Ca/Calmodulin Binding to STIM1 Hydrophobic Residues Facilitates Slow Ca-Dependent Inactivation of the Orai1 Channel.

Background/aims: Store-operated Ca entry (SOCE) through plasma membrane Ca channel Orai1 is essential for many cellular processes. SOCE, activated by ER Ca store-depletion, relies on the gating function of STIM1 Orai1-activating region SOAR of the ER-anchored Ca-sensing protein STIM1. Electrophysiologically, SOCE is characterized as Ca release-activated Ca current (I).

Regulation of Adult CNS Axonal Regeneration by the Post-transcriptional Regulator Cpeb1.

Adult mammalian central nervous system (CNS) neurons are unable to regenerate following axonal injury, leading to permanent functional impairments. Yet, the reasons underlying this regeneration failure are not fully understood. Here, we studied the transcriptome and translatome shortly after spinal cord injury.

Ist2 in the yeast cortical endoplasmic reticulum promotes trafficking of the amino acid transporter Bap2 to the plasma membrane.

The equipment of the plasma membrane in Saccharomyces cerevisiae with specific nutrient transporters is highly regulated by transcription, translation and protein trafficking allowing growth in changing environments. The activity of these transporters depends on a H(+) gradient across the plasma membrane generated by the H(+)-ATPase Pma1. We found that the polytopic membrane protein Ist2 in the cortical endoplasmic reticulum (ER) is required for efficient leucine uptake during the transition from fermentation to respiration.

Oligomerization and Ca2+/calmodulin control binding of the ER Ca2+-sensors STIM1 and STIM2 to plasma membrane lipids.

Ca2+ (calcium) homoeostasis and signalling rely on physical contacts between Ca2+ sensors in the ER (endoplasmic reticulum) and Ca2+ channels in the PM (plasma membrane). STIM1 (stromal interaction molecule 1) and STIM2 Ca2+ sensors oligomerize upon Ca2+ depletion in the ER lumen, contact phosphoinositides at the PM via their cytosolic lysine (K)-rich domains, and activate Ca2+ channels. Differential sensitivities of STIM1 and STIM2 towards ER luminal Ca2+ have been studied but responses towards elevated cytosolic Ca2+ concentration and the mechanism of lipid binding remain unclear.

Multiple glutathione disulfide removal pathways mediate cytosolic redox homeostasis.

Glutathione is central to cellular redox chemistry. The majority of glutathione redox research has been based on the chemical analysis of whole-cell extracts, which unavoidably destroy subcellular compartment-specific information. Compartment-specific real-time measurements based on genetically encoded fluorescent probes now suggest that the cytosolic glutathione redox potential is about 100 mV more reducing than previously thought.