Get ready for fusion: Insights into Mgm1-mediated membrane remodeling
12.06.2015
Schrempp SG, van der Laan M
J Mol Biol. 2015;427(16):2595-8.
Mitochondria are double-membrane bound organelles the form branched tubular networks throughout eukaryotic cells. The mitochondrial network is not a static structure, but undergoes constant remodeling via tightly regulated membrane fusion and fission events. Both, fusion and fission of mitochondria are mediated by large membrane-bound GTPases of the dynamin superfamily. Whereas recent X-ray structural analyses provided important insights into the mechanism of dynamin-driven membrane fission, it has been unclear how members of this protein family facilitate membrane fusion. A detailed analysis of the mitochondrial inner membrane fusion protein Mgm1 and its membrane interaction now shows that Mgm1 mediates clustering of negatively charged phospholipids as well as GTP-dependent local membrane bending and ruffling. Such mechanical disturbance and deformation of the phospholipid bilayer may considerably lower the energetic barrier for mitochondrial inner membrane fusion.
