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Current Proteomics
ISSN (Print): 1570-1646
ISSN (Online): 1875-6247
DOI: 10.2174/1570164611666140412003740

Fibrinogen Alpha Chain Acts as a HBsAg Binding Protein and their Interaction Promotes HepG2 Cell Apoptosis

Author(s): Ping Li, Li Xiao, Ying-Ying Li, Xu Chen, Chuan-Xing Xiao, Jing-Jing Liu, Xiao-Ning Yang, Amarsanaa Jazag, Jian-Lin Ren and Bayasi Guleng
Pages 48-54 (7)
Background and Aims: Our previous yeast two-hybrid screening data showed the Fibrinogen alpha chain (FGA) as one of the candidate binding proteins of S regional of the HBsAg (HBs). In this study, we aimed to define that FGA is a binding protein of HBs and to determine its function in Hepatocellular carcinoma (HCC) tumorigenesis.

Methods: The binding and co-localization between HBs and FGA were confirmed using co-immunoprecipitation and confocal microscopy was employed flow cytometry to analyze cell apoptosis. The involved mechanisms were investigated using protein array and western blot.

Results: Our results indicated that FGA is a binding protein of HBs and is co-localized in the cytoplasm in vitro. Interaction between HBs and FGA significantly induced apoptosis in HepG2 cells. Moreover, knockdown of the FGA protein decreased the expression levels of the pro-survival factors Bcl-XL and Mcl-1, increased the expression of the proapoptotic proteins, and decreased the phosphorylation levels of Akt in this cell.

Conclusion: FGA is a binding protein of HBs and their interaction induced the apoptotic capacity of HepG2 cells, suggesting the interactions between viral and host cell proteins are involved in the development of virus-related hepatitis or HCC.

Binding protein, FGA, HBs, HepG2 cell apoptosis.
Department of Gastroenterology, Zhongshan Hospital affiliated with Xiamen University, 201 Hubin South Road, Xiamen, Fujian Province, China 361004.