[Screening hepatitis B virus X-interactive proteins by yeast two-hybrid system]

Area of Science:

• Hepatology
• Virology
• Molecular Biology

Background:

• Hepatitis B virus X protein (HBx) is a transactivator implicated in hepatocellular carcinoma.
• Protein-protein interactions are vital for HBx transactivation.
• Identifying HBx interacting proteins is key to understanding its oncogenic mechanisms.

Purpose of the Study:

• To screen and identify novel protein interactors of the Hepatitis B virus X protein (HBx).
• To elucidate the molecular mechanisms underlying HBx-mediated oncogenesis.
• To utilize the yeast two-hybrid system for protein-protein interaction discovery.

Main Methods:

• Construction and validation of an HBx bait plasmid (pAS2-1-X) using yeast two-hybrid system.
• Expression of HBx-BD fusion protein confirmed by Western blot.
• Screening of a human liver cDNA library, followed by beta-gal activity assay, segregation analysis, and mating experiments to identify positive interactors.

Main Results:

• Successful construction and expression of the HBx bait plasmid.
• Identification of a single positive clone after rigorous screening and validation steps.
• Bioinformatic analysis revealed high homology of the interacting protein with the Fis gene.

Conclusions:

• Fis protein is identified as a novel binding partner of the Hepatitis B virus X protein (HBx).
• This interaction was confirmed in vivo using the yeast two-hybrid system.
• The discovery of Fis as an HBx interactor provides new insights into viral oncogenesis.