About LAMP / Lysosomal-Associated Membrane Protein:
Lysosomal-Associated Membrane Proteins (LAMP) are types of integral membrane protein present in the lysosomal system. This lysosomal system is an intracellular mechanism which controls the replacement of endogenous and exogenous macromolecules. Lysosomes essentially perform waste disposal in cells. LAMPs account for 50% of the proteins found in the lysosomal membrane. The prominent LAMPs in mammals, LAMP1 and LAMP2 closely interact and a deficiency in either has been linked to certain medical conditions. For example, a deficiency of LAMP-2 is the primary defect in Danon disease.
LAMP Structure
LAMP proteins are made up of a short cytosolic domain of 10-20 amino acids containing single tyrosine or di-leucine motifs. Structurally they consist of two internally homogenous lysosome-luminal domains separated by a proline-rich hinge region. They have a C-terminal extremity where a transmembrane region is located as well as a cytoplasmic tail. Each of the domains contains two disulfide bonds.
Lysosomal-Associated Membrane Protein Function
LAMPs interact with adaptor complexes (APS) affecting the trans-Golgi network and targeting lysosomes. LAMP1 and LAMP2 also interact closely with one another. As well as being structurally alike they are thought to have similar functions. They provide selectins with carbohydrate ligands. They’ve also been shown to stimulate lymphocyte cells in the immune system to release antimicrobial cytotoxicity to destroy invading microorganisms. Both have been connected to tumor cell differentiation and metastasis. Whereas the exact biological functions of LAMP proteins are still unclear, they are mainly associated with the protection, maintenance and adhesion of lysosomes which play a vital role in many cell processes.