The latency global regulator DosR regulon of M. tuberculosis that is stimulated by hypoxia comprises approximately fifty genes including those that codify for putative plasma membrane P-type ATPases. In this work, the influence of hypoxia and the M. tuberculosis DosR on the ATPase activity of M. smegmatis mc2155 plasma membrane was assessed. We found that the basal ATPase activity of plasma membrane vesicles from cells cultured under hypoxia decreased 30% approximately in comparison to the displayed by oxygenated cells. By contrast, the specific Na+/K+ and Ca2+ ATPase activities of plasma membrane increased 2.8 and 3.5-fold respectively, under hypoxia similar to the observed for cells over-expressing the DosR regulator. In addition, we performed bioinformatics analysis that indicated that the Pma1 gene product is a possible alkaline/alkaline earth metal cation P-type ATPase transporter of M. smegmatis. In agreement, RT-qPCR experiments demonstrated that the transcription level of pma1 gene increased under hypoxia at levels similar to M. smegmatis cells over-expressing the M. tuberculosis DosR regulator. The whole findings suggest that hypoxia induces the Na+/K+ and Ca2+ ATPase activity in mycobacterial plasma membrane possibly mediated by the dormancy regulator DosR. |