The present invention provides a method of enhanced protein production that comprises the step of expressing a recombinant gene encoding the protein in eukaryotic cells under conditions in which cleavage of the pro-domain of the protein is inhibited or eliminated. Generally the method of the present invention includes the step of inhibiting or altering the cleavage of a pro-domain of a recombinant protein of interest in order to increase the amount of recombinant protein secreted from a eukaryotic cell. Recombinant proteins that can be prepared using the method of this invention include members of the transforming growth factor-.beta. (TGF-.beta.) superfamily, such as bone morphogenetic proteins. Also provided are genetically engineered cells and polynucleotides for performing the method of the invention.