NEDD4-binding protein 1 suppresses hepatitis B virus replication by regulating viral RNAs

Area of Science:

• Virology
• Hepatology
• Molecular Biology

Background:

• Chronic hepatitis B virus (HBV) infection increases risks for liver cirrhosis and hepatocellular carcinoma.
• Current nucleos(t)ide analogue treatments for HBV require long-term use and can lead to drug resistance.
• Novel therapeutic targets are needed to combat HBV infection effectively.

Purpose of the Study:

• To screen for host factors that suppress HBV replication.
• To identify potential new targets for anti-HBV drug development.

Main Methods:

• A library of 132 RNA-binding proteins (RBPs) was screened for HBV-suppressive activity.
• Hepatocellular carcinoma cell lines were transfected/infected with HBV and RBP expression vectors.
• HBV replication was assessed by measuring intracellular capsid-associated HBV DNA and RNA levels.

Main Results:

• NEDD4-binding protein 1 (N4BP1) was identified as an HBV-suppressive host factor.
• Overexpression of N4BP1 reduced HBV DNA levels, while N4BP1 knockdown/knockout increased them.
• N4BP1 directly binds HBV pregenomic RNA (pgRNA) and regulates its 3.5 and 2.4/2.1 kb transcripts.

Conclusions:

• N4BP1 is a novel host factor that inhibits HBV production.
• N4BP1's anti-HBV activity relies on its KH-like and RNase domains.
• N4BP1 represents a promising new target for developing innovative hepatitis B therapies.