Difference between revisions of "Part:BBa K518010"

Revision as of 23:31, 3 October 2011

sulA promoter

Microbes including Escherichia coli are known to respond to various DNA-injuring stress (ionizing radiation, ultraviolet radiation, peroxides etc...), altering their gene expressions. This response, known as "SOS response", are induced by regulatory protein called RecA, which is activated when binds to single-strand DNA. DNA-RecA complex promotes the self-degradation of LexA, a common repressor for SOS genes.

SulA is responsible for stress-induced halt of cell division. The promoter of sulA, or sulAp, is acutely induced by various stress factors, including ultraviolet irradiation.

Application

We utilized its property (induced-expression by UV irradiation) to design a "UV switch". It became possible to "switch on" a genetic circuit using UV. As a first step for this, we characterized the UV-induced alteration of expressions.

The UV-induced expression level of BBa_K518010 was evaluated using BBa_K518013. As a measurement tool, our dual luciferase assay kit was employed. For detailed infomation, see BBa_K518002.

<Figure: UV-induced expression levels of sulAp. The expression levels of sulAp were evaluated before and after UV induction. We evaluated it using both recA(-) (JM109) and recA(+) (BL21) strain. RecA is known as necessary for releasing sulAp from repression. We successfully demonstrate a significant alteration of expression in recA(+) strain after UV irradiation. The expression level of BBa_J23119, a consensus sequence of E. coli promoters, was simultaneously presented as a comparison. Data is expressed as mean ± S.D.. Data is obtained from three independent experiments.>

Sequence and Features