PUBLICATION

VIAF, a conserved inhibitor of apoptosis (IAP)-interacting factor that modulates caspase activation

Authors
Wilkinson, J.C., Richter, B.W., Wilkinson, A.S., Burstein, E., Rumble, J.M., Balliu, B., and Duckett, C.S.
ID
ZDB-PUB-110111-1
Date
2004
Source
The Journal of biological chemistry   279(49): 51091-51099 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Caspases/metabolism*
  • Open Reading Frames
  • Cloning, Molecular
  • Amino Acid Motifs
  • Transfection
  • RNA Interference
  • Amino Acid Sequence
  • Cell Death
  • Cell Line
  • Sequence Analysis, DNA
  • bcl-2-Associated X Protein
  • Baculoviridae/genetics
  • Two-Hybrid System Techniques
  • DNA, Complementary/metabolism
  • Ubiquitin/metabolism
  • Phosphoproteins/chemistry
  • Sequence Homology, Amino Acid
  • Molecular Sequence Data
  • Blotting, Northern
  • Inhibitor of Apoptosis Proteins
  • Glutathione Transferase/metabolism
  • Base Sequence
  • Humans
  • Plasmids/metabolism
  • Green Fluorescent Proteins/metabolism
  • Carrier Proteins/physiology*
  • Subcellular Fractions
  • Microscopy, Fluorescence
  • Enzyme Activation
  • Viral Proteins/genetics
  • Cytoplasm/metabolism
  • Apoptosis
  • Protein Structure, Tertiary
  • Microscopy, Confocal
  • Proto-Oncogene Proteins c-bcl-2/metabolism
  • Nickel/chemistry
  • Phylogeny
PubMed
15371430 Full text @ J. Biol. Chem.
Abstract
Inhibitor of apoptosis (IAP) proteins are involved in the suppression of apoptosis, signal transduction, cell cycle control and gene regulation. Here we describe the cloning and characterization of viral IAP-associated factor (VIAF), a highly conserved, ubiquitously expressed phosphoprotein with limited homology to members of the phosducin family that associates with baculovirus Op-IAP. VIAF bound Op-IAP both in vitro and in intact cells, with each protein displaying a predominantly cytoplasmic localization. VIAF lacks a consensus IAP binding motif, and overexpression of VIAF failed to prevent Op-IAP from protecting human cells from a variety of apoptotic stimuli, suggesting that VIAF does not function as an IAP antagonist. VIAF was unable to directly inhibit caspase activation in vitro and a reduction of VIAF protein levels by RNA interference led to a decrease in Bax-mediated caspase activation, suggesting that VIAF functions to co-regulate the apoptotic cascade. Finally, VIAF is a substrate for ubiquitination mediated by Op-IAP. Thus, VIAF is a novel IAP-interacting factor that functions in caspase activation during apoptosis.
Genes / Markers
Figures
No images available
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping