Analysis of hepatitis C virus RNA dimerization and core-RNA interactions

Area of Science:

• Virology
• Molecular Biology
• RNA Structure and Function

Background:

• Hepatitis C virus (HCV) core protein exhibits nucleic acid chaperone activity.
• HCV core protein promotes dimerization of the viral 3'-untranslated region (3'-UTR) RNA.
• This dimerization is likely mediated by a conserved RNA motif, the dimer linkage sequence (DLS).

Purpose of the Study:

• To investigate the role of the DLS in HCV RNA dimerization.
• To identify the specific regions of the HCV core protein responsible for RNA chaperone activity.

Main Methods:

• Generation of point mutations within the DLS region of HCV RNA.
• Assessing RNA dimerization in the presence of wild-type and mutant core proteins.
• Structural probing of monomeric and dimeric HCV RNAs.
• Analysis of core protein N-terminal domains for RNA chaperone activity.

Main Results:

• Both plus- and minus-strand HCV 3'-UTRs dimerize with core protein.
• Mutations in the DLS completely abolish RNA dimerization.
• A single point mutation in the DLS abrogated RNA replication in a subgenomic replicon system.
• The N-terminal basic amino acid clusters of the core protein are sufficient for inducing dimerization.

Conclusions:

• The DLS is the primary determinant of HCV 3'-UTR RNA dimerization.
• HCV core protein's N-terminal domains possess significant RNA chaperone activity.
• These findings are critical for understanding HCV replication and genetic variability.