Article révisé par les pairs
Résumé : Calcyphosine is a calcium-binding protein containing four EF-hand domains that is found in several epithelia and in some cells of the central nervous system. In thyroid follicular cells, calcyphosine is synthesized and phosphorylated in response to stimulation by thyrotropin and cAMP agonists. The cDNA coding for dog calcyphosine has been expressed in bacteria under the control of the T7 promoter. Recombinant calcyphosine was purified from crude bacterial lysates by a combination of anion-exchange and hydrophobic interaction chromatography. Phosphorylation assays using the purified catalytic subunit of protein kinase A and the recombinant or the native calcyphosine revealed that, contrary to a previous report, calcyphosine is not significantly phosphorylated by this enzyme in vitro.