Structure and mechanism of the K/H exchanger KefC.

Intracellular potassium (K) homeostasis is fundamental to cell viability. In addition to channels, K levels are maintained by various ion transporters. One major family is the proton-driven K efflux transporters, which in gram-negative bacteria is important for detoxification and in plants is critical for efficient photosynthesis and growth.

Crystal structure of the Na/H antiporter NhaA at active pH reveals the mechanistic basis for pH sensing.

The strict exchange of protons for sodium ions across cell membranes by NaH exchangers is a fundamental mechanism for cell homeostasis. At active pH, Na/H exchange can be modelled as competition between H and Na to an ion-binding site, harbouring either one or two aspartic-acid residues. Nevertheless, extensive analysis on the model Na/H antiporter NhaA from Escherichia coli, has shown that residues on the cytoplasmic surface, termed the pH sensor, shifts the pH at which NhaA becomes active.

Structure and elevator mechanism of the mammalian sodium/proton exchanger NHE9.

Na /H exchangers (NHEs) are ancient membrane-bound nanomachines that work to regulate intracellular pH, sodium levels and cell volume. NHE activities contribute to the control of the cell cycle, cell proliferation, cell migration and vesicle trafficking. NHE dysfunction has been linked to many diseases, and they are targets of pharmaceutical drugs.

The MEMbrane Protein Single ShoT Amplification Recipe: MemStar.

Here, we present a simple overexpression condition for high-throughput screening of membrane proteins in Escherichia coli. For the vast majority of bacterial membrane protein targets tested the MEMbrane protein Single shoT Amplification Recipe-MemStar-leads to high production yields of target protein. The use of MemStar has facilitated structural studies of several transport proteins.

Dimensional complexity and spectral properties of the human sleep EEG. Electroencephalograms.

Objective: The relevance of the dimensional complexity (DC) for the analysis of sleep EEG data is investigated and compared to linear measures.

Methods: We calculated DC of artifact-free 1 min segments of all-night sleep EEG recordings of 4 healthy young subjects. Non-linearity was tested by comparing with DC values of surrogate data.