Patent ID: 7807409

Claim:
A method for the recombinant production of a heterologous polypeptide in a eukaryotic host cell, said method comprising: a) providing a eukaryotic host cell comprising an expression plasmid, wherein the expression plasmid comprises in a 5′ to 3′ direction: aa) a promoter, ab) a nucleic acid encoding a first polypeptide, wherein said first polypeptide is murine immunoglobulin signal sequence comprising SEQ ID NO: 327, ac) a nucleic acid encoding a said second polypeptide, comprising i) a nucleic acid encoding said heterologous polypeptide comprising SEQ ID NO: 12, ii) a nucleic acid encoding a linker, iii) a nucleic acid encoding an immunoglobulin fragment, wherein said second polypeptide further comprises an additional nucleic acid encoding the peptide QIWNN (SEQ ID NO: 472) in 5′ position to the nucleic acid encoding said heterologous polypeptide, ad) a 3′ untranslated region comprising a polyadenylation signal, and b) cultivating the host cell in a culture medium under conditions suitable for the expression of the second polypeptide.