iTRAQ experiment and LC‐MS/MS analysis

SDS/PAGE was used to identify the integrity of the proteins prior to follow‐up experiments. A total of 20 μg of the protein sample was separated by 12% SDS/PAGE and stained. The proteins were collected according to the following protocol: digestion with trypsin; desalting by gel filtration; thrice‐washing with PBS; elution; and lyophilization, as previously described [11]. Then, the iTRAQ reagent (Beyotime, Shanghai, China) was used to label the proteins according to the manufacturer’s protocol.

The labeled peptides were graded using the Rigol L3000 HPLC system (Dalian, China) and a Waters BEH C18 column (4.6 × 250 mm, 5 μm; (Dalian, China). The details of the elution gradient are shown in Table S1. Proteomics analyses were performed using an EASY‐nLCTM 1200 UHPLC system (Thermo Fisher, Waltham, MA, USA) coupled with a Q Exactive HF‐X mass spectrometer (Thermo Fisher) using a linear gradient elution, as listed in Table S2. The separated peptides were analyzed using a Q Exactive HF‐X mass spectrometer (Thermo Fisher).