Calcium-binding and coiled-coil domain-containing protein 1 (Calcoco1) from Mus musculus () binds to a highly conserved N-terminal domain of p160 coactivators, such as GRIP1 (), and thus enhances transcriptional activation by a number of nuclear receptors. Calcoco1 has a central coiled-coil region with three leucine zipper motifs, which is required for its interaction with GRIP1 and may regulate the autonomous transcriptional activation activity of the C-terminal region [].