Hepatitis B virus X protein disrupts stress fiber formation and triggers apoptosis.

Abstract

Cytoskeletal proteins are key participants in the cellular progression to apoptosis. In a previous study we injected nude mice with CCL13-HBx cells and identified in contrast to non-HBx transfected cells a differentially phosphorylated myosin light chain (p-MLC) by two-dimensional PAGE and mass spectrometry of the tumor material. To investigate the role of HBx in myosin light chain kinase (MLCK) signaling pathways, we analyzed the key molecules, p-MLC and MLCK, by western blotting. Immunofluorescence staining analysis showed that HBx disrupted stress fiber formation and that focal adhesion kinase (FAK) and integrin-linked kinase (ILK) were regulated by HBx-mediated phosphatase and tensin homolog (PTEN). We also used pharmacological inhibitors to explore the correlation between cytoskeletal rearrangements and HBx-mediated cell apoptosis via an MLCK and a PTEN-dependent pathway. The results showed that both ML9 and bvp restored the effects caused by HBx induction. Our findings suggest that HBx disrupts stress fiber formation and triggers apoptosis via an MLCK and a PTEN-dependent pathway.

• Authors: Chan-Yen Kuo, Tzu-Yu Chou, Chun-Ming Chen, Yung-Fong Tsai, Guang-Yuh Hwang, Tsong-Long Hwang
• Journal: Virus research (Virus Res) Vol. 175 Issue 1 Pg. 20-9 (Jul 2013) ISSN: 1872-7492 [Electronic] Netherlands
• PMID: 23591626 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Elsevier B.V. All rights reserved.

Chemical References

• Trans-Activators
• Viral Regulatory and Accessory Proteins
• hepatitis B virus X protein
• Myosin-Light-Chain Kinase
• PTEN Phosphohydrolase
• PTEN protein, human

Topics

• Apoptosis
• Cell Line
• Hepatitis B virus (physiology)
• Host-Pathogen Interactions
• Humans
• Myosin-Light-Chain Kinase (metabolism)
• PTEN Phosphohydrolase (metabolism)
• Stress Fibers (metabolism)
• Trans-Activators (metabolism)
• Viral Regulatory and Accessory Proteins