Lysosomes and membrane recycling. A hypothesis

A mechanism for intralysosomal membrane recycling is proposed. After invagination of the lysosomal membrane during autophagy, intralysosomal vesicles are formed. It is suggested that membrane can bleb out from these internal vesicles, probably in the form of very small vesicles, and return to the external lysosomal membrane by membrane fusion. This mechanism would conserve lysosomal membrane during autophay, and is analogous to current models of plasma-membrane recycling. Its relationship to turnover of lysosomal-membrane proteins and other proteins is discussed.