Abstract: A process for the production of a target polypeptide is provided. The process comprises expression of an expression vector for expressing a target polypeptide in a host cell, preferably a mammalian cell, the expression vector comprising an expression cassette comprising a polynucleotide encoding a recombinant polypeptide operably linked to a fibronectin secretion leader sequence; and recovering the target polypeptide.

Abstract: A process for the production of a target polypeptide is provided. The process comprises expression of an expression vector for expressing a target polypeptide in a host cell, preferably a mammalian cell, the expression vector comprising an expression cassette comprising a polynucleotide encoding a recombinant polypeptide operably linked to a fibronectin secretion leader sequence; and recovering the target polypeptide.

Abstract: A perfect palindrome operator sequence-based protein expression system is provided. The expression system comprises a promoter; and a perfect palindrome operator sequence, wherein the promoter is not T7. The expression system is preferably employed for the production of recombinant proteins by fermentation.

Abstract: A perfect palindrome operator sequence-based protein expression system is provided. The expression system comprises a promoter; and a perfect palindrome operator sequence, wherein the promoter is not T7. The expression system is preferably employed for the production of recombinant proteins by fermentation.

Abstract: A process for the production of a target recombinant polypeptide is provided. The process comprises expressing an expression cassette encoding the target polypeptide and co-expressing an expression cassette encoding a mitochondrial foldase. Preferred mitochondrial foldases include Mia 40 and Erv1, and homologs thereof.

Abstract: A process for the production of a target polypeptide is provided. The process comprises expression of an expression vector for expressing a target polypeptide in a host cell, preferably a mammalian cell, the expression vector comprising an expression cassette comprising a polynucleotide encoding a recombinant polypeptide operably linked to a fibronectin secretion leader sequence; and recovering the target polypeptide.

Abstract: An expression vector for expressing a target polypeptide in a prokaryotic cell is provided. The vector comprises a promoter operably linked to a polynucleotide encoding the target polypeptide operably linked to a eukaryotic secretion leader sequence, the eukaryotic secretion leader sequence encoding a signal peptide sequence selected from the group consisting of: a) MLKRSSWLATLGLLTVASVSTIVYA; b) MKKATFITCLLAVLLVSNPIWNA; c) MKVSAAALAVILIATALCAPASA; d) MKVSTAFLCLLLTVSAFSAQVLA; and e) MKCLLLALGLALACAAQA. Processes for expressing polypeptides and prokaryotic microorganisms comprising such vectors are also provided.

Abstract: A process for the production of a target polypeptide is provided. The process comprises expression of an expression vector for expressing a target polypeptide in a host cell, preferably a mammalian cell, the expression vector comprising an expression cassette comprising a polynucleotide encoding a recombinant polypeptide operably linked to a fibronectin secretion leader sequence; and recovering the target polypeptide.

Abstract: An expression vector for expressing a target polypeptide in a prokaryotic cell is provided. The vector comprises a promoter operably linked to a polynucleotide encoding the target polypeptide operably linked to a eukaryotic secretion leader sequence, the eukaryotic secretion leader sequence encoding a signal peptide sequence selected from the group consisting of: a) MLKRSSWLATLGLLTVASVSTIVYA; b) MKKATFITCLLAVLLVSNPIWNA; c) MKVSAAALAVILIATALCAPASA; d) MKVSTAFLCLLLTVSAFSAQVLA; and e) MKCLLLALGLALACAAQA. Processes for expressing polypeptides and prokaryotic microorganisms comprising such vectors are also provided.

Abstract: A perfect palindrome operator sequence-based protein expression system is provided. The expression system comprises a promoter; and a perfect palindrome operator sequence, wherein the promoter is not T7. The expression system is preferably employed for the production of recombinant proteins by fermentation.

Abstract: A perfect palindrome operator sequence-based protein expression system is provided. The expression system comprises a promoter; and a perfect palindrome operator sequence, wherein the promoter is not T7. The expression system is preferably employed for the production of recombinant proteins by fermentation.

Abstract: A process for the production of a target polypeptide is provided. The process comprises expression of an expression vector for expressing a target polypeptide in a host cell, preferably a mammalian cell, the expression vector comprising an expression cassette comprising a polynucleotide encoding a recombinant polypeptide operably linked to a fibronectin secretion leader sequence; and recovering the target polypeptide.

Abstract: An expression vector for expressing a target polypeptide in a prokaryotic cell is provided. The vector comprises a promoter operably linked to a polynucleotide encoding the target polypeptide operably linked to a eukaryotic secretion leader sequence, the eukaryotic secretion leader sequence encoding a signal peptide sequence selected from the group consisting of: a) MLKRSSWLATLGLLTVASVSTIVYA; b) MKKATFITCLLAVLLVSNPIWNA; c) MKVSAAALAVILIATALCAPASA; d) MKVSTAFLCLLLTVSAFSAQVLA; and e) MKCLLLALGLALACAAQA. Processes for expressing polypeptides and prokaryotic microorganisms comprising such vectors are also provided.

Abstract: An expression vector for expressing a target polypeptide in a prokaryotic cell is provided. The vector comprises a promoter operably linked to a polynucleotide encoding the target polypeptide operably linked to a eukaryotic secretion leader sequence, the eukaryotic secretion leader sequence encoding a signal peptide sequence selected from the group consisting of: a) MLKRSSWLATLGLLTVASVSTIVYA; b) MKKATFITCLLAVLLVSNPIWNA; c) MKVSAAALAVILIATALCAPASA; d) MKVSTAFLCLLLTVSAFSAQVLA; and e) MKCLLLALGLALACAAQA. Processes for expressing polypeptides and prokaryotic microorganisms comprising such vectors are also provided.

Abstract: A recombinant yeast of the genus Komagataella which has been transformed with a galactose promoter is provided. The yeast is preferably Komagataella phaffii, and the promoter is preferably a S. cerevisiae GAL1 or GAL10 promoter. Vectors and methods for producing recombinant polypeptides are also provided.

Abstract: A process for the production of a target recombinant polypeptide is provided. The process comprises expressing an expression cassette encoding the target polypeptide and co-expressing an expression cassette encoding a mitochondrial foldase. Preferred mitochondrial foldases include Mia 40 and Erv1, and homologs thereof.

Abstract: A recombinant yeast of the genus Komagataella which has been transformed with a galactose promoter is provided. The yeast is preferably Komagataella phaffii, and the promoter is preferably a S. cerevisiae GAL1 or GAL10 promoter. Vectors and methods for producing recombinant polypeptides are also provided.

Abstract: A perfect palindrome operator sequence-based protein expression system is provided. The expression system comprises a promoter; and a perfect palindrome operator sequence, wherein the promoter is not T7. The expression system is preferably employed for the production of recombinant proteins by fermentation.

Abstract: A perfect palindrome operator sequence-based protein expression system is provided. The expression system comprises a promoter; and a perfect palindrome operator sequence, wherein the promoter is not T7. The expression system is preferably employed for the production of recombinant proteins by fermentation.

Abstract: A protein expression system is provided. The system comprises: a) a T7 RNA polymerase-dependent promoter operably linked to an expression cassette for a protein of interest; and b) an expression cassette for T7 RNA polymerase operably linked to a ?pL promoter and at least two perfect palindrome operator sequences.