Figure 5. Different types of MVBs in animal cells make use of different paradigms for coatless budding away from cytosol.
A. ESCRT- and LBPA-dependent MVBs form from late endosomes in animal cells. LBPA is shown in blue. B. The conserved ESCRT-dependent MVB biogenesis pathway from early endosomes in yeast and animal cells. PI(3)P (green) has been directly visualized in these MVBs. Cholesterol (red) has been visualized in animal cell MVBs but it has not been directly confirmed whether these are ESCRT-dependent or not. C. Specialized formation of MVBs containing polymerized Pmel17. D. Ceramide dependent MVBs bud from raft-like and tetraspanin-enriched microdomains in animal cells. Ceramide is shown in purple.