scholarly journals Nicotinamide inhibits cyclic ADP-ribose-mediated calcium signalling in sea urchin eggs

1996 ◽  
Vol 319 (2) ◽  
pp. 613-617 ◽  
Author(s):  
Jaswinder K SETHI ◽  
Ruth M EMPSON ◽  
Antony GALIONE
Keyword(s):  
Sea Urchin ◽  
Calcium Release ◽  
Calcium Signalling ◽  
Hydrolytic Activity ◽  
Calcium Release Channels ◽  
Adp Ribosyl Cyclase ◽  
Sea Urchin Egg ◽  
Cyclic Adp Ribose ◽  
Single Polypeptide ◽  
Hydrolysis Of

Cyclic ADP ribose (cADPR) is a potent Ca2+-releasing agent, and putative second messenger, the endogenous levels of which are tightly regulated by synthetic (ADP-ribosyl cyclases) and degradative (cADPR hydrolase) enzymes. These enzymes have been characterized in a number of mammalian and invertebrate tissues and their activities are often found on a single polypeptide. β-NAD+, cGMP and nitric oxide (NO) have been reported to mobilize Ca2+ in the sea urchin egg via the cADPR-mediated pathway. We now report that in sea urchin egg homogenates, nicotinamide inhibits the Ca2+-mobilizing action of β-NAD+, cGMP and NO, but has no effect on cADPR-induced Ca2+ release. Moreover, nicotinamide inhibits cGMP-induced regenerative Ca2+ waves in the intact sea urchin egg. By successfully separating the cADPR-metabolizing machinery from that which releases Ca2+, we have shown that nicotinamide inhibits cADPR-mediated Ca2+ signalling at the level of cADPR generation. Importantly, nicotinamide had no effect upon the hydrolysis of cADPR, and its selective action on cyclase activity was supported by its inhibition of purified Aplysia ADP-ribosyl cyclase, which does not exhibit detectable hydrolytic activity. The action of nicotinamide in blocking Ca2+ release by β-NAD+, cGMP and NO strongly suggests that these agents act as modulators of cADPR synthesis rather than to sensitize calcium release channels to cADPR.

Psammechinus miliaris egg homogenate as a model to investigate Ca2+-release mechanisms

1999 ◽  
Vol 79 (2) ◽  
pp. 323-326 ◽  
Author(s):  
Armando A. Genazzani ◽  
Heather L. Wilson ◽  
Antony Galione
Keyword(s):  
Sea Urchin ◽  
Calcium Release ◽  
Lytechinus Pictus ◽  
Release Mechanisms ◽  
Psammechinus Miliaris ◽  
Sea Urchin Egg ◽  
Cyclic Adp Ribose ◽  
The Usa ◽  
Release Model ◽  
Convenient Model

The sea urchin egg has proved a reliable and robust system for measuring intracellular calcium release in response to three independent mechanisms: inositol 1,4,5 trisphosphate, cyclic ADP-ribose and the recently identified molecule, nicotinic acid adenine dinucleotide phosphate (NAADP). These calcium release mechanisms have been studied in homogenates of Lytechinus pictus and Spongylocentrotus purpuratus, which are two sea urchin species located off the west coast of the USA. A new calcium-release model from a species of sea urchin present off the coasts of Britain, Psammechinus miliaris is characterized and described. Although the Ca2+-release characteristics in this species do not differ from those of the other two sea urchin species, it may provide a more economical and convenient model for European scientists.

scholarly journals Identification of bovine liver mitochondrial NAD+ glycohydrolase as ADP-ribosyl cyclase

1997 ◽  
Vol 326 (2) ◽  
pp. 401-405 ◽  
Author(s):  
Mathias ZIEGLER ◽  
Dierk JORCKE ◽  
Manfred SCHWEIGER
Keyword(s):  
Calcium Release ◽  
Bovine Liver ◽  
Enzymic Activity ◽  
Cyclase Activity ◽  
Partial Recovery ◽  
Nad Glycohydrolase ◽  
Adp Ribosyl Cyclase ◽  
Cyclic Adp Ribose ◽  
Hydrolysis Of ◽  
Synthesis And Degradation

The present investigation identifies bovine liver mitochondrial NADase (NAD+ glycohydrolase) as a member of the class of bifunctional ADP-ribosyl cyclases/cyclic ADP-ribose hydrolases, known to be potential second messenger enzymes. These enzymes catalyse the synthesis and degradation of cyclic ADP-ribose, a potent intracellular calcium-mobilizing agent. The mitochondrial enzyme utilized the NAD+ analogues nicotinamide guanine dinucleotide (NGD+) and nicotinamide hypoxanthine dinucleotide (NHD+) to form fluorescent cyclic purine nucleoside diphosphoriboses. ADP-ribosyl cyclase activity was also demonstrated using 32P-labelled NAD+ as substrate. The identity of NADase and ADP-ribosyl cyclase was supported by their co-migration in SDS/polyacrylamide gels. Cyclase activity was visualized directly within the gel by detecting the formation of fluorescent cyclic IDP-ribose from NHD+. The enzyme catalysed the hydrolysis of cyclic ADP-ribose to ADP-ribose. Moreover, in the presence of nicotinamide and cyclic ADP-ribose the enzyme synthesized NAD+. Both the ADP-ribosyl cyclase and NADase activities of the enzyme were strongly inhibited by reducing agents. Treatment of the NADase with dithiothreitol caused the apparent inactivation of the enzyme. Subsequent removal of the reducing agent and addition of oxidized glutathione led to a partial recovery of enzymic activity. The results support a model for pro-oxidant-induced calcium release from mitochondria involving cyclic ADP-ribose as a specific messenger, rather than the non-enzymic modification of proteins by ADP-ribose.

scholarly journals ADP-ribosyl cyclase: an enzyme that cyclizes NAD+ into a calcium-mobilizing metabolite.

1991 ◽  
Vol 2 (3) ◽  
pp. 203-209 ◽  
Author(s):  
H C Lee ◽  
R Aarhus
Keyword(s):  
Sea Urchin ◽  
Exchange Chromatography ◽  
Reaction Products ◽  
Sea Urchin Eggs ◽  
Tissue Extracts ◽  
Adp Ribosyl Cyclase ◽  
Sea Urchin Egg ◽  
Sds Page ◽  
Cyclic Adp Ribose ◽  
Charge Analysis

Cyclic ADP-ribose (cADPR) is a metabolite of NAD+ that is as active as inositol trisphosphate (IP3) in mobilizing intracellular Ca2+ in sea urchin eggs. The activity of the enzyme responsible for synthesizing cADPR is found not only in sea urchin eggs but also in various mammalian tissue extracts, suggesting that cADPR may be a general messenger for Ca2+ mobilization in cells. An aqueous soluble enzyme, thought to be an NADase, has been purified recently from the ovotestis of Aplysia californica (Hellmich and Strumwasser, 1991). This paper shows that the Aplysia enzyme catalyzes the conversion of NAD+ to cADPR and nicotinamide. The Aplysia enzyme was purified by fractionating the soluble extract of Aplysia ovotestis on a Spectra/gel CM column. The purified enzyme appeared as a single band of approximately 29,000 Da on SDS-PAGE but could be further separated into multiple peaks by high-resolution, cation-exchange chromatography. All of the protein peaks had enzymatic activity, indicating that the enzyme had multiple forms differing by charge. Analysis of the reaction products of the enzyme by anion-exchange high-pressure liquid chromatography (HPLC) indicated no ADP-ribose was produced; instead, each mole of NAD+ was converted to equimolar of cADPR and nicotinamide. The identification of the product as cADPR was further substantiated by proton NMR and also by its Ca(2+)-mobilizing activity. Addition of the product to sea urchin egg homogenates induced Ca2+ release and desensitized the homogenate to authentic cADPR but not to IP3. Microinjection of the product into sea urchin eggs elicited Ca2+ transients as well as the cortical exocytosis reaction. Therefore, by the criteria of HPLC, NMR, and calcium-mobilizing activity, the product was identical to cADPR. To distinguish the Aplysia enzyme from the conventional NADases that produce ADP-ribose, we propose to name it ADP-ribosyl cyclase.

Synergistic Calcium Release in the Sea Urchin Egg by Ryanodine and Cyclic ADP Ribose

1994 ◽  
Vol 163 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Wayne R. Buck ◽  
Erin E. Hoffmann ◽  
Terese L. Rakow ◽  
Sheldon S. Shen
Keyword(s):  
Sea Urchin ◽  
Calcium Release ◽  
Sea Urchin Egg ◽  
Cyclic Adp Ribose

cADP-ribose releases Ca2+ from cardiac sarcoplasmic reticulum independently of ryanodine receptor

1997 ◽  
Vol 273 (3) ◽  
pp. H1082-H1089 ◽  
Author(s):  
P. Lahouratate ◽  
J. Guibert ◽  
J. F. Faivre
Keyword(s):  
Endoplasmic Reticulum ◽  
Sarcoplasmic Reticulum ◽  
Ryanodine Receptor ◽  
Sea Urchin ◽  
Calcium Release ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Cardiac Sarcoplasmic Reticulum ◽  
Consistent Effect ◽  
Cyclic Adp Ribose

Cyclic ADP-ribose (cADPR), an endogenous metabolite of beta-NAD+, activates Ca2+ release from endoplasmic reticulum in sea urchin eggs via the ryanodine receptor (RyR) pathway. A similar role has been proposed in cardiac sarcoplasmic reticulum (SR), although this remains controversial. We therefore investigated the ability of cADPR to induce Ca2+ release from canine cardiac SR microsomes using fluo 3 to monitor extravesicular Ca2+ concentration. We found that cADPR induced Ca2+ release in a concentration-dependent manner, whereas neither its precursor, NAD+, nor its metabolite, ADP-ribose, elicited a consistent effect. In addition, an additive effect on calcium release between cADPR and 9-Me-7-Br-eudistomin-D (MBED), an activator of RyR, was found as well as no cross-desensitization between cADPR and MBED. Specific blockers of the RyR did not abolish the cADPR-induced Ca2+ release. These results provide evidence for cADPR-induced Ca2+ release from dog cardiac SR via a novel mechanism which is independent of RyR activation.

Functional visualization of the separate but interacting calcium stores sensitive to NAADP and cyclic ADP-ribose

2000 ◽  
Vol 113 (24) ◽  
pp. 4413-4420 ◽  
Author(s):  
H.C. Lee ◽  
R. Aarhus
Keyword(s):  
Endoplasmic Reticulum ◽  
Sea Urchin ◽  
The Other ◽  
Calcium Stores ◽  
Cellular Functions ◽  
Large Size ◽  
Opposite Pole ◽  
Visual Evidence ◽  
Sea Urchin Egg ◽  
Cyclic Adp Ribose

Cells possess multiple Ca(2+) stores and their selective mobilization provides the spatial-temporal Ca(2+) signals crucial in regulating diverse cellular functions. Except for the inositol trisphosphate (IP(3))-sensitive Ca(2+) stores, the identities and the mechanisms of how these internal stores are mobilized are largely unknown. In this study, we describe two Ca(2+) stores, one of which is regulated by cyclic ADP-ribose (cADPR) and the other by nicotinic acid adenine dinucleotide phosphate (NAADP). We took advantage of the large size of the sea urchin egg and stratified its organelles by centrifugation. Using photolysis to produce either uniform or localized increases of cADPR and NAADP from their respective caged analogs, the two separate stores could be visually identified by Ca(2+) imaging and shown to be segregated to the opposite poles of the eggs. The cADPR-pole also contained the IP(3)-sensitive Ca(2+) stores, the egg nucleus and the endoplasmic reticulum (ER); the latter was visualized using Bodipy-thapsigargin. On the other hand, the mitochondria, as visualized by rhodamine 123, were segregated to the opposite pole together with the NAADP-sensitive calcium stores. Fertilization of the stratified eggs elicited a Ca(2+) wave starting at the cADPR-pole and propagating toward the NAADP-pole. These results provide the first direct and visual evidence that the NAADP-sensitive Ca(2+) stores are novel and distinct from the ER. During fertilization, communicating signals appear to be transmitted from the ER to NAADP-sensitive Ca(2+) stores, leading to their activation.

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