Expression of Yeast Pyruvate Carboxylate in hGM-CSF-Producing CHO Cells

Continuous mammalian cell lines (CCLs) are used to produce manypharmaceutical recombinant combinant proteins. Unfortunately, CCLs have the metabolic disadvantage of being unable to completely oxidize glucose. One strategy to improve the exploitation of glucose to form ATP can be performed by increasing the flux of glucose into the TCA. Irani et al. (1999) have shown that introducing a cytosolic pyruvate carboxylase (PYC2) derived from the yeast Saccharomyces cerevisiae into BHK-21 enabled the cells to transfer glycolysis derived pyruvate into malte which entered the TCA cycle for complete oxidation. As a result, higher yields of recombinant erythropoietin were achieved using PYC2-expressing cells.