Western blotting

Proteins were extracted from cells using RIPA protein extraction buffer (Beyotime Institute of Biotechnology), and were quantified by the Bradford assay as previously described³⁰. The same amount up to 30ug of protein was subjected to 10% SDS-PAGE and transferred to PVDF membranes. After being blocked in 10% skimmed milk, the membranes were incubated with Rab10 polyclonal antibody (1:1000 dilution; cat. no. ab104859, Abcam) at 4 °C overnight, washed 3 times for 5 min and then incubated with the corresponding horseradish peroxidase (HRP)-conjugated anti-rabbit IgG (1:5000 dilution; cat. no. sc-2004 Santa Cruz Biotechnology, Inc.) at room temperature for 60 min. The protein bands were visualized with ECL Super Signal reagent (Pierce; Thermo Fisher Scientific, Inc.). The relative intensity of the bands was determined using Image J software (version 1.41o, Java 1.6.0_10, https://imagej.nih.gov/ij/, Wayen Rasband, National Institutes of Health). Where gels/blots are used in figures were compliance with the digital image and integrity policies (www.nature.com/srep/policies/index.html#digital-image).