Proteins found in this family are similar to the coiled-coil transcriptional coactivator protein coexpressed by Mus musculus (CoCoA/CALCOCO1, Swiss:Q8CGU1). This protein binds to a highly conserved N-terminal domain of p160 coactivators, such as GRIP1 (Swiss:Q61026), 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 [1].

1: CoCoA, a nuclear receptor coactivator which acts through an N-terminal activation domain of p160 coactivators. Kim JH, Li H, Stallcup MR; Mol Cell 2003;12:1537-1549. PMID:14690606