LGALS3

LGALS3, also known as galectin-3, is a member of the galectin family of beta-galactoside-binding lectins. It is encoded by the LGALS3 gene in humans. Galectin-3 is classified as a chimera-type galectin, featuring a C-terminal carbohydrate recognition domain connected to an N-terminal domain that promotes oligomerization and multivalent binding to glycoconjugates.

The protein can be found in multiple cellular compartments, including the cytoplasm, nucleus, and extracellular space. It can be secreted via non-classical pathways and also released by cells such as macrophages. Galectin-3 binds galactose-containing glycans on a wide range of glycoproteins, enabling it to influence cell-cell and cell-matrix interactions, adhesion, migration, and signaling. It participates in immune regulation, inflammation, fibrosis, and wound healing, and it modulates apoptosis with effects that can be context-dependent, sometimes promoting cell survival.

In disease, galectin-3 has been implicated in cancer, where it can affect tumor growth, angiogenesis, invasion, and metastasis; its prognostic value varies with cancer type and context. Extracellular galectin-3 can cross-link glycoproteins on the cell surface to alter signaling pathways, while intracellular galectin-3 can influence mitochondrial integrity and apoptotic responses. Galectin-3 is also studied as a biomarker in several conditions, including heart failure and fibrotic diseases, and has attracted interest as a potential therapeutic target. Regulation occurs at transcriptional and post-translational levels, with modifications that can affect its localization and activity.