Identification and verification of the candidate proteins that interact and collaborate with ATF3 in inhibiting hepatocarcinogenesis

Abstract To identify and verify proteins that interact and collaborate with ATF3 in inhibiting hepatocarcinogenesis. Immunoprecipitation (IP), co-IP and protein spectrum analysis were used to identify the protein which interacted with ATF3 in HepG2. Immunohistochemistry (IHC) and Western blot (WB) were used to detect the expression pattern of ATF3 and its candidate interacting proteins in liver tissue. The protein expression differences were detected by IP in two HepG2 groups. The experimental group was infected by lentiviral vector with ATF3 over-expression and the control group was infected by mock-vehicle. Several protein bands with expression diversity were analyzed by protein spectrum, which revealed several candidate proteins that may be related with ATF3. Peptide sequences were analyzed by Mascot software and NCBI database. Combined with the existing literature and our study results, Gelsolin (GSN) was identified as a protein closely interacting with ATF3 and confirmed by co-IP, IHC and WB. GSN is identified and verified as an interacting protein with ATF3. ATF3 may function as a suppressor of liver cancer via protein-protein interactions with Gelsolin.