A transcriptome screen in yeast identifies a novel assembly factor for the mitochondrial complex III.

Starting from a transcriptome based study of the spatio-temporal expression of yeast genes encoding mitochondrial proteins of unknown function, we have identified the gene BCA1 (YLR077W). A FISH analysis showed that the BCA1 mRNA co-localized with the mitochondrial network. Cellular fractionation revealed that Bca1 is bound to the mitochondrial inner-membrane and protrudes into the inter-membrane space.

A mutation associated with CMT2A neuropathy causes defects in Fzo1 GTP hydrolysis, ubiquitylation, and protein turnover.

Charcot-Marie-Tooth disease type 2A (CMT2A) is caused by mutations in the gene MFN2 and is one of the most common inherited peripheral neuropathies. Mfn2 is one of two mammalian mitofusin GTPases that promote mitochondrial fusion and maintain organelle integrity. It is not known how mitofusin mutations cause axonal degeneration and CMT2A disease.

Spatio-temporal dynamics of yeast mitochondrial biogenesis: transcriptional and post-transcriptional mRNA oscillatory modules.

Examples of metabolic rhythms have recently emerged from studies of budding yeast. High density microarray analyses have produced a remarkably detailed picture of cycling gene expression that could be clustered according to metabolic functions. We developed a model-based approach for the decomposition of expression to analyze these data and to identify functional modules which, expressed sequentially and periodically, contribute to the complex and intricate mitochondrial architecture.

Yeast mitochondrial biogenesis: a role for the PUF RNA-binding protein Puf3p in mRNA localization.

The asymmetric localization of mRNA plays an important role in coordinating posttranscriptional events in eukaryotic cells. We investigated the peripheral mitochondrial localization of nuclear-encoded mRNAs (MLR) in various conditions in which the mRNA binding protein context and the translation efficiency were altered. We identified Puf3p, a Pumilio family RNA-binding protein, as the first trans-acting factor controlling the MLR phenomenon.

The Rieske FeS protein encoded and synthesized within mitochondria complements a deficiency in the nuclear gene.

The Rieske FeS protein, an essential catalytic subunit of the mitochondrial cytochrome bc1 complex, is encoded in yeast by the nuclear gene RIP1, whose deletion leads to a respiratory-deficient phenotype. By using biolistic transformation, we have relocated the nuclear RIP1 gene into mitochondria. To allow its expression within the organelle and to direct its integration downstream of the cox1 gene, we have fused the 3' end of the Saccharomyces douglasii cox1 gene upstream of the mitochondrial copy of RIP1 (RIP1m) flanked by the Saccharomyces cerevisiae cox1 promoter and terminator regions.

A pathogenic cytochrome b mutation reveals new interactions between subunits of the mitochondrial bc1 complex.

Energy transduction in mitochondria involves five oligomeric complexes embedded within the inner membrane. They are composed of catalytic and noncatalytic subunits, the role of these latter proteins often being difficult to assign. One of these complexes, the bc1 complex, is composed of three catalytic subunits including cytochrome b and seven or eight noncatalytic subunits.