Mitochondria Tether to Focal Adhesions During Cell Migration and Regulate Their Size.

Abstract Focal Adhesions (FA) couple the actin cytoskeleton to the extracellular matrix through transmembrane integrin receptors. FA assembly and disassembly regulate cell migration by controlling substrate interaction and the generation of intracellular contractile forces. Here we show that FA interact with mitochondria. Mitochondria are highly dynamic organelles that are now emerging as regulators of mammalian cell motility. We find that mitochondria infiltrate the leading edge of NIH3T3 fibroblasts during migration and tether to FA there. Importantly, we find that FA interacting with mitochondria are larger than those lacking mitochondrial interaction. In addition, inhibition of mitochondrial ATP generation reduces FA size and artificial tethering of FA to mitochondria concomitantly increases their size. Taken together this suggests that mitochondrial interaction with FA is a functional part of cell migration and adhesion.