Revision as of 06:42, 13 October 2018

Cold-inducible RNA-based thermosensor-1

A RNA-based thermosensor that can be used for temperature sensitive post-transcriptional regulation which is based on the change of RNA advanced structure. The cold-inducible RNA-based thermosensors can initiate translation of downstream genes at low temperatures.

1. Usage and Biology

There are multiple families of cold-inducible proteins in prokaryotes, the most widely studied of which are the Csp family of cold shock proteins in E. coli. CspA family is represented by cspA, which has been quite extensively investigated. There is a temperature-sensing region in the 5’untranslated region (5'UTR) of CspA mRNA, which can regulate the accessibility of the translation initiation region by altering the advanced structure of RNA, thereby regulating the initiation of translation.

At low temperatures (<20℃), 5’UTR of cspA mRNA can form an advanced structure called pseudoknot, which is more efficiently translated because the conformation exposes the Shine–Dalgarno (SD) sequence, it is beneficial to recruit ribosomes and somewhat less susceptible to degradation. At normal temperatures, due to thermodynamic instability, pseudoknot unfolds. 5’UTR forms a secondary structure masking Shine–Dalgarno (SD) sequence to block translation initiation region, which impedes translation. We designed a series of cold-inducible RNA-based thermosensors with different melting temperature, intensity and sensitivity based on the pseudoknot structure.

Our team designed synthetic cold-inducible RNA-based thermosensors that are considerably simpler than naturally occurring cspA thermosensors and can be exploited as convenient on/off switches of gene expression.

Sequence and Features