SIGLEC7 Gene - Sialic Acid Binding Ig Like Lectin 7 | Function, Expression & Disease

SIGLEC7 (Sialic Acid Binding Ig Like Lectin 7) is a transmembrane receptor expressed primarily on natural killer (NK) cells and a subset of monocytes. It belongs to the sialic acid-binding immunoglobulin-like lectin (Siglec) family and contains an immunoreceptor tyrosine-based inhibitory motif (ITIM) in its cytoplasmic tail. Upon binding to sialic acid ligands on target cells, SIGLEC7 recruits phosphatases such as SHP-1 and SHP-2, leading to inhibition of NK cell cytotoxicity and cytokine secretion. This inhibitory function plays a role in immune surveillance and has been implicated in tumor immune evasion, autoimmune diseases, and viral infections.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Immune System (Reactome: R-HSA-168256)

• Signaling by SHP-1 (Reactome: R-HSA-1433557)

• Natural killer cell mediated cytotoxicity (KEGG: hsa04650)

• Cell surface interactions at the vascular wall (Reactome: R-HSA-202733)

SIGLEC7 is a type I transmembrane protein of 467 amino acids (UniProt Q9Y286). It contains two extracellular immunoglobulin-like domains (one V-set and one C2-set) that mediate sialic acid binding, and a cytoplasmic tail with one ITIM motif. The protein is heavily glycosylated and exists as a monomer on the cell surface. SIGLEC7 preferentially binds to alpha-2,3- and alpha-2,6-linked sialic acids. Upon ligand engagement, the ITIM recruits SHP-1 and SHP-2 phosphatases, which dephosphorylate activating signaling molecules, thereby inhibiting NK cell activation. The protein is also known as CD328 and p75.