First published online September 9, 2005
Journal of Cell Science 118, 1801e (2005)
© The Company of Biologists Limited
Mitochondria: controlling the fission reaction
Mammalian mitochondria, for mysterious but apparently essential reasons, frequently change shape through fission and fusion. Mitochondrial fission, which is also involved in apoptosis, requires at least two proteins: the cytosolic dynamin-like protein DLP1/Drp1 and the mitochondrial outer membrane protein hFis1, which seems to recruit DLP1 to mitochondria. On p. 4141, Yisang Yoon and colleagues provide new insights into how hFis1 regulates mitochondrial fission by identifying two regions of the protein that are required for this process. The N-terminal region of hFis1 forms six
-helices; among these,
2-
3 and
4-
5 form two tetratricopeptide repeat (TPR) folds that mediate protein-protein interactions. By examining deletion mutants of hFis1, the authors show that the TPR region mediates binding of hFIS1 to DLP1 and that the
1 helix regulates this interaction. They suggest that hFis1 is the main regulator of mitochondrial fission and propose that it acts in a two-step process: recruitment of DLP1 by the TPR motif is followed by
1-mediated release of DLP1 assemblies, which then bind to the mitochondrial surface and mediate membrane fission.
Related articles in JCS:
- Regulation of mitochondrial fission and apoptosis by the mitochondrial outer membrane protein hFis1
- Tianzheng Yu, Randall J. Fox, Lindsay S. Burwell, and Yisang Yoon
JCS 2005 118: 4141-4151.
[Abstract]
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