Sialic acid-binding Ig-like lectin 12 is a protein that in humans is encoded by the SIGLEC12 gene.
Sialic acid-binding immunoglobulin-like lectins (SIGLECs) are a family of cell surface proteins belonging to the immunoglobulin superfamily. They mediate protein-carbohydrate interactions by selectively binding to different sialic acid moieties present on glycolipids and glycoproteins. This gene encodes a member of the SIGLEC3-like subfamily of SIGLECs. Members of this subfamily are characterized by an extracellular V-set immunoglobulin-like domain followed by two C2-set immunoglobulin-like domains, and the cytoplasmic tyrosine-based motifs ITIM and SLAM-like. The encoded protein, upon tyrosine phosphorylation, has been shown to recruit the Src homology 2 domain-containing protein-tyrosine phosphatases SHP1 and SHP2. It has been suggested that the protein is involved in the negative regulation of macrophage signaling by functioning as an inhibitory receptor. This gene is located in a cluster with other SIGLEC3-like genes on 19q13.4. Alternatively spliced transcript variants encoding distinct isoforms have been described for this gene.