Organisms Commons^™

Dpc29 Promotes Post-Initiation Mitochondrial Translation In Saccharomyces Cerevisiae, Kyle A. Hubble, Michael F. Henry

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Mitochondrial ribosomes synthesize essential components of the oxidative phosphorylation (OXPHOS) system in a tightly regulated process. In the yeast Saccharomyces cerevisiae, mitochondrial mRNAs require specific translational activators, which orchestrate protein synthesis by recognition of their target gene's 5'-untranslated region (UTR). Most of these yeast genes lack orthologues in mammals, and only one such gene-specific translational activator has been proposed in humans-TACO1. The mechanism by which TACO1 acts is unclear because mammalian mitochondrial mRNAs do not have significant 5'-UTRs, and therefore must promote translation by alternative mechanisms. In this study, we examined the role of the TACO1 orthologue in yeast. We …

Kinetics Of Dextromethorphan-O-Demethylase Activity And Distribution Of Cyp2d In Four Commonly-Used Subcellular Fractions Of Rat Brain, Barent N. Dubois, Farideh Amirrad, Reza Mehvar

Pharmacy Faculty Articles and Research

The purpose of this study was to compare the enzymatic kinetics and distribution of cytochrome P450 2D (CYP2D) among different rat brain subcellular fractions.

Rat brains were used to prepare total membrane, crude mitochondrial, purified mitochondrial, and microsomal fractions, in addition to total homogenate. Michaelis–Menten kinetics of the brain CYP2D activity was estimated based on the conversion of dextromethorphan (DXM) to dextrorphan using UPLC-MS/MS. Protein levels of CYP2D and subcellular markers were determined by Western blot.

Microsomal CYP2D exhibited high affinity and low capacity, compared with the mitochondrial CYP2D that had a much lower (∼50-fold) affinity but a higher (∼six-fold) …