Two families of mammalian lectin-like adhesion molecules, the selectins and the sialoadhesins, bind glycoconjugate ligands in a sialic acid-dependent manner. The sialic acid-binding immunoglobulin superfamily lectins, designated Siglecs or sialoadhesins, recognize sialylated ligands and play a key role in mediating sialic-acid dependent binding to cells. Siglec-6, also called obesitybinding protein 1, is an adhesion molecule that is highly expressed in placental trophoblasts, as well as in peripheral blood leukocytes. Siglec-6 can bind both N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), the two common sialic acids found in mammalian cells. Together with the other members of the Siglec family, Siglec-6 promotes cell-cell interactions and plays a roll in the innate and adaptive immune systems through glycan recognition.
