ZFIN ID: ZDB-PUB-100211-14
Aquatic birnavirus capsid protein, VP3, induces apoptosis via the Bad-mediated mitochondria pathway in fish and mouse cells
Chiu, C.L., Wu, J.L., Her, G.M., Chou, Y.L., and Hong, J.R.
Date: 2010
Source: Apoptosis : an international journal on programmed cell death   15(6): 653-668 (Journal)
Registered Authors: Her, Guor Muor, Hong, Jiann-Ruey, Wu, Jen-Leih
Keywords: Infectious pancreatic necrosis virus, Submajor capsid VP3, Pro-apoptotic Bad, Mitochondrial membrane potential loss, zfBcl-xL, Antisense RNA
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Apoptosis*
  • Base Sequence
  • Birnaviridae Infections/metabolism
  • Birnaviridae Infections/physiopathology
  • Birnaviridae Infections/veterinary*
  • Birnaviridae Infections/virology
  • Capsid Proteins/genetics
  • Capsid Proteins/metabolism*
  • Caspase 3/metabolism
  • Caspase 9/metabolism
  • Cell Line
  • Fish Diseases/genetics
  • Fish Diseases/metabolism
  • Fish Diseases/physiopathology*
  • Fish Diseases/virology
  • Fish Proteins/genetics
  • Fish Proteins/metabolism*
  • Fishes
  • Gene Expression Regulation, Viral
  • Infectious pancreatic necrosis virus/genetics
  • Infectious pancreatic necrosis virus/metabolism*
  • Mice
  • Mitochondria/metabolism*
  • Molecular Sequence Data
  • NIH 3T3 Cells
  • Signal Transduction*
  • Up-Regulation
  • bcl-Associated Death Protein/genetics
  • bcl-Associated Death Protein/metabolism*
PubMed: 20131002 Full text @ Apoptosis
Aquatic birnavirus induces post-apoptotic necrotic cell death via a newly synthesized protein-dependent pathway. However, the involvement of viral genome-encoded protein(s) in this death process remains unknown. In the present study, we demonstrated that the submajor capsid protein, VP3, up-regulates the pro-apoptotic protein, Bad, in fish and mouse cells. Western blot analysis revealed that VP3 was expressed in CHSE-214 cells at 4 h post-infection (pi), indicating an early role during viral replication. We cloned the VP3 gene and tested its function in fish and mouse cells; VP3 overexpression induced apoptotic cell death by TUNEL assay. In addition, it up-regulated Bad gene expression in zebrafish ZLE cells by threefold at 12 h post-transfection (pt) and in mouse NIH3T3 cells by tenfold at 24 h pt. VP3 up-regulation of Bad expression altered mitochondria function, inducing mitochondrial membrane potential (MMP) loss and activating initiator caspase-9 and effector caspase-3. Furthermore, reduced Bad expression (65% reduction), MMP loss (up to 40%), and enhanced cell viability (up to 60%) upon expression of VP3 antisense RNA in CHSE-214 cells at 24 h post-IPNV infection was observed. Finally, overexpression of the anti-apoptotic gene, zfBcl-xL, reduced VP3-induced apoptotic cell death and caspase-3 activation at 24 h in fish cells. Taken together, these results suggest that aquatic birnavirus VP3 induces apoptosis via up-regulation of Bad expression and mitochondrial disruption, which activates a downstream caspase-3-mediated death pathway that is blocked by zfBcl-xL.