title: Lysosome-related organelles.
abstract: Lysosomes are membrane-bound cytoplasmic organelles involved in intracellular protein degradation. They contain an assortment of soluble acid-dependent hydrolases and a set of highly glycosylated integral membrane proteins. Most of the properties of lysosomes are shared with a group of cell type-specific compartments referred to as 'lysosome-related organelles', which include melanosomes, lytic granules, MHC class II compartments, platelet-dense granules, basophil granules, azurophil granules, and Drosophila pigment granules. In addition to lysosomal proteins, these organelles contain cell type-specific components that are responsible for their specialized functions. Abnormalities in both lysosomes and lysosome-related organelles have been observed in human genetic diseases such as the Chediak-Higashi and Hermansky-Pudlak syndromes, further demonstrating the close relationship between these organelles. Identification of genes mutated in these human diseases, as well as in mouse and Drosophila: pigmentation mutants, is beginning to shed light on the molecular machinery involved in the biogenesis of lysosomes and lysosome-related organelles.
authors.affiliation: Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-5430, USA.
authors.forename: E C
authors.initials: EC
authors.lastname: Dell'Angelica
authors.forename: C
authors.initials: C
authors.lastname: Mullins
authors.forename: S
authors.initials: S
authors.lastname: Caplan
authors.forename: J S
authors.initials: JS
authors.lastname: Bonifacino
mesh_terms: D016115:Albinism, Oculocutaneous / Q000235:genetics; D000818:Animals; D000938:Antigen-Presenting Cells / Q000502:physiology / Q000648:ultrastructure; D001491:Basophils / Q000502:physiology / Q000648:ultrastructure; D001792:Blood Platelets / Q000502:physiology / Q000648:ultrastructure; D002609:Chediak-Higashi Syndrome / Q000235:genetics; D003594:Cytoplasmic Granules / Q000502:physiology; D004330:Drosophila / Q000235:genetics; D006801:Humans; D008247:Lysosomes / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D020460:Melanosomes / Q000502:physiology; D008561:Membrane Fusion; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D009504:Neutrophils / Q000502:physiology / Q000648:ultrastructure; D015388:Organelles / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D008565:Membrane Proteins