Expression of Bacillus subtilis neutral protease gene (nprE) in Saccharomyces cerevisiae

Expression in the yeast Saccharomyces cerevisiae of the intact nprE gene of Bacillus subtilis, which encodes the pre-pro-NprE neutral protease precursor, resulted in intracellular accumulation of unprocessed precursor without detectable secretion or processing of the expressed gene product. When sequences specifying the signal peptide of yeast invertase were fused upstream of sequences encoding the mature NprE enzyme, nprE gene products were secreted into the culture medium. The secreted protein products were, however, highly, glycosylated and biologically inactive.