51
|
Alvarez L, Friedrich BM, Gompper G, Kaupp UB. The computational sperm cell. Trends Cell Biol 2013; 24:198-207. [PMID: 24342435 DOI: 10.1016/j.tcb.2013.10.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 10/13/2013] [Accepted: 10/14/2013] [Indexed: 10/25/2022]
Abstract
Sperm are guided to the egg by a gradient of chemical attractants - a process called chemotaxis. The binding of the chemoattractant to receptors on the surface of the flagellum triggers a cascade of signaling events that eventually lead to an influx of Ca(2+) ions. Based on these Ca(2+) surges, which control the waveform of the flagellar beat, sperm adjust their swimming path toward the egg. In past years, many components of chemotactic signaling have been identified. Moreover, kinetic spectroscopy and imaging techniques unraveled the sequence of cellular events controlling swimming behavior. During navigation in a chemical gradient, sperm perform a surprising variety of computational operations. Here we discuss theoretical concepts of navigation strategies and the cellular underpinnings.
Collapse
Affiliation(s)
- Luis Alvarez
- Center of Advanced European Studies and Research (CAESAR), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
| | - Benjamin M Friedrich
- Max Planck Institute for the Physics of Complex Systems, Nöthnitzer Straße 38, 01187 Dresden, Germany
| | - Gerhard Gompper
- Research Centre Jülich, Institute of Complex Systems (ICS-2), 52425 Jülich, Germany
| | - U Benjamin Kaupp
- Center of Advanced European Studies and Research (CAESAR), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
| |
Collapse
|
52
|
Olson JP, Banghart MR, Sabatini BL, Ellis-Davies GCR. Spectral evolution of a photochemical protecting group for orthogonal two-color uncaging with visible light. J Am Chem Soc 2013; 135:15948-54. [PMID: 24117060 DOI: 10.1021/ja408225k] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Caged compounds are molecules rendered functionally inert by derivatization with a photochemical protecting group. We describe the design logic behind the development of a diethylaminocoumarin (DEAC) caging chromophore, DEAC450, that absorbs blue light strongly (ε450 = 43,000 M(-1) cm(-1)) and violet light 11-fold more weakly. The absorption minimum is in the wavelength range (340-360 nm) that is traditionally used for photolysis of many widely used nitroaromatic caged compounds (e.g., 4-carboxymethoxy-5,7-dinitroindolinyl(CDNI)-GABA). We used this chromophore to synthesize DEAC450-caged cAMP and found this probe was very stable toward aqueous hydrolysis in the electronic ground state but was photolyzed with a quantum efficiency of 0.78. When DEAC450-cAMP and CDNI-GABA where co-applied to striatal cholinergic interneurons, the caged compounds were photolyzed in an chromatically orthogonal manner using blue and violet light so as to modulate the neuronal firing rate in a bidirectional way.
Collapse
Affiliation(s)
- Jeremy P Olson
- Department of Neuroscience, Mount Sinai School of Medicine , New York, New York 10029, United States
| | | | | | | |
Collapse
|
53
|
Affiliation(s)
- U B Kaupp
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, 53175 Bonn, Germany
| |
Collapse
|
54
|
Olson JP, Kwon HB, Takasaki KT, Chiu CQ, Higley MJ, Sabatini BL, Ellis-Davies GCR. Optically selective two-photon uncaging of glutamate at 900 nm. J Am Chem Soc 2013; 135:5954-7. [PMID: 23577752 DOI: 10.1021/ja4019379] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have synthesized a 7-diethylaminocoumarin (DEAC) derivative that allows wavelength-selective two-photon uncaging at 900 nm versus 720 nm. This new caging chromophore, called DEAC450, has an extended π-electron moiety at the 3-position that shifts the absorption spectrum maximum of DEAC from 375 to 450 nm. Two-photon excitation at 900 nm was more than 60-fold greater than at 720 nm. Two-photon uncaging of DEAC450-Glu at 900 nm at spine heads on pyramidal neurons in acutely isolated brain slices generated postsynaptic responses that were similar to spontaneous postsynaptic excitatory miniature currents, whereas significantly higher energies at 720 nm evoked no currents. Since many nitroaromatic caged compounds are two-photon active at 720 nm, optically selective uncaging of DEAC450-caged biomolecules at 900 nm may allow facile two-color optical interrogation of bimodal signaling pathways in living tissue with high resolution for the first time.
Collapse
Affiliation(s)
- Jeremy P Olson
- Department of Neuroscience, Mount Sinai School of Medicine, New York, New York 10029, USA
| | | | | | | | | | | | | |
Collapse
|
55
|
|
56
|
Kashikar ND, Alvarez L, Seifert R, Gregor I, Jäckle O, Beyermann M, Krause E, Kaupp UB. Temporal sampling, resetting, and adaptation orchestrate gradient sensing in sperm. ACTA ACUST UNITED AC 2013; 198:1075-91. [PMID: 22986497 PMCID: PMC3444779 DOI: 10.1083/jcb.201204024] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Sperm use temporal sampling, resetting of intracellular calcium level, and adaptation of their sensitivity to respond to a wide range of chemoattractant concentrations during their voyage toward the egg. Sperm, navigating in a chemical gradient, are exposed to a periodic stream of chemoattractant molecules. The periodic stimulation entrains Ca2+ oscillations that control looping steering responses. It is not known how sperm sample chemoattractant molecules during periodic stimulation and adjust their sensitivity. We report that sea urchin sperm sampled molecules for 0.2–0.6 s before a Ca2+ response was produced. Additional molecules delivered during a Ca2+ response reset the cell by causing a pronounced Ca2+ drop that terminated the response; this reset was followed by a new Ca2+ rise. After stimulation, sperm adapted their sensitivity following the Weber–Fechner law. Taking into account the single-molecule sensitivity, we estimate that sperm can register a minimal gradient of 0.8 fM/µm and be attracted from as far away as 4.7 mm. Many microorganisms sense stimulus gradients along periodic paths to translate a spatial distribution of the stimulus into a temporal pattern of the cell response. Orchestration of temporal sampling, resetting, and adaptation might control gradient sensing in such organisms as well.
Collapse
Affiliation(s)
- Nachiket D Kashikar
- Department of Molecular Sensory Systems, Center of Advanced European Studies and Research, 53175 Bonn, Germany
| | | | | | | | | | | | | | | |
Collapse
|
57
|
Ellis-Davies GC. A chemist and biologist talk to each other about caged neurotransmitters. Beilstein J Org Chem 2013; 9:64-73. [PMID: 23399979 PMCID: PMC3566830 DOI: 10.3762/bjoc.9.8] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Accepted: 12/07/2012] [Indexed: 11/23/2022] Open
Abstract
Caged compounds are small organic molecules that can be photoactivated with brief pulses of light. They are widely used to study a great variety of biological processes by physiologists, cell biologists and neuroscientists. Initially made and invented by biologists in the late 1970s, they are now made mostly by chemists, often without any dialogue with the end users, the biologists. The idea for this review is to stimulate interaction between the two communities to further the creative development and application of these powerful optical probes.
Collapse
Affiliation(s)
- Graham Cr Ellis-Davies
- Department of Neuroscience, Mount Sinai School of Medicine, One Gustave Levy Place, New York, NY 10029, USA
| |
Collapse
|
58
|
Sarker MI, Shahrin T, Steinmetz MG, Timerghazin QK. Photochemical electrocyclic ring closure and leaving group expulsion from N-(9-oxothioxanthenyl)benzothiophene carboxamides. Photochem Photobiol Sci 2013; 12:309-22. [DOI: 10.1039/c2pp25051a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
59
|
Furuta T, Manabe K, Teraoka A, Murakoshi K, Ohtsubo A, Suzuki A. Design, synthesis, and photochemistry of modular caging groups for photoreleasable nucleotides. Org Lett 2012. [PMID: 23205776 DOI: 10.1021/ol3029093] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A modular approach to preparing caged nucleotides having additional properties has been achieved. The modular caging agent includes three components: an amine reactive NHS ester moiety, a photoactive Bhc group, and tosylhydrazone as a precursor of the diazomethyl group. Various amines including biotin and an Arg-Gly-Asp (RGD) peptide were introduced into the key intermediate via amide linkage. The Bio-Bhc-diazo thus synthesized enables the preparation of a photoreleasable siRNA with additional properties.
Collapse
Affiliation(s)
- Toshiaki Furuta
- Department of Biomolecular Science, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, 274-8510, Japan.
| | | | | | | | | | | |
Collapse
|
60
|
Wymann MP, Schultz C. The chemical biology of phosphoinositide 3-kinases. Chembiochem 2012; 13:2022-35. [PMID: 22965647 DOI: 10.1002/cbic.201200089] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 07/13/2012] [Indexed: 01/14/2023]
Abstract
Since its discovery in the late 1980s, phosphoinositide 3-kinase (PI3K), and its isoforms have arguably reached the forefront of signal transduction research. Regulation of this lipid kinase, its functions, its effectors, in short its entire signaling network, has been extensively studied. PI3K inhibitors are frequently used in biochemistry and cell biology. In addition, many pharmaceutical companies have launched drug-discovery programs to identify modulators of PI3Ks. Despite these efforts and a fairly good knowledge of the PI3K signaling network, we still have only a rudimentary picture of the signaling dynamics of PI3K and its lipid products in space and time. It is therefore essential to create and use novel biological and chemical tools to manipulate the phosphoinositide signaling network with spatial and temporal resolution. In this review, we discuss the current and potential future tools that are available and necessary to unravel the various functions of PI3K and its isoforms.
Collapse
Affiliation(s)
- Matthias P Wymann
- Institute of Biochemistry & Genetics, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | | |
Collapse
|
61
|
Weis S, Shafiq Z, Gropeanu RA, del Campo A. Ethyl substituted coumarin-4-yl derivatives as photoremovable protecting groups for amino acids with improved stability for SPPS. J Photochem Photobiol A Chem 2012. [DOI: 10.1016/j.jphotochem.2012.05.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
62
|
Lin Q, Bao C, Cheng S, Yang Y, Ji W, Zhu L. Target-Activated Coumarin Phototriggers Specifically Switch on Fluorescence and Photocleavage upon Bonding to Thiol-Bearing Protein. J Am Chem Soc 2012; 134:5052-5. [DOI: 10.1021/ja300475k] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Qiuning Lin
- Shanghai
Key Laboratory of Functional Materials Chemistry,
Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Chunyan Bao
- Shanghai
Key Laboratory of Functional Materials Chemistry,
Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Shuiyu Cheng
- Shanghai
Key Laboratory of Functional Materials Chemistry,
Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Yunlong Yang
- Shanghai
Key Laboratory of Functional Materials Chemistry,
Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Wei Ji
- Shanghai
Key Laboratory of Functional Materials Chemistry,
Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Linyong Zhu
- Shanghai
Key Laboratory of Functional Materials Chemistry,
Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237, P. R. China
| |
Collapse
|
63
|
Wu T, Tang H, Bohne C, Branda NR. Reporting the Release of Caged Species by a Combination of Two Sequential Photoreactions, a Molecular Switch, and One Color of Light. Angew Chem Int Ed Engl 2012; 51:2741-4. [DOI: 10.1002/anie.201108336] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Indexed: 11/08/2022]
|
64
|
Wu T, Tang H, Bohne C, Branda NR. Reporting the Release of Caged Species by a Combination of Two Sequential Photoreactions, a Molecular Switch, and One Color of Light. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201108336] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
65
|
Abstract
Cell migration is required for many physiological processes, including wound repair and embryogenesis, and relies on precisely orchestrated events that are regulated in a spatially and temporally controlled manner. Most traditional approaches for studying migration, such as genetic methods or the use of chemical inhibitors, do not offer insight into these important components of protein function. However, chemical tools, which respond on a more rapid time scale and in localized regions of the cell, are capable of providing more detailed, real-time information. This Review describes these recent approaches to investigate cell migration and focuses on proteins that are activated by light or small molecules, as well as fluorescent sensors of protein activity.
Collapse
Affiliation(s)
- Brenda N. Goguen
- Departments of Biology and Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Barbara Imperiali
- Departments of Biology and Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
66
|
Boccaccio A, Sagheddu C, Menini A. Flash photolysis of caged compounds in the cilia of olfactory sensory neurons. J Vis Exp 2011:e3195. [PMID: 22064384 DOI: 10.3791/3195] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Photolysis of caged compounds allows the production of rapid and localized increases in the concentration of various physiologically active compounds. Caged compounds are molecules made physiologically inactive by a chemical cage that can be broken by a flash of ultraviolet light. Here, we show how to obtain patch-clamp recordings combined with photolysis of caged compounds for the study of olfactory transduction in dissociated mouse olfactory sensory neurons. The process of olfactory transduction (Figure 1) takes place in the cilia of olfactory sensory neurons, where odorant binding to receptors leads to the increase of cAMP that opens cyclic nucleotide-gated (CNG) channels. Ca entry through CNG channels activates Ca-activated Cl channels. We show how to dissociate neurons from the mouse olfactory epithelium and how to activate CNG channels or Ca-activated Cl channels by photolysis of caged cAMP or caged Ca. We use a flash lamp to apply ultraviolet flashes to the ciliary region to uncage cAMP or Ca while patch-clamp recordings are taken to measure the current in the whole-cell voltage-clamp configuration.
Collapse
|
67
|
Menge C, Heckel A. Coumarin-caged dG for improved wavelength-selective uncaging of DNA. Org Lett 2011; 13:4620-3. [PMID: 21834506 DOI: 10.1021/ol201842x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Herein we report on diethylaminocoumarin (DEACM) as a new photoremovable protecting group for 2'-deoxyguanosine in oligonucleotides. An oligonucleotide with O(6)-DEACM-caged dG was synthesized and photochemically analyzed. The DEACM group shows superior photochemical properties at 405 nm with an uncaging efficiency (ε·φ) for deprotection that is 17 times higher than that for 2-(o-nitrophenyl)-propyl NPP caging groups in the same position. Wavelength-selective deprotection in the presence of NPP groups proceeds up to 80 times faster.
Collapse
Affiliation(s)
- Clara Menge
- Frankfurt Institute for Molecular Life Sciences (FMLS), Goethe University of Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt (M.), Germany
| | | |
Collapse
|
68
|
Goguen BN, Aemissegger A, Imperiali B. Sequential activation and deactivation of protein function using spectrally differentiated caged phosphoamino acids. J Am Chem Soc 2011; 133:11038-41. [PMID: 21692531 DOI: 10.1021/ja2028074] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photolabile caging groups, including the 1-(2-nitrophenyl)ethyl (NPE) group, have been applied to probe many biological processes, including protein phosphorylation. Although studies with NPE-caged phosphoamino acids have provided valuable information, these investigations have been limited to the use of only one caged species in a single experiment. To expand the scope of these tools, we have developed an approach for sequentially uncaging two different phosphopeptides in one system, enabling interrogation of multiple phosphorylation events. We present the synthesis of [7-(diethylamino)coumarin-4-yl]methyl (DEACM)-caged phosphorylated serine, threonine, and tyrosine building blocks for Fmoc-based solid-phase peptide synthesis to allow convenient incorporation of these residues into peptides and proteins. Exposure of DEACM- and NPE-caged phosphopeptides to 420 nm light selectively releases the DEACM group without affecting the NPE-caged peptide. This then enables a subsequent irradiation event at 365 nm to remove the NPE group and liberate a second phosphopeptide. We demonstrate the versatility of this general sequential uncaging approach by applying it to control Wip1 phosphatase with two wavelengths of light.
Collapse
Affiliation(s)
- Brenda N Goguen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | | | | |
Collapse
|
69
|
Priestman MA, Sun L, Lawrence DS. Dual wavelength photoactivation of cAMP- and cGMP-dependent protein kinase signaling pathways. ACS Chem Biol 2011; 6:377-84. [PMID: 21218856 PMCID: PMC3078176 DOI: 10.1021/cb100398e] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The spatial and temporal organization of biological systems offers a level of complexity that is challenging to probe with conventional reagents. Photoactivatable (caged) compounds represent one strategy by which spatiotemporal organizational complexities can be addressed. However, since the vast majority of caged species are triggered by UV light, it is not feasible to orthogonally control two or more spatiotemporal elements of the phenomenon under investigation. For example, the cGMP- and cAMP-dependent protein kinases are highly homologous enzymes, separated in time and space, which mediate the phosphorylation of both distinct and common protein substrates. However, current technology is unable to discriminate, in a temporally or spatially selective fashion, between these enzymes and/or the pathways they influence. We describe herein the intracellular triggering of a cGMP-mediated pathway with 360 nm light and the corresponding cAMP-mediated pathway with 440 nm light. Dual wavelength photoactivation was assessed in A10 cells by monitoring the phosphorylation of vasodilator-stimulated phosphoprotein (VASP), a known substrate for both the cAMP- and cGMP-dependent protein kinases. Illumination at 440 nm elicits a cAMP-dependent phosphorylation of VASP at Ser157, whereas 360 nm exposure triggers the phosphorylation of both Ser157 and Ser239. This is the first example of wavelength-distinct activation of two separate nodes of a common signaling pathway.
Collapse
Affiliation(s)
- Melanie A Priestman
- Department of Chemistry, the Division of Medicinal Chemistry & Natural Products, School of Pharmacy, The University of North Carolina at Chapel Hill, United States
| | | | | |
Collapse
|
70
|
Mentel M, Laketa V, Subramanian D, Gillandt H, Schultz C. Photoaktivierbares und zellmembranpermeables Phosphatidylinositol-3,4,5-trisphosphat. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201007796] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
71
|
Mentel M, Laketa V, Subramanian D, Gillandt H, Schultz C. Photoactivatable and Cell-Membrane-Permeable Phosphatidylinositol 3,4,5-Trisphosphate. Angew Chem Int Ed Engl 2011; 50:3811-4. [DOI: 10.1002/anie.201007796] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Indexed: 11/08/2022]
|
72
|
Nomura W, Narumi T, Ohashi N, Serizawa Y, Lewin NE, Blumberg PM, Furuta T, Tamamura H. Synthetic caged DAG-lactones for photochemically controlled activation of protein kinase C. Chembiochem 2011; 12:535-9. [PMID: 22238145 PMCID: PMC8259317 DOI: 10.1002/cbic.201000670] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Indexed: 11/07/2022]
Abstract
Switching on kinases: Synthetic caged DAG-lactones have been developed and showed decreases of two orders of magnitude, relative to the corresponding parent compounds, in their binding affinities towards PKC. The caged compounds had no effect on the translocation of PKC until after photoactivation. This approach is a potentially powerful tool for probing the PKC signaling cascade.
Collapse
Affiliation(s)
- Wataru Nomura
- Department of Medicinal Chemistry, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan
| | | | | | | | | | | | | | | |
Collapse
|
73
|
Himes JE, Riffell JA, Zimmer CA, Zimmer RK. Sperm chemotaxis as revealed with live and synthetic eggs. THE BIOLOGICAL BULLETIN 2011; 220:1-5. [PMID: 21385951 DOI: 10.1086/bblv220n1p1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Fertilization is one of the least understood fundamental biological processes. How sperm search for and find an egg remains enigmatic. Sperm attraction to egg-derived chemical cues may be significant evolutionarily for maintaining species barriers and important ecologically for increasing gamete encounters. New tools are needed, however, to resolve the functional consequences of these dissolved signal molecules. Freshly spawned eggs from red abalone (Haliotis rufescens) naturally release l-tryptophan, which stimulates chemotactic responses by conspecific sperm. Here, microspheres were manufactured to the approximate size and the same shape as female gametes and formulated to emit controlled doses of chemoattractant, imitating natural l-tryptophan release rates. When experimentally tested for effectiveness, male gametes did not distinguish between chemically impregnated mimics and live eggs, demonstrating that l-tryptophan alone is both necessary and sufficient to promote chemotaxis, and confirming the identity of a native sperm attractant. The techniques that we describe can be used to create synthetic eggs for most animal and plant species, including humans. Egg mimics increase the capacity for experimental manipulation and enable realistic studies of sperm behavior even in the absence of female gametes.
Collapse
Affiliation(s)
- Julie E Himes
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095-1606, USA
| | | | | | | |
Collapse
|
74
|
Chromophores for the Delivery of Bioactive Molecules with Two-Photon Excitation. NEUROMETHODS 2011. [DOI: 10.1007/978-1-61779-031-7_4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
75
|
Activation of membrane-permeant caged PtdIns(3)P induces endosomal fusion in cells. Nat Chem Biol 2010; 6:324-6. [PMID: 20364126 DOI: 10.1038/nchembio.348] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 01/25/2010] [Indexed: 11/08/2022]
Abstract
Phosphatidylinositol 3-phosphate (PtdIns(3)P) is a phospholipid residing on early endosomes, where it is proposed to be involved in endosomal fusion. We synthesized membrane-permeant derivatives of PtdIns(3)P, including a caged version that is to our knowledge the first photoactivatable phosphoinositide derivative developed so far. In living cells, photoactivation of caged PtdIns(3)P induced rapid endosomal fusion in an EEA1-dependent fashion, thus providing in vivo evidence that PtdIns(3)P is a sufficient signal for driving this process.
Collapse
|
76
|
Lin W, Long L, Tan W, Chen B, Yuan L. Coumarin-Caged Rosamine Probes Based on a Unique Intramolecular Carbon-Carbon Spirocyclization. Chemistry 2010; 16:3914-7. [DOI: 10.1002/chem.201000015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
77
|
Obi N, Momotake A, Kanemoto Y, Matsuzaki M, Kasai H, Arai T. 1-Acyl-5-methoxy-8-nitro-1,2-dihydroquinoline: a biologically useful photolabile precursor of carboxylic acids. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2009.12.081] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
78
|
Yu H, Li J, Wu D, Qiu Z, Zhang Y. Chemistry and biological applications of photo-labile organic molecules. Chem Soc Rev 2010; 39:464-73. [DOI: 10.1039/b901255a] [Citation(s) in RCA: 213] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
79
|
Two-color, two-photon uncaging of glutamate and GABA. Nat Methods 2009; 7:123-5. [PMID: 20037590 DOI: 10.1038/nmeth.1413] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 11/30/2009] [Indexed: 11/08/2022]
Abstract
We developed a caged GABA (gamma-aminobutyric acid), which, when combined with an appropriate caged glutamate, allows bimodal control of neuronal membrane potential with subcellular resolution using optically independent two-photon uncaging of each neurotransmitter. We used two-color, two-photon uncaging to fire and block action potentials from rat hippocampal CA1 neurons in brain slices with 720-nm and 830-nm light, respectively. Our method should be generalizable to other chemical messenger pairs.
Collapse
|
80
|
Kotzur N, Briand B, Beyermann M, Hagen V. Wavelength-Selective Photoactivatable Protecting Groups for Thiols. J Am Chem Soc 2009; 131:16927-31. [DOI: 10.1021/ja907287n] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nico Kotzur
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Benoît Briand
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Michael Beyermann
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Volker Hagen
- Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| |
Collapse
|
81
|
Bönigk W, Loogen A, Seifert R, Kashikar N, Klemm C, Krause E, Hagen V, Kremmer E, Strünker T, Kaupp UB. An atypical CNG channel activated by a single cGMP molecule controls sperm chemotaxis. Sci Signal 2009; 2:ra68. [PMID: 19861689 DOI: 10.1126/scisignal.2000516] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Sperm of the sea urchin Arbacia punctulata can respond to a single molecule of chemoattractant released by an egg. The mechanism underlying this extreme sensitivity is unknown. Crucial signaling events in the response of A. punctulata sperm to chemoattractant include the rapid synthesis of the intracellular messenger guanosine 3',5'-monophosphate (cGMP) and the ensuing membrane hyperpolarization that results from the opening of potassium-selective cyclic nucleotide-gated (CNGK) channels. Here, we use calibrated photolysis of caged cGMP to show that approximately 45 cGMP molecules are generated during the response to a single molecule of chemoattractant. The CNGK channel can respond to such small cGMP changes because it is exquisitely sensitive to cGMP and activated in a noncooperative fashion. Like voltage-activated Ca(v) and Na(v) channels, the CNGK polypeptide consists of four homologous repeat sequences. Disabling each of the four cyclic nucleotide-binding sites through mutagenesis revealed that binding of a single cGMP molecule to repeat 3 is necessary and sufficient to activate the CNGK channel. Thus, CNGK has developed a mechanism of activation that is different from the activation of other CNG channels, which requires the cooperative binding of several ligands and operates in the micromolar rather than the nanomolar range.
Collapse
Affiliation(s)
- Wolfgang Bönigk
- Center of Advanced European Studies and Research, Abteilung Molekulare Neurosensorik, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
82
|
TANIGUCHI A. Development of Click Peptide: Stimuli-responsive Precursor Producing Alzheimer's Disease-related Amyloid β Peptide. YAKUGAKU ZASSHI 2009; 129:1227-32. [DOI: 10.1248/yakushi.129.1227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
83
|
Lee HM, Larson DR, Lawrence DS. Illuminating the chemistry of life: design, synthesis, and applications of "caged" and related photoresponsive compounds. ACS Chem Biol 2009; 4:409-27. [PMID: 19298086 DOI: 10.1021/cb900036s] [Citation(s) in RCA: 369] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Biological systems are characterized by a level of spatial and temporal organization that often lies beyond the grasp of present day methods. Light-modulated bioreagents, including analogs of low molecular weight compounds, peptides, proteins, and nucleic acids, represent a compelling strategy to probe, perturb, or sample biological phenomena with the requisite control to address many of these organizational complexities. Although this technology has created considerable excitement in the chemical community, its application to biological questions has been relatively limited. We describe the challenges associated with the design, synthesis, and use of light-responsive bioreagents; the scope and limitations associated with the instrumentation required for their application; and recent chemical and biological advances in this field.
Collapse
Affiliation(s)
- Hsien-Ming Lee
- Departments of Chemistry, Medicinal Chemistry & Natural Products, and Pharmacology, The University of North Carolina, Chapel Hill, North Carolina 27599-3290
| | - Daniel R. Larson
- Department of Anatomy and Structural Biology, The Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461
| | - David S. Lawrence
- Departments of Chemistry, Medicinal Chemistry & Natural Products, and Pharmacology, The University of North Carolina, Chapel Hill, North Carolina 27599-3290
| |
Collapse
|
84
|
Del Valle-Mondragón L, Tenorio-López FA, Torres-Narváez JC, Zarco-Olvera G, Pastelín-Hernández G. Coronary vasodilator activity of vulgarenol, a sesquiterpene isolated from Magnolia grandiflora, and its possible mechanism. Phytother Res 2009; 23:666-71. [PMID: 19107855 DOI: 10.1002/ptr.2696] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The aim of this study was to investigate the biodynamic effects of vulgarenol, a sesquiterpene isolated from Magnolia grandiflora flower petals and its possible mechanism on the Langendorff isolated and perfused heart model. Vulgarenol (5 microm) caused a statistically significant decrease in coronary vascular resistance (15.21 +/- 6.00 dyn s cm(-5) vs 36.80 +/- 5.01 dyn s cm(-5), control group), increased nitric oxide release (223.01 +/- 8.76 pmol/mL vs 61.00 +/- 12.00 pmol/mL, control group) and cyclic guanosine monophosphate accumulation in left ventricular tissue samples (142.17 +/- 8.41 pmol/mg of tissue vs 43.94 +/- 5.00 pmol/mg of tissue, control group). Pre-treatment with 3 microm gadolinium chloride hexahydrate, 100 microm N(omega)-nitro-L-arginine methyl ester hydrochloride, and 10 microm 1H-[1,2,4]oxadiazolo[4,2-a]quinoxalin-1-one significantly abolished the vulgarenol-induced coronary vascular resistance decrease, nitric oxide increased release and cGMP accumulation in left ventricular tissue samples. The results support the fact that nitric oxide and cyclic guanosine monophosphate are likely involved in the endothelium-dependent coronary vasodilation.
Collapse
Affiliation(s)
- L Del Valle-Mondragón
- Departamento de Farmacología, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, México
| | | | | | | | | |
Collapse
|
85
|
Kostikov AP, Malashikhina N, Popik VV. Caging of Carbonyl Compounds as Photolabile (2,5-Dihydroxyphenyl)ethylene Glycol Acetals. J Org Chem 2009; 74:1802-4. [DOI: 10.1021/jo802612f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Vladimir V. Popik
- Department of Chemistry, University of Georgia, Athens, Georgia 30602
| |
Collapse
|
86
|
Davis MJ, Kragor CH, Reddie KG, Wilson HC, Zhu Y, Dore TM. Substituent Effects on the Sensitivity of a Quinoline Photoremovable Protecting Group to One- and Two-Photon Excitation. J Org Chem 2009; 74:1721-9. [DOI: 10.1021/jo802658a] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- M. Jarrett Davis
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | | | - Khalilah G. Reddie
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - Hunter C. Wilson
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - Yue Zhu
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - Timothy M. Dore
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| |
Collapse
|
87
|
Taniguchi A, Skwarczynski M, Sohma Y, Okada T, Ikeda K, Prakash H, Mukai H, Hayashi Y, Kimura T, Hirota S, Matsuzaki K, Kiso Y. Controlled Production of Amyloid β Peptide from a Photo-Triggered, Water-Soluble Precursor “Click Peptide“. Chembiochem 2008; 9:3055-65. [DOI: 10.1002/cbic.200800503] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
88
|
Kostikov AP, Popik VV. Photolabile Protection of 1,2- and 1,3-Diols with Salicylaldehyde Derivatives. Org Lett 2008; 10:5277-80. [DOI: 10.1021/ol802141g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Vladimir V. Popik
- Department of Chemistry, University of Georgia, Athens, Georgia, 30602
| |
Collapse
|
89
|
Stegmaier P, Alonso JM, Campo AD. Photoresponsive surfaces with two independent wavelength-selective functional levels. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11872-11879. [PMID: 18817427 DOI: 10.1021/la802052u] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Two photoremovable protecting groups, namely, nitroveratryloxycarbonyl (NVo) and diethylamino-coumarin-4-yl (DEACM), have been tested for wavelength-selective, independent removal. The chromophores were attached to the amine group of aminopropyltriethoxysilane and used for the modification of silica surfaces. A photolytic experiment on the photosensitive layers allowed us to identify the irradiation conditions for the selective cleavage of the chromophores. UV measurements revealed that the photolabile DEACM group can be cleaved off with UV light at 412 nm without damaging the NVo group. The NVo group could then be removed at 365 nm. Masked irradiation of substrates modified with a 1:1 molar mixture of both silanes allowed the generation of bifunctional patterns after the selective cleavage of DEACM and NVo in a sequential irradiation process. The deprotection reaction was confirmed by coupling two different fluorescent dyes to the liberated amine groups. The expected two-color pattern could be observed by fluorescence microscopy.
Collapse
Affiliation(s)
- Petra Stegmaier
- Max-Planck-Institut fur Metallforschung, Heisenbergstrasse 3, 70569 Stuttgart, Germany
| | | | | |
Collapse
|
90
|
Moll D, Prinz A, Brendel CM, Berrera M, Guske K, Zaccolo M, Genieser HG, Herberg FW. Biochemical characterization and cellular imaging of a novel, membrane permeable fluorescent cAMP analog. BMC BIOCHEMISTRY 2008; 9:18. [PMID: 18578870 PMCID: PMC2443153 DOI: 10.1186/1471-2091-9-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Accepted: 06/25/2008] [Indexed: 11/10/2022]
Abstract
BACKGROUND A novel fluorescent cAMP analog (8-[Pharos-575]- adenosine-3', 5'-cyclic monophosphate) was characterized with respect to its spectral properties, its ability to bind to and activate three main isoenzymes of the cAMP-dependent protein kinase (PKA-Ialpha, PKA-IIalpha, PKA-IIbeta) in vitro, its stability towards phosphodiesterase and its ability to permeate into cultured eukaryotic cells using resonance energy transfer based indicators, and conventional fluorescence imaging. RESULTS The Pharos fluorophore is characterized by a Stokes shift of 42 nm with an absorption maximum at 575 nm and the emission peaking at 617 nm. The quantum yield is 30%. Incubation of the compound to RIIalpha and RIIbeta subunits increases the amplitude of excitation and absorption maxima significantly; no major change was observed with RIalpha. In vitro binding of the compound to RIalpha subunit and activation of the PKA-Ialpha holoenzyme was essentially equivalent to cAMP; RII subunits bound the fluorescent analog up to ten times less efficiently, resulting in about two times reduced apparent activation constants of the holoenzymes compared to cAMP. The cellular uptake of the fluorescent analog was investigated by cAMP indicators. It was estimated that about 7 muM of the fluorescent cAMP analog is available to the indicator after one hour of incubation and that about 600 muM of the compound had to be added to intact cells to half-maximally dissociate a PKA type IIalpha sensor. CONCLUSION The novel analog combines good membrane permeability- comparable to 8-Br-cAMP - with superior spectral properties of a modern, red-shifted fluorophore. GFP-tagged regulatory subunits of PKA and the analog co-localized. Furthermore, it is a potent, PDE-resistant activator of PKA-I and -II, suitable for in vitro applications and spatial distribution evaluations in living cells.
Collapse
Affiliation(s)
- Daniela Moll
- University of Kassel, Department of Biochemistry, Heinrich-Plett-Strasse 40, 34132 Kassel, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
91
|
Thermodynamics of activation gating in olfactory-type cyclic nucleotide-gated (CNGA2) channels. Biophys J 2008; 95:2750-8. [PMID: 18567637 DOI: 10.1529/biophysj.108.129718] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Olfactory-type cyclic nucleotide-gated (CNG) ion channels open by the binding of cyclic nucleotides to a binding domain in the C-terminus. Employing the Eyring rate theory, we performed a thermodynamic analysis of the activation gating in homotetrameric CNGA2 channels. Lowering the temperature shifted the concentration-response relationship to lower concentrations, resulting in a decrease of both the enthalpy DeltaH and entropy DeltaS upon channel opening, suggesting that the order of an open CNGA2 channel plus its environment is higher than that of the closed channel. Activation time courses induced by cGMP concentration jumps were used to study thermodynamics of the transition state. The activation enthalpies DeltaH++ were positive at all cGMP concentrations. In contrast, the activation entropy DeltaS++ was positive at low cGMP concentrations and became then negative at increasing cGMP concentrations. The enthalpic and entropic parts of the activation energies approximately balance each other at all cGMP concentrations, leaving the free enthalpy of activation in the range between 19 and 21 kcal/mol. We conclude that channel activation proceeds through different pathways at different cGMP concentrations. Compared to the unliganded channel, low cGMP concentrations generate a transitional state of lower order whereas high cGMP concentrations generate a transitional state of higher order.
Collapse
|
92
|
Senda N, Momotake A, Arai T. Synthesis and Photocleavage of 7-[{Bis(carboxymethyl)amino}coumarin-4-yl]methyl-Caged Neurotransmitters. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.2384] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
93
|
Schultz C. Molecular tools for cell and systems biology. HFSP JOURNAL 2007; 1:230-48. [PMID: 19404424 DOI: 10.2976/1.2812442] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2007] [Accepted: 10/24/2007] [Indexed: 01/25/2023]
Abstract
The sequencing of the genomes of key organisms and the subsequent identification of genes merely leads us to the next real challenge in modern biology-revealing the precise functions of these genes. Further, detailed knowledge of how the products of these genes behave in space and time is required, including their interactions with other molecules. In order to tackle these considerable tasks, a large and continuously expanding toolbox is required to probe the functions of proteins on a cellular level. Here, the currently available tools are described and future developments are projected. There is no doubt that only the close interplay between the life science disciplines in addition to advances in engineering will be able to meet the challenge.
Collapse
Affiliation(s)
- Carsten Schultz
- Gene Expression Unit, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany
| |
Collapse
|
94
|
Ellis-Davies GCR. Caged compounds: photorelease technology for control of cellular chemistry and physiology. Nat Methods 2007; 4:619-28. [PMID: 17664946 PMCID: PMC4207253 DOI: 10.1038/nmeth1072] [Citation(s) in RCA: 710] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Caged compounds are light-sensitive probes that functionally encapsulate biomolecules in an inactive form. Irradiation liberates the trapped molecule, permitting targeted perturbation of a biological process. Uncaging technology and fluorescence microscopy are 'optically orthogonal': the former allows control, and the latter, observation of cellular function. Used in conjunction with other technologies (for example, patch clamp and/or genetics), the light beam becomes a uniquely powerful tool to stimulate a selected biological target in space or time. Here I describe important examples of widely used caged compounds, their design features and synthesis, as well as practical details of how to use them with living cells.
Collapse
Affiliation(s)
- Graham C R Ellis-Davies
- Department of Pharmacology & Physiology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102, USA.
| |
Collapse
|
95
|
Gorostiza P, Isacoff E. Optical switches and triggers for the manipulation of ion channels and pores. MOLECULAR BIOSYSTEMS 2007; 3:686-704. [PMID: 17882331 DOI: 10.1039/b710287a] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Like fluorescence sensing techniques, methods to manipulate proteins with light have produced great advances in recent years. Ion channels have been one of the principal protein targets of photoswitched manipulation. In combination with fluorescence detection of cell signaling, this has enabled non-invasive, all-optical experiments on cell and tissue function, both in vitro and in vivo. Optical manipulation of channels has also provided insights into the mechanism of channel function. Optical control elements can be classified according to their molecular reversibility as non-reversible phototriggers where light breaks a chemical bond (e.g. caged ligands) and as photoswitches that reversibly photoisomerize. Synthetic photoswitches constitute nanoscale actuators that can alter channel function using three different strategies. These include (1) nanotoggles, which are tethered photoswitchable ligands that either activate channels (agonists) or inhibit them (blockers or antagonists), (2) nanokeys, which are untethered (freely diffusing) photoswitchable ligands, and (3) nanotweezers, which are photoswitchable crosslinkers. The properties of such photoswitches are discussed here, with a focus on tethered photoswitchable ligands. The recent literature on optical manipulation of ion channels is reviewed for the different channel families, with special emphasis on the understanding of ligand binding and gating processes, applications in nanobiotechnology, and with attention to future prospects in the field.
Collapse
Affiliation(s)
- Pau Gorostiza
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | | |
Collapse
|
96
|
Schmidt R, Geissler D, Hagen V, Bendig J. Kinetics study of the photocleavage of (coumarin-4-yl)methyl esters. J Phys Chem A 2007; 109:5000-4. [PMID: 16833851 DOI: 10.1021/jp050581k] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photolabile coumarinylmethyl esters of biomolecules (caged compounds) are new tools for studying spatial and time-dependent aspects of signal transduction in living cells. Herein we describe a fluoresence spectroscopic method for the determination of the rate constants of the photolysis steps of such caged compounds using (6.7-dimethoxycoumarin-4-yl)methyl diethyl phosphate (DMCM-DEP) and sodium (6,7-dimethoxycoumarin-4-yl)methyl sulfate (DMCM-S). DMCM-DEP and DMCM-S are caged compounds which photorelease a proton, the corresponding acid anion, and the strongly fluorescent alcohol DMCM-OH upon excitation. The results of stationary and time-resolved measurements of the photochemistry and the luminescence of both caged compounds indicate that DMCM-OH is produced already during the excitation pulse. The quantitative analysis of the data demonstrates that the first step of the reaction--heterolytic bond cleavage of the coumarinylmethyl ester leading to the ion pair of a DMCM cation and an acid anion--is very fast with a rate constant of k1 approximately 2 x 10(10) s(-1). Recombination of the ion pair occurs with a rate constant of k(rec) approximately 2.3 x 10(9) s(-1) and is about 10 times faster than the competing hydrolysis reaction of the DMCM cation yielding DMCM-OH and a proton. Thus, both caged compounds belong to the fastest phototriggers known.
Collapse
Affiliation(s)
- Reinhard Schmidt
- Institute of Physical and Theoretical Chemistry, J. W. Goethe-University, Marie-Curie-Str. 11, D60439 Frankfurt am Main, Germany
| | | | | | | |
Collapse
|
97
|
Schmidt R, Geissler D, Hagen V, Bendig J. Mechanism of photocleavage of (coumarin-4-yl)methyl esters. J Phys Chem A 2007; 111:5768-74. [PMID: 17564421 DOI: 10.1021/jp071521c] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
(Coumarin-4-yl)methyl esters (CM-A) are caged compounds that, upon excitation, release the masked biologically active acid HA and the highly fluorescent (coumarin-4-yl)methyl alcohol CM-OH very rapidly and in part with high efficiency. The results of photostationary and time-resolved investigations of 25 CM-A esters and corresponding CM-OH alcohols with varying substitution on the (coumarin-4-yl)methyl moiety and a wide variation in the structure of the acidic part have been analyzed. The initial step of the photoreaction is heterolytic ester cleavage leading to the singlet ion pair 1[CM+ A-] with rate constant k1. 1[CM+ A-] hydrolyzes to CM-OH and HA with rate constant k2 or recombines to ground-state CM-A with rate constant krec. 1[CM+ A-] is the key intermediate of the reaction. Stabilization of both CM+ by using electron-donating substituents and A- by increasing the acid strength leads to a strong enhancement of k1 and simultaneously to a diminution of krec. Therefore, stabilization of the ion pair has a two-fold positive effect on the photocleavage of (coumarin-4-yl)methyl esters: increasing the rate of the initial reaction step, which might require less than 30 ps, and increasing the efficiency of product formation.
Collapse
Affiliation(s)
- Reinhard Schmidt
- Institute of Physical and Theoretical Chemistry, J. W. Goethe-University, Max-von-Laue-Strasse 7, D60438 Frankfurt am Main, Germany.
| | | | | | | |
Collapse
|
98
|
Abstract
Biologically active compounds which are light-responsive offer experimental possibilities which are otherwise very difficult to achieve. Since light can be manipulated very precisely, for example, with lasers and microscopes rapid jumps in concentration of the active form of molecules are possible with exact control of the area, time, and dosage. The development of such strategies started in the 1970s. This review summarizes new developments of the last five years and deals with "small molecules", proteins, and nucleic acids which can either be irreversibly activated with light (these compounds are referred to as "caged compounds") or reversibly switched between an active and an inactive state.
Collapse
Affiliation(s)
- Günter Mayer
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.
| | | |
Collapse
|
99
|
Boccaccio A, Menini A. Temporal development of cyclic nucleotide-gated and Ca2+ -activated Cl- currents in isolated mouse olfactory sensory neurons. J Neurophysiol 2007; 98:153-60. [PMID: 17460108 DOI: 10.1152/jn.00270.2007] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A Ca(2+)-activated Cl(-) current constitutes a large part of the transduction current in olfactory sensory neurons. The binding of odorants to olfactory receptors in the cilia produces an increase in cAMP concentration; Ca(2+) enters into the cilia through CNG channels and activates a Cl(-) current. In intact mouse olfactory sensory neurons little is known about the kinetics of the Ca(2+)-activated Cl(-) current. Here, we directly activated CNG channels by flash photolysis of caged cAMP or 8-Br-cAMP and measured the current response with the whole cell voltage-clamp technique in mouse neurons. We measured multiphasic currents in the rising phase of the response at -50 mV. The current rising phase became monophasic in the absence of extracellular Ca(2+), at +50 mV, or when most of the intracellular Cl(-) was replaced by gluconate to shift the equilibrium potential for Cl(-) to -50 mV. These results show that the second phase of the current in mouse intact neurons is attributed to a Cl(-) current activated by Ca(2+), similarly to previous results on isolated frog cilia. The percentage of the total saturating current carried by Cl(-) was estimated in two ways: 1) by measuring the maximum secondary current and 2) by blocking the Cl(-) channel with niflumic acid. We estimated that in the presence of 1 mM extracellular Ca(2+) and in symmetrical Cl(-) concentrations the Cl(-) component can constitute up to 90% of the total current response. These data show how to unravel the CNG and Ca(2+)-activated Cl(-) component of the current rising phase.
Collapse
Affiliation(s)
- Anna Boccaccio
- International School for Advanced Studies, SISSA, Sector of Neurobiology, Basovizza, Trieste, Italy.
| | | |
Collapse
|
100
|
Tenorio-Lopez FA, Valle Mondragon LD, Olvera GZ, Torres Narvaez JC, Pastelin G. Viscum albumaqueous extract induces NOS-2 and NOS-3 overexpression in Guinea pig hearts. Nat Prod Res 2006; 20:1176-82. [PMID: 17127505 DOI: 10.1080/14786410600898979] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Viscum album L. aqueous extract, on the Langendorff isolated and perfused heart model, decreases coronary vascular resistance, when compared to control group (36.00 +/- 2.00 vs. 15.80 +/- 1.96 dyn s cm-5). Our data support the fact that this mechanism involves NOS-2 and NOS-3 overexpression (4.65 and 7.89 times over control, respectively), which is correlated with increases in NO (6.24 +/- 2.49 vs. 147.95 +/- 2.79 pmol) and cGMP production (43.94 +/- 2.00 vs. 74.81 +/- 1.96 pmol mg-1 of tissue), compared to control values. Such an effect is antagonized by gadolinium(III) chloride, L-NAME and ODQ. Therefore, coronary vasodilator effect elicited by V. album L. aqueous extract is mediated by the NO/sGC pathway.
Collapse
Affiliation(s)
- Fermin Alejandro Tenorio-Lopez
- Departamento de Farmacología, Instituto Nacional de Cardiología Ignacio Chávez, Juan Badiano No. 1, Sección XVI, 14080 México D.F., México.
| | | | | | | | | |
Collapse
|