1
|
Beckham JL, van Venrooy AR, Kim S, Li G, Li B, Duret G, Arnold D, Zhao X, Li JT, Santos AL, Chaudhry G, Liu D, Robinson JT, Tour JM. Molecular machines stimulate intercellular calcium waves and cause muscle contraction. NATURE NANOTECHNOLOGY 2023; 18:1051-1059. [PMID: 37430037 DOI: 10.1038/s41565-023-01436-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 05/03/2023] [Indexed: 07/12/2023]
Abstract
Intercellular calcium waves (ICW) are complex signalling phenomena that control many essential biological activities, including smooth muscle contraction, vesicle secretion, gene expression and changes in neuronal excitability. Accordingly, the remote stimulation of ICW could result in versatile biomodulation and therapeutic strategies. Here we demonstrate that light-activated molecular machines (MM)-molecules that perform mechanical work on the molecular scale-can remotely stimulate ICW. MM consist of a polycyclic rotor and stator that rotate around a central alkene when activated with visible light. Live-cell calcium-tracking and pharmacological experiments reveal that MM-induced ICW are driven by the activation of inositol-triphosphate-mediated signalling pathways by unidirectional, fast-rotating MM. Our data suggest that MM-induced ICW can control muscle contraction in vitro in cardiomyocytes and animal behaviour in vivo in Hydra vulgaris. This work demonstrates a strategy for directly controlling cell signalling and downstream biological function using molecular-scale devices.
Collapse
Affiliation(s)
| | | | - Soonyoung Kim
- Department of Electrical Engineering, Rice University, Houston, TX, USA
| | - Gang Li
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Bowen Li
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Guillaume Duret
- Department of Electrical Engineering, Rice University, Houston, TX, USA
| | - Dallin Arnold
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Xuan Zhao
- Department of Electrical Engineering, Rice University, Houston, TX, USA
| | - John T Li
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Ana L Santos
- Department of Chemistry, Rice University, Houston, TX, USA
- IdISBA-Fundación de Investigación Sanitaria de las Islas Baleares, Palma, Spain
| | | | - Dongdong Liu
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Jacob T Robinson
- Department of Bioengineering, Department of Electrical Engineering, Rice University, Houston, TX, USA.
| | - James M Tour
- Department of Chemistry, Smalley-Curl Institute, NanoCarbon Center and Rice Advanced Materials Institute, Department of Materials Science and Nanoengineering, Department of Computer Science, Rice University, Houston, TX, USA.
| |
Collapse
|
2
|
Urban N, Leonhardt M, Schaefer M. Multiplex G Protein-Coupled Receptor Screen Reveals Reliably Acting Agonists and a Gq-Phospholipase C Coupling Mode of GPR30/GPER1. Mol Pharmacol 2023; 103:48-62. [PMID: 36400433 DOI: 10.1124/molpharm.122.000580] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 10/21/2022] [Accepted: 10/27/2022] [Indexed: 11/21/2022] Open
Abstract
G protein-coupled receptors (GPCRs) constitute the most versatile family of pharmacological target proteins. For some "orphan" GPCRs, no ligand or drug-like modulator is known. In this study, we have established and applied a parallelized assay to coscreen 29 different human GPCRs. Three compounds, chlorhexidine, Lys-05, and 9-aminoacridine, triggered transient Ca2+ signals linked to the expression of GPR30. GPR30, also named G protein-coupled estrogen receptor 1 (GPER1), was reported to elicit increases in cAMP in response to 17β-estradiol, 4-hydroxytamoxifen, or G-1. These findings could, however, not be reproduced by other groups, and the deorphanization of GPR30 is, therefore, intensely disputed. The unbiased screen and following experiments in transiently or stably GPR30-overexpressing HEK293 cells did not show responses to 17β-estradiol, 4-hydroxytamoxifen, or G-1. A thorough analysis of the activated signaling cascade revealed a canonical Gq-coupled pathway, including phospholipase C, protein kinase C and ERK activation, receptor internalization, and sensitivity to the Gq inhibitor YM-254890. When expressed in different cell lines, the localization of a fluorescent GPR30 fusion protein appeared variable. An efficient integration into the plasma membrane and stronger functional responses were found in HEK293 and in MCF-7 cells, whereas GPR30 appeared mostly retained in endomembrane compartments in Cos-7 or HeLa cells. Thus, conflicting findings may result from the use of different cell lines. The newly identified agonists and the finding that GPR30 couples to Gq are expected to serve as a starting point for identifying physiologic responses that are controlled by this GPCR. SIGNIFICANCE STATEMENT: This study has identified and thoroughly characterized novel and reliably acting agonists of the G protein-coupled receptor GPER1/GPR30. Applying these agonists, this study demonstrates that GPR30 couples to the canonical Gq-phospholipase C pathway and is rapidly internalized upon continuous exposure to the agonists.
Collapse
Affiliation(s)
- Nicole Urban
- Medical Faculty, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Marion Leonhardt
- Medical Faculty, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Michael Schaefer
- Medical Faculty, Rudolf-Boehm-Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| |
Collapse
|
3
|
A metabolic reaction-diffusion model for PKCα translocation via PIP2 hydrolysis in an endothelial cell. Biochem J 2020; 477:4071-4084. [PMID: 33026061 DOI: 10.1042/bcj20200484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/08/2020] [Accepted: 10/06/2020] [Indexed: 11/17/2022]
Abstract
Hydrolysis of the phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2) at the cell membrane induces the release of inositol 1,4,5-trisphosphate (IP3) into the cytoplasm and diffusion of diacylglycerol (DAG) through the membrane, respectively. Release of IP3 subsequently increases Ca2+ levels in the cytoplasm, which results in activation of protein kinase C α (PKCα) by Ca2+ and DAG, and finally the translocation of PKCα from the cytoplasm to the membrane. In this study, we developed a metabolic reaction-diffusion framework to simulate PKCα translocation via PIP2 hydrolysis in an endothelial cell. A three-dimensional cell model, divided into membrane and cytoplasm domains, was reconstructed from confocal microscopy images. The associated metabolic reactions were divided into their corresponding domain; PIP2 hydrolysis at the membrane domain resulted in DAG diffusion at the membrane domain and IP3 release into the cytoplasm domain. In the cytoplasm domain, Ca2+ was released from the endoplasmic reticulum, and IP3, Ca2+, and PKCα diffused through the cytoplasm. PKCα bound Ca2+ at, and diffused through, the cytoplasm, and was finally activated by binding with DAG at the membrane. Using our model, we analyzed IP3 and DAG dynamics, Ca2+ waves, and PKCα translocation in response to a microscopic stimulus. We found a qualitative agreement between our simulation results and our experimental results obtained by live-cell imaging. Interestingly, our results suggest that PKCα translocation is dominated by DAG dynamics. This three-dimensional reaction-diffusion mathematical framework could be used to investigate the link between PKCα activation in a cell and cell function.
Collapse
|
4
|
Blankenbach KV, Claas RF, Aster NJ, Spohner AK, Trautmann S, Ferreirós N, Black JL, Tesmer JJG, Offermanns S, Wieland T, Meyer zu Heringdorf D. Dissecting G q/11-Mediated Plasma Membrane Translocation of Sphingosine Kinase-1. Cells 2020; 9:cells9102201. [PMID: 33003441 PMCID: PMC7599897 DOI: 10.3390/cells9102201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/25/2020] [Accepted: 09/27/2020] [Indexed: 12/24/2022] Open
Abstract
Diverse extracellular signals induce plasma membrane translocation of sphingosine kinase-1 (SphK1), thereby enabling inside-out signaling of sphingosine-1-phosphate. We have shown before that Gq-coupled receptors and constitutively active Gαq/11 specifically induced a rapid and long-lasting SphK1 translocation, independently of canonical Gq/phospholipase C (PLC) signaling. Here, we further characterized Gq/11 regulation of SphK1. SphK1 translocation by the M3 receptor in HEK-293 cells was delayed by expression of catalytically inactive G-protein-coupled receptor kinase-2, p63Rho guanine nucleotide exchange factor (p63RhoGEF), and catalytically inactive PLCβ3, but accelerated by wild-type PLCβ3 and the PLCδ PH domain. Both wild-type SphK1 and catalytically inactive SphK1-G82D reduced M3 receptor-stimulated inositol phosphate production, suggesting competition at Gαq. Embryonic fibroblasts from Gαq/11 double-deficient mice were used to show that amino acids W263 and T257 of Gαq, which interact directly with PLCβ3 and p63RhoGEF, were important for bradykinin B2 receptor-induced SphK1 translocation. Finally, an AIXXPL motif was identified in vertebrate SphK1 (positions 100–105 in human SphK1a), which resembles the Gαq binding motif, ALXXPI, in PLCβ and p63RhoGEF. After M3 receptor stimulation, SphK1-A100E-I101E and SphK1-P104A-L105A translocated in only 25% and 56% of cells, respectively, and translocation efficiency was significantly reduced. The data suggest that both the AIXXPL motif and currently unknown consequences of PLCβ/PLCδ(PH) expression are important for regulation of SphK1 by Gq/11.
Collapse
Affiliation(s)
- Kira Vanessa Blankenbach
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
| | - Ralf Frederik Claas
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
| | - Natalie Judith Aster
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
| | - Anna Katharina Spohner
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
| | - Sandra Trautmann
- Institut für Klinische Pharmakologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (S.T.); (N.F.)
| | - Nerea Ferreirós
- Institut für Klinische Pharmakologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (S.T.); (N.F.)
| | - Justin L. Black
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA;
| | - John J. G. Tesmer
- Departments of Biological Sciences and of Medicinal Chemistry and Molecular Pharmacology, Purdue University West Lafayette, West Lafayette, IN 47907-2054, USA;
| | - Stefan Offermanns
- Abteilung für Pharmakologie, Max-Planck-Institut für Herz- und Lungenforschung, 61231 Bad Nauheim, Germany;
| | - Thomas Wieland
- Experimentelle Pharmakologie Mannheim, European Center for Angioscience, Universität Heidelberg, 68167 Mannheim, Germany;
| | - Dagmar Meyer zu Heringdorf
- Institut für Allgemeine Pharmakologie und Toxikologie, Universitätsklinikum, Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (K.V.B.); (R.F.C.); (N.J.A.); (A.K.S.)
- Correspondence: ; Tel.: +49-69-6301-3906
| |
Collapse
|
5
|
Sera T, Arai M, Cui Z, Onose K, Karimi A, Kudo S. Unloading of intercellular tension induces the directional translocation of PKCα. J Cell Physiol 2018; 234:9764-9777. [PMID: 30387146 DOI: 10.1002/jcp.27662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/02/2018] [Indexed: 12/13/2022]
Abstract
The migration of endothelial cells (ECs) is closely associated with a Ca2+ -dependent protein, protein kinase Cα (PKCα). The disruption of intercellular adhesion by single-cell wounding has been shown to induce the directional translocation of PKCα. We hypothesized that this translocation of PKCα is induced by mechanical stress, such as unloading of intercellular tension, or by intercellular communication, such as gap junction-mediated and paracrine signaling. In the current study, we found that the disruption of intercellular adhesion induced the directional translocation of PKCα even when gap junction-mediated and paracrine signaling were inhibited. Conversely, it did not occur when the mechanosensitive channel was inhibited. In addition, the strain field of substrate attributable to the disruption of intercellular adhesion tended to be larger at the areas corresponding with PKCα translocation. Recently, we found that a direct mechanical stimulus induced the accumulation of PKCα at the stimulus area, involving Ca 2+ influx from extracellular space. These results indicated that the unloading of intercellular tension induced directional translocation of PKCα, which required Ca 2+ influx from extracellular space. The results of this study indicate the involvement of PKCα in the Ca 2+ signaling pathway in response to mechanical stress in ECs.
Collapse
Affiliation(s)
- Toshihiro Sera
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Masataka Arai
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Zhonghua Cui
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Koichi Onose
- Department of Mechanical Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, Japan
| | - Alireza Karimi
- International Research Fellow, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| | - Susumu Kudo
- Department of Mechanical Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan
| |
Collapse
|
6
|
Arai M, Sera T, Hasegawa T, Kudo S. Spatial and temporal translocation of PKCα in single endothelial cell in response to mechanical stimulus. Exp Cell Res 2018; 367:205-215. [DOI: 10.1016/j.yexcr.2018.03.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 03/28/2018] [Accepted: 03/29/2018] [Indexed: 12/14/2022]
|
7
|
Morita M, Nakane A, Fujii Y, Maekawa S, Kudo Y. High Cell Density Upregulates Calcium Oscillation by Increasing Calcium Store Content via Basal Mitogen-Activated Protein Kinase Activity. PLoS One 2015; 10:e0137610. [PMID: 26398212 PMCID: PMC4580325 DOI: 10.1371/journal.pone.0137610] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 08/20/2015] [Indexed: 01/12/2023] Open
Abstract
Calcium releases of non-excitable cells are generally a combination of oscillatory and non-oscillatory patterns, and factors affecting the calcium dynamics are still to be determined. Here we report the influence of cell density on calcium increase patterns of clonal cell lines. The majority of HeLa cells seeded at 1.5 x 104/cm2 showed calcium oscillations in response to histamine and ATP, whereas cells seeded at 0.5 x 104/cm2 largely showed transient and sustained calcium increases. Cell density also affected the response of HEK293 cells to ATP in a similar manner. High cell density increased the basal activity of the mitogen-activated protein (MAP) kinase and calcium store content, and both calcium oscillation and calcium store content were down-regulated by a MAP kinase inhibitor, U0126. Thus, MAP kinase-mediated regulation of calcium store likely underlie the effect of cell density on calcium oscillation. Calcium increase patterns of HeLa cells were conserved at any histamine concentrations tested, whereas the overexpression of histamine H1 receptor, which robustly increased histamine-induced inositol phospholipid hydrolysis, converted calcium oscillations to sustained calcium increases only at high histamine concentrations. Thus, the consequence of modulating inositol phospholipid metabolism was distinct from that of changing cell density, suggesting the effect of cell density is not attributed to inositol phospholipid metabolism. Collectively, our results propose that calcium increase patterns of non-excitable cells reflect calcium store, which is regulated by the basal MAP kinase activity under the influence of cell density.
Collapse
Affiliation(s)
- Mitsuhiro Morita
- Department of Biology, Kobe University Graduate School of Science, Kobe, Japan
- * E-mail:
| | - Akira Nakane
- Laboratory of Cellular Neurobiology, School of Life Science, Tokyo University of Pharmacy and Life Science, Tokyo, Japan
| | - Yuki Fujii
- Department of Biology, Kobe University Graduate School of Science, Kobe, Japan
| | - Shohei Maekawa
- Department of Biology, Kobe University Graduate School of Science, Kobe, Japan
| | - Yoshihisa Kudo
- Laboratory of Cellular Neurobiology, School of Life Science, Tokyo University of Pharmacy and Life Science, Tokyo, Japan
| |
Collapse
|
8
|
Itsuki K, Imai Y, Hase H, Okamura Y, Inoue R, Mori MX. PLC-mediated PI(4,5)P2 hydrolysis regulates activation and inactivation of TRPC6/7 channels. ACTA ACUST UNITED AC 2014; 143:183-201. [PMID: 24470487 PMCID: PMC4001779 DOI: 10.1085/jgp.201311033] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Transient receptor potential classical (or canonical) (TRPC)3, TRPC6, and TRPC7 are a subfamily of TRPC channels activated by diacylglycerol (DAG) produced through the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) by phospholipase C (PLC). PI(4,5)P2 depletion by a heterologously expressed phosphatase inhibits TRPC3, TRPC6, and TRPC7 activity independently of DAG; however, the physiological role of PI(4,5)P2 reduction on channel activity remains unclear. We used Förster resonance energy transfer (FRET) to measure PI(4,5)P2 or DAG dynamics concurrently with TRPC6 or TRPC7 currents after agonist stimulation of receptors that couple to Gq and thereby activate PLC. Measurements made at different levels of receptor activation revealed a correlation between the kinetics of PI(4,5)P2 reduction and those of receptor-operated TRPC6 and TRPC7 current activation and inactivation. In contrast, DAG production correlated with channel activation but not inactivation; moreover, the time course of channel inactivation was unchanged in protein kinase C-insensitive mutants. These results suggest that inactivation of receptor-operated TRPC currents is primarily mediated by the dissociation of PI(4,5)P2. We determined the functional dissociation constant of PI(4,5)P2 to TRPC channels using FRET of the PLCδ Pleckstrin homology domain (PHd), which binds PI(4,5)P2, and used this constant to fit our experimental data to a model in which channel gating is controlled by PI(4,5)P2 and DAG. This model predicted similar FRET dynamics of the PHd to measured FRET in either human embryonic kidney cells or smooth muscle cells, whereas a model lacking PI(4,5)P2 regulation failed to reproduce the experimental data, confirming the inhibitory role of PI(4,5)P2 depletion on TRPC currents. Our model also explains various PLC-dependent characteristics of channel activity, including limitation of maximum open probability, shortening of the peak time, and the bell-shaped response of total current. In conclusion, our studies demonstrate a fundamental role for PI(4,5)P2 in regulating TRPC6 and TRPC7 activity triggered by PLC-coupled receptor stimulation.
Collapse
Affiliation(s)
- Kyohei Itsuki
- Department of Physiology, School of Medicine, Fukuoka University, Fukuoka 814-0180, Japan
| | | | | | | | | | | |
Collapse
|
9
|
Klein AS, Tannert A, Schaefer M. Cholesterol sensitises the transient receptor potential channel TRPV3 to lower temperatures and activator concentrations. Cell Calcium 2013; 55:59-68. [PMID: 24406294 DOI: 10.1016/j.ceca.2013.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 12/04/2013] [Accepted: 12/07/2013] [Indexed: 11/16/2022]
Abstract
TRPV3, a thermosensitive cation channel, is predominantly expressed in keratinocytes. It contributes to physiological processes such as thermosensation, nociception, and skin development. TRPV3 is polymodally regulated by chemical agonists, innocuous heat, intracellular acidification or by membrane depolarization. By manipulating the content of plasma membrane cholesterol, a key modulator of the physicochemical properties of biological membranes, we here addressed the question, how the lipid environment influences TRPV3. Cholesterol supplementation robustly potentiated TRPV3 channel activity by sensitising it to lower concentrations of chemical activators. In addition, the thermal activation of TRPV3 is significantly shifted to lower temperatures in cholesterol-enriched cells. The sensitising effect of cholesterol was not caused by an increased plasma membrane targeting of the channel. In HaCaT keratinocytes, which natively express TRPV3, a cholesterol-mediated sensitisation of TRPV3-like responses was reproduced. The cholesterol-dependent modulation of TRPV3 activity may provide a molecular mechanism to interpret its involvement in keratinocyte differentiation.
Collapse
Affiliation(s)
- Anke S Klein
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, Germany
| | - Astrid Tannert
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, Germany
| | - Michael Schaefer
- Rudolf-Boehm-Institut für Pharmakologie und Toxikologie, Universität Leipzig, Leipzig, Germany.
| |
Collapse
|
10
|
Convolution-based one and two component FRAP analysis: theory and application. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 38:649-61. [PMID: 19238375 DOI: 10.1007/s00249-009-0422-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 01/22/2009] [Accepted: 01/29/2009] [Indexed: 10/21/2022]
Abstract
The method of fluorescence redistribution after photobleaching (FRAP) is increasingly receiving interest in biological applications as it is nowadays used not only to determine mobility parameters per se, but to investigate dynamic changes in the concentration or distribution of diffusing molecules. Here, we develop a new simple convolution-based approach to analyze FRAP data using the whole image information. This method does not require information about the timing and localization of the bleaching event but uses the first image acquired directly after photobleaching to calculate the intensity distributions, instead. Changes in pools of molecules with different velocities, which are monitored by applying repetitive FRAP experiments within a single cell, can be analyzed by means of a global model by assuming two global diffusion coefficients with changing portions. We validate the approach by simulation and show that translocation of the YFP-fused PH-domain of phospholipase Cdelta1 can be quantitatively monitored by FRAP analysis in a time-resolved manner. The new FRAP data analysis procedure may be applied to investigate signal transduction pathways using biosensors that change their mobility. An altered mobility in response to the activation of signaling cascades may result either from an altered size of the biosensor, e.g. due to multimerization processes or from translocation of the sensor to an environment with different viscosity.
Collapse
|
11
|
Lichte K, Rossi R, Danneberg K, Braak MT, Kürschner U, Jakobs KH, Kleuser B, Heringdorf DMZ. Lysophospholipid Receptor-Mediated Calcium Signaling in Human Keratinocytes. J Invest Dermatol 2008; 128:1487-98. [DOI: 10.1038/sj.jid.5701207] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
12
|
Oyasu M, Fujimiya M, Kashiwagi K, Ohmori S, Imaeda H, Saito N. Immunogold electron microscopic demonstration of distinct submembranous localization of the activated gammaPKC depending on the stimulation. J Histochem Cytochem 2007; 56:253-65. [PMID: 18040079 DOI: 10.1369/jhc.7a7291.2007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We examined the precise intracellular translocation of gamma subtype of protein kinase C (gammaPKC) after various extracellular stimuli using confocal laser-scanning fluorescent microscopy (CLSM) and immunogold electron microscopy. By CLSM, treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) resulted in a slow and irreversible accumulation of green fluorescent protein (GFP)-tagged gammaPKC (gammaPKC-GFP) on the plasma membrane. In contrast, treatment with Ca(2+) ionophore and activation of purinergic or NMDA receptors induced a rapid and transient membrane translocation of gammaPKC-GFP. Although each stimulus resulted in PKC localization at the plasma membrane, electron microscopy revealed that gammaPKC showed a subtle but significantly different localization depending on stimulation. Whereas TPA and UTP induced a sustained localization of gammaPKC-GFP on the plasma membrane, Ca(2+) ionophore and NMDA rapidly translocated gammaPKC-GFP to the plasma membrane and then restricted gammaPKC-GFP in submembranous area (<500 nm from the plasma membrane). These results suggest that Ca(2+) influx alone induced the association of gammaPKC with the plasma membrane for only a moment and then located this enzyme at a proper distance in a touch-and-go manner, whereas diacylglycerol or TPA tightly anchored this enzyme on the plasma membrane. The distinct subcellular targeting of gammaPKC in response to various stimuli suggests a novel mechanism for PKC activation.
Collapse
Affiliation(s)
- Miho Oyasu
- Laboratory of Molecular Pharmacology, Biosignal Research Center, Kobe University, Kobe, Japan
| | | | | | | | | | | |
Collapse
|
13
|
Morita M, Yoshiki F, Nakane A, Okubo Y, Kudo Y. Receptor- and calcium-dependent induced inositol 1,4,5-trisphosphate increases in PC12h cells as shown by fluorescence resonance energy transfer imaging. FEBS J 2007; 274:5147-57. [PMID: 17850333 DOI: 10.1111/j.1742-4658.2007.06035.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The production and further metabolism of inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] require several calcium-dependent enzymes, but little is known about subsequent calcium-dependent changes in cellular Ins(1,4,5)P3. To study the calcium dependence of muscarinic acetylcholine receptor-induced Ins(1,4,5)P3 increases in PC12h cells, we utilized an Ins(1,4,5)P3 imaging system based on fluorescence resonance energy transfer and using green fluorescent protein variants fused with the pleckstrin homology domain of phospholipase C-delta1. The intracellular calcium concentration, monitored by calcium imaging, was adjusted by thapsigargin pretreatment or alterations in extracellular calcium concentration, enabling rapid receptor-independent changes in calcium concentration via store-operated calcium influx. We found that Ins(1,4,5)P3 production was increased by a combination of receptor- and calcium-dependent components, rather than by calcium alone. The level of Ins(1,4,5)P3 induced by the receptor was found to be half that induced by the combined receptor and calcium components. Increases in calcium levels prior to receptor activation did not affect the subsequent receptor-induced Ins(1,4,5)P3 increase, indicating that calcium does not influence Ins(1,4,5)P3 production without receptor activation. Removal of both the receptor agonists and calcium rapidly restored calcium and Ins(1,4,5)P3 levels, whereas removal of calcium alone restored calcium to its basal concentration. Similar calcium-dependent increases in Ins(1,4,5)P3 were also observed in Chinese hamster ovary cells expressing m1 muscarinic acetylcholine receptor, indicating that the observed calcium dependence is common to Ins(1,4,5)P3 production. To our knowledge, our results are the first showing receptor- and calcium-dependent components within cellular Ins(1,4,5)P3.
Collapse
Affiliation(s)
- Mitsuhiro Morita
- Laboratory of Cellular Neurobiology, School of Life Science, Tokyo University of Pharmacy and Life Science, Japan.
| | | | | | | | | |
Collapse
|
14
|
Thaler CD, Kuo RC, Patton C, Preston CM, Yagisawa H, Epel D. Phosphoinositide metabolism at fertilization of sea urchin eggs measured with a GFP-probe. Dev Growth Differ 2005; 46:413-23. [PMID: 15606487 DOI: 10.1111/j.1440-169x.2004.00758.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Fertilization elicits a dramatic, transient rise in Ca2+ within the egg which is an essential component of egg activation and consequent initiation of development. In the sea urchin egg, three distinct Ca2+ stores have been identified which could, either individually or in combination, initiate Ca2+ release at fertilization. Inositol 1,4,5-trisphosphate (IP3) production by phospholipase C (PLC) has been suggested as the singular signal in initiating the Ca2+ transient. Other studies indicate that Ca2+ stores gated by cyclic adenosine diphosphate ribose (cADPR) or nicotinic acid adenine dinucleotide phosphate (NAADP) are also necessary. We have examined the temporal relationship between the Ca2+ rise and IP3 production at fertilization in vivo within individual eggs using a green fluorescent protein (GFP) coupled to a pleckstrin homology (PH) domain that can detect changes in IP3. Translocation of the probe occurred after the Ca2+ rise was initiated. Earlier, and possibly smaller, IP3 changes could not be excluded due to limitations in probe sensitivity. High IP3 levels are maintained during the decline in cytoplasmic Ca2+, suggesting that later IP3 metabolism might not be related to regulation of Ca2+, but may function to modulate other PIP2 regulated events such as actin polymerization or reflect other novel phosphoinositide signaling pathways.
Collapse
Affiliation(s)
- Catherine D Thaler
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | | | | | | | | | | |
Collapse
|
15
|
Johenning F, Wenk M, Uhlén P, DeGray B, Lee E, de Camilli P, Ehrlich B. InsP3-mediated intracellular calcium signalling is altered by expression of synaptojanin-1. Biochem J 2005; 382:687-94. [PMID: 15080793 PMCID: PMC1133826 DOI: 10.1042/bj20040418] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2004] [Accepted: 04/14/2004] [Indexed: 11/17/2022]
Abstract
Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] plays an important physiological role as a precursor for the InsP3-mediated intracellular calcium (Ca2+) signalling cascade. It also regulates membrane trafficking, actin function and transmembrane proteins. SJ-1 (synaptojanin-1), a phosphoinositide phosphatase, regulates the turnover of a PtdIns(4,5)P2 pool involved in clathrin and actin dynamics at the cell surface. We tested the interrelationship of this pool with PtdIns(4,5)P2 pools involved in Ca2+ signalling by expressing in Chinese-hamster ovary cells full-length SJ-1 or its 5-Pase (inositol 5-phosphatase) domain. SJ-1 significantly attenuated the generation of Ca2+ oscillations induced by ATP and the 5-Pase domain mimicked this effect. These changes correlated with increased PtdIns(4,5)P2 phosphatase activity of cellular extracts. Overexpression of the endoplasmic reticulum-anchored PtdIns(4)P phosphatase Sac1 did not affect Ca2+ oscillations, although it increased the Ca2+ efflux rate from intracellular stores. The ability of SJ-1 to alter intracellular Ca2+ signalling indicates a close functional interrelationship between plasma membrane PtdIns(4,5)P2 pools that control actin and endocytosis and those involved in the regulation of specific spatio-temporal Ca2+ signals.
Collapse
Affiliation(s)
- Friedrich W. Johenning
- *Departments of Pharmacology, Cell and Molecular Physiology, Yale University School of Medicine, New Haven, CT, U.S.A
- †Institute for Anatomy, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Markus R. Wenk
- ‡Departments of Cell Biology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, U.S.A
| | - Per Uhlén
- *Departments of Pharmacology, Cell and Molecular Physiology, Yale University School of Medicine, New Haven, CT, U.S.A
| | - Brenda DeGray
- *Departments of Pharmacology, Cell and Molecular Physiology, Yale University School of Medicine, New Haven, CT, U.S.A
| | - Eunkyung Lee
- ‡Departments of Cell Biology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, U.S.A
| | - Pietro de Camilli
- ‡Departments of Cell Biology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT, U.S.A
| | - Barbara E. Ehrlich
- *Departments of Pharmacology, Cell and Molecular Physiology, Yale University School of Medicine, New Haven, CT, U.S.A
- To whom correspondence should be addressed (email )
| |
Collapse
|