The 1x myc-tagged cDNA encoding for human CIS2 protein was subcloned into a pET-29a+ vector in order to express and produce a recombinant S-peptide tagged and 1x myc-tagged protein in Escherichia coli BL21(DE3). The constitutively expressed protein was isolated from inclusion bodies by a simple solubilization-renaturation procedure and purified by anion-exchange chromatography on Q-Sepharose. The recombinant form was found to be pure and monomeric as judged by both SDS-PAGE and gel-filtration chromatography and its biological activity was proven by its ability to bind to the tyrosine-phosphorylated cytosolic fragment of human growth hormone receptor fused to glutathione-S-transferase. Recombinant CIS2 was compared by biochemical, immunological, and molecular methods to the CIS2 protein expressed in eukaryotic cells. This report describes the first substantial production of biologically active recombinant human CIS2.
Bibliographical noteFunding Information:
We thank Dr. Nils Billestrup from Hagedorn Research Institute (Denmark) for the gift of bacterial plasmid encoding the GST–GHR. This work was supported by the Israeli Science Foundation (Grant 460/99) to A. Gertler and O. Livnah and partially supported by a grant (to B. Velkeniers) from the Ministry of Scientific Research of the Brussels-Capital Region.
- Growth hormone receptor
- Recombinant proteins