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Team:TUDelft/Temperature overview
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====Virulence derived expression==== | ====Virulence derived expression==== | ||
| - | Various pathogenic microorganisms express virulence proteins only inside a host. It has been shown | + | Various pathogenic microorganisms express virulence proteins only inside a host. It has been shown in the 90's this is induced by the increased temperature having effect on translation but not on transcription [http://jb.asm.org/cgi/reprint/174/13/4275][http://jb.asm.org/cgi/reprint/175/24/7901]. Examples of microorganisms using this temperature induced virulence are ''Salmonella'' [http://www3.interscience.wiley.com/cgi-bin/fulltext/118542064/PDFSTART], ''Yersinia pestis'' or ''Listeria monocytogenes''. Of course we won't work with these virulent genes, only with the regulating mRNA sequences in front of them. An induction temperature of 37 degrees seems logical. |
====(Designed)G-Quadruplex structures==== | ====(Designed)G-Quadruplex structures==== | ||
Revision as of 08:36, 14 July 2008
Contents |
Bacterial Thermometer
We want to create an RNA-based system that is able to have differential gene expression when temperature changes take place (kind of similar to the Berkeley iGEM 2006 - riboregulator lock/key part [http://parts.mit.edu/wiki/index.php/Berkeley2006-RiboregulatorsMain]).
There are several systems suggested in literature that are based on RNA secondary structure. The idea in general is that if the temperature drops below a certain temperature, the RNA will form stable base-pairs on the Shine-Dalgarno sequence, disabling the ribosome to bind. The base-pairing of the RNA will impair the ability of the cell to express the protein encoded behind it. In this way gene expression can be regulated on the RNA level by temperature. The different ways that are described in literature are:
Virulence derived expression
Various pathogenic microorganisms express virulence proteins only inside a host. It has been shown in the 90's this is induced by the increased temperature having effect on translation but not on transcription [http://jb.asm.org/cgi/reprint/174/13/4275][http://jb.asm.org/cgi/reprint/175/24/7901]. Examples of microorganisms using this temperature induced virulence are Salmonella [http://www3.interscience.wiley.com/cgi-bin/fulltext/118542064/PDFSTART], Yersinia pestis or Listeria monocytogenes. Of course we won't work with these virulent genes, only with the regulating mRNA sequences in front of them. An induction temperature of 37 degrees seems logical.
(Designed)G-Quadruplex structures
As described by Wieland et al. [http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6VRP-4P8YWVM-7-8&_cdi=6240&_user=499885&_orig=search&_coverDate=07%2F30%2F2007&_sk=999859992&view=c&wchp=dGLbVzz-zSkzS&md5=97741390ae4ff0d9a8c4d5f41beb0f1d&ie=/sdarticle.pdf] it is possible to design sequences that form tertiary structures occluding the RBS. A temperature range of 30 - 35 degrees has been achieved.
ROSE
Repressor Of heat-Shock gene Expression (ROSE) is the (conserved) mRNA sequence found in front of some prokaryotic heat-shock proteins.[http://www.nature.com/emboj/journal/v25/n11/pdf/7601128a.pdf] Turning this into a biobrick should allow induction of translation by heating to 42 degrees.
