Fine-Tuning TOM-Mitochondrial Import via Ubiquitin.

Given their polyvalent functions, an inherent challenge that mitochondria face is the exposure to mitochondrial import stresses, culminating in their dysfunction. Recently, mitochondrial import of several mitochondrial substrates was shown to be regulated via a ‘tug of war’ between USP30 and MARCH5, two ubiquitin-related enzymes located at the TOM complex.