life. Here, we show that cytokinins induce the strong expression of the M. tuberculosis gene, Rv0077c. We found that a TetR-like transcriptional regulator, Rv0078, directly repressed expression of the Rv0077c gene. Strikingly, cytokinin-induced expression of Rv0077c resulted in a loss of acid-fast staining of M. tuberculosis. Although acid-fast staining is thought to be associated with changes in the bacterial cell envelope and virulence, Rv0077c-induced loss of acid-fastness did not affect antibiotic susceptibility or attenuate bacterial growth in mice. Collectively, these findings show cytokinins signal transcriptional changes that affect the M. tuberculosis cell envelope, and that cytokinin signaling is no longer limited to the kingdom plantae.

The extreme plant‐growth‐promoting properties ofPantoea phytobeneficialisMSR2 revealed by functional and genomic analysis

“…CK‐nucleosides are converted to free‐base forms by Lonely Guy (LOG) proteins that encode a cytokinin riboside 5′‐monophosphate phosphoribohydrolase (Kurakawa et al ., ). These enzymes have been described in detail in plants such as Arabidopsis thaliana and Oryza sativa , and in bacteria such as Mycobacterium tuberculosis (Samanovic et al ., ) and Corynebacterium glutamicum (Seo and Kim, ). Interestingly, strain MSR2 possesses one gene encoding a LOG family protein (CTZ24_24430) present in plasmid pMSR2C, which has a high identity to the described LOGs of plants (~47.5%) and bacteria (47.3%).…”

CAPRIB: a user-friendly tool to study amino acid changes and selection for the exploration of intra-genus evolution

“…There are only a few studies on the role of this family of molecules that is similar to a phytohormone influencing plant growth and development [60]. Some have shown that it can influence signaling in M. tuberculosis [69] whereas others have discovered that cytokinin accumulation is conditionally deleterious as it can lead to an aldehyde breakdown product that kills mycobacteria in the presence of nitric oxide produced by macrophages [59]. It remains to be tested if evolution has sacrificed, in a biological tradeoff, the growth speed of the slowgrowing mycobacteria by altering, for example, the cytokinin pathway, in order to allow a better survival in macrophages or other types of macrophage-like cells such as amebae.…”

The Hulks and the Deadpools of the Cytokinin Universe: A Dual Strategy for Cytokinin Production, Translocation, and Signal Transduction

“…Recently, CK signalling was elucidated in bacteria [ 244 , 265 ]. The receptor from Xanthomonas campestris pv.…”

“…In the human pathogen Mycobacterium tuberculosis , CK induces the formation of a lipid-like molecule, which binds to a repressor and de-represses the expression of a responsive gene. However, unlike canonical CK signalling, the Mycobacterium one is significantly inhibited by adenine [ 265 ].…”