Identification of a second stanniocalcin cDNA in mouse and human: stanniocalcin 2.

It has recently been shown that mammals contain a gene encoding a protein that is related to stanniocalcin (STC), a hormone previously considered to be present only in bony fish where it plays a major role in Ca2+ homeostasis. Here we report the identification in the mouse and human of a cDNA, STC-2, that shows significant similarity to the first mammalian STC (which we now rename STC-1). Northern analysis revealed that mammalian STC-2, like STC-1, is expressed in a wide variety of tissues. In contrast to STC-1, the predicted amino acid sequence of STC-2 contains a cluster of histidine residues in the C-terminal portion of the protein, which suggests that STC-2 may interact with metal ions.