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Research has been conducted on the alpha-D-Galp-(1(approaches)3)-D-Man. The synthesis of this compound which is present in type-2 glycoinositolphospholipids and in the lipophosphoglycan core of Leishmania has been carried out and is described.

PI 3-kinases and PTEN are discussed in this minireview, which considers how opposites attract by chemical means. Phosphatidylinositol lipids are central as mediators in diverse intracellular signaling pathways. Recent research into how the metabolism of these lipids by phosphatidylinositol 3-kinases and the PTEN 3-phosphoinositide phosphatase may coordinate G protein coupled signaling pathways during eukaryotic chemotaxis.

Research has been conducted on the inositol phosphate derivatives. The synthesis of the inositol stereoisomers' derivatives and all conduritol diastereomers has been carried out via the enzymatic resolution of conduritol B and C derivatives and the details are reported.

Research has been conducted on the spicamycin congeners. The synthesis of these congeners has been carried out starting from the cyclitol myo-inositol and the results demonstrate the N-glycoside linkage construction in spicamycin.

Research has been conducted on inositol monophosphatase, an enzyme in the biosynthesis of myo-inositol from insitol-1-phosphate. The activity of this monophosphatase has been investigated and the results of expression, purification and biochemical characterization of Mycobacterium tuberculosis SuhB which possesses high homology degree with human inositol monophosphatase are described.

Inositol is involved in several aspects of reproduction. It affects overall embryogenesis, may prevent neural tube defects, and stimulates the production of lung surfactant. This article will review the involvement of inositol in reproduction. After describing the biologic function of inositol and its derivatives, studies are quoted in which the role of inositol in fertility, embryogenesis, fetal development, and pregnancy outcome are examined. Key Words: inositol, reproduction, fertility, embryogenesis, fetal development

Research has been conducted on the inositol pyrophosphates. Results indicate that these pyrophosphates mediate homologous DNA recombination in Saccharomyces cerevisae.

The dynamic properties of the inositol (1,4,5)-trisphosphate (I[P.sub.3]) receptor are crucial for the control of intracellular [Ca.sup.2+], including the generation of [Ca.sup.2+] oscillations and waves. However, many models of this receptor do not agree with recent experimental data on the dynamic responses of the receptor. We construct a model of the I[P.sub.3] receptor and fit the model to dynamic and steady-state experimental data from type-2 I[P.sub.3] receptors. Our results indicate that, (i) [Ca.sup.2+] binds to the receptor using saturating, not mass-action, kinetics; (i) [Ca.sup.2+] decreases the rate of I[P.sub.3] binding while simultaneously increasing the steady-state sensitivity of the receptor to I[P.sub.3]; (iii) the rate of [Ca.sup.2+]-induced receptor activation increases with [Ca.sup.2+] and is faster than [Ca.sup.2+]-induced receptor inactivation; and (iv) I[P.sub.3] receptors are sequentially activated and inactivated by [Ca.sup.2+] even when I[P.sub.3] is bound. Our results emphasize that measurement of steady-state properties alone is insufficient to characterize the functional properties of the receptor.

Results show that iolT and iolF genes encode inositol transporter proteins with the former mediating inositol uptake and utilization. Data indicate that iolT is regulated by the IolR repressor.

Research has been conducted on the alkali metal ions Li (super)+, Na (super)+ and K (super)+ in the constrained inositol orthoformate derivatives. The structural features conductive to the complexation of these metal ions have been investigated in solution, in the solid state and in the gas phase via the electrospray ionization mass spectroscopy and the details are discussed.

Kwan, H. Y., Y. Huang, S. K. Kong, and X. Yao. cGMP abolishes agonist-induced [[Ca.sup.2+].sub.i] oscillations in human bladder epithelial cells. Am J Physiol Renal Physiol 281: F1067-F1074, 2001. First published August 9, 2001; 10.1152/ajprenal.00031.2001.--Cytosolic calcium oscillations may permit cells to respond to information provided by increases in intracellular [Ca.sup.2+] concentration ([[Ca.sup.2+]sub.i]) while avoiding prolonged exposure to constantly elevated [[Ca.sup.2+]sub.i]. In this study, we demonstrated that agonists could induce [Ca.sup.2+] oscillations in human bladder epithelial cells. Application of 10 [micro]M acetylcholine or 200 nM bradykinin triggered an initial [Ca.sup.2+] transient that was followed by periodic [[Ca.sup.2+]sub.i] oscillations. The oscillations did not depend on extracellular [Ca.sup.2+]. 8-Bromoguanosine 3',5'-cyclic monophosphate abolished acetylcholine- or bradykinin-induced oscillations. Elevation of cellular cGMP by dipyridamole, an inhibitor of cGMP-specific phosphodiesterase, also terminated the [[Ca.sup.2+]sub.i] oscillations. The inhibitory effect of cGMP could be reversed by KT-5823, a highly specific inhibitor of protein kinase G (PKG), suggesting that the action of cGMP was mediated by PKG. Comparison of the effect of cGMP with that of xestospongin C, an inhibitor of the inositol 1,4,5-trisphosphate (I[P.sub.3]) receptor, revealed similarities between the action of cGMP and xestospongin C. Therefore, it is likely that cGMP and PKG may target a signal transduction step(s) linked to I[P.sub.3] receptor-mediated [Ca.sup.2+] release. protein kinase G; inositol 1,4,5-triphosphate; calcium release; nitric oxide; intracellular calcium concentration; guanosine 3',5'-cyclic monophosphate Received 5 February 2001; accepted in final form 23 July 2001

Research has been conducted on the fully phosphorylated glycosylphosphatidyl inositol anchor pseudohexasaccharide. The retrosynthesis of this compound has led to the building blocks and the results are discussed.

Research has been conducted on the Bacillus subtilis inositol operon involved in the myo-inositol catabolism. The results indicate that the catabolite repression is mediated by CcpA and that CcpA binds to the catabolite-responsive elements.

Research has been conducted on the myo-inositol. The incorporation and turnover of this myo-inositol in phosphatidylinositol and the rates of this incorporation and turnover have been investigated via the cultured mouse cortical neurons.

Research has been conducted on the Cu (super)II complex. The interaction of this complex with the 1,3,5-trideoxy-1,3,5-tris(dimethylamino)-cis-inositol ligand has been examined in both solid state and in solution and the phosphoesterase activity of the produced complexes has been tested.

Research has been conducted on the inositol polyphosphates. The synthesis of the inositol diastereoisomers as enantiomerically pure forms carried out starting with 6-O-acetyl-5-enopyranosides is described.

Results demonstrate that a functional myo-inositol dehydrogenase gene is essential for efficient nitrogen fixation and nodulation of soybean by Sinorhizobium fredii USDA191 as shown by the inability of mutants to establish and nodulate even when population of 10-fold higher is used.

Research has been conducted on the Archaeoglobus fulgidus inositol-1-phosphate synthase gene overexpressed in Escherichia coli. Results indicate that this archaeal synthase is a class II aldolase.

The endoplasmic reticulum (ER) of the mature mouse egg consists of a fine tubular network and pronounced accumulations in the cortex. The ER was visualized both in intact eggs and with in vitro preparations of the cortex using the fluorescent lipophilic dye, DiI. Immunofiuorescent labeling of the ER in isolated cortical preparations demonstrated that the ER clusters contain inositol 1,4,5-trisphosphate (IP(sub 3)) receptors, indicating an important involvement in sperm-induced Ca(super 2+). transients, which are triggered by IP(sub 3). We imaged the ER during fertilization and the subsequent Ca(super 2+) transients and found that the clusters remained intact throughout this period. Recovery of fluorescence after photobleaching established that the ER clusters are continuous with the reticular ER network and that these structures remain stable and continuous throughout the time of fertilization-induced Ca(super 2+) transients; continuity also remained during IP(sub 3) injection. These results indicate that, in contrast to echinoderm eggs, the ER of mouse eggs does not become disrupted when it releases Ca(super 2+) at fertilization. The localization and apparent stability of the cortical ER clusters may be important in generating Ca(super 2+) oscillations, which are characteristic of fertilized mammalian eggs. Imaging of intracellular Ca(super 2+) revealed that Ca(super 2+) transients originate in the hemisphere of the egg that contains abundant ER clusters, thus the mouse contains a stable cortical pacemaker responsible for generating Ca(super 2+) waves. Key Words: endoplasmic reticulum; mouse egg; calcium waves; inositol trisphosphate; calcium stores; fertilization.

Disruption of sblA in Streptomyces lividans is discussed. This disruption makes expression of a heterologous alpha-amylase gene in the presence of glucose possible. In a transposition mutant of S. lividans TK24, the usually glucose-repressible expression of a heterologous alpha amylase gene was rendered resistant to glucose repression.

A study was conducted to determine whether reduced type I IP3 receptor (IP3R) is essential in diabetic kidney disease. In evaluating type I IP3R expression in the kidney of streptozotocin-induced diabetic rats and mice, it was found that there is reduced type I IP3R in glomerular and vascular smooth muscle cells in the diabetic kidney, which may have a part in the modified renal vasoregulation and renal hypertrophy of diabetes.

A study was conducted to examine the effects of Mg2+ and Ba2+ on the single-channel properties of inositol 1,4,5-triphosphate receptors. The identity of the Xenopus IP3R channel was determined in outer nuclear membrane patches while stage VI oocytes were isolated from the ovary. Results indicated that divalent cations minimize currents using a mechanism supporting the permeation block of the IP3R.

A study was conducted to determine the single-channel properties of inositol (1,4,5)-triphosphate receptor (InsP3R) which is heterologously expressed in HEK-293 cells. Findings showed that recombinant InsP3R retained specific InsP3 binding properties and were recognized by anti-InsP3R rabbit polyclonal antibody. Gating and conductance properties of recombinant neuronal rat InsP3R-I were similar to properties of native rate cerebellar InsP3R. These suggested that rat neuronal InsP3R-I cDNA encodes a protein sufficient to produce InsP3-gated channel.

Byline: Carmen J. Williams (a), Lisa M. Mehlmann (a ), Laurinda A. Jaffe (a ), Gregory S. Kopf (a), Richard M. Schultz (a)(a ) Abstract: Embryonic development is initiated after the fertilizing sperm contacts the egg and triggers a process termed 'egg activation,' resulting in calcium release, cortical granule exocytosis, recruitment of maternal mRNAs, and cell cycle resumption. Heterotrimeric guanine nucleotide-binding proteins (G proteins) may be involved in mouse egg activation since inhibition of G protein [beta][gamma] subunits partially inhibits sperm-induced cell cycle resumption. In addition, specific events of egg activation can be initiated in the absence of sperm by acetylcholine stimulation of mouse eggs overexpressing the human m1 muscarinic receptor, a G protein-coupled receptor. In somatic cells, G protein in the G.sub.q family couple ligand stimulation of the m1 muscarinic receptor to activation of phospholipase C, resulting in the production of inositol 1,4,5-trisphosphate (IP.sub.3) and IP.sub.3-mediated release of intracellular calcium. Since IP.sub.3-mediated calcium release is involved in egg activation at fertilization, we have examined the role of G.sub.q family G proteins in both sperm-independent (muscarinic receptor-mediated) and sperm-induced egg activation using a function-blocking antibody raised against the common C-terminal region of G.sub.q and G.sub.11 proteins. We show that this antibody effectively inhibits G.sub.q family G proteins in mouse eggs by demonstrating that the antibody inhibits egg activation in response to stimulation of the m1 muscarinic receptor. This same antibody, however, does not inhibit sperm-induced egg activation events. These results indicate that although activation of G.sub.q family G proteins can result in egg activation in the mouse, it is unlikely that these proteins are used by the sperm to initiate egg activation at fertilization. Author Affiliation: (a) Center for Research on Reproduction and Women's Health and Department of Ob/Gyn, University of Pennsylvania Health System, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (a ) Department of Physiology, University of Connecticut Health Center, Farmington, Connecticut 06032 (a ) Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 Article History: Received 15 January 1998; Accepted 5 March 1998

Scs2p is an integral membrane protein in the endoplasmic reticulum of the yeast, Saccharomyces cerevisiae. The protein is necessary in the metabolism of inositol as it activates the expression of the INO1. This protein is coded by the gene SCS2 and weighs 35 kilodalton. Although Scs2p is a component of the endoplasmic reticulum, there is no evidence that it functions in protein transport and secretion.

The intracellular calcium (Ca) release channel inositol 1,4,5-trisphosphate (InsPsub3) receptor, is found in most cell types. An increase in cytoplasmic Ca is observed on activation of the InsPsub3-gated channel. The Ca dependence of InsPsub3-gated channel activity was measured as a function of InsPsub3 concentration. InsPsub3 binding and channel activity was also compared. Interactions between Ca and InsPsub3 with the InsPsub3-gated channel were found to be complex.

The effects of long-term, hypoxemia-induced reductions in cerebrovascular contractility on the density and affinity of inositol 1,4,5-triphosphate [Ins(1,4,5)P3] were analyzed in the cerebral arteries of sheep. Vascular Ins(1,4,5)P3-R density increased as a function of developmental age in the common carotid artery and aorta of sheep. High-altitude, long-term hypoxia was also associated with a significant decrease in Ins(1,4,5)P3-R density in the common carotid artery and main bran cerebral blood vessels of fetal and adult sheep.

Valproic acid and lithium are effective anti-bipolar drugs. We recently showed that lithium stimulated the release of glutamate in monkey and mouse cerebral cortex slices, which, through activation of the N-methyl-D-aspartate receptor, increased accumulation of inositol 1,4,5-trisphosphate [Ins(1,4,5)[P.sub.3]]. We show here that valproate behaves similarly to lithium in that at therapeutic concentrations it stimulates glutamate release and Ins(1,4,5)[P.sub.3] accumulation in mouse cerebral cortex slices. The fact that these two effects are a common denominator for two structurally unrelated anti-bipolar drugs suggests that these effects are important in their antibipolar action. The effects of maximal concentrations of lithium and valproate on glutamate release are additive, suggesting different mechanisms for release, which are discussed. The additivity of the two drugs on glutamate release is consistent with the clinical benefit of combining the two drugs in the treatment of subsets of bipolar patients, e.g., in rapid cycling manic-depression. Unlike lithium, valproate does not increase accumulation of inositol monophosphates, inositol bisphosphates, or inositoi 1,3,4-trisphosphate. This is additional evidence against the 'inositol depletion' hypothesis, which states that, by trapping inositol in the form of inositol monophosphates and certain inositol polyphosphates, lithium exerts its antimanic action by inhibiting resynthesis of phosphoinositides with resultant blunting of Ins(1,4,5)[P.sub.3] signaling.

The effects of 2-omicron, C-methylene-myo-inositol (MMI) on myo-inositol transport were analyzed in Madin-Darby canine kidney (MDCK) cells to determine the role of myo-inositol under hypertonic conditions. Analysis of myo-inositol transport in MDCK cells after the administration of MMI indicated the presence of inhibited myo-inositol transport due to the inactivation of the Na+-dependent component. Furthermore, MMI coupled with betaine increased the colony-forming efficiency of MDCK cells.

The role of alpha1-adrenergic receptor (alpha1-AR) density and norepinephrine (NE)-induced inositol 1,4,5-triphosphate (IP3) in NE-mediated contraction changes were analyzed in sheep cerebral arteries. Development differences in the contractility of cerebral artery to NE is mediated by changes in aplha1-AR density which affects vascular agonist sensitivity. Furthermore, the common carotid arteries of fetus and newborn infants exhibited little IP3 response to NE compared to the anterior and middle cerebral arteries.

Perfused rat hearts were analyzed to determine the effects of an 8-week dietary supplementation of n-3 long chain polyunsaturated fatty acids (n-3 PUFA) on cardiac D-myo-inositol 1,4,5-trisphosphate (Ins(1,4,5)P3). Dietary supplementation with n-3 PUFA inhibited the release of reperfusion-induced Ins(1,4,5)P3 in rat ischemic models. Reperfusion arrythmia was also inhibited by dietary Ins(1,4,5)P3 in rat regional ischemia models.

The stimulation of acinar cells by inositol 1,4,5-triphosphate produced asynchronous increases in Ca2+ levels that are characterized as a coordinated oscillatory cycle that passes between the cells. The focal application of additional antagonists to the acinar cells did not alter the generation and propagation of Ca2+ signals indicating an activation-mechanism that is not dependent on the generation of secondary messengers. Enhanced acinar secretions after stimulation also indicate the possible role of gap-junctional communication.

Receptors for 1,4,5-trisphosphate signal the need for changes in the calcium ion concentration within the cell. The two receptor types for inositol interact in regulating calcium ion influx. Changing the ratio of both types of receptors seems to change the signal induced by inositol. Dominance of type 1 receptors raises the speed of propagation of ion release in the membrane. Meanwhile, more type 3 receptors increase the amount and length of calcium influx.

Neural and endothelial cells are able to osmotically regulate their intake of myoinositol in a manner similar to renal cells. These cells raised their production of myoinositol transporter which then directly increased the amount of transported myoinositol when the cells were exposed to hypertonic conditions. Hypotonic conditions led to lower myoinositol transporter production and, consequently, lower myoinositol levels in the cells.

Betaine and inositol decrease the glycerophosphocholine (GPC) content of cultured Madin-Darby canine kidney cells by increasing GPC breakdown by GPC:choline phosphodiesterase. The effect of betaine and inositol is higher in isosmotic or high-NaCl medium than that in high-urea medium. This is due to inhibition of betaine and inositol accumulation by urea. Maintenance of total osmolyte level involves the reciprocal control of GPC, with respect to other related osmolytes, in response to high tonicity.

The modulation of the expression of the genes that prepare phospholipid in the presence of inositol in yeasts probably involves the release of the cognate activator gene, INO2, and the inhibition of the negative-acting gene, OPI1. The biosynthesis of phospholipids is affected by the regulation of transcription of INO2 and OPI1. However, transcription of the INO2 gene which is under the control of the GALI promoter gene, is unaffected by inositol but is influenced by galactose.

Enzyme assays suggest the involvement of 2-keto-myo-inositol and D-2,3-diketo-4-deoxy epi-inositol in the myo-inositol catabolism of Rhizobium leguminosarum bv. viciae. Growth of R. leguminosarum on myo-inositol increases the enzyme's myo-inositol dehydrogenase and 2-keto-myo-inositol dehydratase. Examination of the growth in glucose as carbon source and resuspension studies in myo-inositol show that O2 consumption is an inducible route. Mutation studies reveal the necessity of intra-cellular dicarboxylation for the repression of these enzymes. Isolation and studies of three transposon mutants that do not induce both enzymes suggest that myo-inositol is not vital as an energy source in bacteriods.

Development of rat mesangial cell cultures with high galactose or glucose levels to characterize factors that help upregulate myo-inositol (MI) transport reveals that high level glucose or galactose initiates protein synthesis with intact polymerized actin to help upregulate MI transport in the cells. Tolrestat, an aldose reductase inhibitor, suppresses the upregulation of MI transport in the isolated glomeruli and cultured mesangial cells, suggesting that activation of the polyol pathway is essential for the upregulation process.

Heparin and NaCl inhibit the binding of inositol 1,4,5-trisphosphate receptor to microsomes of the eggs of sea urchins. The inhibition was detected using an affinity-purified antibody in the C-terminal of the inositol 1,4,5-triphosphate which is the 373 kilo-dalton protein. Inositol 1,4,5-triphosphate receptors are present homogeneously throughout the cytoplasm of the egg.

The role of inositol lipids in mediating some of the effects of extracellular matrix on cellular form and functions was investigated. The study protocol involved the measurement of the effects of adhesion to fibronectin (FN) on the lipid phosphatidylinositol bisphosphate (PIP2) and its hydrolysis products diacylglycerol and inositol triphosphate. PIP2 and its hydrolysis products have functions in cytoskeletal regulation and as second messengers, respectively. The reults showed that adhesion to FN stimulates inositol lipid synthesis and increases PDGF-induced inositol lipid breakdown.

CK1.4 Chinese hamster ovary cells produced by transfection with the gene for cattle heart Na+-Ca2+ exhanger were studied. The study showed that exchanging external Na+ with K+ resulted in a significant increase in Ca2+ uptake by Na+-loaded cells. Nontransfected cells showed a decrease in the 45Ca2+ uptake when the external Na+ was replaced with K+. CK1.4 cells provide excellent study models because of the stable expression of sufficient exchanger to biochemical and innunological analysis.