Patent ID: 7514237

Claim:
A mammalian cell for improved expression of a protein of interest, the mammalian cell comprising: at least one recombinant expression cassette encoding a protein of interest, and at least another recombinant expression cassette encoding an X-box binding protein 1 (XBP1) protein comprising an amino acid sequence of SEQ ID NO:6 or a functional variant thereof having at least 90% sequence identity to SEQ ID NO:6, wherein the XBP1 protein or the functional variant thereof binds the endogenous ER stress response element (ERSE) or the endogenous unfolded protein response element (UPRE) of the mammalian cell to enhance the protein folding or processing capacity of the mammalian cell, and wherein the improved expression of the protein of interest is a result of enhanced protein folding or processing capacity of the mammalian cell.