Fig. 5

Release of CD133 into the extracellular environment in association with microvesicles and/or exosomes. a CD133 is extracellularly released in association with MVs after budding from microvilli or the primary cilium. The association of CD133 with cholesterol-rich lipid rafts and/or its interaction with Arp2/3 complexes, among other interactors, might favor the formation and budding of MVs. b CD133 is released in association with exosomes after the fusion of the late endosome/multivesicular body (LE/MVB) with the plasma membrane. Alternatively, LE/MVB can fuse with lysosomes, resulting in the CD133 degradation. CD133 endocytosis and sorting into intralumenal vesicles within the LE/MVB may be promoted via its ubiquitination at lysine (K) 848 and its interactions with TSG101 and/or syntenin-1 that are involved with Alix, syndecan, and the ESCRT machinery in the exosome biogenesis. Illustrations in panels a and b are based on data presented in Refs [177, 182, 278] and [24, 81, 165], respectively