Closed-Loop Auditory Stimulation (CLAS) During Sleep Augments Language and Discovery Learning.

Slow oscillation (SO) brainwaves observed during sleep have been shown to reflect the process of memory consolidation, that underlies the critical role of sleep in learning, memory, and other cognitive functions. Closed-loop auditory stimulation (CLAS) uses tones presented in phase with SOs to increase their amplitude and number, along with other brainwave signatures related to memory consolidation. Prior studies have found that CLAS maximizes the ability to perform rote memorization tasks, although this remains controversial.

MetOSite: an integrated resource for the study of methionine residues sulfoxidation.

Motivation: The oxidation of protein-bound methionine to form methionine sulfoxide has traditionally been regarded as an oxidative damage. However, growing evidences support the view of this reversible reaction also as a regulatory post-translational modification. Thus, the oxidation of methionine residues has been reported to have multiple and varied implications for protein function.

Protein-protein interfaces from cytochrome c oxidase I evolve faster than nonbinding surfaces, yet negative selection is the driving force.

Respiratory complexes are encoded by two genomes (mitochondrial DNA [mtDNA] and nuclear DNA [nDNA]). Although the importance of intergenomic coadaptation is acknowledged, the forces and constraints shaping such coevolution are largely unknown. Previous works using cytochrome c oxidase (COX) as a model enzyme have led to the so-called "optimizing interaction" hypothesis.

Mutational bias plays an important role in shaping longevity-related amino acid content in mammalian mtDNA-encoded proteins.

During the course of evolution, amino acid shifts might have resulted in mitochondrial proteomes better endowed to resist oxidative stress. However, owing to the problem of distinguishing between functional constraints/adaptations in protein sequences and mutation-driven biases in the composition of these sequences, the adaptive value of such amino acid shifts remains under discussion. We have analyzed the coding sequences of mtDNA from 173 mammalian species, dissecting the effect of nucleotide composition on amino acid usages.

Thermodynamic stability explains the differential evolutionary dynamics of cytochrome b and COX I in mammals.

By using a combination of evolutionary and structural data from 231 species, we have addressed the relationship between evolution and structural features of cytochrome b and COX I, two mtDNA-encoded proteins. The interior of cytochrome b, in contrast to that of COX I, exhibits a remarkable tolerance to changes. The higher evolvability of cytochrome b contrasts with the lower rate of synonymous substitutions of its gene when compared to that of COX I, suggesting that the latter is subjected to a stronger purifying selection.