1
|
Collins J, Piscopio RA, Reyland ME, Johansen CG, Benninger RKP, Farnsworth NL. Cleavage of protein kinase c δ by caspase-3 mediates proinflammatory cytokine-induced apoptosis in pancreatic islets. J Biol Chem 2024; 300:107611. [PMID: 39074637 PMCID: PMC11381875 DOI: 10.1016/j.jbc.2024.107611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 07/04/2024] [Accepted: 07/17/2024] [Indexed: 07/31/2024] Open
Abstract
In type 1 diabetes (T1D), autoreactive immune cells infiltrate the pancreas and secrete proinflammatory cytokines that initiate cell death in insulin producing islet β-cells. Protein kinase C δ (PKCδ) plays a role in mediating cytokine-induced β-cell death; however, the exact mechanisms are not well understood. To address this, we used an inducible β-cell specific PKCδ KO mouse as well as a small peptide inhibitor of PKCδ. We identified a role for PKCδ in mediating cytokine-induced β-cell death and have shown that inhibiting PKCδ protects pancreatic β-cells from cytokine-induced apoptosis in both mouse and human islets. We determined that cytokines induced nuclear translocation and activity of PKCδ and that caspase-3 cleavage of PKCδ may be required for cytokine-mediated islet apoptosis. Further, cytokine activated PKCδ increases activity both of proapoptotic Bax with acute treatment and C-Jun N-terminal kinase with prolonged treatment. Overall, our results suggest that PKCδ mediates cytokine-induced apoptosis via nuclear translocation, cleavage by caspase-3, and upregulation of proapoptotic signaling in pancreatic β-cells. Combined with the protective effects of PKCδ inhibition with δV1-1, the results of this study will aid in the development of novel therapies to prevent or delay β-cell death and preserve β-cell function in T1D.
Collapse
Affiliation(s)
- Jillian Collins
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado, USA
| | - Robert A Piscopio
- Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Mary E Reyland
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Chelsea G Johansen
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado, USA
| | - Richard K P Benninger
- Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA; Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
| | - Nikki L Farnsworth
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado, USA; Barbara Davis Center for Childhood Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA.
| |
Collapse
|
2
|
Comyn T, Preat T, Pavlowsky A, Plaçais PY. PKCδ is an activator of neuronal mitochondrial metabolism that mediates the spacing effect on memory consolidation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.06.561186. [PMID: 38948698 PMCID: PMC11212906 DOI: 10.1101/2023.10.06.561186] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Relevance-based selectivity and high energy cost are two distinct features of long-term memory (LTM) formation that warrant its default inhibition. Spaced repetition of learning is a highly conserved cognitive mechanism that can lift this inhibition. Here, we questioned how the spacing effect integrates experience selection and energy efficiency at the cellular and molecular levels. We showed in Drosophila that spaced training triggers LTM formation by extending over several hours an increased mitochondrial metabolic activity in neurons of the associative memory center, the mushroom bodies (MBs). We found that this effect is mediated by PKCδ, a member of the so-called 'novel PKC' family of enzymes, which uncovers the critical function of PKCδ in neurons as a regulator of mitochondrial metabolism for LTM. Additionally, PKCδ activation and translocation to mitochondria result from LTM-specific dopamine signaling on MB neurons. By bridging experience-dependent neuronal circuit activity with metabolic modulation of memory-encoding neurons, PKCδ signaling binds the cognitive and metabolic constraints underlying LTM formation into a unified gating mechanism.
Collapse
Affiliation(s)
- Typhaine Comyn
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Thomas Preat
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
| | - Alice Pavlowsky
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
- Co-corresponding authors
| | - Pierre-Yves Plaçais
- Energy & Memory, Brain Plasticity Unit, CNRS, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75005 Paris, France
- Co-corresponding authors
| |
Collapse
|
3
|
Su Q, Zhang J, Lin W, Zhang JF, Newton AC, Mehta S, Yang J, Zhang J. Sensitive Fluorescent Biosensor Reveals Differential Subcellular Regulation of PKC. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.29.587373. [PMID: 38586003 PMCID: PMC10996667 DOI: 10.1101/2024.03.29.587373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
The protein kinase C (PKC) family of serine/threonine kinases, which consist of three distinctly regulated subfamilies, have long been established as critical for a variety of cellular functions. However, how PKC enzymes are regulated at different subcellular locations, particularly at emerging signaling hubs such as the ER, lysosome, and Par signaling complexes, is unclear. Here, we present a sensitive Excitation Ratiometric (ExRai) C Kinase Activity Reporter (ExRai-CKAR2) that enables the detection of minute changes in subcellular PKC activity. Using ExRai-CKAR2 in conjunction with an enhanced diacylglycerol (DAG) biosensor capable of detecting intracellular DAG dynamics, we uncover the differential regulation of PKC isoforms at distinct subcellular locations. We find that G-protein coupled receptor (GPCR) stimulation triggers sustained PKC activity at the ER and lysosomes, primarily mediated by Ca2+ sensitive conventional PKC (cPKC) and novel PKC (nPKC), respectively, with nPKC showing high basal activity due to elevated basal DAG levels on lysosome membranes. The high sensitivity of ExRai-CKAR2, targeted to either the cytosol or Par-complexes, further enabled us to detect previously inaccessible endogenous atypical PKC (aPKC) activity in 3D organoids. Taken together, ExRai-CKAR2 is a powerful tool for interrogating PKC regulation in response to physiological stimuli.
Collapse
Affiliation(s)
- Qi Su
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jing Zhang
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
| | - Wei Lin
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jin-Fan Zhang
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Alexandra C Newton
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
| | - Sohum Mehta
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jing Yang
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
- Department of Pediatrics, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Jin Zhang
- Department of Pharmacology, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Moores Cancer Center, University of California San Diego, La Jolla, CA, USA
- Shu Chien-Gene Lay Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| |
Collapse
|
4
|
Colgan LA, Parra-Bueno P, Holman HL, Tu X, Jain A, Calubag MF, Misler JA, Gary C, Oz G, Suponitsky-Kroyter I, Okaz E, Yasuda R. Dual Regulation of Spine-Specific and Synapse-to-Nucleus Signaling by PKCδ during Plasticity. J Neurosci 2023; 43:5432-5447. [PMID: 37277178 PMCID: PMC10376934 DOI: 10.1523/jneurosci.0208-22.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/18/2023] [Accepted: 05/27/2023] [Indexed: 06/07/2023] Open
Abstract
The activity-dependent plasticity of synapses is believed to be the cellular basis of learning. These synaptic changes are mediated through the coordination of local biochemical reactions in synapses and changes in gene transcription in the nucleus to modulate neuronal circuits and behavior. The protein kinase C (PKC) family of isozymes has long been established as critical for synaptic plasticity. However, because of a lack of suitable isozyme-specific tools, the role of the novel subfamily of PKC isozymes is largely unknown. Here, through the development of fluorescence lifetime imaging-fluorescence resonance energy transfer activity sensors, we investigate novel PKC isozymes in synaptic plasticity in CA1 pyramidal neurons of mice of either sex. We find that PKCδ is activated downstream of TrkB and DAG production, and that the spatiotemporal nature of its activation depends on the plasticity stimulation. In response to single-spine plasticity, PKCδ is activated primarily in the stimulated spine and is required for local expression of plasticity. However, in response to multispine stimulation, a long-lasting and spreading activation of PKCδ scales with the number of spines stimulated and, by regulating cAMP response-element binding protein activity, couples spine plasticity to transcription in the nucleus. Thus, PKCδ plays a dual functional role in facilitating synaptic plasticity.SIGNIFICANCE STATEMENT Synaptic plasticity, or the ability to change the strength of the connections between neurons, underlies learning and memory and is critical for brain health. The protein kinase C (PKC) family is central to this process. However, understanding how these kinases work to mediate plasticity has been limited by a lack of tools to visualize and perturb their activity. Here, we introduce and use new tools to reveal a dual role for PKCδ in facilitating local synaptic plasticity and stabilizing this plasticity through spine-to-nucleus signaling to regulate transcription. This work provides new tools to overcome limitations in studying isozyme-specific PKC function and provides insight into molecular mechanisms of synaptic plasticity.
Collapse
Affiliation(s)
- Lesley A Colgan
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Paula Parra-Bueno
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Heather L Holman
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Xun Tu
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Anant Jain
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Mariah F Calubag
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Jaime A Misler
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Chancellor Gary
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Goksu Oz
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Irena Suponitsky-Kroyter
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Elwy Okaz
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| | - Ryohei Yasuda
- Neuronal Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, Florida 33458
| |
Collapse
|
5
|
Biosensors for the detection of protein kinases: Recent progress and challenges. Microchem J 2022. [DOI: 10.1016/j.microc.2022.107961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
6
|
Spatial regulation of AMPK signaling revealed by a sensitive kinase activity reporter. Nat Commun 2022; 13:3856. [PMID: 35790710 PMCID: PMC9256702 DOI: 10.1038/s41467-022-31190-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 06/06/2022] [Indexed: 12/13/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a master regulator of cellular energetics which coordinates metabolism by phosphorylating a plethora of substrates throughout the cell. But how AMPK activity is regulated at different subcellular locations for precise spatiotemporal control over metabolism is unclear. Here we present a sensitive, single-fluorophore AMPK activity reporter (ExRai AMPKAR), which reveals distinct kinetic profiles of AMPK activity at the mitochondria, lysosome, and cytoplasm. Genetic deletion of the canonical upstream kinase liver kinase B1 (LKB1) results in slower AMPK activity at lysosomes but does not affect the response amplitude at lysosomes or mitochondria, in sharp contrast to the necessity of LKB1 for maximal cytoplasmic AMPK activity. We further identify a mechanism for AMPK activity in the nucleus, which results from cytoplasmic to nuclear shuttling of AMPK. Thus, ExRai AMPKAR enables illumination of the complex subcellular regulation of AMPK signaling.
Collapse
|
7
|
Black JD, Affandi T, Black AR, Reyland ME. PKCα and PKCδ: Friends and Rivals. J Biol Chem 2022; 298:102194. [PMID: 35760100 PMCID: PMC9352922 DOI: 10.1016/j.jbc.2022.102194] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/13/2022] [Accepted: 06/21/2022] [Indexed: 01/06/2023] Open
Abstract
PKC comprises a large family of serine/threonine kinases that share a requirement for allosteric activation by lipids. While PKC isoforms have significant homology, functional divergence is evident among subfamilies and between individual PKC isoforms within a subfamily. Here, we highlight these differences by comparing the regulation and function of representative PKC isoforms from the conventional (PKCα) and novel (PKCδ) subfamilies. We discuss how unique structural features of PKCα and PKCδ underlie differences in activation and highlight the similar, divergent, and even opposing biological functions of these kinases. We also consider how PKCα and PKCδ can contribute to pathophysiological conditions and discuss challenges to targeting these kinases therapeutically.
Collapse
Affiliation(s)
- Jennifer D Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE.
| | - Trisiani Affandi
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus
| | - Adrian R Black
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, NE
| | - Mary E Reyland
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus.
| |
Collapse
|
8
|
Targeting PKC in microglia to promote remyelination and repair in the CNS. Curr Opin Pharmacol 2021; 62:103-108. [PMID: 34965482 DOI: 10.1016/j.coph.2021.11.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/19/2021] [Indexed: 01/28/2023]
Abstract
Microglia and CNS-infiltrating macrophages play significant roles in the pathogenesis of neuroinflammatory and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. Prolonged and dysregulated inflammatory responses by these innate immune cells can have deleterious effects on the surrounding CNS microenvironment, which can worsen neurodegeneration and demyelination. However, although chronic activation of pro-inflammatory microglia is maladaptive, other functional microglial subtypes play beneficial roles during CNS repair and regeneration. Therefore, there is a tremendous interest in understanding the underlying mechanism of the activation of these reparative/regenerative microglia. In this review, we focus on the potential role of PKC, a downstream signaling molecule of TREM2 and PLCγ2, and PKC modulators in promoting the activation of reparative/regenerative microglial subtypes as a novel therapy for neuroinflammatory and neurodegenerative diseases.
Collapse
|
9
|
Renkhold L, Kollmann R, Inderwiedenstraße L, Kienitz MC. PKC-isoform specific regulation of receptor desensitization and KCNQ1/KCNE1 K + channel activity by mutant α 1B-adrenergic receptors. Cell Signal 2021; 91:110228. [PMID: 34958868 DOI: 10.1016/j.cellsig.2021.110228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 11/25/2022]
Abstract
Activation of a specific protein kinase C (PKC) isoform during stimulation of Gq protein-coupled receptors (GqPCRs) is determined by homologous receptor desensitization that controls the spatiotemporal formation of downstream Gq signalling molecules. Furthermore, GqPCR-activated PKC isoforms specifically regulate receptor activity via a negative feedback mechanism. In the present study, we investigated the contribution of several phosphorylation sites in the α1B-adrenergic receptor (α1B-AR) for PKC and G protein coupled receptor kinase 2 (GRK2) to homologous receptor desensitization and effector modulation. We analyzed signalling events downstream to human wildtype α1B-ARs and α1B-ARs lacking PKC or GRK2 phosphorylation sites (Δ391-401, α1B-ΔPKC-AR and Δ402-520, α1B-ΔGRK-AR) by means of FRET-based biosensors in HEK293 that served as online-assays of receptor activity. K+ currents through KCNQ1/KCNE1 channels (IKs), which are regulated by both phosphatidylinositol 4,5-bisphosphate (PIP2)-depletion and/or phosphorylation by PKC, were measured as a functional readout of wildtype and mutant α1B-AR receptor activity. As a novel finding, we provide evidence that deletion of PKC and GRK2 phosphorylation sites in α1B-ARs abrogates the contribution of PKCα to homologous receptor desensitization. Instead, the time course of mutant receptor activity was specifically modulated by PKCβ. Mutant α1B-ARs displayed pronounced homologous receptor desensitization that was abolished by PKCβ-specific pharmacological inhibitors. IKs modulation during stimulation of wildtype and mutant α1B-ARs displayed transient inhibition and current facilitation after agonist withdrawal with reduced capability of mutant α1B-ARs to induce IKs inhibition. Pharmacological inhibition of the PKCβ isoform did not augment IKs reduction by mutant α1B-ARs, but shifted IKs modulation towards current facilitation. Coexpression of an inactive (dominant-negative) PKCδ isoform (DN-PKCδ) abolished IKs facilitation in α1B-ΔGRK-AR-expressing cells, but not in α1B-ΔPKC-AR-expressing cells. The data indicate that the differential modulation of IKs activity by α1B-ΔGRK- and α1B-ΔPKC-receptors is attributed to the activation of entirely distinct novel PKC isoforms. To summarize, specific phosphorylation sites within the wildtype and mutant α1B-adrenergic receptors are targeted by different PKC isoforms, resulting in differential regulation of receptor desensitization and effector function.
Collapse
Affiliation(s)
- Lina Renkhold
- Klinik für Hautkrankheiten, Universitätsklinikum Münster, Von-Esmarch-Str. 58, D-48149 Münster, Deutschland, Germany
| | - Rike Kollmann
- Department of Cellular Physiology, Institute of Physiology, Ruhr University Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany
| | - Leonie Inderwiedenstraße
- Department of Cellular Physiology, Institute of Physiology, Ruhr University Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany
| | - Marie-Cecile Kienitz
- Department of Cellular Physiology, Institute of Physiology, Ruhr University Bochum, Universitätsstrasse 150, D-44801 Bochum, Germany.
| |
Collapse
|
10
|
Quilty F, Freeley M, Gargan S, Gilmer J, Long A. Deoxycholic acid induces proinflammatory cytokine production by model oesophageal cells via lipid rafts. J Steroid Biochem Mol Biol 2021; 214:105987. [PMID: 34438042 DOI: 10.1016/j.jsbmb.2021.105987] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/18/2021] [Accepted: 08/21/2021] [Indexed: 11/28/2022]
Abstract
The bile acid component of gastric refluxate has been implicated in inflammation of the oesophagus including conditions such as gastro-oesophageal reflux disease (GORD) and Barrett's Oesophagus (BO). Here we demonstrate that the hydrophobic bile acid, deoxycholic acid (DCA), stimulated the production of IL-6 and IL-8 mRNA and protein in Het-1A, a model of normal oesophageal cells. DCA-induced production of IL-6 and IL-8 was attenuated by pharmacologic inhibition of the Protein Kinase C (PKC), MAP kinase, tyrosine kinase pathways, by the cholesterol sequestering agent, methyl-beta-cyclodextrin (MCD) and by the hydrophilic bile acid, ursodeoxycholic acid (UDCA). The cholesterol-interacting agent, nystatin, which binds cholesterol without removing it from the membrane, synergized with DCA to induce IL-6 and IL-8. This was inhibited by the tyrosine kinase inhibitor genistein. DCA stimulated the phosphorylation of lipid raft component Src tyrosine kinase (Src). while knockdown of caveolin-1 expression using siRNA resulted in a decreased level of IL-8 production in response to DCA. Taken together, these results demonstrate that DCA stimulates IL-6 and IL-8 production in oesophageal cells via lipid raft-associated signaling. Inhibition of this process using cyclodextrins represents a novel therapeutic approach to the treatment of inflammatory diseases of the oesophagus including GORD and BO.
Collapse
Affiliation(s)
- Francis Quilty
- School of Pharmacy and Pharmaceutical Science, Trinity College Dublin, Dublin 2, Ireland; Trinity Translational Medicine Institute, Trinity College Dublin, St James's Hospital, Dublin 8, Ireland
| | - Michael Freeley
- School of Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Siobhan Gargan
- Trinity Translational Medicine Institute, Trinity College Dublin, St James's Hospital, Dublin 8, Ireland
| | - John Gilmer
- School of Pharmacy and Pharmaceutical Science, Trinity College Dublin, Dublin 2, Ireland; Trinity Translational Medicine Institute, Trinity College Dublin, St James's Hospital, Dublin 8, Ireland
| | - Aideen Long
- Trinity Translational Medicine Institute, Trinity College Dublin, St James's Hospital, Dublin 8, Ireland.
| |
Collapse
|
11
|
Zheng CR, Singh A, Libby A, Silver PA, Libby EA. Modular and Single-Cell Sensors of Bacterial Ser/Thr Kinase Activity. ACS Synth Biol 2021; 10:2340-2350. [PMID: 34463482 DOI: 10.1021/acssynbio.1c00250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
At the single-cell level, protein kinase activity is typically inferred from downstream transcriptional reporters. However, promoters are often coregulated by several pathways, making the activity of a specific kinase difficult to deconvolve. Here, we present modular, direct, and specific sensors of bacterial kinase activity, including FRET-based sensors, as well as a synthetic transcription factor based on the lactose repressor (LacI) that has been engineered to respond to phosphorylation. We demonstrate the utility of these sensors in measuring the activity of PrkC, a conserved bacterial Ser/Thr kinase, in different growth conditions from single cells to colonies. We also show that PrkC activity increases in response to a cell-wall active antibiotic that blocks the late steps in peptidoglycan synthesis (cefotaxime), but not the early steps (fosfomycin). These sensors have a modular design that should generalize to other bacterial signaling systems in the future.
Collapse
Affiliation(s)
- Christine R. Zheng
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
| | - Abhyudai Singh
- Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Alexandra Libby
- Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey 08544, United States
| | - Pamela A. Silver
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
| | - Elizabeth A. Libby
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
| |
Collapse
|
12
|
Lenkavska L, Tomkova S, Horvath D, Huntosova V. Searching for combination therapy by clustering methods: Stimulation of PKC in Golgi apparatus combined with hypericin induced PDT. Photodiagnosis Photodyn Ther 2020; 31:101813. [PMID: 32442674 DOI: 10.1016/j.pdpdt.2020.101813] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/28/2020] [Accepted: 05/04/2020] [Indexed: 02/07/2023]
Abstract
Cancer cell metabolism is a very attractive target for anticancer treatments. This work focuses on protein kinase C (PKC) signaling in the U87 MG glioma. By means of western blot, fluorescence and time-resolved fluorescence microscopy the correlation between the Golgi apparatus (GA), lysosomes and mitochondria were evaluated. The known regulators of PKC were applied to cancer cells. Phorbol myristate acetate (PMA) was chosen as the activator of PKC. Gö6976, hypericin and rottlerin, the inhibitors of PKCα and PKCδ were selected as well. Stabilization, destabilization processes occurring in cells allow classification of observations into several groups. Multiple versions of hierarchical cluster analysis have been applied and similarities have been found between organelles and PKC regulators. The method identified GA as an extraordinary organelle whose functionality is significantly influenced by PKC regulators as well as oxidative stress. Therefore, combination therapy has been designed according to the results of the cluster analysis. Furthermore, the efficacy of photodynamic therapy mediated by hypericin, and the consequent apoptosis, was significantly increased during the treatment. To our knowledge, this is the first demonstration of the effectiveness of the clustering in the given area.
Collapse
Affiliation(s)
- Lenka Lenkavska
- Department of Biophysics, Faculty of Science, P. J. Safarik University in Kosice, 041 54, Kosice, Slovakia.
| | - Silvia Tomkova
- Department of Biophysics, Faculty of Science, P. J. Safarik University in Kosice, 041 54, Kosice, Slovakia.
| | - Denis Horvath
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Safarik University in Kosice, 041 54, Kosice, Slovakia.
| | - Veronika Huntosova
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Safarik University in Kosice, 041 54, Kosice, Slovakia.
| |
Collapse
|
13
|
Schmitz-Peiffer C. Deconstructing the Role of PKC Epsilon in Glucose Homeostasis. Trends Endocrinol Metab 2020; 31:344-356. [PMID: 32305097 DOI: 10.1016/j.tem.2020.01.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/22/2020] [Accepted: 01/24/2020] [Indexed: 02/06/2023]
Abstract
The failure of insulin to suppress glucose production by the liver is a key aspect of the insulin resistance seen in type 2 diabetes. Lipid-activated protein kinase C epsilon has long been identified as an important mediator of diet-induced glucose intolerance and hepatic insulin resistance and the current view emphasizes a mechanism involving phosphorylation of the insulin receptor by the kinase to inhibit downstream insulin action. However, the significance of this direct effect in the liver has now been challenged by tissue-specific deletion of PKCε, which demonstrated a more prominent role for the kinase in adipose tissue to promote glucose intolerance. New insights regarding the role of PKCε therefore contribute to the understanding of indirect effects on hepatic glucose metabolism.
Collapse
Affiliation(s)
- Carsten Schmitz-Peiffer
- Garvan Institute of Medical Research, Darlinghurst Sydney, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales, Sydney, NSW 2010, Australia.
| |
Collapse
|
14
|
Hanáková K, Bernatík O, Kravec M, Micka M, Kumar J, Harnoš J, Ovesná P, Paclíková P, Rádsetoulal M, Potěšil D, Tripsianes K, Čajánek L, Zdráhal Z, Bryja V. Comparative phosphorylation map of Dishevelled 3 links phospho-signatures to biological outputs. Cell Commun Signal 2019; 17:170. [PMID: 31870452 PMCID: PMC6927192 DOI: 10.1186/s12964-019-0470-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 10/22/2019] [Indexed: 12/28/2022] Open
Abstract
Background Dishevelled (DVL) is an essential component of the Wnt signaling cascades. Function of DVL is controlled by phosphorylation but the molecular details are missing. DVL3 contains 131 serines and threonines whose phosphorylation generates complex barcodes underlying diverse DVL3 functions. In order to dissect the role of DVL phosphorylation we analyzed the phosphorylation of human DVL3 induced by previously reported (CK1ε, NEK2, PLK1, CK2α, RIPK4, PKCδ) and newly identified (TTBK2, Aurora A) DVL kinases. Methods Shotgun proteomics including TiO2 enrichment of phosphorylated peptides followed by liquid chromatography tandem mass spectrometry on immunoprecipitates from HEK293T cells was used to identify and quantify phosphorylation of DVL3 protein induced by 8 kinases. Functional characterization was performed by in-cell analysis of phospho-mimicking/non-phosphorylatable DVL3 mutants and supported by FRET assays and NMR spectroscopy. Results We used quantitative mass spectrometry and calculated site occupancies and quantified phosphorylation of > 80 residues. Functional validation demonstrated the importance of CK1ε-induced phosphorylation of S268 and S311 for Wnt-3a-induced β-catenin activation. S630–643 cluster phosphorylation by CK1, NEK2 or TTBK2 is essential for even subcellular distribution of DVL3 when induced by CK1 and TTBK2 but not by NEK2. Further investigation showed that NEK2 utilizes a different mechanism to promote even localization of DVL3. NEK2 triggered phosphorylation of PDZ domain at S263 and S280 prevents binding of DVL C-terminus to PDZ and promotes an open conformation of DVL3 that is more prone to even subcellular localization. Conclusions We identify unique phosphorylation barcodes associated with DVL function. Our data provide an example of functional synergy between phosphorylation in structured domains and unstructured IDRs that together dictate the biological outcome. Video Abtract.
Graphical abstract ![]()
Collapse
Affiliation(s)
- Kateřina Hanáková
- CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic.,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ondřej Bernatík
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic.,Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Marek Kravec
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
| | - Miroslav Micka
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
| | - Jitender Kumar
- CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Jakub Harnoš
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
| | - Petra Ovesná
- Institute of Biostatistics and Analyses, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Petra Paclíková
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
| | - Matěj Rádsetoulal
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic
| | - David Potěšil
- CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Konstantinos Tripsianes
- CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Lukáš Čajánek
- Department of Histology and Embryology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Zbyněk Zdráhal
- CEITEC-Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic. .,National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic.
| | - Vítězslav Bryja
- Department of Experimental Biology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic. .,Department of Cytokinetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
| |
Collapse
|
15
|
Niemeyer A, Rinne A, Kienitz MC. Receptor-specific regulation of atrial GIRK channel activity by different Ca2+-dependent PKC isoforms. Cell Signal 2019; 64:109418. [DOI: 10.1016/j.cellsig.2019.109418] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/11/2019] [Accepted: 09/11/2019] [Indexed: 12/23/2022]
|
16
|
Marrocco V, Bogomolovas J, Ehler E, Dos Remedios CG, Yu J, Gao C, Lange S. PKC and PKN in heart disease. J Mol Cell Cardiol 2019; 128:212-226. [PMID: 30742812 PMCID: PMC6408329 DOI: 10.1016/j.yjmcc.2019.01.029] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 01/30/2019] [Accepted: 01/31/2019] [Indexed: 12/22/2022]
Abstract
The protein kinase C (PKC) and closely related protein kinase N (PKN) families of serine/threonine protein kinases play crucial cellular roles. Both kinases belong to the AGC subfamily of protein kinases that also include the cAMP dependent protein kinase (PKA), protein kinase B (PKB/AKT), protein kinase G (PKG) and the ribosomal protein S6 kinase (S6K). Involvement of PKC family members in heart disease has been well documented over the years, as their activity and levels are mis-regulated in several pathological heart conditions, such as ischemia, diabetic cardiomyopathy, as well as hypertrophic or dilated cardiomyopathy. This review focuses on the regulation of PKCs and PKNs in different pathological heart conditions and on the influences that PKC/PKN activation has on several physiological processes. In addition, we discuss mechanisms by which PKCs and the closely related PKNs are activated and turned-off in hearts, how they regulate cardiac specific downstream targets and pathways, and how their inhibition by small molecules is explored as new therapeutic target to treat cardiomyopathies and heart failure.
Collapse
Affiliation(s)
- Valeria Marrocco
- Division of Cardiology, School of Medicine, University of California-San Diego, La Jolla, USA
| | - Julius Bogomolovas
- Division of Cardiology, School of Medicine, University of California-San Diego, La Jolla, USA; Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, School of Cardiovascular Medicine and Sciences, British Heart Foundation Research Excellence Centre, King's College London, New Hunt's House, Guy's Campus, London SE1 1UL, UK
| | | | - Jiayu Yu
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chen Gao
- Division of Molecular Medicine, Department of Anesthesiology, David Geffen School of Medicine at UCLA, University of California-Los Angeles, Los Angeles, USA.
| | - Stephan Lange
- Division of Cardiology, School of Medicine, University of California-San Diego, La Jolla, USA; University of Gothenburg, Wallenberg Laboratory, Department of Molecular and Clinical Medicine, Institute of Medicine, Gothenburg, Sweden.
| |
Collapse
|
17
|
Kajimoto T, Caliman AD, Tobias IS, Okada T, Pilo CA, Van AAN, Andrew McCammon J, Nakamura SI, Newton AC. Activation of atypical protein kinase C by sphingosine 1-phosphate revealed by an aPKC-specific activity reporter. Sci Signal 2019; 12:eaat6662. [PMID: 30600259 PMCID: PMC6657501 DOI: 10.1126/scisignal.aat6662] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Atypical protein kinase C (aPKC) isozymes are unique in the PKC superfamily in that they are not regulated by the lipid second messenger diacylglycerol, which has led to speculation about whether a different second messenger acutely controls their function. Here, using a genetically encoded reporter that we designed, aPKC-specific C kinase activity reporter (aCKAR), we found that the lipid mediator sphingosine 1-phosphate (S1P) promoted the cellular activity of aPKC. Intracellular S1P directly bound to the purified kinase domain of aPKC and relieved autoinhibitory constraints, thereby activating the kinase. In silico studies identified potential binding sites on the kinase domain, one of which was validated biochemically. In HeLa cells, S1P-dependent activation of aPKC suppressed apoptosis. Together, our findings identify a previously undescribed molecular mechanism of aPKC regulation, a molecular target for S1P in cell survival regulation, and a tool to further explore the biochemical and biological functions of aPKC.
Collapse
Affiliation(s)
- Taketoshi Kajimoto
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA.
- Division of Biochemistry, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan
| | - Alisha D Caliman
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA
| | - Irene S Tobias
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA
| | - Taro Okada
- Division of Biochemistry, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan
| | - Caila A Pilo
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA
| | - An-Angela N Van
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA
| | - J Andrew McCammon
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA
| | - Shun-Ichi Nakamura
- Division of Biochemistry, Department of Biochemistry and Molecular Biology, Graduate School of Medicine, Kobe University, Kobe 650-0017, Japan
| | - Alexandra C Newton
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92037, USA.
| |
Collapse
|
18
|
Samuels AL, Louw A, Zareie R, Ingley E. Control of nuclear-cytoplasmic shuttling of Ankrd54 by PKCδ. World J Biol Chem 2017; 8:163-174. [PMID: 28924458 PMCID: PMC5579962 DOI: 10.4331/wjbc.v8.i3.163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/28/2017] [Accepted: 05/15/2017] [Indexed: 02/05/2023] Open
Abstract
AIM To identify and characterize the effect of phosphorylation on the subcellular localization of Ankrd54.
METHODS HEK293T cells were treated with calyculin A, staurosporin or phorbol 12-myristate 13-acetate (PMA). Cells were transfected with eGFP-tagged Ankrd54 with or without Lyn tyrosine kinase (wild-type, Y397F mutant, or Y508F mutant). The subcellular localization was assessed by immunofluorescence imaging of cells, immunoblotting of subcellular fractionations. The phosphorylation of Ankrd54 was monitored using Phos-tagTM gel retardation. Phosphorylated peptides were analysed by multiple-reaction-monitoring (MRM) proteomic analysis.
RESULTS Activation of PKC kinases using PMA promoted nuclear export of Ankrd54 and correlated with increased Ankrd54 phosphorylation, assayed using Phos-tagTM gel retardation. Co-expression of an active form of the PKCδ isoform specifically promoted both phosphorylation and cytoplasmic localization of Ankrd54, while PKCδ, Akt and PKA did not. Alanine mutation of several serine residues in the amino-terminal region of Ankrd54 (Ser14, Ser17, Ser18, Ser19) reduced both PMA induced cytoplasmic localization and phosphorylation of Ankrd54. Using MRM proteomic analysis, phosphorylation of the Ser18 residue of Ankrd54 was readily detectable in response to PMA stimulation. PMA stimulation of cells co-expressing Ankrd54 and Lyn tyrosine kinase displayed increased co-immunoprecipitation and enhanced co-localization in the cytoplasm.
CONCLUSION We identify phosphorylation by PKCδ as a major regulator of nuclear-cytoplasmic shuttling of Ankrd54, and its interaction with the tyrosine kinase Lyn.
Collapse
Affiliation(s)
- Amy L Samuels
- Cell Signalling Group, Harry Perkins Institute of Medical Research and Centre for Medical Research, the University of Western Australia, Nedlands, WA 6009, Australia
| | - Alison Louw
- Cell Signalling Group, Harry Perkins Institute of Medical Research and Centre for Medical Research, the University of Western Australia, Nedlands, WA 6009, Australia
| | - Reza Zareie
- Proteomics International Laboratories Ltd, Nedlands, WA 6009, Australia
- Proteowa Pty Ltd, SABC, Murdoch University, Murdoch, WA 6150, Australia
| | - Evan Ingley
- Cell Signalling Group, Harry Perkins Institute of Medical Research and Centre for Medical Research, the University of Western Australia, Nedlands, WA 6009, Australia
- Cell Signalling Group, School of Veterinary and Health Sciences, Murdoch University, Murdoch, WA 6150, Australia.
| |
Collapse
|
19
|
Protein kinase C mechanisms that contribute to cardiac remodelling. Clin Sci (Lond) 2017; 130:1499-510. [PMID: 27433023 DOI: 10.1042/cs20160036] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/18/2016] [Indexed: 12/12/2022]
Abstract
Protein phosphorylation is a highly-regulated and reversible process that is precisely controlled by the actions of protein kinases and protein phosphatases. Factors that tip the balance of protein phosphorylation lead to changes in a wide range of cellular responses, including cell proliferation, differentiation and survival. The protein kinase C (PKC) family of serine/threonine kinases sits at nodal points in many signal transduction pathways; PKC enzymes have been the focus of considerable attention since they contribute to both normal physiological responses as well as maladaptive pathological responses that drive a wide range of clinical disorders. This review provides a background on the mechanisms that regulate individual PKC isoenzymes followed by a discussion of recent insights into their role in the pathogenesis of diseases such as cancer. We then provide an overview on the role of individual PKC isoenzymes in the regulation of cardiac contractility and pathophysiological growth responses, with a focus on the PKC-dependent mechanisms that regulate pump function and/or contribute to the pathogenesis of heart failure.
Collapse
|
20
|
Reyland ME, Jones DNM. Multifunctional roles of PKCδ: Opportunities for targeted therapy in human disease. Pharmacol Ther 2016; 165:1-13. [PMID: 27179744 DOI: 10.1016/j.pharmthera.2016.05.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The serine-threonine protein kinase, protein kinase C-δ (PKCδ), is emerging as a bi-functional regulator of cell death and proliferation. Studies in PKCδ-/- mice have confirmed a pro-apoptotic role for this kinase in response to DNA damage and a tumor promoter role in some oncogenic contexts. In non-transformed cells, inhibition of PKCδ suppresses the release of cytochrome c and caspase activation, indicating a function upstream of apoptotic pathways. Data from PKCδ-/- mice demonstrate a role for PKCδ in the execution of DNA damage-induced and physiologic apoptosis. This has led to the important finding that inhibitors of PKCδ can be used therapeutically to reduce irradiation and chemotherapy-induced toxicity. By contrast, PKCδ is a tumor promoter in mouse models of mammary gland and lung cancer, and increased PKCδ expression is a negative prognostic indicator in Her2+ and other subtypes of human breast cancer. Understanding how these distinct functions of PKCδ are regulated is critical for the design of therapeutics to target this pathway. This review will discuss what is currently known about biological roles of PKCδ and prospects for targeting PKCδ in human disease.
Collapse
Affiliation(s)
- Mary E Reyland
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - David N M Jones
- Department of Pharmacology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| |
Collapse
|
21
|
Bullenkamp J, Gäken J, Festy F, Chong EZ, Ng T, Tavassoli M. Apoptin interacts with and regulates the activity of protein kinase C beta in cancer cells. Apoptosis 2016; 20:831-42. [PMID: 25828882 DOI: 10.1007/s10495-015-1120-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Apoptin, the VP3 protein from chicken anaemia virus (CAV), induces tumour cell-specific cell death and represents a potential future anti-cancer therapeutic. In tumour but not in normal cells, Apoptin is phosphorylated and translocates to the nucleus, enabling its cytotoxic activity. Recently, the β isozyme of protein kinase C (PKCβ) was shown to phosphorylate Apoptin in multiple myeloma cell lines. However, the exact mechanism and nature of interaction between PKCβ and Apoptin remain unclear. Here we investigated the physical and functional link between PKCβ and CAV-Apoptin as well as with the recently identified Apoptin homologue derived from human Gyrovirus (HGyV). In contrast to HCT116 colorectal cancer cells the normal colon mucosa cell lines expressed low levels of PKCβI and showed reduced Apoptin activation, as evident by cytoplasmic localisation, decreased phosphorylation and lack of cytotoxic activity. Co-immunoprecipitation and proximity ligation assay studies identified binding of both CAV- and HGyV-Apoptin to PKCβI in HCT116 cells. Using Apoptin deletion constructs the N-terminal domain of Apoptin was found to be required for interacting with PKCβI. FRET-based PKC activity reporter assays by fluorescence lifetime imaging microscopy showed that expression of Apoptin in cancer cells but not in normal cells triggers a significant increase in PKC activity. Collectively, the results demonstrate a novel cancer specific interplay between Apoptin and PKCβI. Direct interaction between the two proteins leads to Apoptin-induced activation of PKC and consequently activated PKCβI mediates phosphorylation of Apoptin to promote its tumour-specific nuclear translocation and cytotoxic function.
Collapse
Affiliation(s)
- Jessica Bullenkamp
- Department of Molecular Oncology, King's College London, Guy's Campus, Hodgkin Building, London, SE1 1UL, UK
| | | | | | | | | | | |
Collapse
|
22
|
González-Vera JA, Morris MC. Fluorescent Reporters and Biosensors for Probing the Dynamic Behavior of Protein Kinases. Proteomes 2015; 3:369-410. [PMID: 28248276 PMCID: PMC5217393 DOI: 10.3390/proteomes3040369] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/30/2015] [Accepted: 10/23/2015] [Indexed: 12/20/2022] Open
Abstract
Probing the dynamic activities of protein kinases in real-time in living cells constitutes a major challenge that requires specific and sensitive tools tailored to meet the particular demands associated with cellular imaging. The development of genetically-encoded and synthetic fluorescent biosensors has provided means of monitoring protein kinase activities in a non-invasive fashion in their native cellular environment with high spatial and temporal resolution. Here, we review existing technologies to probe different dynamic features of protein kinases and discuss limitations where new developments are required to implement more performant tools, in particular with respect to infrared and near-infrared fluorescent probes and strategies which enable improved signal-to-noise ratio and controlled activation of probes.
Collapse
Affiliation(s)
- Juan A González-Vera
- Cell Cycle Biosensors & Inhibitors, Department of Amino Acids, Peptides and Proteins, Institute of Biomolecules Max Mousseron (IBMM) CNRS-UMR 5247, 15 Avenue Charles Flahault, Montpellier 34093, France.
| | - May C Morris
- Cell Cycle Biosensors & Inhibitors, Department of Amino Acids, Peptides and Proteins, Institute of Biomolecules Max Mousseron (IBMM) CNRS-UMR 5247, 15 Avenue Charles Flahault, Montpellier 34093, France.
| |
Collapse
|
23
|
Antal CE, Hudson AM, Kang E, Zanca C, Wirth C, Stephenson NL, Trotter EW, Gallegos LL, Miller CJ, Furnari FB, Hunter T, Brognard J, Newton AC. Cancer-associated protein kinase C mutations reveal kinase's role as tumor suppressor. Cell 2015; 160:489-502. [PMID: 25619690 PMCID: PMC4313737 DOI: 10.1016/j.cell.2015.01.001] [Citation(s) in RCA: 247] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/12/2014] [Accepted: 12/24/2014] [Indexed: 12/24/2022]
Abstract
Protein kinase C (PKC) isozymes have remained elusive cancer targets despite the unambiguous tumor promoting function of their potent ligands, phorbol esters, and the prevalence of their mutations. We analyzed 8% of PKC mutations identified in human cancers and found that, surprisingly, most were loss of function and none were activating. Loss-of-function mutations occurred in all PKC subgroups and impeded second-messenger binding, phosphorylation, or catalysis. Correction of a loss-of-function PKCβ mutation by CRISPR-mediated genome editing in a patient-derived colon cancer cell line suppressed anchorage-independent growth and reduced tumor growth in a xenograft model. Hemizygous deletion promoted anchorage-independent growth, revealing that PKCβ is haploinsufficient for tumor suppression. Several mutations were dominant negative, suppressing global PKC signaling output, and bioinformatic analysis suggested that PKC mutations cooperate with co-occurring mutations in cancer drivers. These data establish that PKC isozymes generally function as tumor suppressors, indicating that therapies should focus on restoring, not inhibiting, PKC activity.
Collapse
Affiliation(s)
- Corina E Antal
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92093, USA
| | - Andrew M Hudson
- Signalling Networks in Cancer Group, Cancer Research UK Manchester Institute, University of Manchester, Manchester M20 4BX, UK
| | - Emily Kang
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
| | - Ciro Zanca
- Ludwig Institute for Cancer Research, University of California at San Diego, La Jolla, CA 92093, USA
| | - Christopher Wirth
- Applied Computational Biology and Bioinformatics Group, Cancer Research UK Manchester Institute, University of Manchester, Manchester M20 4BX, UK
| | - Natalie L Stephenson
- Signalling Networks in Cancer Group, Cancer Research UK Manchester Institute, University of Manchester, Manchester M20 4BX, UK
| | - Eleanor W Trotter
- Signalling Networks in Cancer Group, Cancer Research UK Manchester Institute, University of Manchester, Manchester M20 4BX, UK
| | - Lisa L Gallegos
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA; Biomedical Sciences Graduate Program, University of California at San Diego, La Jolla, CA 92093, USA
| | - Crispin J Miller
- Applied Computational Biology and Bioinformatics Group, Cancer Research UK Manchester Institute, University of Manchester, Manchester M20 4BX, UK
| | - Frank B Furnari
- Ludwig Institute for Cancer Research, University of California at San Diego, La Jolla, CA 92093, USA
| | | | - John Brognard
- Signalling Networks in Cancer Group, Cancer Research UK Manchester Institute, University of Manchester, Manchester M20 4BX, UK.
| | - Alexandra C Newton
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA.
| |
Collapse
|
24
|
Kedei N, Chen JQ, Herrmann MA, Telek A, Goldsmith PK, Petersen ME, Keck GE, Blumberg PM. Molecular systems pharmacology: isoelectric focusing signature of protein kinase Cδ provides an integrated measure of its modulation in response to ligands. J Med Chem 2014; 57:5356-69. [PMID: 24906106 PMCID: PMC4216220 DOI: 10.1021/jm500417b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Protein
kinase C (PKC), a validated therapeutic target for cancer
chemotherapy, provides a paradigm for assessing structure–activity
relations, where ligand binding has multiple consequences for a target.
For PKC, ligand binding controls not only PKC activation and multiple
phosphorylations but also subcellular localization, affecting subsequent
signaling. Using a capillary isoelectric focusing immunoassay system,
we could visualize a high resolution isoelectric focusing signature
of PKCδ upon stimulation by ligands of the phorbol ester and
bryostatin classes. Derivatives that possessed different physicochemical
characteristics and induced different patterns of biological response
generated different signatures. Consistent with different patterns
of PKCδ localization as one factor linked to these different
signatures, we found different signatures for activated PKCδ
from the nuclear and non-nuclear fractions. We conclude that the capillary
isoelectric focusing immunoassay system may provide a window into
the integrated consequences of ligand binding and thus afford a powerful
platform for compound development.
Collapse
Affiliation(s)
- Noemi Kedei
- Laboratory of Cancer Biology and Genetics, ‡Collaborative Protein Technology Resource, Laboratory of Cell Biology, and §Office of Science and Technology Partnerships, Center for Cancer Research, National Cancer Institute , Bethesda, Maryland 20892, United States
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
Protein kinase C (PKC) is a family of phospholipid-dependent serine/threonine kinases, which can be further classified into three PKC isozymes subfamilies: conventional or classic, novel or nonclassic, and atypical. PKC isozymes are known to be involved in cell proliferation, survival, invasion, migration, apoptosis, angiogenesis, and drug resistance. Because of their key roles in cell signaling, PKC isozymes also have the potential to be promising therapeutic targets for several diseases, such as cardiovascular diseases, immune and inflammatory diseases, neurological diseases, metabolic disorders, and multiple types of cancer. This review primarily focuses on the activation, mechanism, and function of PKC isozymes during cancer development and progression.
Collapse
|
26
|
Cone AC, Cavin G, Ambrosi C, Hakozaki H, Wu-Zhang AX, Kunkel MT, Newton AC, Sosinsky GE. Protein kinase Cδ-mediated phosphorylation of Connexin43 gap junction channels causes movement within gap junctions followed by vesicle internalization and protein degradation. J Biol Chem 2014; 289:8781-98. [PMID: 24500718 PMCID: PMC3979370 DOI: 10.1074/jbc.m113.533265] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 01/29/2014] [Indexed: 01/14/2023] Open
Abstract
Phosphorylation of gap junction proteins, connexins, plays a role in global signaling events involving kinases. Connexin43 (Cx43), a ubiquitous and important connexin, has several phosphorylation sites for specific kinases. We appended an imaging reporter tag for the activity of the δ isoform of protein kinase C (PKCδ) to the carboxyl terminus of Cx43. The FRET signal of this reporter is inversely related to the phosphorylation of serine 368 of Cx43. By activating PKC with the phorbol ester phorbol 12,13-dibutyrate (PDBu) or a natural stimulant, UTP, time lapse live cell imaging movies indicated phosphorylated Ser-368 Cx43 separated into discrete domains within gap junctions and was internalized in small vesicles, after which it was degraded by lysosomes and proteasomes. Mutation of Ser-368 to an Ala eliminated the response to PDBu and changes in phosphorylation of the reporter. A phosphatase inhibitor, calyculin A, does not change this pattern, indicating PKC phosphorylation causes degradation of Cx43 without dephosphorylation, which is in accordance with current hypotheses that cells control their intercellular communication by a fast and constant turnover of connexins, using phosphorylation as part of this mechanism.
Collapse
Affiliation(s)
- Angela C. Cone
- From the National Center for Microscopy and Imaging Research
| | - Gabriel Cavin
- From the National Center for Microscopy and Imaging Research
| | - Cinzia Ambrosi
- From the National Center for Microscopy and Imaging Research
| | | | | | | | | | - Gina E. Sosinsky
- From the National Center for Microscopy and Imaging Research
- the Department of Neurosciences, University of California, San Diego, California 92093
| |
Collapse
|
27
|
Wie SM, Adwan TS, DeGregori J, Anderson SM, Reyland ME. Inhibiting tyrosine phosphorylation of protein kinase Cδ (PKCδ) protects the salivary gland from radiation damage. J Biol Chem 2014; 289:10900-10908. [PMID: 24569990 DOI: 10.1074/jbc.m114.551366] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Radiation therapy for head and neck cancer can result in extensive damage to normal adjacent tissues such as the salivary gland and oral mucosa. We have shown previously that tyrosine phosphorylation at Tyr-64 and Tyr-155 activates PKCδ in response to apoptotic stimuli by facilitating its nuclear import. Here we have identified the tyrosine kinases that mediate activation of PKCδ in apoptotic cells and have explored the use of tyrosine kinase inhibitors for suppression of irradiation-induced apoptosis. We identify the damage-inducible kinase, c-Abl, as the PKCδ Tyr-155 kinase and c-Src as the Tyr-64 kinase. Depletion of c-Abl or c-Src with shRNA decreased irradiation- and etoposide-induced apoptosis, suggesting that inhibitors of these kinases may be useful therapeutically. Pretreatment with dasatinib, a broad spectrum tyrosine kinase inhibitor, blocked phosphorylation of PKCδ at both Tyr-64 and Tyr-155. Expression of "gate-keeper" mutants of c-Abl or c-Src that are active in the presence of dasatinib restored phosphorylation of PKCδ at Tyr-155 and Tyr-64, respectively. Imatinib, a c-Abl-selective inhibitor, also specifically blocked PKCδ Tyr-155 phosphorylation. Dasatinib and imatinib both blocked binding of PKCδ to importin-α and nuclear import, demonstrating that tyrosine kinase inhibitors can inhibit nuclear accumulation of PKCδ. Likewise, pretreatment with dasatinib also suppressed etoposide and radiation induced apoptosis in vitro. In vivo, pre-treatment of mice with dasatinib blocked radiation-induced apoptosis in the salivary gland by >60%. These data suggest that tyrosine kinase inhibitors may be useful prophylactically for protection of nontumor tissues in patients undergoing radiotherapy of the head and neck.
Collapse
Affiliation(s)
- Sten M Wie
- Program in Structural Biology and Biochemistry; Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045
| | - Tariq S Adwan
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045
| | - James DeGregori
- Department of Biochemistry and Molecular Genetics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045
| | - Steven M Anderson
- Department of Pathology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045
| | - Mary E Reyland
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Anschutz Medical Campus, Aurora, Colorado 80045.
| |
Collapse
|
28
|
Hertel F, Zhang J. Monitoring of post-translational modification dynamics with genetically encoded fluorescent reporters. Biopolymers 2014; 101:180-7. [PMID: 23576192 PMCID: PMC3883948 DOI: 10.1002/bip.22254] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/01/2013] [Indexed: 11/06/2022]
Abstract
Post-translational modifications (PTMs) of proteins are essential mechanisms for virtually all dynamic processes within cellular signaling networks. Genetically encoded reporters based on fluorescent proteins (FPs) are powerful tools for spatiotemporal visualization of cellular parameters. Consequently, commonly used modular biosensor designs have been adapted to generate several protein-based indicators for monitoring various PTMs or the activity of corresponding enzymes in living cells, providing new biological insights into dynamics and regulatory functions of individual PTMs. In this review, we describe the application of general design strategies focusing on PTMs and discuss important considerations for engineering feasible indicators depending on the purpose. Moreover, we present developments and enhancements of PTM biosensors from selected studies and give an outlook on future perspectives of this versatile approach.
Collapse
Affiliation(s)
- Fabian Hertel
- The Johns Hopkins University School of Medicine, Department of Pharmacology and Molecular Sciences, Baltimore, MD 21205, USA
| | - Jin Zhang
- The Johns Hopkins University School of Medicine, Department of Pharmacology and Molecular Sciences, Baltimore, MD 21205, USA
| |
Collapse
|
29
|
Oldach L, Zhang J. Genetically encoded fluorescent biosensors for live-cell visualization of protein phosphorylation. ACTA ACUST UNITED AC 2014; 21:186-97. [PMID: 24485761 DOI: 10.1016/j.chembiol.2013.12.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Revised: 11/22/2013] [Accepted: 12/10/2013] [Indexed: 11/30/2022]
Abstract
Fluorescence-based, genetically encodable biosensors are widely used tools for real-time analysis of biological processes. Over the last few decades, the number of available genetically encodable biosensors and the types of processes they can monitor have increased rapidly. Here, we aim to introduce the reader to general principles and practices in biosensor development and highlight ways in which biosensors can be used to illuminate outstanding questions of biological function. Specifically, we focus on sensors developed for monitoring kinase activity and use them to illustrate some common considerations for biosensor design. We describe several uses to which kinase and second-messenger biosensors have been put, and conclude with considerations for the use of biosensors once they are developed. Overall, as fluorescence-based biosensors continue to diversify and improve, we expect them to continue to be widely used as reliable and fruitful tools for gaining deeper insights into cellular and organismal function.
Collapse
Affiliation(s)
- Laurel Oldach
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 307 Hunterian Building, 725 North Wolfe Street, Baltimore, MD 21205, USA
| | - Jin Zhang
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 307 Hunterian Building, 725 North Wolfe Street, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Department of Oncology, The Johns Hopkins University School of Medicine, 307 Hunterian Building, 725 North Wolfe Street, Baltimore, MD 21205, USA.
| |
Collapse
|
30
|
Abstract
Kinase signaling is under tight spatiotemporal control, with signaling hubs within the cell often coordinated by protein scaffolds. Genetically encoded kinase activity reporters afford a unique tool to interrogate the rate, amplitude, and duration of kinase signaling at specific locations throughout the cell. This protocol describes how to assay kinase activity at a protein scaffold in live cells using a fluorescence resonance energy transfer (FRET)-based kinase activity sensor for protein kinase D (PKD) as an example.
Collapse
|
31
|
Abstract
PKC (protein kinase C) has been in the limelight since the discovery three decades ago that it acts as a major receptor for the tumour-promoting phorbol esters. Phorbol esters, with their potent ability to activate two of the three classes of PKC isoenzymes, have remained the best pharmacological tool for directly modulating PKC activity. However, with the discovery of other phorbol ester-responsive proteins, the advent of various small-molecule and peptide modulators, and the need to distinguish isoenzyme-specific activity, the pharmacology of PKC has become increasingly complex. Not surprisingly, many of the compounds originally touted as direct modulators of PKC have subsequently been shown to hit many other cellular targets and, in some cases, not even directly modulate PKC. The complexities and reversals in PKC pharmacology have led to widespread confusion about the current status of the pharmacological tools available to control PKC activity. In the present review, we aim to clarify the cacophony in the literature regarding the current state of bona fide and discredited cellular PKC modulators, including activators, small-molecule inhibitors and peptides, and also address the use of genetically encoded reporters and of PKC mutants to measure the effects of these drugs on the spatiotemporal dynamics of signalling by specific isoenzymes.
Collapse
Affiliation(s)
- Alyssa X. Wu-Zhang
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0721, (858) 534-4527, Fax: (858) 822-5888
| | - Alexandra C. Newton
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0721, (858) 534-4527, Fax: (858) 822-5888
| |
Collapse
|
32
|
From FRET Imaging to Practical Methodology for Kinase Activity Sensing in Living Cells. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 113:145-216. [DOI: 10.1016/b978-0-12-386932-6.00005-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
33
|
Gonzalez-Garcia JR, Machaty Z, Lai FA, Swann K. The dynamics of PKC-induced phosphorylation triggered by Ca2+ oscillations in mouse eggs. J Cell Physiol 2013; 228:110-9. [PMID: 22566126 PMCID: PMC3746124 DOI: 10.1002/jcp.24110] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 04/25/2012] [Indexed: 12/31/2022]
Abstract
Fertilization of mammalian eggs is characterized by a series of Ca(2+) oscillations triggered by a phospholipase C activity. These Ca(2+) increases and the parallel generation of diacylglycerol (DAG) stimulate protein kinase C (PKC). However, the dynamics of PKC activity have not been directly measured in living eggs. Here, we have monitored the dynamics of PKC-induced phosphorylation in mouse eggs, alongside Ca(2+) oscillations, using fluorescent C-kinase activity reporter (CKAR) probes. Ca(2+) oscillations triggered either by sperm, phospholipase C zeta (PLCζ) or Sr(2+) all caused repetitive increases in PKC-induced phosphorylation, as detected by CKAR in the cytoplasm or plasma membrane. The CKAR responses lasted for several minutes in both the cytoplasm and plasma membrane then returned to baseline values before subsequent Ca(2+) transients. High frequency oscillations caused by PLCζ led to an integration of PKC-induced phosphorylation. The conventional PKC inhibitor, Gö6976, could inhibit CKAR increases in response to thapsigargin or ionomycin, but not the repetitive responses seen at fertilization. Repetitive increases in PKCδ activity were also detected during Ca(2+) oscillations using an isoform-specific δCKAR. However, PKCδ may already be mostly active in unfertilized eggs, since phorbol esters were effective at stimulating δCKAR only after fertilization, and the PKCδ-specific inhibitor, rottlerin, decreased the CKAR signals in unfertilized eggs. These data show that PKC-induced phosphorylation outlasts each Ca(2+) increase in mouse eggs but that signal integration only occurs at a non-physiological, high Ca(2+) oscillation frequency. The results also suggest that Ca(2+) -induced DAG formation on intracellular membranes may stimulate PKC activity oscillations at fertilization.
Collapse
Affiliation(s)
| | - Zoltan Machaty
- Department of Animal Sciences, Purdue UniversityWest Lafayette, Indiana
| | - F Anthony Lai
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff UniversityCardiff, UK
| | - Karl Swann
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff UniversityCardiff, UK
| |
Collapse
|
34
|
Nhu Ngoc Van T, Morris MC. Fluorescent Sensors of Protein Kinases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 113:217-74. [DOI: 10.1016/b978-0-12-386932-6.00006-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
35
|
Kang JH, Toita R, Kim CW, Katayama Y. Protein kinase C (PKC) isozyme-specific substrates and their design. Biotechnol Adv 2012; 30:1662-72. [DOI: 10.1016/j.biotechadv.2012.07.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Revised: 07/17/2012] [Accepted: 07/18/2012] [Indexed: 11/30/2022]
|
36
|
Wu-Zhang AX, Murphy AN, Bachman M, Newton AC. Isozyme-specific interaction of protein kinase Cδ with mitochondria dissected using live cell fluorescence imaging. J Biol Chem 2012; 287:37891-906. [PMID: 22988234 DOI: 10.1074/jbc.m112.412635] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
PKCδ signaling to mitochondria has been implicated in both mitochondrial apoptosis and metabolism. However, the mechanism by which PKCδ interacts with mitochondria is not well understood. Using FRET-based imaging, we show that PKCδ interacts with mitochondria by a novel and isozyme-specific mechanism distinct from its canonical recruitment to other membranes such as the plasma membrane or Golgi. Specifically, we show that PKCδ interacts with mitochondria following stimulation with phorbol esters or, in L6 myocytes, with insulin via a mechanism that requires two steps. In the first step, PKCδ translocates acutely to mitochondria by a mechanism that requires its C1A and C1B domains and a Leu-Asn sequence in its turn motif. In the second step, PKCδ is retained at mitochondria by a mechanism that depends on its C2 domain, a unique Glu residue in its activation loop, intrinsic catalytic activity, and the mitochondrial membrane potential. In contrast, of these determinants, only the C1B domain is required for the phorbol ester-stimulated translocation of PKCδ to other membranes. PKCδ also basally localizes to mitochondria and increases mitochondrial respiration via many of the same determinants that promote its agonist-evoked interaction. PKCδ localized to mitochondria has robust activity, as revealed by a FRET reporter of PKCδ-specific activity (δCKAR). These data support a model in which multiple determinants unique to PKCδ drive a specific interaction with mitochondria that promotes mitochondrial respiration.
Collapse
Affiliation(s)
- Alyssa X Wu-Zhang
- Department of Pharmacology, University of California San Diego, La Jolla, California 92093, USA
| | | | | | | |
Collapse
|
37
|
Protein kinase cδ in apoptosis: a brief overview. Arch Immunol Ther Exp (Warsz) 2012; 60:361-72. [PMID: 22918451 DOI: 10.1007/s00005-012-0188-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Accepted: 08/06/2012] [Indexed: 12/21/2022]
Abstract
Protein kinase C-delta (PKCδ), a member of the lipid-regulated serine/threonine PKC family, has been implicated in a wide range of important cellular processes. In the past decade, the critical role of PKCδ in the regulation of both intrinsic and extrinsic apoptosis pathways has been widely explored. In most cases, over-expression or activation of PKCδ results in the induction of apoptosis. The phosphorylations and multiple cell organelle translocations of PKCδ initiate apoptosis by targeting multiple downstream effectors. During apoptosis, PKCδ is proteolytically cleaved by caspase-3 to generate a constitutively activated catalytic fragment, which amplifies apoptosis cascades in nucleus and mitochondria. However, PKCδ also exerts its anti-apoptotic and pro-survival roles in some cases. Therefore, the complicated role of PKCδ in apoptosis appears to be stimulus and cell type dependent. This review is mainly focused on how PKCδ gets activated in diverse ways in response to apoptotic signals and how PKCδ targets different downstream regulators to sponsor or restrain apoptosis induction.
Collapse
|
38
|
|
39
|
Scott JD, Newton AC. Shedding light on local kinase activation. BMC Biol 2012; 10:61. [PMID: 22805055 PMCID: PMC3398854 DOI: 10.1186/1741-7007-10-61] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 07/16/2012] [Indexed: 11/19/2022] Open
Abstract
Phosphorylation is the predominant language of cell signaling. And, as with any common language, an abundance of dialects has evolved to convey complex information. We discuss here how biosensors are being used to decode this language, affording an unprecedented glimpse into spatio-temporal patterns of protein phosphorylation events within the cell.
Collapse
Affiliation(s)
- John D Scott
- Howard Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine,1959 Pacific Ave, NE, Seattle, WA 98195 USA.
| | | |
Collapse
|
40
|
Ruiz-Loredo AY, López E, López-Colomé AM. Thrombin stimulates stress fiber assembly in RPE cells by PKC/CPI-17-mediated MLCP inactivation. Exp Eye Res 2012; 96:13-23. [DOI: 10.1016/j.exer.2012.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 01/11/2012] [Accepted: 01/17/2012] [Indexed: 12/29/2022]
|
41
|
Smolinska MJ, Page TH, Urbaniak AM, Mutch BE, Horwood NJ. Hck Tyrosine Kinase Regulates TLR4-Induced TNF and IL-6 Production via AP-1. THE JOURNAL OF IMMUNOLOGY 2011; 187:6043-51. [DOI: 10.4049/jimmunol.1100967] [Citation(s) in RCA: 243] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
42
|
Snow JB, Gonzalez Bosc LV, Kanagy NL, Walker BR, Resta TC. Role for PKCβ in enhanced endothelin-1-induced pulmonary vasoconstrictor reactivity following intermittent hypoxia. Am J Physiol Lung Cell Mol Physiol 2011; 301:L745-54. [PMID: 21803871 DOI: 10.1152/ajplung.00020.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Intermittent hypoxia (IH) resulting from sleep apnea causes both systemic and pulmonary hypertension. Enhanced endothelin-1 (ET-1)-induced vasoconstrictor reactivity is thought to play a central role in the systemic hypertensive response to IH. However, whether IH similarly increases pulmonary vasoreactivity and the signaling mechanisms involved are unknown. The objective of the present study was to test the hypothesis that IH augments ET-1-induced pulmonary vasoconstrictor reactivity through a PKCβ-dependent signaling pathway. Responses to ET-1 were assessed in endothelium-disrupted, pressurized pulmonary arteries (∼150 μm inner diameter) from eucapnic-IH [(E-IH) 3 min cycles, 5% O(2)-5% CO(2)/air flush, 7 h/day; 4 wk] and sham (air-cycled) rats. Arteries were loaded with fura-2 AM to monitor vascular smooth muscle (VSM) intracellular Ca(2+) concentration ([Ca(2+)](i)). E-IH increased vasoconstrictor reactivity without altering Ca(2+) responses, suggestive of myofilament Ca(2+) sensitization. Consistent with our hypothesis, inhibitors of both PKCα/β (myr-PKC) and PKCβ (LY-333-531) selectively decreased vasoconstriction to ET-1 in arteries from E-IH rats and normalized responses between groups, whereas Rho kinase (fasudil) and PKCδ (rottlerin) inhibition were without effect. Although E-IH did not alter arterial PKCα/β mRNA or protein expression, E-IH increased basal PKCβI/II membrane localization and caused ET-1-induced translocation of these isoforms away from the membrane fraction. We conclude that E-IH augments pulmonary vasoconstrictor reactivity to ET-1 through a novel PKCβ-dependent mechanism that is independent of altered PKC expression. These findings provide new insights into signaling mechanisms that contribute to vasoconstriction in the hypertensive pulmonary circulation.
Collapse
Affiliation(s)
- Jessica B Snow
- Dept. of Cell Biology and Physiology, Univ. of New Mexico Health Sciences Center, MSC 08-4750, 1 Univ. of New Mexico, Albuquerque, NM 87131-0001, USA.
| | | | | | | | | |
Collapse
|
43
|
Grinnell KL, Harrington EO. Interplay between FAK, PKCδ, and p190RhoGAP in the regulation of endothelial barrier function. Microvasc Res 2011; 83:12-21. [PMID: 21549132 DOI: 10.1016/j.mvr.2011.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 04/15/2011] [Accepted: 04/16/2011] [Indexed: 11/16/2022]
Abstract
Disruption of either intercellular or extracellular junctions involved in maintaining endothelial barrier function can result in increased endothelial permeability. Increased endothelial permeability, in turn, allows for the unregulated movement of fluid and solutes out of the vasculature and into the surrounding connective tissue, contributing to a number of disease states, including stroke and pulmonary edema (Ermert et al., 1995; Lee and Slutsky, 2010; van Hinsbergh, 1997; Waller et al., 1996; Warboys et al., 2010). Thus, a better understanding of the molecular mechanisms by which endothelial cell junction integrity is controlled is necessary for development of therapies aimed at treating such conditions. In this review, we will discuss the functions of three signaling molecules known to be involved in regulation of endothelial permeability: focal adhesion kinase (FAK), protein kinase C delta (PKCδ), and p190RhoGAP (p190). We will discuss the independent functions of each protein, as well as the interplay that exists between them and the effects of such interactions on endothelial function.
Collapse
Affiliation(s)
- Katie L Grinnell
- Vascular Research Laboratory, Providence VA Medical Center, Department of Medicine, Warren Alpert Medical School of Brown University, Providence, RI 02908, USA
| | | |
Collapse
|