The disclosure provides fusion proteins containing N-terminal signal peptides fused to immunogenic polypeptides. The immunogenic polypeptides may be from viruses, bacteria, or fungi. The disclosure also provides elevated expression of the immunogenic polypeptides using the N-terminal signal peptide. The N-terminal signal peptides enhance synthesis of the protein, particularly where the protein is neither a secretory nor a transmembrane peptide. The fusion proteins may be used to diagnose disease and to induce immune responses.
