Expression and localization of myo-inositol-1-phosphate synthase (MIPS) in developing seeds of Arabidopsis thaliana was investigated. MIPS is an essential enzyme for production of inositol and inositol phosphates via its circularization of glucose-6-phosphate as the initial step. myo-inositol-6-phosphate (InsP(6) or phytic acid) is the predominant form of phosphorus found in seeds and accumulat...

Inositol 1,4,5-triphosphate receptors (Insp(3)Rs) and ryanodine receptors (ryRs) act as cationic channels transporting calcium ions from the endoplasmic reticulum to cytosol by forming tetramers and are proteins localized to the endoplasmic reticulum (ER). Despite the absence of classical calcium-binding motifs, calcium channeling occurs at the transmembrane domain. We have investigated putativ...

Using a permeabilization strategy to introduce Ins(3,4,5,6) P(4) into mesophyll protoplasts of Commelina communis, we have identified Ins(3,4,5,6) P(4) 1-kinase activity in mesophyll cells. Multiple InsP(3) isomers were identified in Spirodela polyrhiza and Arabidopsis. Only two of these, Ins(1,2,3) P(3) and Ins(3,4,6) P(3), have previously been identified in plants and only in monocots. The is...

M(1) muscarinic (M(1)AChRs) and B(2) bradykinin (B(2)Rs) receptors are two PLCbeta-coupled receptors that mobilize Ca(2+) in nonexcitable cells. In many neurons, however, B(2)Rs but not M(1)AChRs mobilize intracellular Ca(2+). We have studied the membrane organization and dynamics underlying this coupling specificity by using Trp channels as biosensors for real-time detection of PLCbeta product...

Inositol phosphates function as second messengers for a variety of extracellular signals. Ins(1,4,5)P(3) generated by phospholipase C-mediated hydrolysis of phosphatidylinositol bisphosphate, triggers numerous cellular processes by regulating calcium release from internal stores. The Ins(1,4,5)P(3) signal is coupled to a complex metabolic cascade involving a series of phosphatases and kinases. ...

Endothelial injury is the primary event that leads to a variety of severe vascular disorders. Mechanical injury elicits a Ca(2+) response in the endothelium of excised rat aorta, which comprises an initial Ca(2+) release from inositol-1,4,5-trisphosphate (InsP(3))-sensitive stores followed by a long-lasting decay phase due to Ca(2+) entry through uncoupled connexons. The Ca(2+) signal may also ...

1 There are two basic types of interconnection agreements between providers in the Internet: peering and transit. A decision every Internet network service provider (INSP) has to make is which other peering/transit INSPs to connect with. The potential peering/transit partners differ (obviously) in the advertised routes and they may differ quite drastically in the amount and type of costs (line ...

Bronchodilator drugs produce variable improvements in forced expiratory volume in 1 s (FEV(1)), but larger changes in end-expiratory lung volume (EELV) in chronic obstructive pulmonary disease (COPD), which were suggested to be related to the presence of expiratory flow limitation (EFL) at rest. We tested this concept in 42 COPD patients (FEV(1) 42.3+/-13.8% predicted) during spontaneous breath...

Large bacterial protein toxins autotranslocate functional effector domains to the eukaryotic cell cytosol, resulting in alterations to cellular functions that ultimately benefit the infecting pathogen. Among these toxins, the clostridial glucosylating toxins (CGTs) produced by Gram-positive bacteria and the multifunctional-autoprocessing RTX (MARTX) toxins of Gram-negative bacteria have distinc...