PT  - JOURNAL ARTICLE
AU  - Lina Carlini
AU  - Dora Mahecic
AU  - Tatjana Kleele
AU  - Aurélien Roux
AU  - Suliana Manley
TI  - Membrane bending energy and tension govern mitochondrial division
AID  - 10.1101/255356
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 255356
4099  - http://biorxiv.org/content/early/2018/01/29/255356.short
4100  - http://biorxiv.org/content/early/2018/01/29/255356.full
AB  - Mitochondria rely on cellular machinery for their division, which is an essential component of metabolic response of the cell. Many division factors have been identified; however, a framework accounting for the energetic requirements of the mitochondrial fission process is lacking. We report that the presence of an active constriction does not ensure fission. Instead, by measuring constrictions down to ~100 nm with time-lapse super-resolution microscopy, we found that 34% of constrictions failed to divide and ‘reversed’ to an unconstricted state. Higher local curvatures - reflecting an increased bending energy – made constriction sites more likely to divide, but often with a significant residual energy barrier to fission. Our data suggest that membrane tension, largely arising from pulling forces, could account for this missing energy. These results lead us to propose that mitochondrial fission is probabilistic, and can be modeled as arising from bending energy complemented by a fluctuating membrane tension.