Related Experiment Video
Updated: Oct 7, 2026

Development of a Hepatitis B Virus Reporter System to Monitor the Early Stages of the Replication Cycle
Published on: February 1, 2017
Hepatitis C virus core protein transactivates insulin-like growth factor II gene transcription through acting
1Liver Cell Signal Transduction Laboratory, Bioscience Research Division, Korea Research Institute of Bioscience and Biotechnology, Taejon, Korea 305-606.
Abstract:
The possibility that hepatitis C virus core gene product (HCV-core) acts as a transactivator in insulin-like growth factor II (IGF-II) gene transcription was tested. HCV-core protein increases endogenous IGF-II expression from promoter 4 (P4) of the IGF-II gene through two cis-acting elements: Sp1 and Egr1 binding sites. Sp1 and Egr1 both bind to IGF-II P4 and functionally cooperate in mediating the maximal activity of IGF-II P4. HCV-core protein induced the binding of Sp1 and Egr1 on its binding sites on IGF-II P4. In addition, Sp1 and Egr1 were stimulated to phosphorylate by HCV-core, and its DNA binding activity was up-regulated upon HCV-core transfection. Transfection with HCV-core in HepG2 cells stimulated the membrane translocation of protein kinase C (PKC) and the treatment of HCV-core transfected cells with calphostin C, a PKC inhibitor, blocked induction of Sp1 and Egr1 DNA binding activity, and eventually transcriptional transactivations of the IGF-II gene. Increasing the DNA binding activity of the phosphorylated form of Sp1 and Egr1 might be an important mechanism for regulating IGF-II gene expression and for promoting cell division during hepatic carcinogenesis. These results indicate that HCV-core functions as a positive regulator of IGF-II transcription through the PKC pathway and that Sp1 and Egr1 are direct targets of the transcriptional regulation of the IGF-II gene which plays an important role in hepatitis C virus pathogenesis during the formation of hepatocellular carcinoma (HCC).
Related Concept Videos
Cell Specific Gene Expression
Eukaryotic Transcription Inhibitors
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Eukaryotic Transcription Activators
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
Hepatitis
Insulin: The Receptor and Signaling Pathways
Insulin Secretory Vesicles

