CALCOCO1 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 . This protein 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. CoCoA 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.