Proteasomal processing of the viral replicase ORF1 facilitates HEV-induced liver fibrosis.

ABSTRACT: Chronic infections with hepatitis E virus (HEV), especially those of genotype 3 (G3), frequently lead to liver fibrosis and cirrhosis in patients. However, the causation and mechanism of liver fibrosis triggered by chronic HEV infection remain poorly understood. Here, we found that the viral multiple-domain replicase (ORF1) undergoes unique ubiquitin-proteasomal processing leading to formation of the HEV-Derived SMAD Activator (HDSA), a viral polypeptide lacking putative helicase and RNA polymerase domains. The HDSA is stable, non-HSP90-bound, localizes to the nucleus, and is abundant in G3 HEV-infected hepatocytes of various origins. Markedly, the HDSA in hepatocytes potentiates the fibrogenic TGF-β/SMAD pathway by forming compact complexes with SMAD3 to facili

SUBMITTER: Zhang F 

PROVIDER: S-EPMC11929459 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature