Galectin-3, a 29-31kD protein, is a member of large family of b-galactoside binding animal lectins. It is a chimeric molecule consisting of both carbohydrate recognition and collagen-like domains, with an extra N-terminal tail consisting of 8-13 copies of a 9aa repeat consensus sequence that is rich in proline, tyrosine, and glycine. It is mainly a cytosolic molecule but can easily traverse the intracellular and the plasma membranes to visit the nucleus, mitochondria. It is secreted by various cell types including monocytes, macrophages, and epithelial cells. The released protein can function as an extracellular molecule to activate cells, mediate cell-cell and cell-ECM interactions, and induce migration of monocytes, macrophages, and endothelial cells, probably by binding to pertinent receptors through lectin-carbohydrate interactions. More recently, cell surface galectin-3 was implicated in restricting T cell receptor clustering and thus negatively regulating T cell activation. As a multifunctional protein it acts as an antiapoptotic protein and protects cells from apoptosis by inducing G1 arrest in response to loss of cell anchorage. Galectin-3 has also been associated with the progression of cancer, as well as being a mediator of inflammation.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.