PRODUCTION AND SECRETION OF RECOMBINANT PROTEINS IN DICTYOSTELIUM-DISCOIDEUM

We have expressed useful amounts of three recombinant proteins in a ne w eukaryotic host/vector system. The cellular slime mold Dictyostelium discoideum efficiently secreted two recombinant products, a soluble f orm of the normally cell surface associated D. discoideum glycoprotein (PsA) and the heterologous protein glutathione-S-transferase (GST) fr om Schistosomajaponicum, while the enzyme P-glucuronidase (GUS) from E scherichia coli,vas cell associated. Up to 20mg/l of recombinant PsA a nd 1mg/l of GST were obtained after purification from a standard, pept one based growth medium. The secretion signal peptide was correctly cl eaved from the recombinant GST- and PsA-proteins and the expression of recombinant PsA was shown to be stable for at least one hundred gener ations in the absence of selection.