Western blot
Cells were lysed in radio immunoprecipitation assay (RIPA) lysis buffer as described previously (Li et al., 2014). The whole cell lysates were collected and separated by 10% SDS-PAGE and subsequently electro-transferred onto a polyvinylidene difluoride membrane (Millipore Corp., Bedford, MA). The blocked membrane was incubated with the indicated antibodies. Final detection was performed using a chemiluminescent substrate system (Cell signaling, CA).