Lysosome-associated membrane protein 1 and 2 (LAMP1 and LAMP2) are two abundant lysosomal membrane proteins. Both are transmembrane proteins and are heavily glycosylated at the amino-terminal luminal side of the lysosomal inner leaflet, which protects the proteins from proteolysis. The carboxy terminus of LAMP1 is exposed to the cytoplasm and contains a tyrosine sorting motif that targets LAMP to lysosomal membranes. LAMP1 and LAMP2 are 37% homologous in their protein sequences. Both LAMP1 and LAMP2 are involved in regulating lysosomal motility during lysosome-phagosome fusion and cholesterol trafficking.
