Learn More
As sperm prepare for fertilization, surface Ca(2+) channels must open to initiate required, Ca(2+)-mediated events. However, the molecular identity and functional properties of sperm Ca(2+) channels remain uncertain. Here, we use rapid local perfusion and single-cell photometry to examine the kinetics of calcium responses of mouse sperm to depolarizing(More)
Pituitary gonadotropes transduce hormonal input into cytoplasmic calcium ([Ca(2+)](cyt)) oscillations that drive rhythmic exocytosis of gonadotropins. Using Calcium Green-1 and rhod-2 as optical measures of cytoplasmic and mitochondrial free Ca(2+), we show that mitochondria sequester Ca(2+) and tune the frequency of [Ca(2+)](cyt) oscillations in rat(More)
The vacuolar (H(+))-ATPases (or V-ATPases) are structurally related to the F(1)F(0) ATP synthases of mitochondria, chloroplasts and bacteria, being composed of a peripheral (V(1)) and an integral (V(0)) domain. To further investigate the arrangement of subunits in the V-ATPase complex, covalent cross-linking has been carried out on the V-ATPase from(More)
The role of NR4A1 in apoptosis is controversial. Pancreatic β-cells often face endoplasmic reticulum (ER) stress under adverse conditions such as high free fatty acid (FFA) concentrations and sustained hyperglycemia. Severe ER stress results in β-cell apoptosis. The aim of this study was to analyze the role of NR4A1 in ER stress-mediated β-cell apoptosis(More)
Zinc is an essential nutrient for all organisms, which is involved in the function of numerous key enzymes in metabolism. Two gene families have been identified involved in zinc homeostasis. ZnT transporters reduce intracellular zinc while Zip transporters increase intracellular zinc. Previous studies in our laboratory have shown that Zip-1, ZnT-1, Zip-2(More)
To investigate the function of subunit D in the vacuolar H(+)-ATPase (V-ATPase) complex, random and site-directed mutagenesis was performed on the VMA8 gene encoding subunit D in yeast. Mutants were selected for the inability to grow at pH 7.5 but the ability to grow at pH 5.5. Mutations leading to reduced levels of subunit D in whole cell lysates were(More)
The vacuolar [H(+)]-ATPases (V-ATPases) are composed of a peripheral V(1) domain and a membrane-embedded V(0) domain. Reversible dissociation of the V(1) and V(0) domains has been observed in both yeast and insects and has been suggested to represent a general regulatory mechanism for controlling V-ATPase activity in vivo. In yeast, dissociation of the(More)
BACKGROUND NR4A3/NOR-1 is a member of the NR4A orphan nuclear receptor subfamily, which contains early response genes that sense and respond to a variety of stimuli in the cellular environment. The role of NR4A3 in insulin expression in pancreatic beta cells remains unknown. METHODS Dynamic changes in NR4A3 were examined in a pancreatic beta-cell line,(More)
  • 1