Proteometabolomic response of Deinococcus radiodurans exposed to UVC and vacuum conditions: Initial studies prior to the Tanpopo space mission

PLoS One. 2017 Dec 15;12(12):e0189381. doi: 10.1371/journal.pone.0189381. eCollection 2017.

Abstract

The multiple extremes resistant bacterium Deinococcus radiodurans is able to withstand harsh conditions of simulated outer space environment. The Tanpopo orbital mission performs a long-term space exposure of D. radiodurans aiming to investigate the possibility of interplanetary transfer of life. The revealing of molecular machinery responsible for survivability of D. radiodurans in the outer space environment can improve our understanding of underlying stress response mechanisms. In this paper, we have evaluated the molecular response of D. radiodurans after the exposure to space-related conditions of UVC irradiation and vacuum. Notably, scanning electron microscopy investigations showed that neither morphology nor cellular integrity of irradiated cells was affected, while integrated proteomic and metabolomic analysis revealed numerous molecular alterations in metabolic and stress response pathways. Several molecular key mechanisms of D. radiodurans, including the tricarboxylic acid cycle, the DNA damage response systems, ROS scavenging systems and transcriptional regulators responded in order to cope with the stressful situation caused by UVC irradiation under vacuum conditions. These results reveal the effectiveness of the integrative proteometabolomic approach as a tool in molecular analysis of microbial stress response caused by space-related factors.

MeSH terms

  • Bacterial Proteins / metabolism*
  • Citric Acid Cycle
  • Deinococcus / metabolism
  • Deinococcus / radiation effects*
  • Deinococcus / ultrastructure
  • Microbial Viability
  • Proteome / metabolism*
  • Space Flight
  • Ultraviolet Rays
  • Vacuum

Substances

  • Bacterial Proteins
  • Proteome

Grants and funding

The study was conducted within the MOMEDOS (molecular mechanisms of Deinococcus radiodurans survivability in outer space) project, funded by the FFG (Österreischiche Forschungsförderungsgesellschaft—https://www.ffg.at/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.