Adenophostin A Can Stimulate Ca2+ Influx without Depleting the Inositol 1,4,5-Trisphosphate-sensitive Ca2+ Stores in the Xenopus Oocyte

Delisle, Sylvain; Marksberry, Erik W.; Bonnett, Carl J.; Jenkins, David J.; Potter, Barry V. L.; Takahashi, Masaaki; Tanzawa, Kazuhiko

doi:10.1074/jbc.272.15.9956

Cited by 32 publications

(33 citation statements)

References 35 publications

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“…Utilizing Ca 2ϩ -dependent chloride currents as an indirect assay of [Ca 2ϩ ] i changes, both DeLisle et al (8) and Hartzell et al (9) observed activation of Ca 2ϩ entry with low concentrations of adenophostin A (ϳ100 pM (8) and ϳ50 pM (9)). DeLisle et al saw no evidence of Ca 2ϩ release with these concentrations, whereas Hartzell et al observed small chloride currents attributable to intracellular release.…”

Section: Fig 2 Effect Of (245)ip 3 (1 M) Microinjected Into An Oomentioning

confidence: 99%

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confidence: 99%

“…Interestingly, two studies performed in Xenopus oocytes (8,9) suggested a site of action for adenophostin A in addition to that on intracellular Ca 2ϩ stores. In both studies, low concentrations of adenophostin A (Ͻ10 nM) appeared to preferentially activate the Ca 2ϩ entry process, although Hartzell et al (9), unlike DeLisle et al (8), could not find a clear dissociation between Ca 2ϩ release and Ca 2ϩ entry. In a subsequent report, Machaca and Hartzell (10) found that the diffusion of adenophostin A throughout the oocyte was considerably slower than that of IP 3 and concluded that this might explain the apparently diminished Ca 2ϩ release signal.…”

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Adenophostin A Induces Spatially Restricted Calcium Signaling in Xenopus laevis Oocytes

Bird

Takahashi²,

Tanzawa³

et al. 1999

Journal of Biological Chemistry

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Xenopus laevis oocytes have proven a useful model system for studying the inositol 1,4,5-trisphosphate ((1,4,5)IP 3 ) 1 -mediated calcium signaling system, providing insights into mechanisms of calcium oscillations (1) and capacitative Ca 2ϩ entry (2, 3). In many cell types, including Xenopus oocytes, activation of surface membrane receptors results in a biphasic Ca 2ϩ response composed of an initial mobilization of internally stored Ca 2ϩ , followed by entry of extracellular Ca 2ϩ (4). Much is known about the role of (1,4,5)IP 3 in mobilizing intracellular Ca 2ϩ , and a working model for the Ca 2ϩ entry process is described by the capacitative model (5, 6) according to which the depletion of intracellular (1,4,5)IP 3 -sensitive Ca 2ϩ stores signals the activation of plasma membrane calcium channels.Recently, a metabolite of Penicillium brevicompactum, adenophostin A, has been isolated and demonstrated to be an agonist for the (1,4,5)IP 3 receptor and to have a potency ϳ100-fold greater than that of (1,4,5)IP 3 (7). Interestingly, two studies performed in Xenopus oocytes (8, 9) suggested a site of action for adenophostin A in addition to that on intracellular Ca 2ϩ stores. In both studies, low concentrations of adenophostin A (Ͻ10 nM) appeared to preferentially activate the Ca (10) found that the diffusion of adenophostin A throughout the oocyte was considerably slower than that of IP 3 and concluded that this might explain the apparently diminished Ca 2ϩ release signal.In this study, we have used confocal microscopy to monitor directly spatial as well as temporal aspects of the effects of adenophostin A on intracellular Ca 2ϩ in Xenopus oocytes using the calcium-sensitive dye Calcium Green. Our results confirm that diffusion of adenophostin A throughout the oocytes is slower than that of IP 3 and additionally indicate that low concentrations of adenophostin A cause a confined mobilization of intracellular Ca 2ϩ that is capable of supporting spatially restricted Ca 2ϩ oscillations and spatially restricted Ca 2ϩ entry. This unique action of adenophostin A provides new insights into the role of IP 3 receptor binding in [Ca 2ϩ ] i oscillations and also into the spatial relationships between intracellular Ca 2ϩ release and activation of capacitative calcium entry. MATERIALS AND METHODS Isolation of Xenopus OocytesAdult albino female X. laevis (Xenopus One, Ann Arbor, MI) were anesthetized by hypothermia and decapitated. The ovaries were then removed and stored in ND96 buffer (96 mM NaCl, 2 mM KCl, 1 mM MgCl 2 , 1 mM CaCl 2 , and 5 mM HEPES (pH 7.6)). Stage V and VI oocytes were manually dissected free from the ovaries and follicles and maintained in ND96 buffer at 18°C until used.

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Section: Fig 2 Effect Of (245)ip 3 (1 M) Microinjected Into An Oomentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Adenophostin A Induces Spatially Restricted Calcium Signaling in Xenopus laevis Oocytes

Bird

Takahashi²,

Tanzawa³

et al. 1999

Journal of Biological Chemistry

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“…To better understand how cytoplasmic Ca 2+ influences these two types of synapses in a coordinated manner, we elevated intracellular Ca 2+ levels by infusing adenophostin-A (100 nM in the recording pipette, Fig. 1) into pyramidal neurons to trigger Ca 2+ release from IP 3 -sensitive intracellular stores (Takahashi et al, 1994;Delisle et al, 1997;Correa et al, 2001).…”

Section: Intracellular Camentioning

confidence: 99%

“…We have therefore investigated whether a counterbalance exists among synaptic, somatic and axonal activities, and whether cytoplasmic Ca 2+ coordinates this counterbalance. For this, we elevated the levels of cytoplasmic Ca 2+ by using adenophostin-A, a potent and specific agonist of inositol (1,4,5)-trisphosphate receptors (IP 3 Rs), to evoke Ca 2+ release from intracellular stores (Takahashi et al, 1994;Delisle et al, 1997;Correa et al, 2001) and applied modulators of Ca 2+ -signaling pathways via whole-cell perfusion into pyramidal neurons in cortical slices. The elucidation of how neuronal homeostasis is maintained will provide insight for addressing homeostatic mechanisms in other cell types.…”

Section: Introductionmentioning

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Homeostasis established by coordination of subcellular compartment plasticity improves spike encoding

Chen

Wang

2008

Journal of Cell Science

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Homeostasis in cells maintains their survival and functions. The plasticity at neurons and synapses may destabilize their signal encoding. The rapid recovery of cellular homeostasis is needed to secure the precise and reliable encoding of neural signals necessary for well-organized behaviors. We report a homeostatic process that is rapidly established through Ca2+-induced coordination of functional plasticity among subcellular compartments. An elevation of cytoplasmic Ca2+ levels raises the threshold potentials and refractory periods of somatic spikes, and strengthens the signal transmission at glutamatergic and GABAergic synapses, in which synaptic potentiation shortens refractory periods and lowers threshold potentials. Ca2+ signals also induce an inverse change of membrane excitability at the soma versus the axon. The integrative effect of Ca2+-induced plasticity among the subcellular compartments is homeostatic in nature, because it stabilizes neuronal activities and improves spike timing precision. Our study of neuronal homeostasis that is fulfilled by rapidly coordinating subcellular compartments to improve neuronal encoding sheds light on exploring homeostatic mechanisms in other cell types.

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Synthesis of Photoaffinity Derivatives of Adenophostin A

et al. 2000

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Photoaffinity derivatives 7 and 8 of adenophostin A, modified at the 5′‐ and 1′‐positions, were prepared by a chemoselective reaction of the aminophostins 15 and 30 with N‐succinimidyl p‐benzoyl‐2,3‐dihydrocinnamate (p‐benzoyldihydrocinnamoyl‐N‐hydroxysuccinimide; BZDC‐NHS, 21). The latter compound was prepared by Heck coupling of 4‐iodobenzophenone (16) with methyl acrylate.

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Adenophostin A Can Stimulate Ca2+ Influx without Depleting the Inositol 1,4,5-Trisphosphate-sensitive Ca2+ Stores in the Xenopus Oocyte

Cited by 32 publications

References 35 publications

Adenophostin A Induces Spatially Restricted Calcium Signaling in Xenopus laevis Oocytes

Adenophostin A Induces Spatially Restricted Calcium Signaling in Xenopus laevis Oocytes

Homeostasis established by coordination of subcellular compartment plasticity improves spike encoding

Synthesis of Photoaffinity Derivatives of Adenophostin A

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