Apoptosis-inducing proteins in chicken anemia virus and TT virus.
Torque teno viruses (TTVs) share several genomic similarities with the chicken anemia virus (CAV). CAV encodes the protein apoptin that specifically induces apoptosis in (human) tumor cells. Functional studies reveal that apoptin induces apoptosis in a very broad range of (human) tumor cells. A putative TTV open reading frame (ORF) in TTV genotype 1, named TTV apoptosis inducing protein (TAIP), it induces, like apoptin, p53-independent apoptosis in various human hepatocarcinoma cell lines to a similar level as apoptin. In comparison to apoptin, TAIP action is less pronounced in several analyzed human non-hepatocarcinoma-derived cell lines. Detailed sequence analysis has revealed that the TAIP ORF is conserved within a limited group of the heterogeneous TTV population. However, its N-terminal half, N-TAIP, is rather well conserved in a much broader set of TTV isolates. The similarities between apoptin and TAIP, and their relevance for the development and treatment of diseases is discussed.
de Smit
M H
MH
Department of Molecular Genetics, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands. m.smit@chem.leidenuniv.nl
Noteborn
M H M
MH
D000595:Amino Acid Sequence; D017209:Apoptosis / Q000502:physiology*; D036022:Capsid Proteins / Q000235:genetics / Q000502:physiology*; D045744:Cell Line, Tumor; D002472:Cell Transformation, Viral; D017727:Chicken anemia virus / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D006801:Humans; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D022783:Torque teno virus / Q000235:genetics / Q000276:immunology / Q000502:physiology*
D036022:Capsid Proteins; C091717:VP3 protein, Chicken anemia virus