Recombinant mammal cells, method of producing thereof, and method of producing proteins of interest

摘要

The present invention relates to a method of expressing an objective protein at a high level and stably as well as for a long period even in the absence of a selection drug with a recombinant mammal cell. More particularly, the present invention relates to a method of producing an objective protein by providing a recombinant mammal cell having multiple copies of the exogenous objective protein gene expression unit integrated into a hypoxanthine-phosphoribosyl transferase enzyme (hprt) gene locus and culturing said cell.