Expression cloning: transient expression and rescue from mammalian cells

Abstract

Abstract Cloning strategies based on transient expression in mammalian cells have been used effectively to isolate CDNAs encoding secreted, cell surface, and intracellular proteins. The first application of transient expression in mam malian cells in cloning was the isolation of CDNAs encoding the lymphokine GM-CSF (granulocyte macrophage colony stimulating factor) (1, 2). This was followed by the use of transient expression in mammalian cells in conjunction with antibody panning (3) to isolate CDNAs encoding cell surface proteins (4, 5). Transient expression in mammalian cells has also been used to isolate cell surface receptors based on the ability of the transfected cells to bind to either fluorescein-conjugated (6) or radiolabelled (7) ligands or ligand immobilized on a solid phase (8, 9) or ligand expressed on a cell surface (10). Recently, transient expression in mammalian cells has also been used to isolate CDNAs encoding intracellular proteins (11, 12).