Identification of the late endosome LE/MVB proteome related to the endosomal microautophagy eMI activity in the rat liver.

To identify the late endosome LE/MVB proteome related to the endosomal microautophagy eMI activity we purified subcellular organelles including cytosol, late endosomes (LE/MVBs) and lysosomes (CMA+) from the rat liver and performed co-Ip experiment with antibodies directed against the major cellular chaperones mediating CMA and eMI. As such, we analyzed Hsc70-interacting proteins in LE/MVB, CMA+ lysosomes and cytosol by performing pull-down experiments (co-IP) using anti-Hsc70 antibodies. A comparative analysis of the Hsc-70 interactomes revealed that proteins bound to Hsc70 in cytosol and LE/MVBs or in cytosol and CMA+ lysosomes were considered eMI or CMA substrates, respectively.