Plays an important role in chaperone-mediated autophagy, a process that mediates lysosomal degradation of proteins in response to various stresses and as part of the normal turnover of proteins with a long biological half-live (PubMed:8662539, PubMed:11082038). Binds target proteins, such as GAPDH, and targets them for lysosomal degradation (PubMed:8662539, PubMed:11082038, PubMed:18644871). Plays a role in lysosomal protein degradation in response to starvation (PubMed:11082038). Required for the fusion of autophagosomes with lysosomes during autophagy. Cells that lack LAMP2 express normal levels of VAMP8, but fail to accumulate STX17 on autophagosomes, which is the most likely explanation for the lack of fusion between autophagosomes and lysosomes. Required for normal degradation of the contents of autophagosomes. Required for efficient MHCII-mediated presentation of exogenous antigens via its function in lysosomal protein degradation; antigenic peptides generated by proteases in the endosomal/lysosomal compartment are captured by nascent MHCII subunits. Is not required for efficient MHCII-mediated presentation of endogenous antigens (By similarity). Monomer (PubMed:18644871). Forms large homooligomers (PubMed:11082038, PubMed:18644871). Interacts (via its cytoplasmic region) with HSPA8 (PubMed:18644871). Interacts with HSP90 in the lysosome lumen; this enhances LAMP2 stability (PubMed:18644871). Interacts with MLLT11 (By similarity). Interacts with ABCB9 (By similarity). Interacts with FURIN (By similarity). This protein shuttles between lysosomes, endosomes, and the plasma membrane. Detected in liver, kidney, spleen and macrophages (at protein level). Extensively N-glycosylated (PubMed:1794981, PubMed:18644871). Contains a minor proportion of O-linked glycans (PubMed:1794981). Contains sialylated glycans (PubMed:1794981). Belongs to the LAMP family.