Poster abstracts

Poster number 43 submitted by Jonathan Picking

Establishing inducible expression in the hyperthermophilic Archaea: Characterization and manipulation of the first archaeal riboswitch

Jonathan W. Picking (The Ohio State Biochemistry Program, The Ohio State University), Jenny Tran (Microbiology, The Ohio State University), Thomas J. Santangelo (Microbiology, The Ohio State University)

Abstract:
The functional characterization and manipulation of archaeal genomes is crucial towards further understanding evolutionary relationships among the three domains and leveraging the Archaea for promising biotechnological roles.
Thermococcus kodakarensis is a hyperthermophilic, anaerobic archaeon that is easily cultured, retains significant biotechnology potential, and for which an abundance of available genetic tools exists. Many genetic manipulations of T. kodakarensis are now routine, however, a critical deficiency is the inability to induce, modulate, or turn off gene expression in a growing culture. No current method approaches the versatility and utility of inducible systems available in bacteria or eukaryotes.
Herein we describe a putative riboswitch – to our knowledge the first characterized in Archaea – and present evidence that it may be an effective, self-contained means to induce and modulate gene expression. In 2012, Baker et al. described a bacterial riboswitch that responds to fluoride to stimulate expression of a fluoride exporter, resulting in increased tolerance to fluoride. Sequence analysis of the T. kodakarensis genome revealed a homologous RNA element, evocatively located upstream of a gene with homology to known fluoride exporters. Several lines of evidence indicate that this RNA element is a bona fide fluoride-responsive riboswitch. Thus, we hypothesize: (i) T. kodakarensis encodes a fluoride exporter, the expression of which is controlled by a fluoride-responsive riboswitch, and (ii) this riboswitch may be generally adapted to modulate gene expression in T. kodakarensis. Herein we present initial evidence consistent with these hypotheses, while research to confirm the mechanism of action and adapt the riboswitch for general use is ongoing.

References:
Science. 2012 Jan 13;335(6065):233-5. Epub 2011 Dec 22.
Widespread genetic switches and toxicity resistance proteins for fluoride.
Baker JL, Sudarsan N, Weinberg Z, Roth A, Stockbridge RB, Breaker RR.

Keywords: Archaea, Riboswitch, Induction