A monoclonal antibody which blocks InsP(3)-induced Ca(2+) release from isolated endoplasmic reticulum was used to isolate a novel 4.0 kb cDNA from a human erythroleukaemia (HEL) cell cDNA expression library. A corresponding mRNA transcript of approx. 4.2 kb was present in all human cell lines and tissues examined, but cardiac and skeletal muscle had an additional transcript of 6.4 kb. The ident...

We introduce a new method for purifying recombinant proteins expressed in bacteria using a highly specific, inducible, self-cleaving protease tag. This tag is comprised of the Vibrio cholerae MARTX toxin cysteine protease domain (CPD), an autoprocessing enzyme that cleaves exclusively after a leucine residue within the target protein-CPD junction. Importantly, V. cholerae CPD is specifically ac...

Most of the phosphorus in seeds is accumulated in the form of phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate, InsP₆). This molecule is a strong chelator of cations important for nutrition, such as iron, zinc, magnesium, and calcium. For this reason, InsP₆ is considered an antinutritional factor. In recent years, efforts to biofortify seeds through the generation of low phytic acid (lpa)...

Neuronal Ca(2+) signals can affect excitability and neural circuit formation. Ca(2+) signals are modified by Ca(2+) flux from intracellular stores as well as the extracellular milieu. However, the contribution of intracellular Ca(2+) stores and their release to neuronal processes is poorly understood. Here, we show by neuron-specific siRNA depletion that activity of the recently identified stor...

The role of insulin in modulating phosphoinositide breakdown and accumulation of inositol phosphates was investigated in isolated rat pancreatic islets by using GPAIS (guinea-pig anti-insulin antiserum> that neutralizes effects of insulin in the medium. At either 3.0 mmor 16.7 mM-glucose or 3.0 mM-glucose plus I0 uM-arecaidine propargyl ester (muscarinic receptor agonist), GPAIS (but not contro...

OBJECTIVE The purpose of this study was to test the hypothesis that H(2)O(2) contributes to the EDHF phenomenon by mobilizing endothelial Ca(2+) stores. METHODS AND RESULTS Myograph studies with rabbit iliac arteries demonstrated that EDHF-type relaxations evoked by the SERCA inhibitor cyclopiazonic acid (CPA) required activation of K(Ca) channels and were potentiated by exogenous H(2)O(2) an...

The uncoupling of metabotropic glutamate receptors (mGluRs) from heterotrimeric G proteins represents an essential feedback mechanism that protects neurons against receptor overstimulation that may ultimately result in damage. The desensitization of mGluR signaling is mediated by both second messenger-dependent protein kinases and G protein-coupled receptor kinases (GRKs). Unlike mGluR1, the at...

Ca(2+) uptake by mitochondria is a potentially important buffering system able to control cytosolic [Ca(2+)]. In chromaffin cells, we have shown previously that stimulation of either Ca(2+) entry or Ca(2+) release via ryanodine receptors triggers large increases in mitochondrial [Ca(2+)] ([Ca(2+)](M)) approaching the millimolar range, whose blockade dramatically enhances catecholamine secretion...

Intracytoplasmic sperm injection (ICSI) in pigs is a technique with potential application in diverse fields of animal production and biomedicine. Even though there are some cases of live offspring resulting from this technique, its yield is still quite low compared to other species. The aim of this study was to evaluate different factors affecting the ICSI performance. This was done by studying...

Both morphological and paleontological characteristics support the hypothesis of a monophyletic origin of crocodilian and avian groups. However, while the erythrocytes of all birds studied to date are reported to contain high levels of inositol pentakisphosphate (InsP(5)), which acts as an allosteric effector of hemoglobin, this molecule has not been reported in crocodilian erythrocytes. In thi...