Cytochrome c binding to Apaf-1: The effects of dATP and ionic strength
AUTOR(ES)
Purring-Koch, Cherie
FONTE
The National Academy of Sciences
RESUMO
In the apoptosis pathway in mammals, cytochrome c and dATP are critical cofactors in the activation of caspase 9 by Apaf-1. Until now, the detailed sequence of events in which these cofactors interact has been unclear. Here, we show through fluorescence polarization experiments that cytochrome c can bind to Apaf-1 in the absence of dATP; when dATP is added to the cytochrome c·Apaf-1 complex, further assembly occurs to produce the apoptosome. These findings, along with the discovery that the exposed heme edge of cytochrome c is involved in the cytochrome c·Apaf-1 interaction, are confirmed through enhanced chemiluminescence visualization of native PAGE gels and through acrylamide fluorescence quenching experiments. We also report here that the cytochrome c·Apaf-1 interaction depends highly on ionic strength, indicating that there is a strong electrostatic interaction between the two proteins.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=17271Documentos Relacionados
- Enzymatic synthesis of deoxyribonucleotides, 8. The effects of ATP and dATP in the CDP reductase system from E. coli.
- Two novel dATP analogs for DNA photoaffinity labeling
- Resistance of an adenosine kinase-deficient human lymphoblastoid cell line to effects of deoxyadenosine on growth, S-adenosylhomocysteine hydrolase inactivation, and dATP accumulation.
- Test of the potential of a dATP surrogate for sequencing via MALDI-MS.
- Adenosine kinase inhibition promotes survival of fetal adenosine deaminase–deficient thymocytes by blocking dATP accumulation
