Apaf-1, a human protein homologous to C. elegans CED-4, participates in cytochrome c-dependent activation of caspase-3.
We report here the purification and cDNA cloning of Apaf-1, a novel 130 kd protein from HeLa cell cytosol that participates in the cytochrome c-dependent activation of caspase-3. The NH2-terminal 85 amino acids of Apaf-1 show 21% identity and 53% similarity to the NH2-terminal prodomain of the Caenorhabditis elegans caspase, CED-3. This is followed by 320 amino acids that show 22% identity and 48% similarity to CED-4, a protein that is believed to initiate apoptosis in C. elegans. The COOH-terminal region of Apaf-1 comprises multiple WD repeats, which are proposed to mediate protein-protein interactions. Cytochrome c binds to Apaf-1, an event that may trigger the activation of caspase-3, leading to apoptosis.
Pubmed ID: 9267021 RIS Download
Amino Acid Sequence | Animals | Apoptotic Protease-Activating Factor 1 | Caenorhabditis elegans | Caenorhabditis elegans Proteins | Calcium-Binding Proteins | Caspase 3 | Caspases | Cell Line | Cloning, Molecular | Cysteine Endopeptidases | Cytochrome c Group | Cytosol | DNA, Complementary | Enzyme Activation | Enzyme Precursors | HeLa Cells | Helminth Proteins | Humans | Molecular Sequence Data | Proteins | Recombinant Proteins | Sequence Alignment | Sequence Homology, Amino Acid | Transfection