| Autor: |
R M, Kluck, L M, Ellerby, H M, Ellerby, S, Naiem, M P, Yaffe, E, Margoliash, D, Bredesen, A G, Mauk, F, Sherman, D D, Newmeyer |
| Rok vydání: |
2000 |
| Předmět: |
|
| Zdroj: |
The Journal of biological chemistry. 275(21) |
| ISSN: |
0021-9258 |
| Popis: |
Cytochrome c released from vertebrate mitochondria engages apoptosis by triggering caspase activation. We previously reported that, whereas cytochromes c from higher eukaryotes can activate caspases in Xenopus egg and mammalian cytosols, iso-1 and iso-2 cytochromes c from the yeast Saccharomyces cerevisiae cannot. Here we examine whether the inactivity of the yeast isoforms is related to a post-translational modification of lysine 72, N-epsilon-trimethylation. This modification was found to abrogate pro-apoptotic activity of metazoan cytochrome c expressed in yeast. However, iso-1 cytochrome c lacking the trimethylation modification also was devoid of pro-apoptotic activity. Thus, both lysine 72 trimethylation and other features of the iso-1 sequence preclude pro-apoptotic activity. Competition studies suggest that the lack of pro-apoptotic activity was associated with a low affinity for Apaf-1. As cytochromes c that lack apoptotic function still support respiration, different mechanisms appear to be involved in the two activities. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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