Use of the Morganella morganii phoC Gene as Reporter in Bacterial and Yeast Hosts

In this chapter are described the applications of the Morganella morganii phoC gene, encoding a molecular class A nonspecific phosphatase, as a reporter both in prokaryotic (Escherichia coli ) and in eukaryotic (Saccharomyces cerevisiae ) systems. The activity of PhoC can be detected by means of simple, sensitive, and relatively inexpensive tests in either qualitative (histo-chemical) or quantitative (liquid) assays. The methods are suitable to monitor gene expression and to determine transcriptional activity and the inducibility of a promoter or other regulatory elements. The intrinsic properties of phoC could be also exploited for studies on secretion, or in applications where the host cell should be recovered still viable after the reporter assay for further analysis. Indeed, in S. cerevisiae , the PhoC protein is secreted very efficiently into the culture medium and its activity can be easily assessed without interfering with the growth conditions required by the experimental approach of choice.