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Shipton ML, Riley AM, Rossi AM, Brearley CA, Taylor CW, Potter BVL. Both d- and l-Glucose Polyphosphates Mimic d- myo-Inositol 1,4,5-Trisphosphate: New Synthetic Agonists and Partial Agonists at the Ins(1,4,5)P 3 Receptor. J Med Chem 2020; 63:5442-5457. [PMID: 32286062 PMCID: PMC7260056 DOI: 10.1021/acs.jmedchem.0c00215] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
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Chiral sugar derivatives are potential
cyclitol surrogates of the
Ca2+-mobilizing intracellular messenger d-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3]. Six novel polyphosphorylated analogues derived from both d- and l-glucose were synthesized. Binding to Ins(1,4,5)P3 receptors [Ins(1,4,5)P3R] and the ability to release
Ca2+ from intracellular stores via type 1 Ins(1,4,5)P3Rs were investigated. β-d-Glucopyranosyl 1,3,4-tris-phosphate,
with similar phosphate regiochemistry and stereochemistry to Ins(1,4,5)P3, and α-d-glucopyranosyl 1,3,4-tris-phosphate
are full agonists, being equipotent and 23-fold less potent than Ins(1,4,5)P3, respectively, in Ca2+-release assays and similar
to Ins(1,4,5)P3 and 15-fold weaker in binding assays. They
can be viewed as truncated analogues of adenophostin A and refine
understanding of structure-activity relationships for this Ins(1,4,5)P3R agonist. l-Glucose-derived ligands, methyl α-l-glucopyranoside 2,3,6-trisphosphate and methyl α-l-glucopyranoside 2,4,6-trisphosphate, are also active, while
their corresponding d-enantiomers, methyl α-d-glucopyranoside 2,3,6-trisphosphate and methyl α-d-glucopyranoside 2,4,6-trisphosphate, are inactive. Interestingly,
both l-glucose-derived ligands are partial agonists: they
are among the least efficacious agonists of Ins(1,4,5)P3R yet identified, providing new leads for antagonist development.
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Affiliation(s)
- Megan L Shipton
- Drug Discovery & Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, U. K
| | - Andrew M Riley
- Drug Discovery & Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, U. K
| | - Ana M Rossi
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U. K
| | - Charles A Brearley
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U. K
| | - Colin W Taylor
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, U. K
| | - Barry V L Potter
- Drug Discovery & Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, U. K
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2
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Mills SJ, Rossi AM, Konieczny V, Bakowski D, Taylor CW, Potter BVL. d- chiro-Inositol Ribophostin: A Highly Potent Agonist of d- myo-Inositol 1,4,5-Trisphosphate Receptors: Synthesis and Biological Activities. J Med Chem 2020; 63:3238-3251. [PMID: 32052631 PMCID: PMC7104261 DOI: 10.1021/acs.jmedchem.9b01986] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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Analogues
of the Ca2+-releasing intracellular messenger d-myo-inositol 1,4,5-trisphosphate [1, Ins(1,4,5)P3] are important synthetic targets. Replacement
of the α-glucopyranosyl motif in the natural product mimic adenophostin 2 by d-chiro-inositol in d-chiro-inositol adenophostin 4 increased
the potency. Similar modification of the non-nucleotide Ins(1,4,5)P3 mimic ribophostin 6 may increase the activity. d-chiro-Inositol ribophostin 10 was synthesized by coupling as building blocks suitably protected
ribose 12 with l-(+)-3-O-trifluoromethylsulfonyl-6-O-p-methoxybenzyl-1,2:4,5-di-O-isopropylidene-myo-inositol 11. Separable
diastereoisomeric 3-O-camphanate esters of (±)-6-O-p-methoxy-benzyl-1,2:4,5-di-O-isopropylidene-myo-inositol allowed the preparation
of 11. Selective trans-isopropylidene
deprotection in coupled 13, then monobenzylation gave
separable regioisomers 15 and 16. p-Methoxybenzyl group deprotection of 16, phosphitylation/oxidation,
then deprotection afforded 10, which was a full agonist
in Ca2+-release assays; its potency and binding affinity
for Ins(1,4,5)P3R were similar to those of adenophostin.
Both 4 and 10 elicited a store-operated
Ca2+ current ICRAC in patch-clamped cells, unlike
Ins(1,4,5)P3 consistent with resistance to metabolism. d-chiro-Inositol ribophostin is the most potent
small-molecule Ins(1,4,5)P3 receptor agonist without a
nucleobase yet synthesized.
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Affiliation(s)
- Stephen J Mills
- Drug Discovery & Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Ana M Rossi
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Vera Konieczny
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Daniel Bakowski
- Centre of Integrative Physiology, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, United Kingdom
| | - Colin W Taylor
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Barry V L Potter
- Drug Discovery & Medicinal Chemistry, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
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3
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Dohle W, Su X, Mills SJ, Rossi A, Taylor CW, Potter BVL. A synthetic cyclitol-nucleoside conjugate polyphosphate is a highly potent second messenger mimic. Chem Sci 2019; 10:5382-5390. [PMID: 31171961 PMCID: PMC6540904 DOI: 10.1039/c9sc00445a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/23/2019] [Indexed: 12/11/2022] Open
Abstract
Reactions that form sec-sec ethers are well known, but few lead to compounds with dense functionality around the O-linkage. Replacement of the α-glucopyranosyl unit of adenophostin A, a potent d-myo-inositol 1,4,5-trisphosphate (IP3R) agonist, with a d-chiro-inositol surrogate acting substantially as a pseudosugar, leads to "d-chiro-inositol adenophostin". At its core, this cyclitol-nucleoside trisphosphate comprises a nucleoside sugar linked via an axial d-chiro-inositol 1-hydroxyl-adenosine 3'-ribose ether linkage. A divergent synthesis of d-chiro-inositol adenophostin has been achieved. Key features of the synthetic strategy to produce a triol for phosphorylation include a new selective mono-tosylation of racemic 1,2:4,5-di-O-isopropylidene-myo-inositol using tosyl imidazole; subsequent conversion of the product into separable camphanate ester derivatives, one leading to a chiral myo-inositol triflate used as a synthetic building block and the other to l-5-O-methyl-myo-inositol [l-(+)-bornesitol] to assign the absolute configuration; the nucleophilic coupling of an alkoxide of a ribose pent-4-ene orthoester unit with a structurally rigid chiral myo-inositol triflate derivative, representing the first sec-sec ether formation between a cyclitol and ribose. Reaction of the coupled product with a silylated nucleobase completes the assembly of the core structure. Further protecting group manipulation, mixed O- and N-phosphorylation, and subsequent removal of all protecting groups in a single step achieves the final product, avoiding a separate N6 protection/deprotection strategy. d-chiro-Inositol adenophostin evoked Ca2+ release through IP3Rs at lower concentrations than adenophostin A, hitherto the most potent known agonist of IP3Rs.
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Affiliation(s)
- Wolfgang Dohle
- Medicinal Chemistry & Drug Discovery
, Department of Pharmacology
, University of Oxford
,
Mansfield Road
, Oxford
, OX1 3QT
, UK
.
; Tel: +44-1865-271945
| | - Xiangdong Su
- Medicinal Chemistry & Drug Discovery
, Department of Pharmacology
, University of Oxford
,
Mansfield Road
, Oxford
, OX1 3QT
, UK
.
; Tel: +44-1865-271945
| | - Stephen J. Mills
- Medicinal Chemistry & Drug Discovery
, Department of Pharmacology
, University of Oxford
,
Mansfield Road
, Oxford
, OX1 3QT
, UK
.
; Tel: +44-1865-271945
| | - Ana M. Rossi
- Department of Pharmacology
, University of Cambridge
,
Tennis Court Road
, Cambridge
, CB2 1PD
, UK
| | - Colin W. Taylor
- Department of Pharmacology
, University of Cambridge
,
Tennis Court Road
, Cambridge
, CB2 1PD
, UK
| | - Barry V. L. Potter
- Medicinal Chemistry & Drug Discovery
, Department of Pharmacology
, University of Oxford
,
Mansfield Road
, Oxford
, OX1 3QT
, UK
.
; Tel: +44-1865-271945
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4
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Konieczny V, Stefanakis JG, Sitsanidis ED, Ioannidou NAT, Papadopoulos NV, Fylaktakidou KC, Taylor CW, Koumbis AE. Synthesis of inositol phosphate-based competitive antagonists of inositol 1,4,5-trisphosphate receptors. Org Biomol Chem 2016; 14:2504-14. [PMID: 26818818 DOI: 10.1039/c5ob02623g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP3Rs) are intracellular Ca(2+) channels that are widely expressed in animal cells, where they mediate the release of Ca(2+) from intracellular stores evoked by extracellular stimuli. A diverse array of synthetic agonists of IP3Rs has defined structure-activity relationships, but existing antagonists have severe limitations. We combined analyses of Ca(2+) release with equilibrium competition binding to IP3R to show that (1,3,4,6)IP4 is a full agonist of IP3R1 with lower affinity than (1,4,5)IP3. Systematic manipulation of this meso-compound via a versatile synthetic scheme provided a family of dimeric analogs of 2-O-butyryl-(1,3,4,6)IP4 and (1,3,4,5,6)IP5 that compete with (1,4,5)IP3 for binding to IP3R without evoking Ca(2+) release. These novel analogs are the first inositol phosphate-based competitive antagonists of IP3Rs with affinities comparable to that of the only commonly used competitive antagonist, heparin, the utility of which is limited by off-target effects.
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Affiliation(s)
- Vera Konieczny
- Department of Pharmacology, Tennis Court Road, Cambridge, CB2 1PD, UK.
| | - John G Stefanakis
- Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
| | - Efstratios D Sitsanidis
- Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
| | - Natalia-Anastasia T Ioannidou
- Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
| | - Nikolaos V Papadopoulos
- Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
| | - Konstantina C Fylaktakidou
- Laboratory of Organic, Bioorganic and Natural Product Chemistry, Molecular Biology and Genetics Department, Democritus University of Thrace, 68100 Alexandroupolis, Greece
| | - Colin W Taylor
- Department of Pharmacology, Tennis Court Road, Cambridge, CB2 1PD, UK.
| | - Alexandros E Koumbis
- Laboratory of Organic Chemistry, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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5
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Saleem H, Tovey SC, Riley AM, Potter BVL, Taylor CW. Stimulation of inositol 1,4,5-trisphosphate (IP3) receptor subtypes by adenophostin A and its analogues. PLoS One 2013; 8:e58027. [PMID: 23469136 PMCID: PMC3585173 DOI: 10.1371/journal.pone.0058027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 01/30/2013] [Indexed: 11/25/2022] Open
Abstract
Inositol 1,4,5-trisphosphate receptors (IP3R) are intracellular Ca(2+) channels. Most animal cells express mixtures of the three IP3R subtypes encoded by vertebrate genomes. Adenophostin A (AdA) is the most potent naturally occurring agonist of IP3R and it shares with IP3 the essential features of all IP3R agonists, namely structures equivalent to the 4,5-bisphosphate and 6-hydroxyl of IP3. The two essential phosphate groups contribute to closure of the clam-like IP3-binding core (IBC), and thereby IP3R activation, by binding to each of its sides (the α- and β-domains). Regulation of the three subtypes of IP3R by AdA and its analogues has not been examined in cells expressing defined homogenous populations of IP3R. We measured Ca(2+) release evoked by synthetic adenophostin A (AdA) and its analogues in permeabilized DT40 cells devoid of native IP3R and stably expressing single subtypes of mammalian IP3R. The determinants of high-affinity binding of AdA and its analogues were indistinguishable for each IP3R subtype. The results are consistent with a cation-π interaction between the adenine of AdA and a conserved arginine within the IBC α-domain contributing to closure of the IBC. The two complementary contacts between AdA and the α-domain (cation-π interaction and 3″-phosphate) allow activation of IP3R by an analogue of AdA (3″-dephospho-AdA) that lacks a phosphate group equivalent to the essential 5-phosphate of IP3. These data provide the first structure-activity analyses of key AdA analogues using homogenous populations of all mammalian IP3R subtypes. They demonstrate that differences in the Ca(2+) signals evoked by AdA analogues are unlikely to be due to selective regulation of IP3R subtypes.
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Affiliation(s)
- Huma Saleem
- Department of Pharmacology, Cambridge, United Kingdom
| | | | - Andrew M. Riley
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Barry V. L. Potter
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
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6
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Ogawa S, Tezuka Y. Convenient synthesis of 3- and 6-deoxy-d-myo-inositol phosphate analogues from (+)-epi- and (−)-vibo-quercitols. Bioorg Med Chem Lett 2006; 16:5238-43. [PMID: 16904317 DOI: 10.1016/j.bmcl.2006.06.096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2005] [Revised: 04/07/2006] [Accepted: 06/26/2006] [Indexed: 11/20/2022]
Abstract
Starting from (+)-epi- and (-)-vibo-quercitols readily produced by bioconversion of myo-inositol, some biologically interesting phosphate and polyphosphate analogues, including the Ins(1,4,5)P(3) derivatives of 3-deoxy- and 6-deoxy-D-myo-inositol, could be readily prepared in a conventional manner. In addition, chemical modification at C-2 of the 3-deoxy Ins(1,4,5)P(3) provided 2-epimer, and 2-deoxy and 2-deoxy-2-fluoro forms. Eight polyphosphate analogues obtained were assayed for biological activity against PDH-Pase and PDH-K, and G6Pase, but none proved positive.
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Affiliation(s)
- Seiichiro Ogawa
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, Hiyoshi, Yokohama 223-8522, Japan.
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7
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Mills SJ, Dozol H, Vandeput F, Backers K, Woodman T, Erneux C, Spiess B, Potter BVL. 3-Hydroxybenzene 1,2,4-Trisphosphate, a Novel Second Messenger Mimic and unusual Substrate for Type-I myo-Inositol 1,4,5-Trisphosphate 5-Phosphatase: Synthesis and Physicochemistry. Chembiochem 2006; 7:1696-706. [PMID: 16964627 DOI: 10.1002/cbic.200600125] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
3-Hydroxybenzene 1,2,4-trisphosphate 4 is a new myo-inositol 1,4,5-trisphosphate analogue based on the core structure of benzene 1,2,4-trisphosphate 2 with an additional hydroxyl group at position-3, and is the first noninositol based compound to be a substrate for inositol 1,4,5-trisphosphate 5-phosphatase. In physicochemical studies on 2, when three equivalents of protons were added, the (31)P NMR spectrum displayed monophasic behaviour in which phosphate-1 and phosphate-2 behaved independently in most of the studied pH range. For compound 4, phosphate-2 and phosphate-4 interacted with the 3-OH group, which does not titrate at physiological pH, displaying complex biphasic behaviour which demonstrated co-operativity between these groups. Phosphate-1 and phosphate-2 strongly interacted with each other and phosphate-4 experienced repulsion because of the interaction of the 3-OH group. Benzene 1,2,4-trisphosphate 2 is resistant to inositol 1,4,5-trisphosphate type I 5-phosphatase catalysed dephosphorylation. However, surprisingly, 3-hydroxybenzene 1,2,4-trisphosphate 4 was dephosphorylated by this 5-phosphatase to give the symmetrical 2,3-dihydroxybenzene 1,4-bisphosphate 16. The extra hydroxyl group is shown to form a hydrogen bond with the vicinal phosphate groups at -15 degrees C, and (1)H NMR titration of the ring and hydroxyl protons in 4 shows the OH proton to be strongly stabilized as soon as the phosphate groups are deprotonated. The effect of the phenolic 3-OH group in compound 4 confirms a critical role for the 6-OH group of the natural messenger in the dephosphorylation mechanism that persists even in radically modified analogues.
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Affiliation(s)
- Stephen J Mills
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, BA2 7AY, UK
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8
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Laporte R, Hui A, Laher I. Pharmacological modulation of sarcoplasmic reticulum function in smooth muscle. Pharmacol Rev 2005; 56:439-513. [PMID: 15602008 DOI: 10.1124/pr.56.4.1] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The sarco/endoplasmic reticulum (SR/ER) is the primary storage and release site of intracellular calcium (Ca2+) in many excitable cells. The SR is a tubular network, which in smooth muscle (SM) cells distributes close to cellular periphery (superficial SR) and in deeper aspects of the cell (deep SR). Recent attention has focused on the regulation of cell function by the superficial SR, which can act as a buffer and also as a regulator of membrane channels and transporters. Ca2+ is released from the SR via two types of ionic channels [ryanodine- and inositol 1,4,5-trisphosphate-gated], whereas accumulation from thecytoplasm occurs exclusively by an energy-dependent sarco-endoplasmic reticulum Ca2+-ATPase pump (SERCA). Within the SR, Ca2+ is bound to various storage proteins. Emerging evidence also suggests that the perinuclear portion of the SR may play an important role in nuclear transcription. In this review, we detail the pharmacology of agents that alter the functions of Ca2+ release channels and of SERCA. We describe their use and selectivity and indicate the concentrations used in investigating various SM preparations. Important aspects of cell regulation and excitation-contractile activity coupling in SM have been uncovered through the use of such activators and inhibitors of processes that determine SR function. Likewise, they were instrumental in the recent finding of an interaction of the SR with other cellular organelles such as mitochondria. Thus, an appreciation of the pharmacology and selectivity of agents that interfere with SR function in SM has greatly assisted in unveiling the multifaceted nature of the SR.
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Affiliation(s)
- Régent Laporte
- Ferring Research Institute, Inc., Ferring Pharmaceuticals, San Diego, California, USA
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9
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Synthese eines 1,2-trans-konfigurierten, äquatorialen Glycosyl-phosphonat-Analogen vonD-myo-Inositol-1,4,5-trisphosphat. Helv Chim Acta 2004. [DOI: 10.1002/hlca.19930760224] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Sureshan KM, Shashidhar MS, Praveen T, Das T. Regioselective Protection and Deprotection of Inositol Hydroxyl Groups. Chem Rev 2003; 103:4477-503. [PMID: 14611268 DOI: 10.1021/cr0200724] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kana M Sureshan
- Division of Organic Synthesis, National Chemical Laboratory, Pune 411 008, India
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11
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Nerou EP, Riley AM, Potter BV, Taylor CW. Selective recognition of inositol phosphates by subtypes of the inositol trisphosphate receptor. Biochem J 2001; 355:59-69. [PMID: 11256949 PMCID: PMC1221712 DOI: 10.1042/0264-6021:3550059] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Synthetic analogues of inositol trisphosphate (IP(3)), all of which included structures equivalent to the 4,5-bisphosphate of (1,4,5)IP(3), were used to probe the recognition properties of rat full-length type 1, 2 and 3 IP(3) receptors expressed in insect Spodoptera frugiperda 9 cells. Using equilibrium competition binding with [(3)H](1,4,5)IP(3) in Ca(2+)-free cytosol-like medium, the relative affinities of the receptor subtypes for (1,4,5)IP(3) were type 3 (K(d)=11+/-2 nM)>type 2 (K(d)=17+/-2 nM)>type 1 (K(d)=24+/-4 nM). (1,4,5)IP(3) binding was reversibly stimulated by increased pH, but the subtypes differed in their sensitivity to pH (type 1>type 2>type 3). For all three subtypes, the equatorial 6-hydroxy group of (1,4,5)IP(3) was essential for high-affinity binding, the equatorial 3-hydroxy group significantly improved affinity, and the axial 2-hydroxy group was insignificant; a 1-phosphate (or in its absence, a 2-phosphate) improved binding affinity. The subtypes differed in the extents to which they tolerated inversion of the 3-hydroxy group of (1,4,5)IP(3) (type 1>type 2>type 3), and this probably accounts for the selectivity of (1,4,6)IP(3) for type 1 receptors. They also differed in their tolerance of inversion, removal or substitution (by phosphate) of the 2-hydroxy group (types 2 and 3>type 1), hence the selectivity of (1,2,4,5)IP(4) for type 2 and 3 receptors. Removal of the 3-hydroxy group or its replacement by fluorine or CH(2)OH was best tolerated by type 3 receptors, and accounts for the selectivity of 3-deoxy(1,4,5)IP(3) for type 3 receptors. Our results provide the first systematic analysis of the recognition properties of IP(3) receptor subtypes and have identified the 2- and 3-positions of (1,4,5)IP(3) as key determinants of subtype selectivity.
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Affiliation(s)
- E P Nerou
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QJ, U.K
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12
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Alves Benı́cio AA, Da Silva AD, De Almeida MV, Da Silva MM, Dov Gero S. Stereoselective synthesis of 2,6-dideoxy; 3,6-dideoxy; 2,3,6-trideoxy-inositol 1,4,5-trisphosphate and 6-deoxy-inositol 1,3,4,5-tetrakisphosphate analogues from 6-deoxy- d -inositol precursors. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(00)01112-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Horne G, Potter BV. Synthesis of the enantiomers of 6-deoxy-myo-inositol 1,3,4,5-tetrakisphosphate, structural analogues of myo-inositol 1,3,4,5-tetrakisphosphate. Chemistry 2001; 7:80-7. [PMID: 11205029 DOI: 10.1002/1521-3765(20010105)7:1<80::aid-chem80>3.0.co;2-b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
D-myo-Inositol 1,3,4,5-tetrakisphosphate [Ins(1,3,4,5)P4] is produced rapidly from the established second messenger D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P4] in stimulated cells. Despite extensive investigations, in particular concerning its potential role in mediating cellular Ca2+ influx, no exact cellular function has been described for this inositol phosphate; however, binding sites have been identified in a number of tissues and it has been shown to act synergistically with Ins(1,4,5)P3. To assist in the elucidation of the mechanism of action and structural requirements within the Ins(1,3,4,5)P4 moiety that are necessary for recognition and activation of the receptor, structural analogues of this tetrakisphosphate are required. Routes for the synthesis of racemic 6-deoxy-myo-inositol 1,3,4,5-tetrakisphosphate [6-deoxy-DL-Ins(1,3,4,5)P4] and the chiral antipodes D- and L-6-deoxy-myo-inositol 1,3,4,5-tetrakisphosphate are described here. The racemic tetrakisphosphate was synthesised from DL-1,2-O-isopropylidene-myo-inositol in eight steps. Deoxygenation at C-6 was achieved following the Barton-McCombie procedure. Both chiral tetrakisphosphates were synthesised through resolution of racemic cis-diol 6-deoxy-1,4,5-tri-O-p-methoxybenzyl-myo-inositol with the chiral auxiliary (S)-(+)-O-acetylmandelic acid. Absolute configuration was confirmed by synthesis of the known D-6-deoxy-myo-inositol. Both D-6-deoxy-Ins(1,3,4,5)P4 and its enantiomer will be useful tools to unravel the enigmatic role of Ins(1,3,4,5)P4 in the polyphosphoinositide pathway of signal transduction.
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Affiliation(s)
- G Horne
- Department of Pharmacy and Pharmacology, University of Bath, UK
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14
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Murphy CT, Riley AM, Mills SJ, Lindley CJ, Potter BV, Westwick J. myo-inositol 1,4,6-trisphosphorothioate and myo-inositol 1,3, 6-trisphosphorothioate: partial agonists with very low intrinsic activity at the platelet myo-inositol 1,4,5-trisphosphate receptor. Mol Pharmacol 2000; 57:595-601. [PMID: 10692501 DOI: 10.1124/mol.57.3.595] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Racemic mixtures and enantiomerically pure D-isomers of both myo-inositol 1,3,6-trisphosphorothioate [Ins(1,3,6)PS(3)] and myo-inositol 1,4,6-trisphosphorothioate [Ins(1,4,6)PS(3)], prepared by total synthesis, were examined in Ca(2+) flux and binding assays. Both D-Ins(1,3,6)PS(3) and D-Ins(1,4,6)PS(3) were shown to be low intrinsic activity partial agonists at the platelet myo-inositol 1,4, 5-trisphosphate [Ins(1,4,5)P(3)] receptor, releasing less than 20% of the Ins(1,4,5)P(3)-sensitive Ca(2+) store. D-Ins(1,4,6)PS(3) displaced specifically bound [(3)H]Ins(1,4,5)P(3) from rat cerebellar membranes, although displacement was some 34-fold weaker than by D-Ins(1,4,5)P(3). D-Ins(1,4,6)PS(3) displaced [(3)H]Ins(1,4, 5)P(3) from cerebellar membranes with roughly twice the affinity of DL-Ins(1,4,6)PS(3) (IC(50) value = 1.4 +/- 0.35 microM compared with 2.15 +/- 0.13 microM), whereas D-Ins(1,3,6)PS(3) displaced [(3)H]Ins(1,4,5)P(3) with roughly twice the affinity of DL-Ins(1,3, 6)PS(3) (IC(50) value = 17.5 +/- 5.8 microM compared with 34 +/- 10 microM), confirming that the activity of both these phosphorothioates resides in their D-enantiomers. Increasing concentrations of either D-Ins(1,3,6)PS(3) or D-Ins(1,4,6)PS(3) were able to partially antagonize Ca(2+) release induced by submaximal concentrations of Ins(1,4,5)P(3), an inhibition that could be overcome by increasing the concentration of Ins(1,4,5)P(3), suggesting competition for binding at the Ins(1,4,5)P(3)-R. The only low-efficacy partial agonists at the Ins(1,4,5)P(3)-R discovered to date have been phosphorothioates; the novel D-Ins(1,3,6)PS(3) and D-Ins(1,4,6)PS(3) can now be added to this small group of analogs. However, D-Ins(1,4,6)PS(3) has a relatively high affinity for the Ins(1,4,5)P(3)-R but maintains the lowest efficacy of all the partial agonists thus far identified. As such, it may be a useful tool for pharmacological intervention in the polyphosphoinositide pathway and an important lead compound for the development of further Ins(1,4,5)P(3)-R antagonists.
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Affiliation(s)
- C T Murphy
- Department of Pharmacy and Pharmacology, University of Bath, Bath, UK.
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15
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Felemez M, Schlewer G, Jenkins DJ, Correa V, Taylor CW, Potter BV, Spiess B. Inframolecular studies of the protonation of 1d-1,2,4/3,5-cyclopentanepentaol 1,3,4-trisphosphate, a ring-contracted analogue of 1d-myo-inositol 1,4,5-trisphosphate. Carbohydr Res 1999. [DOI: 10.1016/s0008-6215(99)00193-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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16
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17
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da Silva AD, Benicio AAA, Gero SD. Enantioselective synthesis of some 6-deoxy-halodeoxy inositol derivatives. Tetrahedron Lett 1999. [DOI: 10.1016/s0040-4039(99)01307-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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Liu C, Davis RJ, Nahorski SR, Ballereau S, Spiess B, Potter BV. Synthesis, calcium mobilizing, and physicochemical properties of D-chiro-inositol 1,3,4,6-tetrakisphosphate, a novel and potent ligand at the D-myo-inositol 1,4,5-trisphosphate receptor. J Med Chem 1999; 42:1991-8. [PMID: 10354407 DOI: 10.1021/jm980733i] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of a novel and potent ligand at the D-myo-inositol 1,4, 5-trisphosphate receptor (InsP3R) is described. D-chiro-Inositol 1,3, 4,6-tetrakisphosphate (7) and L-chiro-inositol 1,3,4, 6-tetrakisphosphate (ent-7) have been synthesized from D-2, 5-di-O-benzyl-chiro-inositol and L-2,5-di-O-benzyl-chiro-inositol, respectively. The potency of binding and Ca2+ release of 7 and ent-7 were examined in L15 and Lvec cells. 7 was a full agonist at the InsP3R in both cells, and ent-7 was inactive. The results are compared to those from D-myo-inositol 1,4,5-trisphosphate (1), DL-scyllo-inositol 1,2,4-trisphosphate (2), DL-myo-inositol 1,2,4, 5-tetrakisphosphate (3), scyllo-inositol 1,2,4,5-tetrakisphosphate (4), D-myo-inositol 2,4,5-trisphosphate (5), and D-chiro-inositol 1, 3,4-trisphosphate (6). The protonation processes of 7 have also been investigated by 31P NMR titration experiments.
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Affiliation(s)
- C Liu
- Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, U.K
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19
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Stereoselective synthesis of inositol mono, bis and trisphosphate analogues from 6-deoxy- d -inositol precursors. Tetrahedron 1999. [DOI: 10.1016/s0040-4020(99)00365-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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20
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Wilcox RA, Primrose WU, Nahorski SR, Challiss RA. New developments in the molecular pharmacology of the myo-inositol 1,4,5-trisphosphate receptor. Trends Pharmacol Sci 1998; 19:467-75. [PMID: 9850611 DOI: 10.1016/s0165-6147(98)01260-7] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Receptor-mediated activation of phospholipase C to generate inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] is a ubiquitous signalling pathway in mammalian systems. A family of three IP3 receptor subtype monomers form functional tetramers, which act as effectors for Ins(1,4,5)P3, providing a ligand-gated channel that allows Ca2+ ions to move between cellular compartments. As IP3 receptors are located principally, although not exclusively, in the endoplasmic reticular membrane, Ins(1,4,5)P3 is considered to be a second messenger that mobilizes Ca2+ from intracellular stores. Ca2+ store mobilization by Ins(1,4,5)P3 can be shown to contribute to a variety of physiological and pathophysiological phenomena, and therefore the IP3 receptor represents a novel, potential pharmacological target. In this article, Rob Wilcox and colleagues review recent developments in IP3 receptor pharmacology, with particular emphasis on ligand molecular recognition by this receptor-channel complex. The potential for designing non-inositol phosphate-based agonists and antagonists is also discussed.
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Affiliation(s)
- R A Wilcox
- School of Medicine, Flinders University, Adelaide, Australia
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21
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Rudolf MT, Li WH, Wolfson N, Traynor-Kaplan AE, Schultz C. 2-Deoxy derivative is a partial agonist of the intracellular messenger inositol 3,4,5,6-tetrakisphosphate in the epithelial cell line T84. J Med Chem 1998; 41:3635-44. [PMID: 9733488 DOI: 10.1021/jm970781n] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We have synthesized the first deoxy analogues of myo-inositol 3,4,5, 6-tetrakisphosphate (1) [Ins(3,4,5,6)P4], rac-2-deoxy-myo-inositol 3, 4,5,6-tetrakisphosphate (rac-2), 2-deoxy-myo-inositol 1,4,5, 6-tetrakisphosphate (ent-2), and rac-1-deoxy-myo-inositol 3,4,5, 6-tetrakisphosphate (rac-3). In order to evaluate the binding properties of the three derivatives to the yet unidentified intracellular binding sites for Ins(3,4,5,6)P4, the analogues were converted to membrane-permeant derivatives. Starting with common inositol precursors, various forms of Barton-McCombie deoxygenation and classical protection/deprotection procedures yielded the desired precursors rac-1-O-butyryl-2-deoxy-myo-inositol (rac-12), ent-3-O-butyryl-2-deoxy-myo-inositol (ent-12), and rac-2-O-butyryl-1-deoxy-myo-inositol (rac-19), respectively. Phosphorylation and subsequent deprotection yielded rac-2, ent-2, and rac-3. Alternatively, phosphorylation followed by alkylation with acetoxymethyl bromide gave the membrane-permeant derivatives 1-O-butyryl-2-deoxy-myo-inositol 3,4,5,6-tetrakisphosphate octakis(acetoxymethyl) ester (rac-5), 3-O-butyryl-2-deoxy-myo-inositol 1,4,5,6-tetrakisphosphate octakis(acetoxymethyl) ester (ent-5), and 2-O-butyryl-1-deoxy-myo-inositol 3,4,5,6-tetrakisphosphate octakis(acetoxymethyl) ester (rac-6), respectively. We examined the potency of the membrane-permeant deoxy derivatives in inhibition of calcium-mediated chloride secretion (CaMCS) in intact T84 cells. Compared to the 1,2-di-O-butyryl-myo-inositol 3,4,5, 6-tetrakisphosphate octakis(acetoxymethyl) ester (4), the membrane-permeant derivative of Ins(3,4,5,6)P4 (1), the 2-deoxy derivative (rac-5) exhibited a slightly weaker inhibitory effect, while the enantiomerically pure 2-deoxy-Ins(1,4,5,6)P4 (ent-5) and the 1-deoxy derivative (rac-6) were inactive. As expected, the effect was stereoselective. Thus, the 1-hydroxyl group is apparently essential for binding and the inhibitory effect of Ins(3,4,5,6)P4 on chloride secretion, whereas the 2-hydroxyl group plays a less important role.
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Affiliation(s)
- M T Rudolf
- Institut für Organische Chemie, Abt. Bioorganische Chemie, Universität Bremen UFT, Leobener Strasse, 28359 Bremen, Germany
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22
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Riley AM, Guédat P, Schlewer G, Spiess B, Potter BVL. A Conformationally Restricted Cyclic Phosphate Analogue of Inositol Trisphosphate: Synthesis and Physicochemical Properties. J Org Chem 1998. [DOI: 10.1021/jo9714425] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Andrew M. Riley
- Department of Medicinal Chemistry, School of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, U.K., and Laboratoire de Pharmacochimie Moléculaire, Faculté de Pharmacie, Universite Louis Pasteur, Strasbourg, France
| | - Philippe Guédat
- Department of Medicinal Chemistry, School of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, U.K., and Laboratoire de Pharmacochimie Moléculaire, Faculté de Pharmacie, Universite Louis Pasteur, Strasbourg, France
| | - Gilbert Schlewer
- Department of Medicinal Chemistry, School of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, U.K., and Laboratoire de Pharmacochimie Moléculaire, Faculté de Pharmacie, Universite Louis Pasteur, Strasbourg, France
| | - Bernard Spiess
- Department of Medicinal Chemistry, School of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, U.K., and Laboratoire de Pharmacochimie Moléculaire, Faculté de Pharmacie, Universite Louis Pasteur, Strasbourg, France
| | - Barry V. L. Potter
- Department of Medicinal Chemistry, School of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, U.K., and Laboratoire de Pharmacochimie Moléculaire, Faculté de Pharmacie, Universite Louis Pasteur, Strasbourg, France
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23
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Dubreuil D, Cleophax J, de Almeida MV, Verre-Sebrié C, Liaigre J, Vass G, Gero SD. Stereoselective synthesis of 6-deoxy and 3,6-dideoxy-D-myo-inositol precursors of deoxy-myo-inositol phosphate analogues from D-galactose. Tetrahedron 1997. [DOI: 10.1016/s0040-4020(97)10101-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Yoshikawa F, Morita M, Monkawa T, Michikawa T, Furuichi T, Mikoshiba K. Mutational analysis of the ligand binding site of the inositol 1,4,5-trisphosphate receptor. J Biol Chem 1996; 271:18277-84. [PMID: 8663526 DOI: 10.1074/jbc.271.30.18277] [Citation(s) in RCA: 195] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
To define the structural determinants for inositol 1,4, 5-trisphosphate (IP3) binding of the type 1 inositol 1,4, 5-trisphosphate receptor (IP3R1), we developed a means of expressing the N-terminal 734 amino acids of IP3R1 (T734), which contain the IP3 binding region, in Escherichia coli. The T734 protein expressed in E. coli exhibited a similar binding specificity and affinity for IP3 as the native IP3R from mouse cerebellum. Deletion mutagenesis, in which T734 was serially deleted from the N terminus up to residue 215, markedly reduced IP3 binding activity. However, when deleted a little more toward the C terminus (to residues 220, 223, and 225), the binding activity was retrieved. Further N-terminal deletions over the first 228 amino acids completely abolished it again. C-terminal deletions up to residue 579 did not affect the binding activity, whereas those up to residue 568 completely abolished it. In addition, the expressed 356-amino acid polypeptide (residues 224-579) exhibited specific binding activity. Taken together, residues 226-578 were sufficient and close enough to the minimum region for the specific IP3 binding, and thus formed an IP3 binding "core." Site-directed mutagenesis was performed on 41 basic Arg and Lys residues within the N-terminal 650 amino acids of T734. We showed that single amino acid substitutions for 10 residues, which were widely distributed within the binding core and conserved among all members of the IP3R family, significantly reduced the binding activity. Among them, three (Arg-265, Lys-508, and Arg-511) were critical for the specific binding, and Arg-568 was implicated in the binding specificity for various inositol phosphates. We suggest that some of these 10 residues form a basic pocket that interacts with the negatively charged phosphate groups of IP3.
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Affiliation(s)
- F Yoshikawa
- Department of Molecular Neurobiology, Institute of Medical Science, University of Tokyo, Japan
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25
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Schultz C, Burmester A, Stadler C. Synthesis, separation, and identification of different inositol phosphates. Subcell Biochem 1996; 26:371-413. [PMID: 8744272 DOI: 10.1007/978-1-4613-0343-5_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- C Schultz
- Institute for Organic Chemistry, University of Bremen, Germany
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26
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Potter BVL, Lampe D. Die Chemie der Inositlipid-vermittelten zellulären Signalübertragung. Angew Chem Int Ed Engl 1995. [DOI: 10.1002/ange.19951071804] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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27
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Cleophax J, Dubreuil D, Gero SD, Loupy A, de Almeida MV, Da Silva AD, Vass G, Bischoff E, Perzbom E, Hecker G, Lockhoff O. Enantioselective synthesis of inositols as intermediates for the preparation of deoxy-inositol phosphates from D-galactose. Bioorg Med Chem Lett 1995. [DOI: 10.1016/0960-894x(95)00120-i] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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28
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Van Dijken P, Lammers AA, Ozaki S, Potter BV, Erneux C, Van Haastert PJ. Phosphorylation of inositol 1,4,5-trisphosphate analogues by 3-kinase and dephosphorylation of inositol 1,3,4,5-tetrakisphosphate analogues by 5-phosphatase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 226:561-6. [PMID: 8001571 DOI: 10.1111/j.1432-1033.1994.tb20081.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A series of 32P-labeled D-myo-inositol 1,3,4,5-tetrakisphosphate [Ins(1,3,4,5)P4] analogues was enzymically prepared from the corresponding D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] analogues using recombinant rat brain Ins(1,4,5)P3 3-kinase and [gamma-32P]ATP. Ins(1,4,5)P3 analogues with bulky groups at the 2-OH position, substitutions of phosphates by thiophosphates and D-6-deoxy-myo-Ins(1,4,5)P3 were tested. Using [3H]Ins(1,4,5)P3 and ATP gamma S, a [3H]Ins(1,3,4,5)P4 analogue with a thiophosphate at the D-3 position was prepared. The D-4 and/or D-5 phosphate group seemed to be important for 3-kinase activity, while the OH group at position 6 was not crucial. The addition of bulky groups at the 2-OH position did not prevent phosphorylation. The labeled Ins(1,3,4,5)P4 analogues were purified and their degradation by type-I Ins(1,4,5)P3/Ins(1,3,4,5)P4 5-phosphatase was compared with the degradation of Ins(1,3,4,5)P4. Substitution of the phosphate group at positions 1 or 3 by a thiophosphate, or the addition of bulky groups at the 2-OH position did not prevent degradation. D-6-Deoxy-myo-inositol 1,3,4,5-tetrakisphosphate could not be degraded by the 5-phosphatase, indicating the importance of the 6-OH group for 5-phosphatase action. D-6-Deoxy-myo-inositol 1,3,4,5-tetrakisphosphate could be an important tool in elucidating the cellular functions of Ins(1,3,4,5)P4.
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Affiliation(s)
- P Van Dijken
- Department of Biochemistry, University of Groningen, The Netherlands
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29
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Wilcox RA, Challiss RA, Traynor JR, Fauq AH, Ognayanov VI, Kozikowski AP, Nahorski SR. Molecular recognition at the myo-inositol 1,4,5-trisphosphate receptor. 3-position substituted myo-inositol 1,4,5-trisphosphate analogues reveal the binding and Ca2+ release requirements for high affinity interaction with the myo-inositol 1,4,5-trisphosphate receptor. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47092-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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30
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Wilcox RA, Safrany ST, Lampe D, Mills SJ, Nahorski SR, Potter BV. Modification at C2 of myo-inositol 1,4,5-trisphosphate produces inositol trisphosphates and tetrakisphosphates with potent biological activities. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 223:115-24. [PMID: 8033885 DOI: 10.1111/j.1432-1033.1994.tb18972.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Novel 2-position-modified D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] analogues, DL-2-deoxy-2-fluoro-myo-inositol 1,4,5-trisphosphate [DL-2F-Ins(1,4,5)P3], DL-myo-inositol 1,2,4,5-tetrakisphosphate [DL-Ins(1,2,4,5)P4], DL-scyllo-inositol 1,2,4-trisphosphate [DL-sc-Ins(1,2,4)P3], scyllo-inositol 1,2,4,5-tetrakisphosphate [sc-Ins(1,2,4,5)P4] and scyllo-inositol 1,2,4,5-tetrakisphosphorothioate [sc-Ins(1,2,4,5)PS4] were investigated for their ability to bind to the Ins(1,4,5)P3 receptor, mobilise intracellular Ca2+ stores and interact with metabolic enzymes. With the exception of sc-Ins(1,2,4,5)PS4, all the Ins(1,4,5)P3 analogues potently displaced [3H]Ins(1,4,5)P3 from its receptor in bovine adrenal cortex and were apparently potent full agonists at the Ca2+ mobilising Ins(1,4,5)P3 receptor of SH-SY5Y cells, giving respective IC50 and EC50 values of: sc-Ins(1,2,4,5)P4 (IC50 14 nM, EC50 77 nM), DL-2F-Ins(1,4,5)P3 (IC50 25 nM, EC50 105 nM), DL-Ins(1,2,4,5)P4 (IC50 26 nM, EC50 163 nM), DL-sc-Ins(1,2,4)P3 (IC50 52 nM, EC50 171 nM), compared to Ins(1,4,5)P3 (IC50 4 nM, EC50 52 nM). sc-Ins(1,2,4,5)P4 was equipotent to Ins(1,4,5)P3 for Ca2+ release making it the most potent inositol tetrakisphosphate and indeed Ins(1,4,5)P3 analogue yet characterised. In contrast, although sc-Ins(1,2,4,5)P4 (IC50 425 nM, EC50 1603 nM) was a significantly weaker ligand and agonist than Ins(1,4,5)P3, it was a partial agonist of high intrinsic activity with maximally effective concentrations releasing only about 80% of Ins(1,4,5)P3-sensitive Ca2+ stores of SH-SY5Y cells. Ins(1,4,5)P3 and sc-Ins(1,2,4,5)P4 were readily metabolised by Ins(1,4,5)P3 3-kinase and 5-phosphatase activities, DL-2F-Ins(1,4,5)P3 and DL-sc-Ins(1,2,4)P3 were resistant to 5-phosphatase, while sc-Ins(1,2,4,5)PS4 and DL-Ins(1,2,4,5)P4 were resistant to both 3-kinase and 5-phosphatase activity and were potent inhibitors of the 5-phosphatase enzyme (Ki = 300 nM and 2.9 microM, respectively). These results demonstrate that modification of the 2-position of Ins(1,4,5)P3, even with an anionic group, does not critically affect Ins(1,4,5)P3 binding interaction or Ca2+ release, suggesting that the 2-OH of Ins(1,4,5)P3 fails to interact significantly with the binding site of its receptor. However, modification remote from the crucial vicinal 4,5-bisphosphate can affect analogue efficacy in Ca2+ release.
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Affiliation(s)
- R A Wilcox
- Department of Cell Physiology and Pharmacology, University of Leicester, England
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31
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Lambert DG, Nahorski SR. Carbachol-stimulated calcium entry in SH-SY5Y human neuroblastoma cells: which route? ACTA ACUST UNITED AC 1994; 86:77-82. [PMID: 1343598 DOI: 10.1016/s0928-4257(05)80010-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
M3 muscarinic receptors expressed on SH-SY5Y human neuroblastoma cells are linked to phosphoinositide turnover and rises in [Ca2+]i. The rise in [Ca2+]i is biphasic with the peak phase being due to release from an intracellular Ins(1,4,5)P3-sensitive site and the plateau phase being due to Ca2+ entry across the plasma membrane. Ca2+ entry does not appear to involve voltage sensitive Ca2+ channels, a pertussis toxin sensitive G-protein-operated Ca2+ channel or Ins(1,4,5)P3/Ins(1,3,4,5)P4-operated Ca2+ channel. We suggest that carbachol-stimulated Ca2+ entry in SH-SY5Y human neuroblastoma cells occurs via receptor operated Ca2+ channels and through capacitive refilling.
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Affiliation(s)
- D G Lambert
- Department of Pharmacology and Therapeutics, University of Leicester, UK
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32
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Craxton A, Erneux C, Shears S. Inositol 1,4,5,6-tetrakisphosphate is phosphorylated in rat liver by a 3-kinase that is distinct from inositol 1,4,5-trisphosphate 3-kinase. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)41784-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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33
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Mills SJ, Al-Hafidh J, Westwick J, Potter BV. Myo-inositol 1,4,6-trisphosphate: A new synthetic Ca2+-mobilising inositol phosphate. Bioorg Med Chem Lett 1993. [DOI: 10.1016/s0960-894x(01)80723-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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34
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Hirata M, Watanabe Y, Yoshida M, Koga T, Ozaki S. Roles for hydroxyl groups of D-myo-inositol 1,4,5-trisphosphate in the recognition by its receptor and metabolic enzymes. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)36508-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Potter BVL. Synthetic Analogues of the Second Messenger D-MYOInositol 1,4,5 Trisphosphate as Receptor Agonists and Inhibitors of the Enzymes of the Polyphosphoinositide Pathway of Signal Transduction. PHOSPHORUS SULFUR 1993. [DOI: 10.1080/10426509308032379] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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36
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Poitras M, Bernier S, Boulay G, Fournier A, Guillemette G. Interaction of benzene 1,2,4-trisphosphate with inositol 1,4,5-trisphosphate receptor and metabolizing enzymes. Eur J Pharmacol 1993; 244:203-10. [PMID: 8384566 DOI: 10.1016/0922-4106(93)90145-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In a wide variety of cells, inositol 1,4,5-trisphosphate (InsP3) is an important second messenger involved in the regulation of intracellular Ca2+ concentration. InsP3 interacts with specific receptors and triggers the release of sequestered Ca2+ from an internal store. We have synthesized a structural analogue of InsP3 by phosphorylation of the free hydroxyl groups of 1,2,4-benzenetriol with dibenzylphosphorochloridate. The product benzene 1,2,4-trisphosphate (BzP3) was shown to interact with InsP3 receptor and InsP3 metabolizing enzymes of bovine adrenal cortex. BzP3 competitively blocked InsP3 binding to adrenal cortex microsomes with a half-maximal efficiency at 34 microM. This affinity was about 10,000 times lower than that of InsP3 for its receptor. The Ca2+ releasing activity of BzP3 on the same microsomal preparation was monitored with the fluorescent indicator fura-2. BzP3 had no agonistic effect on this activity but it was able to inhibit InsP3-induced Ca2+ release in a dose-dependent manner. The activity of InsP3 phosphatase was also studied. BzP3 inhibited the activity of the phosphatase with a half-maximal efficiency of 32 microM. BzP3 was also able to inhibit the activity of the cytosolic InsP3 kinase with a half-maximal efficiency of 6.1 microM. These results show that BzP3 is interacting with the three specific recognition sites for InsP3 in the bovine adrenal cortex. The inhibitory effect of this compound is relatively more potent on the metabolizing enzymes than on the Ca(2+)-mobilizing receptor.
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Affiliation(s)
- M Poitras
- Department of Pharmacology, Faculty of Medicine, University of Sherbrooke, Quebec, Canada
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37
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Kindman LA, Meyer T. Use of intracellular Ca2+ stores from rat basophilic leukemia cells to study the molecular mechanism leading to quantal Ca2+ release by inositol 1,4,5-trisphosphate. Biochemistry 1993; 32:1270-7. [PMID: 8448137 DOI: 10.1021/bi00056a011] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Quantal Ca2+ release is a novel motif for the mediation of signal transduction in which the amplitude of a biological response following multiple stepwise increases in agonist concentration is retained. The release of Ca2+ from permeabilized cells in response to the second messenger inositol 1,4,5-trisphosphate (InsP3) proceeds in this fashion. The mechanisms leading to quantal Ca2+ release are unknown. InsP3 releases 50-90% of the Ca2+ sequestered within the intracellular stores of mammalian cells permeabilized with saponin. However, preparation of microsomes results in the loss of this sensitivity. In this report, functionally intact intracellular Ca2+ stores were isolated from rat basophilic leukemia (RBL) cells by osmotic lysis followed by differential and sucrose density gradient centrifugation. From this preparation, 64% of the stored Ca2+ is released by InsP3. We demonstrate that quantal Ca2+ release is retained by isolated Ca2+ stores and is identical to that observed in permeabilized cells. Addition of a subsaturating (28 nM) concentration of InsP3 to permeabilized cells at 37 degrees C results in the release of only a small fraction of the sequestered Ca2+. When the cells are cooled to 11 degrees C, the remaining Ca2+ is rapidly released. Hence, the mechanism leading to the quantal nature of Ca2+ release is reversible and is thus not likely to be the result of a covalent modification of the channel protein or of the Ca2+ store.(ABSTRACT TRUNCATED AT 250 WORDS)
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MESH Headings
- Animals
- Calcimycin/pharmacology
- Calcium/metabolism
- Computer Simulation
- DNA, Neoplasm/analysis
- Inositol 1,4,5-Trisphosphate/analogs & derivatives
- Inositol 1,4,5-Trisphosphate/pharmacology
- Inositol 1,4,5-Trisphosphate/physiology
- Kinetics
- L-Lactate Dehydrogenase/analysis
- Leukemia, Basophilic, Acute/metabolism
- Microsomes/drug effects
- Microsomes/metabolism
- Quantum Theory
- Rats
- Second Messenger Systems
- Structure-Activity Relationship
- Subcellular Fractions/metabolism
- Tumor Cells, Cultured
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Affiliation(s)
- L A Kindman
- Department of Cell Biology, Stanford University Medical Center, California 94305
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38
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Beaucage SL, Iyer RP. The synthesis of specific ribonucleotides and unrelated phosphorylated biomolecules by the phosphoramidite method. Tetrahedron 1993. [DOI: 10.1016/s0040-4020(01)81543-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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39
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Synthesis and binding studies of an optically pure hexadeoxy-1,4,5-tris(methylenesulfonic acid) analogue of IP3. Tetrahedron Lett 1993. [DOI: 10.1016/s0040-4039(00)60551-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Wilcox RA, Nahorski SR, Sawyer DA, Liu C, Potter BV. The role of the 2- and 3-hydroxyl groups of 1D-myo-inositol 1,4,5-trisphosphate in the mobilisation of calcium from permeabilised human 1321N1 astrocytoma cells. Carbohydr Res 1992; 234:237-46. [PMID: 1334801 DOI: 10.1016/0008-6215(92)85051-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The functional significance of the 2- and 3-hydroxyl groups of 1 D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] was probed by using Ins(1,4,5)P3 analogues variously modified at positions 2 and 3 or elsewhere. The intrinsic activities of these compounds were compared to that of Ins(1,4,5)P3, using the calcium-mobilising receptor of the 1321N1 human astrocytoma cell line. The ligand-binding affinities were also determined using membrane preparations from rat cerebellum and bovine adrenal cortex. The results show that HO-2 and HO-3 of Ins(1,4,5)P3 have a relatively insignificant role in receptor binding and calcium release. However, the possibility of a regulatory role for the 3-position of Ins(1,4,5)P3 in these processes is proposed.
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Affiliation(s)
- R A Wilcox
- Department of Pharmacology and Therapeutics, University of Leicester, United Kingdom
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41
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Dreef CE, Jansze JP, Elie CJ, van der Marel GA, van Boom JH. Synthesis of racemic 5-phosphonate analogues of myo-inositol 1,4,5-tris- and 1,3,4,5-tetrakis-phosphate. Carbohydr Res 1992; 234:37-50. [PMID: 1468080 DOI: 10.1016/0008-6215(92)85037-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
(+/-)-2,3,6-Tri-O-benzyl-5-O-p-methoxybenzyl-myo-inositol and (+/-)-2,6-di-O-benzyl-5-O-p-methoxy-benzyl-myo-inositol, accessible readily from (+/-)-3,6-di-O-allyl-1,2-O-cyclohexylidene-myo-inositol, were phosphitylated with dibenzyl N,N-di-isopropylphosphoramidite, and the resulting phosphite triesters were oxidised with tert-butyl hydroperoxide to give the corresponding fully protected myo-inositol 1,4-bis- (12) and 1,3,4-tris-phosphate (13) derivatives. Cleavage of the p-methoxybenzyl group from 12 and 13, phosphonylation with bis[6-(trifluoromethyl)benzotriazol-1-yl] methylphosphonate or (difluoromethyl)phosphonic di(1,2,4-triazolide), followed by treatment in situ with benzyl alcohol, and then hydrogenolysis of the benzyl groups gave the 5-methylphosphonate and 5-[(difluoromethyl)phosphonate] analogues of myo-inositol 1,4,5-tris- and 1,3,4,5-tetrakis-phosphate. The 5-methylphosphonate analogue of myo-inositol 1,4,5-trisphosphate acted as a calcium antagonist in permeabilized human platelets.
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Affiliation(s)
- C E Dreef
- Department of Chemistry, Leiden University, Netherlands
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42
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Liu C, Nahorski SR, Potter BV. Synthesis from quebrachitol of 1l-chiro-inositol 2,3,5-trisphosphate, an inhibitor of the enzymes of 1d-myo-inositol 1,4,5-trisphosphate metabolism. Carbohydr Res 1992. [DOI: 10.1016/0008-6215(92)85042-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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43
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Safrany ST, Wilcox RA, Liu C, Potter BV, Nahorski SR. 3-position modification of myo-inositol 1,4,5-trisphosphate: consequences for intracellular Ca2+ mobilisation and enzyme recognition. Eur J Pharmacol 1992; 226:265-72. [PMID: 1330634 DOI: 10.1016/0922-4106(92)90071-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The ability of the novel D-myo-inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) analogues, L-chiro-inositol 2,3,5-trisphosphate (L-ch-Ins(2,3,5)P3) and D-3-deoxy-3-fluoro-myo-inositol 1,4,5-trisphosphate (3F-Ins(1,4,5)P3), to bind to the Ins(1,4,5)P3 receptor, mobilise intracellular Ca2+ stores and interact with metabolic enzymes has been investigated. L-ch-Ins(2,3,5)P3 and 3F-Ins(1,4,5)P3 were bound by the Ins(1,4,5)P3 receptor from bovine adrenal cortex with relatively high affinity (Ki values 60.4 and 8.0 nM respectively) but with lower affinity than Ins(1,4,5)P3 (KD = 5.9 nM). Both analogues were apparent full agonists at the Ca2+ mobilising receptor in SH-SY5Y cells, but were less potent than Ins(1,4,5)P3 (EC50 L-ch-Ins(2,3,5)P3 = 1.4 microM, 3F-Ins(1,4,5)P3 = 0.37 microM and Ins(1,4,5)P3 = 0.12 microM). L-ch-Ins(2,3,5)P3 and 3F-Ins(1,4,5)P3 were resistant to Ins(1,4,5)P3 3-kinase, and were potent inhibitors of the enzyme (Ki values 7.1 and 8.6 microM respectively). 3F-Ins(1,4,5)P3 was hydrolysed by Ins(1,4,5)P3 5-phosphatase at a similar rate to Ins(1,4,5)P3, but inhibited dephosphorylation of [3H]Ins(1,4,5)P3 with high potency (apparent Ki = 3.9 microM) L-ch-Ins(2,3,5)P3 was also recognised by the enzyme with high affinity (Ki = 7.7 microM) but was resistant to hydrolysis. These results suggest that the environment around C-3 is of major importance for recognition not only by Ins(1,4,5)P3 3-kinase but also by Ins(1,4,5)P3 5-phosphatase.
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Affiliation(s)
- S T Safrany
- Department of Pharmacology and Therapeutics, University of Leicester, UK
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44
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Lambert DG, Wojcikiewicz RJ, Safrany ST, Whitham EM, Nahorski SR. Muscarinic receptors, phosphoinositide metabolism and intracellular calcium in neuronal cells. Prog Neuropsychopharmacol Biol Psychiatry 1992; 16:253-70. [PMID: 1317042 DOI: 10.1016/0278-5846(92)90078-s] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
1. We have utilised SH-SY5Y human neuroblastoma cells and primary cultures of rat neonatal cerebellar granule cells, both expressing M3 muscarinic receptors, to examine agonist driven polyphosphoinositide hydrolysis and alterations in intracellular calcium. 2. Stimulation of SH-SY5Y cells leads to a biphasic increase in intracellular calcium, the initial peak being due to the release of calcium from an intracellular store and the second maintained phase being due to calcium entry across the plasma membrane. The channel involved does not appear to be voltage sensitive, to involve a pertussis toxin sensitive G protein, or be opened by inositol polyphosphates. 3. Muscarinic receptor stimulation also leads to increased inositol polyphosphate formation in SH-SY5Y cells. Ins(1,4,5)P3 mass formation was biphasic in profile whereas Ins(1,3,4,5)P4 mass formation was slower and monophasic in profile. These data are consistent with substantial activity of 5-phosphatase (dephosphorylating Ins(1,4,5)P3 to Ins(1,4)P2) and 3-kinase (phosphorylating Ins(1,4,5)P3 to Ins(1,3,4,5)P4) in SH-SY5Y cells. 4. In order to better understand the role of Ins(1,4,5)P3 and its metabolites in calcium homeostasis we have examined the ability of a variety of natural and synthetic analogues to release intracellular sequestered calcium. The Ins(1,4,5)P3 calcium mobilizing receptor displays a remarkable degree of stereo- and positional selectivity with the most potent agonist to date being Ins(1,4,5)P3 (EC50 = 0.09 microM). 5. As an alternative to the continuous SH-SY5Y neuroblastoma (tumour derived) cell line we have used the primary cultured cerebellar granule cell. These cells also display a biphasic increase in Ins(1,4,5)P3 mass and a subsequent release of intracellular stored calcium. In our hands carbachol appears to increase calcium influx, a response which is only visible in the absence of magnesium.
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Affiliation(s)
- D G Lambert
- Department of Pharmacology and Therapeutics, University of Leicester, UK
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45
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Baron CB, Pompeo JN, Azim S. Inositol 1,4,5-trisphosphate compartmentalization in tracheal smooth muscle. Arch Biochem Biophys 1992; 292:382-7. [PMID: 1731607 DOI: 10.1016/0003-9861(92)90006-i] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pool sizes of inositol phosphate species in myo-[3H]inositol-labeled porcine tracheal smooth muscle were determined under three conditions: (a) unstimulated; (b) stimulated with carbachol; (c) atropine-relaxed from a carbachol contraction. In unstimulated muscle, the inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) content was 14 pmol/100 nmol lipid P1. This is equivalent to a mean [Ins(1,4,5)P3] of about 3 microM (in total cellular water), a level about 30-fold in excess of that required for Ca2+ release from Ins(1,4,5)P3-sensitive sarcoplasmic reticulum (SR). Pool sizes of breakdown products of Ins(1,4,5)P3 were relatively small or absent in unstimulated muscle, suggesting that, under this condition, Ins(1,4,5)P3 was sequestered and had limited access to Ins(1,4,5)P3 5-phosphatase and/or 3-kinase. During carbachol stimulation, the Ins(1,4,5)P3 pool did not increase while those of other mono-, di-, and trisphosphate isomers increased over 10-fold. Subsequent atropine-induced relaxation resulted in a partial depletion (40%) of total tissue Ins(1,4,5)P3. Decreases in Ins(1,4,5)P3 were paralleled by decreases in Ins(1,4)P2 and Ins(1,3,4)P3. During contraction a portion of total tissue Ins(1,4,5)P3 has access to Ins(1,4,5)P3 3-kinase and 5-phosphatase and to Ins(1,4,5)P3-sensitive SR, though during antagonist-induced relaxation access to Ins(1,4,5)P3-sensitive SR for Ca2+ release is restricted. Data are consistent with a mechanism by which a large pool of Ins(1,4,5)P3 present in the unstimulated state in a sequestered compartment can contribute in activated muscle to increases in [Ins(1,4,5)P3] in a nonsequestered compartment, controlling SR Ca2+ release.
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Affiliation(s)
- C B Baron
- Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia 19104-6085
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46
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Noble NJ, Dubreuil D, Potter B. Total synthesis of myo-inositol-1-phosphate-4,5-pyrophosphate, a novel second messenger analogue, via myo-inositol-1-phosphate-4,5-bisphosphorothioate. Bioorg Med Chem Lett 1992. [DOI: 10.1016/s0960-894x(00)80172-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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47
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Safrany ST, Sawyer DA, Nahorski SR, Potter BV. Synthetic D- and L-enantiomers of 2,2-difluoro-2-deoxy-myo-inositol 1,4,5-trisphosphate interact differently with myo-inositol 1,4,5-trisphosphate binding proteins: identification of a potent small molecule 3-kinase inhibitor. Chirality 1992; 4:415-22. [PMID: 1334423 DOI: 10.1002/chir.530040703] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The ability of two enantiomeric fluoro-analogues of D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] to mobilize intracellular Ca2+ stores in SH-SY5Y neuroblastoma cells has been investigated. (-)-D-2,2-difluoro-2-deoxy-myo-Ins(1,4,5)P3 [D-2,2-F2-Ins(1,4,5)P3] was a full agonist [EC50 0.21 microM] and slightly less potent than D-Ins(1,4,5)P3 [EC50 0.13 microM]. (+)-L-2,2-F2Ins(1,4,5)P3 was a very poor agonist, confirming the stereospecificity of the Ins(1,4,5)P3 receptor. D-2,2-F2-Ins(1,4,5)P3 mobilized Ca2+ with broadly similar kinetics to Ins(1,4,5)P3 and was a substrate for Ins(1,4,5)P3 3-kinase inhibiting Ins(1,4,5)P3 phosphorylation (apparent Ki = 10.2 microM) but was recognised less well than Ins(1,4,5)P3. L-2,2-F2-Ins(1,4,5)P3 was a potent competitive inhibitor of 3-kinase (Ki = 11.9 microM). Whereas D-2,2-F2-Ins(1,4,5)P3 was a good substrate for Ins(1,4,5)P3 5-phosphatase, L-2,2-F2Ins(1,4,5)P3 was a relatively potent inhibitor (Ki = 19.0 microM).
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Affiliation(s)
- S T Safrany
- Department of Pharmacology and Therapeutics, University of Leicester, United Kingdom
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48
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Luong TT, Poitras M, Boulay G, Guillemette G. Interaction of polyanions with the recognition sites for inositol 1,4,5-trisphosphate in the bovine adrenal cortex. Eur J Pharmacol 1991; 208:213-21. [PMID: 1663045 DOI: 10.1016/0922-4106(91)90098-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Inositol 1,4,5-trisphosphate (InsP3) serves as a second messenger for Ca2+ mobilization in a wide variety of cells. InsP3 activates a specific receptor/channel located on an internal Ca2+ store. Because heparin has already been shown to block the action of InsP3, we have looked at the influence of other polyanions (dextran sulfate and polyvinyl sulfate) on the action and metabolism of InsP3 in the bovine adrenal cortex. Polyvinyl sulfate blocked InsP3 binding to adrenal cortex microsomes with a half-maximal efficiency of 250 nM. Scatchard analyses revealed that this effect was not competitive. The Ca2+ releasing activity of InsP3 on the same microsomal preparation was monitored with the fluorescent indicator, fura-2. Polyvinyl sulfate blocked this activity with a half-maximal efficiency of 80 nM. The effect of polyvinyl sulfate could not be overcome by supramaximal doses of InsP3, suggesting a non-competitive inhibitory effect. The activity of InsP3 phosphatase from bovine adrenal cortex microsomes was also studied. Polyvinyl sulfate inhibited the activity of the phosphatase with a half-maximal efficiency of 5 microM. Lineweaver-Burk plots revealed that this effect was not competitive. Polyvinyl sulfate was able to inhibit the activity of InsP3 kinase from bovine adrenal cortex cytosol. The half-maximal dose was 15 nM and the Lineweaver-Burk analysis showed that the inhibition was not competitive. The effect of dextran sulfate 5000 (DS-5000) on these activities was also studied. DS-5000 inhibited in a competitive manner the binding of InsP3 to its receptor (IC50 of 34 microM), the release of Ca2+ induced by InsP3 (IC50 of 6.5 microM) and the activity of InsP3 phosphatase (IC50 of 57 microM).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T T Luong
- Department of Pharmacology, Faculty of Medicine, University of Sherbrooke, Quebec, Canada
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49
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Abstract
Inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) is a soluble intracellular messenger formed rapidly after activation of a variety of cell-surface receptors that stimulate phosphoinositidase C activity. The initial response to Ins(1,4,5)P3 is a rapid Ca2+ efflux from nonmitochondrial intracellular stores which are probably specialized subcompartments of the endoplasmic reticulum, although their exact identities remain unknown. This initial response is followed by more complex Ca2+ signals: regenerative Ca2+ waves propagate across the cell, repetitive Ca2+ spikes occur, and stimulated Ca2+ entry across the plasma membrane contributes to the sustained Ca2+ signal. The mechanisms underlying these complex Ca2+ signals are unknown, although Ins(1,4,5)P3 is clearly involved. The intracellular receptor that mediates Ins(1,4,5)P3-stimulated Ca2+ mobilization has been purified and functionally reconstituted, and its amino acid sequence deduced from its cDNA sequence. These studies demonstrate that the Ins(1,4,5)P3 receptor has an integral Ca2+ channel separated from the Ins(1,4,5)P3 binding site by a long stretch of residues some of which form binding sites for allosteric regulators, and some of which are substrates for phosphorylation. In this review, we discuss the ligand recognition characteristics of Ins(1,4,5)P3 receptors, and their functional properties in their native environment and after purification, and we relate these properties to what is known of the structure of the receptor. In addition to regulation by Ins(1,4,5)P3, the Ins(1,4,5)P3 receptor is subject to many additional regulatory influences which include Ca2+, adenine nucleotides, pH and phosphorylation by protein kinases. Many of the functional and structural characteristics of the Ins(1,4,5)P3 receptor show striking similarities to another intracellular Ca2+ channel, the ryanodine receptor. These properties of the Ins(1,4,5)P3 are discussed, and their possible roles in contributing to the complex Ca2+ signals evoked by extracellular stimuli are considered.
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Affiliation(s)
- C W Taylor
- Department of Pharmacology, Cambridge, U.K
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50
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Sawyer DA, Potter BVL. Total synthesis of L-2,2-difluoro-2-deoxy-MYO-inositol 1,4,5-trisphosphate, a potent inhibitor of the enzymes of d-MYO-inositol 1,4,5-trisphosphate metabolism. Bioorg Med Chem Lett 1991. [DOI: 10.1016/s0960-894x(01)81052-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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