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Wu W, Shao X, Zhao J, Wu M. Controllable Photodynamic Therapy Implemented by Regulating Singlet Oxygen Efficiency. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2017; 4:1700113. [PMID: 28725533 PMCID: PMC5515253 DOI: 10.1002/advs.201700113] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 04/08/2017] [Indexed: 05/25/2023]
Abstract
With singlet oxygen (1O2) as the active agent, photodynamic therapy (PDT) is a promising technique for the treatment of various tumors and cancers. But it is hampered by the poor selectivity of most traditional photosensitizers (PS). In this review, we present a summary of controllable PDT implemented by regulating singlet oxygen efficiency. Herein, various controllable PDT strategies based on different initiating conditions (such as pH, light, H2O2 and so on) have been summarized and introduced. More importantly, the action mechanisms of controllable PDT strategies, such as photoinduced electron transfer (PET), fluorescence resonance energy transfer (FRET), intramolecular charge transfer (ICT) and some physical/chemical means (e.g. captivity and release), are described as a key point in the article. This review provide a general overview of designing novel PS or strategies for effective and controllable PDT.
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Affiliation(s)
- Wenting Wu
- State Key Laboratory of Heavy Oil ProcessingChina University of PetroleumQingdao266580China
- State Key Laboratory of Fine ChemicalsSchool of Chemical EngineeringDalian University of TechnologyDalian116024P. R. China
| | - Xiaodong Shao
- State Key Laboratory of Heavy Oil ProcessingChina University of PetroleumQingdao266580China
| | - Jianzhang Zhao
- State Key Laboratory of Fine ChemicalsSchool of Chemical EngineeringDalian University of TechnologyDalian116024P. R. China
| | - Mingbo Wu
- State Key Laboratory of Heavy Oil ProcessingChina University of PetroleumQingdao266580China
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2
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Modulating Ca2+ release by the IP3R/Ca2+ channel as a potential therapeutic treatment for neurological diseases. Pharm Pat Anal 2014; 2:629-36. [PMID: 24237170 DOI: 10.4155/ppa.13.42] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Recent research into neurodegenerative disorders found that their pathogeneses have a link to the inositol 1,4,5-trisphosphate receptors (IP3R). This is encouraging, because despite extensive efforts, researchers have not fully understood the pathophysiologies of those disorders, and have yet to find the cure. The IP3R provides a possible point of convergence that new therapeutic drugs can target. This review highlights patents that manipulate activities of the IP3R. They generally involve the use of peptides designed from the amino acid sequences of IP3R-binding proteins, and of buffers that limit the availability of its ligand, IP3. Additionally, one of them details the use of a chromophore-conjugated small synthetic molecule to directly inhibit the IP3R in a highly spatiotemporally specific manner. Although many of them have only been tested in vitro or are in the early stages of in vivo application, more research-effective therapies for neurodegenerative diseases can hopefully be developed.
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3
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Saleem H, Tovey SC, Rahman T, Riley AM, Potter BVL, Taylor CW. Stimulation of inositol 1,4,5-trisphosphate (IP3) receptor subtypes by analogues of IP3. PLoS One 2013; 8:e54877. [PMID: 23372785 PMCID: PMC3556037 DOI: 10.1371/journal.pone.0054877] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 12/17/2012] [Indexed: 11/19/2022] Open
Abstract
Most animal cells express mixtures of the three subtypes of inositol 1,4,5-trisphosphate receptor (IP(3)R) encoded by vertebrate genomes. Activation of each subtype by different agonists has not hitherto been examined in cells expressing defined homogenous populations of IP(3)R. Here we measure Ca(2+) release evoked by synthetic analogues of IP(3) using a Ca(2+) indicator within the lumen of the endoplasmic reticulum of permeabilized DT40 cells stably expressing single subtypes of mammalian IP(3)R. Phosphorylation of (1,4,5)IP(3) to (1,3,4,5)IP(4) reduced potency by ~100-fold. Relative to (1,4,5)IP(3), the potencies of IP(3) analogues modified at the 1-position (malachite green (1,4,5)IP(3)), 2-position (2-deoxy(1,4,5)IP(3)) or 3-position (3-deoxy(1,4,5)IP(3), (1,3,4,5)IP(4)) were similar for each IP(3)R subtype. The potency of an analogue, (1,4,6)IP(3), in which the orientations of the 2- and 3-hydroxyl groups were inverted, was also reduced similarly for all three IP(3)R subtypes. Most analogues of IP(3) interact similarly with the three IP(3)R subtypes, but the decrease in potency accompanying removal of the 1-phosphate from (1,4,5)IP(3) was least for IP(3)R3. Addition of a large chromophore (malachite green) to the 1-phosphate of (1,4,5)IP(3) only modestly reduced potency suggesting that similar analogues could be used to measure (1,4,5)IP(3) binding optically. These data provide the first structure-activity analyses of key IP(3) analogues using homogenous populations of each mammalian IP(3)R subtype. They demonstrate broadly similar structure-activity relationships for all mammalian IP(3)R subtypes and establish the potential utility of (1,4,5)IP(3) analogues with chromophores attached to the 1-position.
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MESH Headings
- Amino Acid Sequence
- Animals
- Calcium/metabolism
- Cell Line
- Gene Expression
- Inositol 1,4,5-Trisphosphate/chemistry
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate Receptors/chemistry
- Inositol 1,4,5-Trisphosphate Receptors/genetics
- Inositol 1,4,5-Trisphosphate Receptors/metabolism
- Kinetics
- Ligands
- Mice
- Models, Molecular
- Molecular Docking Simulation
- Molecular Sequence Data
- Molecular Structure
- Protein Binding
- Rats
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Structure-Activity Relationship
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Affiliation(s)
- Huma Saleem
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Stephen C. Tovey
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, 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
| | - Colin W. Taylor
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
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4
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Rowland MM, Gong D, Bostic HE, Lucas N, Cho W, Best MD. Microarray analysis of Akt PH domain binding employing synthetic biotinylated analogs of all seven phosphoinositide headgroup isomers. Chem Phys Lipids 2011; 165:207-15. [PMID: 22178158 DOI: 10.1016/j.chemphyslip.2011.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 11/29/2011] [Accepted: 12/02/2011] [Indexed: 12/19/2022]
Abstract
Signaling lipids control many of the most important biological pathways, typically by recruiting cognate protein binding targets to cell surfaces, thereby regulating both their function and subcellular localization. A critical family of signaling lipids is that of the phosphatidylinositol polyphosphates (PIP(n)s), which is composed of seven isomers that vary based on phosphorylation pattern. A key protein that is activated upon PIP(n) binding is Akt, which then plays important roles in regulating the cell cycle, and is thus aberrant in disease. Characterization of protein-PIP(n) binding interactions is hindered by the complexity of the membrane environment and of the PIP(n) structures. Herein, we describe two rapid assays of use for characterizing protein-PIP(n) binding interactions. First, a microplate-based binding assay was devised to characterize the binding of effectors to immobilized synthetic PIP(n) headgroup-biotin conjugates corresponding to all seven isomers. The assay was implemented for simultaneous analysis of Akt-PH domain, indicating PI(3,4,5)P(3) and PI(3,4)P(2) as the primary ligands. In addition, density-dependant studies indicated that the amount of ligand immobilized on the surface affected the amplitude of protein binding, but not the affinity, for Akt-PH. Since the PIP(n) ligand motifs used in this analysis lack the membrane environment and glycerolipid backbone, yet still exhibit high-affinity protein binding, these results narrow down the structural requirements for Akt recognition. Additionally, binding detection was also achieved through microarray analysis via the robotic pin printing of ligands onto glass slides in a miniaturized format. Here, fluorescence-based detection provided sensitive detection of binding using minimal amounts of materials. Due to their high-throughput and versatile attributes, these assays provide invaluable tools for probing and perturbing protein-membrane binding interactions.
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Affiliation(s)
- Meng M Rowland
- Department of Chemistry, The University of Tennessee, Knoxville, TN 37996, United States
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5
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Rowland MM, Bostic HE, Gong D, Speers AE, Lucas N, Cho W, Cravatt BF, Best MD. Phosphatidylinositol 3,4,5-trisphosphate activity probes for the labeling and proteomic characterization of protein binding partners. Biochemistry 2011; 50:11143-61. [PMID: 22074223 DOI: 10.1021/bi201636s] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Phosphatidylinositol polyphosphate lipids, such as phosphatidylinositol 3,4,5-trisphosphate [PI(3,4,5)P₃], regulate critical biological processes, many of which are aberrant in disease. These lipids often act as site-specific ligands in interactions that enforce membrane association of protein binding partners. Herein, we describe the development of bifunctional activity probes corresponding to the headgroup of PI(3,4,5)P₃ that are effective for identifying and characterizing protein binding partners from complex samples, namely cancer cell extracts. These probes contain both a photoaffinity tag for covalent labeling of target proteins and a secondary handle for subsequent detection or manipulation of labeled proteins. Probes bearing different secondary tags were exploited, either by direct attachment of a fluorescent dye for optical detection or by using an alkyne that can be derivatized after protein labeling via click chemistry. First, we describe the design and modular synthetic strategy used to generate multiple probes with different reporter tags of use for characterizing probe-labeled proteins. Next, we report initial labeling studies using purified protein, the PH domain of Akt, in which probes were found to label this target, as judged by in-gel detection. Furthermore, protein labeling was abrogated by controls including competition with an unlabeled PI(3,4,5)P₃ headgroup analogue as well as through protein denaturation, indicating specific labeling. In addition, probes featuring linkers of different lengths between the PI(3,4,5)P₃ headgroup and photoaffinity tag led to variations in protein labeling, indicating that a shorter linker was more effective in this case. Finally, proteomic labeling studies were performed using cell extracts; labeled proteins were observed by in-gel detection and characterized using postlabeling with biotin, affinity chromatography, and identification via tandem mass spectrometry. These studies yielded a total of 265 proteins, including both known and novel candidate PI(3,4,5)P₃-binding proteins.
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Affiliation(s)
- Meng M Rowland
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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6
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Rossi AM, Tovey SC, Rahman T, Prole DL, Taylor CW. Analysis of IP3 receptors in and out of cells. Biochim Biophys Acta Gen Subj 2011; 1820:1214-27. [PMID: 22033379 DOI: 10.1016/j.bbagen.2011.10.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 10/07/2011] [Accepted: 10/08/2011] [Indexed: 10/16/2022]
Abstract
BACKGROUND Inositol 1,4,5-trisphosphate receptors (IP3R) are expressed in almost all animal cells. Three mammalian genes encode closely related IP3R subunits, which assemble into homo- or hetero-tetramers to form intracellular Ca2+ channels. SCOPE OF THE REVIEW In this brief review, we first consider a variety of complementary methods that allow the links between IP3 binding and channel gating to be defined. How does IP3 binding to the IP3-binding core in each IP3R subunit cause opening of a cation-selective pore formed by residues towards the C-terminal? We then describe methods that allow IP3, Ca2+ signals and IP3R mobility to be examined in intact cells. A final section briefly considers genetic analyses of IP3R signalling. MAJOR CONCLUSIONS All IP3R are regulated by both IP3 and Ca2+. This allows them to initiate and regeneratively propagate intracellular Ca2+ signals. The elementary Ca2+ release events evoked by IP3 in intact cells are mediated by very small numbers of active IP3R and the Ca2+-mediated interactions between them. The spatial organization of these Ca2+ signals and their stochastic dependence on so few IP3Rs highlight the need for methods that allow the spatial organization of IP3R signalling to be addressed with single-molecule resolution. GENERAL SIGNIFICANCE A variety of complementary methods provide insight into the structural basis of IP3R activation and the contributions of IP3-evoked Ca2+ signals to cellular physiology. This article is part of a Special Issue entitled Biochemical, biophysical and genetic approaches to intracellular calcium signaling.
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7
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Abstract
Quantification of the associations between biomolecules is required both to predict and understand the interactions that underpin all biological activity. Fluorescence polarization (FP) provides a nondisruptive means of measuring the association of a fluorescent ligand with a larger molecule. We describe an FP assay in which binding of fluorescein-labeled inositol 1,4,5-trisphosphate (IP(3)) to N-terminal fragments of IP(3) receptors can be characterized at different temperatures and in competition with other ligands. The assay allows the standard Gibbs free energy (ΔG°), enthalpy (ΔH°) and entropy (ΔS°) changes of ligand binding to be determined. The method is applicable to any purified ligand-binding site for which an appropriate fluorescent ligand is available. FP can be used to measure low-affinity interactions in real time without the use of radioactive materials, it is nondestructive and, with appropriate care, it can resolve ΔH° and ΔS°. The first part of the protocol, protein preparation, may take several weeks, whereas the FP measurements, once they have been optimized, would normally take 1-6 h.
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Affiliation(s)
- Ana M Rossi
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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8
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Best MD, Zhang H, Prestwich GD. Inositol polyphosphates, diphosphoinositol polyphosphates and phosphatidylinositol polyphosphate lipids: Structure, synthesis, and development of probes for studying biological activity. Nat Prod Rep 2010; 27:1403-30. [DOI: 10.1039/b923844c] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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9
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Selective photoinactivation of protein function through environment-sensitive switching of singlet oxygen generation by photosensitizer. Proc Natl Acad Sci U S A 2008; 105:28-32. [PMID: 18172220 DOI: 10.1073/pnas.0611717105] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chromophore-assisted light inactivation is a promising technique to inactivate selected proteins with high spatial and temporal resolution in living cells, but its use has been limited because of the lack of a methodology to prevent nonspecific photodamage in the cell owing to reactive oxygen species generated by the photosensitizer. Here we present a design strategy for photosensitizers with an environment-sensitive off/on switch for singlet oxygen ((1)O(2)) generation, which is switched on by binding to the target, to improve the specificity of protein photoinactivation. (1)O(2) generation in the unbound state is quenched by photoinduced electron transfer, whereas (1)O(2) generation can occur in the hydrophobic environment provided by the target protein, after specific binding. Inositol 1,4,5-trisphosphate receptor, which has been suggested to have a hydrophobic pocket around the ligand binding site, was specifically inactivated by an environment-sensitive photosensitizer-conjugated inositol 1,4,5-trisphosphate receptor ligand without (1)O(2) generation in the cytosol of the target cells, despite light illumination, demonstrating the potential of environment-sensitive photosensitizers to allow high-resolution control of generation of reactive oxygen species in the cell.
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10
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Mochizuki T, Kondo Y, Abe H, Tovey SC, Dedos SG, Taylor CW, Paul M, Potter BVL, Matsuda A, Shuto S. Synthesis of adenophostin A analogues conjugating an aromatic group at the 5'-position as potent IP3 receptor ligands. J Med Chem 2006; 49:5750-8. [PMID: 16970399 DOI: 10.1021/jm060310d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous structure-activity relationship studies of adenophostin A, a potent IP(3) receptor agonist, led us to design the novel adenophostin A analogues 5a-c, conjugating an aromatic group at the 5'-position to develop useful IP(3) receptor ligands. The common key intermediate, a D-ribosyl alpha-D-glucoside 10alpha, was stereoselectively synthesized by a glycosidation with the 1-sulfinylglucoside donor 11, which was conformationally restricted by a 3,4-O-cyclic diketal protecting group. After introduction of an aromatic group at the 5-position of the ribose moiety, an adenine base was stereoselectively introduced at the anomeric beta-position to form 7a-c, where the tetra-O-i-butyryl donors 9a-c were significantly more effective than the corresponding O-acetyl donor. Thus, the target compounds 5a-c were synthesized via phosphorylation of the 2', 3' ', and 4' '-hydroxyls. The potencies of compounds 5a-c for Ca(2+) release were shown to be indistinguishable from that of adenophostin A, indicating that bulky substitutions at the 5'-position of adenophostin A are well-tolerated in the receptor binding. This biological activity of 5a-c can be rationalized by molecular modeling using the ligand binding domain of the IP(3) receptor.
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Affiliation(s)
- Tetsuya Mochizuki
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan
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11
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Chrétien F, Roussel F, Hilly M, Mauger J, Chapleur Y. New Sugar‐Based Permeant Analogs of D‐ Myo ‐Inositol 1,4,5‐Trisphosphate Mimicking the Effect of Vasopressin: Synthesis and Biologic Evaluation*. J Carbohydr Chem 2005. [DOI: 10.1081/car-200068070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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12
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Yogo T, Kikuchi K, Inoue T, Hirose K, Iino M, Nagano T. Modification of Intracellular Ca2+ Dynamics by Laser Inactivation of Inositol 1,4,5-Trisphosphate Receptor Using Membrane-Permeant Probes. ACTA ACUST UNITED AC 2004; 11:1053-8. [PMID: 15324806 DOI: 10.1016/j.chembiol.2004.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2004] [Revised: 05/06/2004] [Accepted: 05/11/2004] [Indexed: 10/26/2022]
Abstract
A membrane-permeant malachite green-conjugated IP3 analog (MGIP3/PM) was synthesized as a probe for small molecule-based CALI (smCALI), and its effect on the Ca2+ signaling in intact DT40 chicken B cells was examined. In DT40 B cells treated with the smCALI probe, laser irradiation inhibited IP3-induced Ca2+ oscillations in response to B cell receptor stimulation, demonstrating that IP3R was acutely inactivated. We then applied smCALI to clarify the mechanism of capacitative Ca2+ entry (CCE), in which involvement of IP3R has been suggested. Despite the inactivation of IP3R by smCALI, thapsigargin-induced CCE remained unaffected, providing evidence that functional IP3R is not required for CCE in DT40 cells. These results demonstrate the potency of the smCALI technique for the study of the roles of IP3R in complex intracellular Ca2+ dynamics.
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MESH Headings
- Animals
- Calcium/metabolism
- Calcium Channels/metabolism
- Calcium Signaling/drug effects
- Cell Line
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Cell Membrane Permeability
- Chickens
- Inositol 1,4,5-Trisphosphate/analogs & derivatives
- Inositol 1,4,5-Trisphosphate/metabolism
- Inositol 1,4,5-Trisphosphate/pharmacology
- Inositol 1,4,5-Trisphosphate Receptors
- Lasers
- Molecular Structure
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/metabolism
- Rosaniline Dyes/chemistry
- Rosaniline Dyes/metabolism
- Thapsigargin/pharmacology
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Affiliation(s)
- Takatoshi Yogo
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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13
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Abstract
Lipid signaling by phosphoinositides (PIP(n)s) involves an array of proteins with lipid recognition, kinase, phosphatase, and phospholipase functions. Understanding PIP(n) pathway signaling requires identification and characterization of PIP(n)-interacting proteins. Moreover, spatiotemporal localization and physiological function of PIP(n)-protein complexes must be elucidated in cellular and organismal contexts. For protein discovery to functional elucidation, reporter-linked phosphoinositides or tethered PIP(n)s have been essential. The phosphoinositide 3-kinase (PI 3-K) signaling pathway has recently emerged as an important source of potential "druggable" therapeutic targets in human pathophysiology in both academic and pharmaceutical environments. This review summarizes the chemistry of PIP(n) affinity probes and their use in identifying macromolecular targets. The process of target validation will be described, i.e., the use of tethered PIP(n)s in determining PIP(n) selectivity in vitro and in establishing the function of PIP(n)-protein complexes in living cells.
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Affiliation(s)
- Glenn D Prestwich
- Department of Medicinal Chemistry, The University of Utah, 419 Wakara Way, Suite 205, Salt Lake City, UT 84108, USA.
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14
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Inoue T, Kikuchi K, Hirose K, Iino M, Nagano T. Spatiotemporal laser inactivation of inositol 1,4,5-trisphosphate receptors using synthetic small-molecule probes. CHEMISTRY & BIOLOGY 2003; 10:503-9. [PMID: 12837383 DOI: 10.1016/s1074-5521(03)00122-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A malachite green-conjugated inositol 1,4,5-trisphosphate (MGIP(3)) induces specific inactivation of IP(3) receptor (IP(3)R) in tissue samples upon laser irradiation. To verify potential usefulness of the method for studies of cellular Ca(2+) signaling, we conducted laser inactivation at the single-cell level and show that IP(3)R was inactivated with extremely high spatiotemporal resolution. In the presence of MGIP(3), the Ca(2+) release function of IP(3)R in single B lymphoma cells decayed exponentially with increasing duration of laser irradiation with a time constant of 3.4 s. Moreover, by confining laser irradiation to a spatially distinct region of differentiated PC12 cells, subcellular inactivation of IP(3)R was attained, as revealed by a loss of local Ca(2+) signal. Such real-time inactivation of IP(3)R only within a subcellular region may provide a powerful method for investigating spatiotemporal dynamics of Ca(2+) signaling.
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MESH Headings
- Animals
- Calcium Channels/drug effects
- Calcium Channels/metabolism
- Calcium Channels/radiation effects
- Calcium Signaling/drug effects
- Calcium Signaling/radiation effects
- Chickens
- Inositol 1,4,5-Trisphosphate/chemistry
- Inositol 1,4,5-Trisphosphate/pharmacology
- Inositol 1,4,5-Trisphosphate Receptors
- Ion Channel Gating
- Lasers
- Lymphoma, B-Cell
- Methods
- Molecular Probes
- PC12 Cells
- Rats
- Receptors, Cytoplasmic and Nuclear/drug effects
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Cytoplasmic and Nuclear/radiation effects
- Rosaniline Dyes/chemistry
- Time Factors
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Affiliation(s)
- Takanari Inoue
- Graduate School of Pharmaceutical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, 113-0033, Tokyo, Japan
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15
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Nakanishi W, Kikuchi K, Inoue T, Hirose K, Iino M, Nagano T. Hydrophobic modifications at 1-phosphate of inositol 1,4,5-trisphosphate analogues enhance receptor binding. Bioorg Med Chem Lett 2002; 12:911-3. [PMID: 11958992 DOI: 10.1016/s0960-894x(02)00044-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Inositol 1,4,5-trisphosphate (IP(3)) analogues were synthesized in order to investigate the importance of the environment of 1-phosphate of IP(3) for strong binding to the IP(3) receptor. Our results show that hydrophobic modifications of the 1-phosphate moiety enhance the binding affinity, with considerable latitude of substituent structure.
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Affiliation(s)
- Waka Nakanishi
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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16
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Inoue T, Kikuchi K, Hirose K, Iino M, Nagano T. Small molecule-based laser inactivation of inositol 1,4,5-trisphosphate receptor. CHEMISTRY & BIOLOGY 2001; 8:9-15. [PMID: 11182315 DOI: 10.1016/s1074-5521(00)00051-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Chromophore-assisted laser inactivation (CALI) is a powerful method for the study of in situ protein function in cellular processes. By using CALI, it is possible to abrogate the function of a target protein with unprecedented spatial and temporal resolution. However, CALI has some limitations, which restrict wider biological application, owing mainly to the use of antibody for target recognition. To circumvent the limitations, we have developed small molecule-based CALI (smCALI). RESULTS The inositol 1,4,5-trisphosphate receptor (IP3R) was selected as the target protein and a malachite green-conjugated IP3 analog, MGIP3, was used as a small-molecular probe. We examined the effect of MGIP3-based CALI on Ca2+ release via IP3R using permeabilized smooth muscle cells. When the cells were treated with MGIP3 followed by laser irradiation, the IP3-induced Ca2+ release rate was decreased in a concentration- and irradiation time-dependent manner. The effect was specific for IP3R, because the Ca2+ uptake function of the co-localized sarco/endoplasmic reticulum Ca2+-ATPase was not affected. CONCLUSIONS IP3R was specifically inactivated by smCALI using MGIP3. The efficiency of inactivation was calculated to be substantially greater than that of antibody-based CALI. The efficient and specific inactivation of IP3R would allow us to obtain an insight into spatiotemporal roles of IP3R in various cell functions. Our results may be considered to be a first step for a wider application of smCALI as a useful method to study spatiotemporal protein functions.
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Affiliation(s)
- T Inoue
- Graduate School of Pharmaceutical Sciences, University of Tokyo, Japan
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17
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Abstract
The application of surface plasmon resonance biosensors in life sciences and pharmaceutical research continues to increase. This review provides a comprehensive list of the commercial 1999 SPR biosensor literature and highlights emerging applications that are of general interest to users of the technology. Given the variability in the quality of published biosensor data, we present some general guidelines to help increase confidence in the results reported from biosensor analyses.
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Affiliation(s)
- R L Rich
- Center for Biomolecular Interaction Analysis, University of Utah School of Medicine, Salt Lake City 84132, USA
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Mehrotra B, Myszka DG, Prestwich GD. Binding kinetics and ligand specificity for the interactions of the C2B domain of synaptogmin II with inositol polyphosphates and phosphoinositides. Biochemistry 2000; 39:9679-86. [PMID: 10933784 DOI: 10.1021/bi000487o] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Synaptotagmin II (Syt II) is a key protein in the calcium-dependent exocytosis of synaptic vesicles. It contains two domains homologous to the C2 regulatory region of protein kinase C. The C2A domain acts as a calcium sensor, while the C2B domain has high affinity for inositol polyphosphates (InsP(n)()s) and phosphoinositide polyphosphates (PtdInsP(n)()s). We describe the use of a surface plasmon resonance biosensor in determining the binding kinetics of the C2B domain with InsP(n)() and PtdInsP(n) ligands. Biosensor surfaces were prepared with covalently attached Ins(1,4,5)P(3), Ins(1,3,4,5)P(4), and InsP(6) ligands. The interactions of bacterially expressed His(6)-tagged C2B and (C2A+C2B) domains of Syt II were examined in the presence and absence of competing InsP(n)s and PtdInsP(n)s. Both His(6)-C2B and His(6)-(C2A+C2B) exhibited the highest affinity for the Ins(1,3,4,5)P(4)-modified surface with a K(D) value of 6 nM. The His(6)-(C2A+C2B) had a 10-fold lower association rate constant for the InsP(6)-linked surface (k(a) = 4.6 x 10(3) M(-1) s(-1)) than for the Ins(1,3,4,5)P(4)-modified surface (k(a) = 6.8 x 10(4) M(-1) s(-1)). Two water-soluble phosphoinositides, dioctanoyl-PtdIns(3,4,5)P(3) and dioctanoyl-PtdIns(4,5)P(2), were superior to the soluble InsP(n)s in displacing binding to the Ins(1,3,4,5)P(4)-modified surface. The binding of His(6)-C2B and His(6)-(C2A+C2B) to InsP(n) surfaces did not show significant calcium dependence. These data support a model in which the binding of the C2B domain of Syt II to PtdInsP(n)s is important for the docking and/or fusion of the secretory vesicles to the synaptic plasma membrane.
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Affiliation(s)
- B Mehrotra
- Department of Medicinal Chemistry, The University of Utah, 30 South 2000 East, Room 201, Salt Lake City, Utah 84112-5820, USA
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