Come in from the Cold

For high-throughput screening and crystallography studies, it is often necessary to express large quantities of protein--a process that is complicated if the protein is toxic to the cells in which it is expressed. To combat this difficulty, transcription of the gene of interest is repressed while the cells are grown to a high density and then induced by the addition of reagents such as IPTG or tetracycline. Although chemical induction has been successfully used to regulate protein expression for

Aileen Constans
Sep 2, 2001
For high-throughput screening and crystallography studies, it is often necessary to express large quantities of protein--a process that is complicated if the protein is toxic to the cells in which it is expressed. To combat this difficulty, transcription of the gene of interest is repressed while the cells are grown to a high density and then induced by the addition of reagents such as IPTG or tetracycline. Although chemical induction has been successfully used to regulate protein expression for standard academic research, its use in high-throughput studies of cytotoxic proteins is limited, because low levels of transcription occur even in very tightly regulated systems prior to induction.

Addressing this problem, Cytos Biotechnology AG of Zürich-Schlieren, Switzerland, has designed an inducible expression vector that uncouples transcription from induction. The system uses the vector pCytTS, which is derived from the alphavirus DNA vector p987SinRep96. The vector contains the gene for a temperature-sensitive...