LOSS OF CALCYPHOSINE GENE-EXPRESSION MOUSE AND OTHER RODENTS

Calcyphosine-for calcium binding and regulated by cyclic AMP through p hosphorylation protein-is a target of both the cyclic AMP and the Ca+-phophatidylinositol cascades first isolated from dog thyroid, and the n from rabbit and human brain. Although the exact function of this 24k D protein is unknown, calcyphosine could be implicated in the cross-si gnaling between these cascades to coordinate cellular proliferation an d differentiation. Here, we report the sequence of a pseudogene which is the murine calcyphosine homologue, and demonstrate that it represen ts the unique sequence homologous to the dog calcyphosine gene in the murine genome, The lack of expression of this murine pseudogene in bra in and thyroid-two major sites of dog calcyphosine expression-was exte nded to 5 other rodents, and suggest the existence of alternative path way(s) to fill the function of calcyphosine in rodents. (C) 1997 Acade mic Press.