Progress in 2010

Respiratory chain subunits are made up of proteins encoded by nuclear and mitochondrial DNA, which assemble to form functional enzymes. New findings reveal that the mitochondrial translation of Cox1, the core component of cytochromecoxidase, is directly coupled to the assembly of this respiratory complex.

Mitophagy is the selective elimination of mitochondria through autophagy. Recent studies have uncovered the molecular mechanisms mediating mitophagy in yeast and mammalian cells and have revealed that the dysregulation of one of these mechanisms — the PINK1–parkin-mediated signalling pathway — may contribute to Parkinson's disease.

Transport protein particle (TRAPP; also known as trafficking protein particle) complexes activate the GTPase Ypt1 or RAB1 to regulate membrane traffic in yeast and mammals, respectively. Two different TRAPP complexes tether coated vesicles during endoplasmic reticulum–Golgi and intra-Golgi traffic, respectively, and a third complex functions in autophagy. The TRAPP complexes thereby connect GTPase activation to unique membrane-tethering events.

In mammalian cells, several proteins that are not part of the core replication machinery promote the efficient restart of stalled replication forks, which suggests that fork restart pathways exist. Different models of restart can be envisaged, which involve DNA helicases, nucleases, homologous recombination factors and DNA double-strand breaks.

Several human neurological and neuromuscular diseases are caused by the expansion of repetitive DNA tracts. Understanding the DNA metabolic processes responsible for the expansion (or lengthening) and contraction (or shortening) of DNA repeats might open new therapeutic avenues for the treatment of these diseases.