Physical interaction between hepatitis C virus NS4B protein and CREB-RP/ATF6beta

Area of Science:

• Virology
• Molecular Biology
• Cellular Biology

Background:

• Hepatitis C virus (HCV) infection poses a significant global health challenge.
• Understanding host-pathogen interactions is crucial for developing antiviral strategies.
• Endoplasmic reticulum (ER) stress is implicated in viral pathogenesis.

Purpose of the Study:

• To identify cellular proteins interacting with the HCV NS4B protein.
• To investigate the functional implications of the NS4B-host protein interaction in the context of ER stress.

Main Methods:

• Yeast two-hybrid assay to screen for interacting proteins.
• Co-immunoprecipitation and confocal microscopy in mammalian cells to confirm interactions.
• Analysis of specific protein domains involved in the interaction.

Main Results:

• CREB-RP/ATF6beta was identified as a binding partner of HCV NS4B.
• The N-terminal half of NS4B and the bZIP domain of CREB-RP/ATF6beta mediate the interaction.
• Interaction was confirmed in mammalian cells.
• ATF6alpha also interacted with NS4B, though less strongly.

Conclusions:

• HCV NS4B physically interacts with ER stress-induced transcription factors CREB-RP/ATF6beta and ATF6alpha.
• NS4B may modulate cellular responses to ER stress via these interactions.
• This interaction offers a potential target for therapeutic intervention against HCV.