Lipocalin 8 (LCN8)

The lipocalins are a family of proteins which transport small hydrophobic molecules such as steroids, bilins, retinoids, and lipids. They share limited regions of sequence homology and a common tertiary structure architecture. This is an eight stranded antiparallel beta-barrel with a repeated + 1 topology enclosing an internal ligand binding site. Members of the lipocalin family, such as LCN8, have a common structure consisting of an 8-stranded antiparallel beta-barrel that forms a cup-shaped ligand-binding pocket or calyx. Lipocalins generally bind small hydrophobic ligands and transport them to specific cells. Mouse Lcn8 is expressed specifically in epididymis, and Northern blot analysis showed that expression began at 3 weeks of age. Expression of Lcn8 in mouse epididymis disappeared after castration and was not restored by testosterone administration.