Mechanistic Analysis of a Dynamin Effector
Laura L. Lackner,
Jennifer S. Horner,
Jodi Nunnari*
Dynamin-related proteins (DRPs) can generate forces to remodel
membranes. In cells, DRPs require additional proteins [DRP-associated
proteins (DAPs)] to conduct their functions. To dissect the
mechanistic role of a DAP, we used the yeast mitochondrial division
machine as a model, which requires the DRP Dnm1, and two other
proteins, Mdv1 and Fis1. Mdv1 played a postmitochondrial targeting
role in division by specifically interacting and coassembling
with the guanosine triphosphate–bound form of Dnm1. This
regulated interaction nucleated and promoted the self-assembly
of Dnm1 into helical structures, which drive membrane scission.
The nucleation of DRP assembly probably represents a general
regulatory strategy for this family of filament-forming proteins,
similar to F-actin regulation.
* To whom correspondence should be addressed. E-mail: jmnunnari{at}ucdavis.edu
