Lysosome-Related Organelles

Lysosome-related organelles (LROs) are a group of cell-type-specific membrane compartments in metazoans that share several features, including low pH and certain luminal contents, with lysosomes. Despite sharing features with lysosomes, the LROs of higher animals are highly specialized in terms of their morphology and composition, and they perform specialized functions, including pigmentation, hemostasis, immunity, and lung plasticity. Because of their importance in biological activities, defects in the biogenesis and/or transport of LROs are known to cause human genetic diseases, including Griscelli syndrome (GS) and Hermansky-Pudlak syndrome (HPS), which are characterized by hypopigmentation of hair and skin, delayed blood clotting, immunodeficiency, and/or pulmonary fibrosis.