6,920 research outputs found
Precursors and post-translational transport of proteins in the assembly of the mitochondrial inner membrane
Alien Registration- Richard, Eva (Sanford, York County)
https://digitalmaine.com/alien_docs/6255/thumbnail.jp
When the fingers do the talking: A study of group participation for different kinds of shareable surfaces
and other research outputs When the fingers do the talking: A study of group par-ticipation for different kinds of shareable surface
Does Intraindividual Variability of Personality States Improve Perspective Taking? An Ecological Approach Integrating Personality and Social Cognition
Research integrating cognitive abilities and personality has focused on the role of personality traits. We propose a theory on the role of intraindividual variability of personality states (hereafter state variability) on perspective taking, in particular, the ability to infer other peoples’ mental states. First, we review the relevant research on personality psychology and social cognition. Second, we propose two complementary routes by which state variability relates to anchoring and adjustment in perspective taking. The first route, termed ego-dispersion, suggests that an increased state variability decreases egocentric bias, which reduces anchoring. The second route, termed perspective-pooling, suggests that an increased state variability facilitates efficient adjustment. We also discuss how our theory can be investigated empirically. The theory is rooted in an ecological interpretation of personality and social cognition, and flags new ways for integrating these fields of research
Assembly of mitochondria
The majority of mitochondrial proteins are synthesized on cytoplasmic ribosomes and transferred to the mitochondria where they are assembled to supramolecular structures. The intracellular transfer of these proteins appears to occur by a post-translational mechanism, i.e., it involves extramitochondrial precursor forms which are translocated in a step independent from translation. The synthesis and transfer of individual proteins was investigated in vivo, or in vitro employing homologous and heterologous cell free systems for protein synthesis. Cytochrome c was initially made as the apoprotein. This precursor protein was converted to the holoprotein on uptake by mitochondria in reconstituted systems. Integrity of mitochondria was essential for the apo to holo conversion. In the case of the ADP/ATP carrier protein, an integral transmembrane protein of the inner mitochondrial membrane, the initial translation product had the same apparent molecular weight as the mature protein. It was found in soluble form in the post-ribosomal supernatant. Citrate synthase, a matrix protein, was synthesized as a precursor with an apparent molecular weight of 47 000. Transfer to the mitochondria was accompanied by cleavage to yield a molecular weight of 45 000. The significance of these results in relation to the mechanisms of intracellular transfer and of assembly of the individual proteins is discussed
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Selenium persistency and speciation in the tissues of lambs following the withdrawal of dietary high-dose selenium-enriched yeast
The objective was to determine the concentration of total selenium (Se) and the proportion of total Se comprised as selenomethionine (SeMet) and selenocysteine (SeCys) in post mortem tissues of lambs in the six weeks period following the withdrawal of a diet containing high dose selenized yeast (SY), derived from a specific strain of Saccharomyces cerevisae CNCM (Collection Nationale de Culture de Micro-organism) I-3060. Thirty Texel x Suffolk lambs used in this study had previously received diets (91 days) containing either high dose SY (HSY; 6.30 mg Se/kg DM) or an unsupplemented control (C; 0.13 mg Se/kg DM). Following the period of supplementation all lambs were then offered a complete pelleted diet, without additional Se (0.15 mg Se/kg DM), for 42 days. At enrollment and 21 and 42 days later, five lambs from each treatment were blood sampled, euthanased and samples of heart, liver, kidney and skeletal muscle (Longissimus Dorsi and Psoas Major) tissue were retained. Total Se concentration in whole blood and tissues was significantly (P < 0.001) higher in HSY lambs at all time points that had previously received long term exposure to high dietary concentrations of SY. The distribution of total Se and the proportions of total Se comprised as SeMet and SeCys differed between tissues, treatment and time points. Total Se was greatest in HSY liver and kidney (22.64 and 18.96 mg Se/kg DM, respectively) and SeCys comprised the greatest proportion of total Se. Conversely, cardiac and skeletal muscle (Longissimus Dorsi and Psoas Major) tissues had lower total Se concentration (10.80, 7.02 and 7.82 mg Se/kg DM, respectively) and SeMet was the predominant selenized amino acid. Rates of Se clearance in HSY liver (307 µg Se/day) and kidney (238 µg Se/day) were higher compared with HSY cardiac tissue (120 µg Se/day) and skeletal muscle (20 µg Se/day). In conclusion differences in Se clearance rates were different between tissue types, reflecting the relative metabolic activity of each tissue, and appear to be dependant upon the proportions of total Se comprised as either SeMet or SeCys
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