HBx is encoded by the smallest HBV ORF and is 154 amino acids in size. It is required for viral infection in vivo . It has been shown to be a key regulator of viral replication, as well as host cell functions, by modulating a wide variety of cellular processes, including transcription, cell cycle progression, DNA damage repair, and apoptosis [2,3]. HBx has been suggested to transactivate a variety of viral and cellular promoters . Its role may be rely on the modification of the cellular environment by transactivating cellular genes in infected hepatocytes to facilitate viral replication. It may also have a role in the pathogenesis of virus-induced hepatocellular carcinoma.
Woodchuck hepatitis virus X protein is required for viral infection in vivo.
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