*2.8. Western Blotting*

Cells were lysed in RIPA lysis buffer (0.5M Tris-HCl, pH 7.4, 1.5M NaCl, 2.5% deoxycholic acid, 10% NP-40, 10 mM EDTA, protease inhibitor), and the protein lysates were subjected to SDS-PAGE followed by electroblotting onto a PVDF membrane. Membranes were probed with the following primary antibodies: α-galactosidase A, TSG101 (GeneTex, Irvine, CA, USA), CD63 (Santa Cruz Biotechnology, Dallas, TX, USA), Calnexin (Abcam, Cambridge, MA, USA) GDRID2, VPS36, VTI1A (Proteintech Group, Wuhan, Hubei, P.R.C), LC3 (Novus Biologicals, Centennial, CO, USA), Rab11 and GAPDH (Cell Signaling Technology, Denver, MA, USA). The bands were visualized by chemiluminescence detection reagents.
