PT  - JOURNAL ARTICLE
AU  - Marie I. Samanovic
AU  - Hao-Chi Hsu
AU  - Marcus B. Jones
AU  - Victoria Jones
AU  - Michael R. McNeil
AU  - Samuel H. Becker
AU  - Susan Zhang
AU  - Ashley T. Jordan
AU  - Miroslav Strnad
AU  - Mary Jackson
AU  - Huilin Li
AU  - K. Heran Darwin
TI  - Cytokinin signaling alters acid-fast staining of <em>Mycobacterium tuberculosis</em>
AID  - 10.1101/168815
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 168815
4099  - http://biorxiv.org/content/early/2017/07/26/168815.short
4100  - http://biorxiv.org/content/early/2017/07/26/168815.full
AB  - It was recently reported the human-exclusive pathogen Mycobacterium (M.) tuberculosis secretes cytokinins, which had only been known as plant hormones. While cytokinins are well-established, adenine-based signaling molecules in plants, they have never been shown to participate in signal transduction in other kingdoms of life. M. tuberculosis is not known to interact with plants. Therefore we tested the hypothesis that cytokinins trigger transcriptional changes within this bacterial species. Here, we show cytokinins induced the strong expression of the M. tuberculosis gene, Rv0077c. We found that Rv0077c expression is repressed by a TetR-like transcriptional repressor, Rv0078. Strikingly, cytokinin-induced expression of Rv0077c resulted in a loss of acid-fast staining of M. tuberculosis. While 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, consistent with an unaltered mycolic acid profile of Rv0077c-expressing cells. Collectively, these findings show cytokinins signal transcriptional changes that affect M. tuberculosis acid-fastness, and that cytokinin signaling is no longer limited to the kingdom plantae.