LAMP-2/CD107b: Proteins and Enzymes

Lysosomal associated membrane protein 2 (LAMP-2), also known as CD107b and LGP110, is an approximately 110 kDa transmembrane glycoprotein that is a major component of lysosomal membranes. Within the lumenal domain, human LAMP2 shares approximately 64% aa sequence identity with mouse and rat LAMP-2. LAMP-2 itself is subject to lysosomal degradation following cleavage of its lumenal domain. It mediates the lysosomal uptake of the chaperone HSC73 in complex with cargo proteins and is required for the lysosomal destruction of autophagic vacuoles. In cytotoxic T cells and mast cells, LAMP-2 is expressed in the membranes of intracellular granules that contain effector molecules such as perforin, granzymes, eicosanoids, and histamine. Up-regulated LAMP-2 at the plasma membrane serves as an indicator of cell activation of CD8+ T cells, mast cells, monocytes, and platelets. LAMP-2 is a native ligand for lectins Galectin-1 and Galectin-3.