Novel Stress Resistance Mechanisms in Extremely Thermoacidophilic Archaea
Abstract
Certain extremophilic microorganisms inhabit environmental niches that are especiallyexclusive. Extremely thermoacidophilic archaea (Topt > 70°C, pHopt < 3.5) must deal with ‘life inhot acid’, in addition to surviving in the face of perturbations in temperature, pH, toxic metalsconcentrations and nutrient levels. The mechanisms by which extreme thermoacidophiles dealwith their inhospitable biotope are largely unexplored due to intrinsic experimental difficulties instudying this group of archaea and the associated lack of molecular genetic tools for utilizingmolecular biological methods. However, genetic systems are now becoming available and can beimplemented to probe how biology functions in such otherwise debilitating environments. Themechanisms of stress response and resistance utilized by extreme thermoacidophiles, ifdeciphered, will not only expand our knowledge on biological limits but also inform strategiesfor enhancing extremophily that could make less extremophilic organisms more robust.We have identified novel stress resistance mechanisms in extreme thermoacidophiles that allowthem to survive at supra-optimal temperatures and in the presence of toxic metals, such asuranium. These mechanisms rely on small proteins, referred to as toxins, which can degradeRNA, and antitoxins, also small proteins that silence the toxins under normal growth conditions.Under stress, the toxin and antitoxin disengage, thereby freeing the toxin to degrade specificRNA targets that steer the organism to a survival mode. While toxins and antitoxins are notunique to extreme thermoacidophiles, we hypothesize that they play an essential role in stresssurvival in extreme environments. By understanding the mechanisms that regulate toxinantitoxindynamics, prospects for strategically manipulating these systems to enhanceextremophily become possible.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 28, 2017
- Source ID
- FA95501710268
Entities
People
- Robert M. Kelly
Organizations
- Air Force Office of Scientific Research
- North Carolina State University
- United States Air Force