Endocytosis of caveolae and lipid rafts.
After internalisation lipid raft and caveolae-derived vesicles fuse with caveosomes where their cargo is sorted for delivery to the endoplasmic reticulum (ER), Golgi and the classical endocytic system. The connections between caveosomes and the classical endocytic sytem are poorly defined; studies of glycosphingolipid (GSL) trafficking represent the best example of a putative link. Unlike the other pathways, pinocytosis is dynamin-independent and represents an alternative route for GPI-anchored protein endocytosis; this pathway ultimately merges with the classical endocytic system in perinuclear recycling endosomes. Abbreviations: Cholera Toxin, CTx; Transferrin, Tfn. (Taken form: Plasma membrane microdomains: organisation, function and trafficking Mol Membr Biol. 2004 May-Jun;21(3):193-205.)
Los procesos de endocitosis, se complementan con procesos de exocitosis, también mediados por vesículas que se fusionan a la membrana plasmática.
Esta importación y exportación de moléculas en las células, juega un papel muy importante en la comunicación entre órganos, en los organismos pluricelulares.