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Brown CN, Bayer KU. Studying CaMKII: Tools and standards. Cell Rep 2024; 43:113982. [PMID: 38517893 PMCID: PMC11088445 DOI: 10.1016/j.celrep.2024.113982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 02/19/2024] [Accepted: 03/06/2024] [Indexed: 03/24/2024] Open
Abstract
The Ca2+/calmodulin (CaM)-dependent protein kinase II (CaMKII) is a ubiquitous mediator of cellular Ca2+ signals with both enzymatic and structural functions. Here, we briefly introduce the complex regulation of CaMKII and then provide a comprehensive overview of the expanding toolbox to study CaMKII. Beyond a variety of distinct mutants, these tools now include optical methods for measurement and manipulation, with the latter including light-induced inhibition, stimulation, and sequestration. Perhaps most importantly, there are now three mechanistically distinct classes of specific CaMKII inhibitors, and their combined use enables the interrogation of CaMKII functions in a manner that is powerful and sophisticated yet also accessible. This review aims to provide guidelines for the interpretation of the results obtained with these tools, with careful consideration of their direct and indirect effects.
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Affiliation(s)
- Carolyn Nicole Brown
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Karl Ulrich Bayer
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA.
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Fujii H, Kidokoro H, Kondo Y, Kawaguchi M, Horigane SI, Natsume J, Takemoto-Kimura S, Bito H. Förster resonance energy transfer-based kinase mutation phenotyping reveals an aberrant facilitation of Ca2+/calmodulin-dependent CaMKIIα activity in de novo mutations related to intellectual disability. Front Mol Neurosci 2022; 15:970031. [PMID: 36117912 PMCID: PMC9474683 DOI: 10.3389/fnmol.2022.970031] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
CaMKIIα plays a fundamental role in learning and memory and is a key determinant of synaptic plasticity. Its kinase activity is regulated by the binding of Ca2+/CaM and by autophosphorylation that operates in an activity-dependent manner. Though many mutations in CAMK2A were linked to a variety of neurological disorders, the multiplicity of its functional substrates renders the systematic molecular phenotyping challenging. In this study, we report a new case of CAMK2A P212L, a recurrent mutation, in a patient with an intellectual disability. To quantify the effect of this mutation, we developed a FRET-based kinase phenotyping strategy and measured aberrance in Ca2+/CaM-dependent activation dynamics in vitro and in synaptically connected neurons. CaMKIIα P212L revealed a significantly facilitated Ca2+/CaM-dependent activation in vitro. Consistently, this mutant showed faster activation and more delayed inactivation in neurons. More prolonged kinase activation was also accompanied by a leftward shift in the CaMKIIα input frequency tuning curve. In keeping with this, molecular phenotyping of other reported CAMK2A de novo mutations linked to intellectual disability revealed aberrant facilitation of Ca2+/CaM-dependent activation of CaMKIIα in most cases. Finally, the pharmacological reversal of CAMK2A P212L phenotype in neurons was demonstrated using an FDA-approved NMDA receptor antagonist memantine, providing a basis for targeted therapeutics in CAMK2A-linked intellectual disability. Taken together, FRET-based kinase mutation phenotyping sheds light on the biological impact of CAMK2A mutations and provides a selective, sensitive, quantitative, and scalable strategy for gaining novel insights into the molecular etiology of intellectual disability.
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Affiliation(s)
- Hajime Fujii
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- *Correspondence: Hajime Fujii
| | - Hiroyuki Kidokoro
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yayoi Kondo
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masahiro Kawaguchi
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shin-ichiro Horigane
- Department of Neuroscience I, Research Institute of Environmental Medicine (RIEM), Nagoya University, Nagoya, Japan
- Department of Molecular/Cellular Neuroscience, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Jun Natsume
- Department of Pediatrics, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Developmental Disability Medicine, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Sayaka Takemoto-Kimura
- Department of Neuroscience I, Research Institute of Environmental Medicine (RIEM), Nagoya University, Nagoya, Japan
- Department of Molecular/Cellular Neuroscience, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Haruhiko Bito
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Haruhiko Bito
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Photoactivatable CaMKII induces synaptic plasticity in single synapses. Nat Commun 2021; 12:751. [PMID: 33531495 PMCID: PMC7854602 DOI: 10.1038/s41467-021-21025-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 01/06/2021] [Indexed: 01/06/2023] Open
Abstract
Optogenetic approaches for studying neuronal functions have proven their utility in the neurosciences. However, optogenetic tools capable of inducing synaptic plasticity at the level of single synapses have been lacking. Here, we engineered a photoactivatable (pa)CaMKII by fusing a light-sensitive domain, LOV2, to CaMKIIα. Blue light or two-photon excitation reversibly activated paCaMKII. Activation in single spines was sufficient to induce structural long-term potentiation (sLTP) in vitro and in vivo. paCaMKII activation was also sufficient for the recruitment of AMPA receptors and functional LTP in single spines. By combining paCaMKII with protein activity imaging by 2-photon FLIM-FRET, we demonstrate that paCaMKII activation in clustered spines induces robust sLTP via a mechanism that involves the actin-regulatory small GTPase, Cdc42. This optogenetic tool for dissecting the function of CaMKII activation (i.e., the sufficiency of CaMKII rather than necessity) and for manipulating synaptic plasticity will find many applications in neuroscience and other fields. Optogenetic control of molecules is important in cell biology and neuroscience. Here, the authors describe an optogenetic tool to control the Ca²+/calmodulin-dependent protein kinase II and use it to control plasticity at the single synapse level.
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Dissection of Protein Kinase Pathways in Live Cells Using Photoluminescent Probes: Surveillance or Interrogation? CHEMOSENSORS 2018. [DOI: 10.3390/chemosensors6020019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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The CaMKII holoenzyme structure in activation-competent conformations. Nat Commun 2017; 8:15742. [PMID: 28589927 PMCID: PMC5467236 DOI: 10.1038/ncomms15742] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 04/25/2017] [Indexed: 12/18/2022] Open
Abstract
The Ca2+/calmodulin-dependent protein kinase II (CaMKII) assembles into large 12-meric holoenzymes, which is thought to enable regulatory processes required for synaptic plasticity underlying learning, memory and cognition. Here we used single particle electron microscopy (EM) to determine a pseudoatomic model of the CaMKIIα holoenzyme in an extended and activation-competent conformation. The holoenzyme is organized by a rigid central hub complex, while positioning of the kinase domains is highly flexible, revealing dynamic holoenzymes ranging from 15–35 nm in diameter. While most kinase domains are ordered independently, ∼20% appear to form dimers and <3% are consistent with a compact conformation. An additional level of plasticity is revealed by a small fraction of bona-fide 14-mers (<4%) that may enable subunit exchange. Biochemical and cellular FRET studies confirm that the extended state of CaMKIIα resolved by EM is the predominant form of the holoenzyme, even under molecular crowding conditions. Ca2+/calmodulin-dependent protein kinase II (CaMKII) forms a 12 subunit holoenzyme central to synaptic plasticity. Here the authors report a 3D structure of the CaMKII holoenzyme in an activation-competent state obtained by single particle EM, and suggest a role for the intrinsically disordered linker domain in facilitating cooperative activation.
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Zhong C, Wei P, Zhang YHP. Enhancing functional expression of codon-optimized heterologous enzymes in Escherichia coli BL21(DE3) by selective introduction of synonymous rare codons. Biotechnol Bioeng 2016; 114:1054-1064. [PMID: 27943233 DOI: 10.1002/bit.26238] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 12/07/2016] [Accepted: 12/08/2016] [Indexed: 12/12/2022]
Abstract
Rare codon in a heterologous gene may cause premature termination of protein synthesis, misincorporation of amino acids, and/or slow translation of mRNA, decreasing the heterologous protein expression. However, its hypothetical function pertaining to functional protein folding has been barely reported. Here, we investigated the effects of selective introduction of synonymous rare codons (SRCs) to two codon-optimized (i.e., rare codon-free) genes sucrose phosphorylase (SP) gene from Thermoanaerobacterium thermosaccharolyticum and amidohydrolase gene from Streptomyces caatingaensis on their expression levels in Escherichia coli BL21(DE3). We investigated the introduction of a single SRC to the coding regions of alpha-helix, beta-strand, or linker in the first half of rare codon-free sp and ah gene. The introduction of a single SRC in the beginning of the coding regions of beta-strand greatly enhanced their soluble expression levels as compared to the other regions. Also, we applied directed evolution to test multi-SRC-containing sp gene mutants for enhanced soluble SP expression levels. To easily identify the soluble SP expression level of colonies growing on Petri dishes, mCherry fluorescent protein was used as a SP-folding reporter when it was fused to the 3' end of the sp gene mutant libraries. After three rounds of screening, the best sp gene mutant containing nine SRCs exhibited an approximately six-fold enhancement in soluble protein expression level as compared to the wild-type and rare codon-free sp control. This study suggests that the selective introduction of SRCs can attenuate translation at specific points and such discontinuous attenuation can temporally separate the translation of segments of the peptide chains and actively coordinates their co-translational folding, resulting in enhanced functional protein expression. Biotechnol. Bioeng. 2017;114: 1054-1064. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Chao Zhong
- Department of Biological Systems Engineering, Virginia Tech, 304 Seitz Hall, Blacksburg, Virginia, 24061.,College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, China
| | - Ping Wei
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 211800, China
| | - Yi-Heng Percival Zhang
- Department of Biological Systems Engineering, Virginia Tech, 304 Seitz Hall, Blacksburg, Virginia, 24061.,Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
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Nakahata Y, Nabekura J, Murakoshi H. Dual observation of the ATP-evoked small GTPase activation and Ca 2+ transient in astrocytes using a dark red fluorescent protein. Sci Rep 2016; 6:39564. [PMID: 28004840 PMCID: PMC5177924 DOI: 10.1038/srep39564] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 11/23/2016] [Indexed: 11/22/2022] Open
Abstract
Intracellular signal transduction involves a number of biochemical reactions, which largely consist of protein-protein interactions and protein conformational changes. Monitoring Förster resonance energy transfer (FRET) by fluorescence lifetime imaging microscopy (FLIM), called FLIM-FRET, is one of the best ways to visualize such protein dynamics. Here, we attempted to apply dark red fluorescent proteins with significantly smaller quantum yields. Application of the dark mCherry mutants to single-molecule FRET sensors revealed that these dark mCherry mutants are a good acceptor in a pair with mRuby2. Because the FRET measurement between mRuby2 and dark mCherry requires only the red region of wavelengths, it facilitates dual observation with other signaling sensors such as genetically encoded Ca2+ sensors. Taking advantage of this approach, we attempted dual observation of Ca2+ and Rho GTPase (RhoA and Cdc42) activities in astrocytes and found that ATP triggers both RhoA and Cdc42 activation. In early phase, while Cdc42 activity is independent of Ca2+ transient evoked by ATP, RhoA activity is Ca2+ dependent. Moreover, the transient Ca2+ upregulation triggers long-lasting Cdc42 and RhoA activities, thereby converting short-term Ca2+ signaling to long-term signaling. Thus, the new FRET pair should be useful for dual observation of intracellular biochemical reactions.
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Affiliation(s)
- Yoshihisa Nakahata
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Hideji Murakoshi
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan
- Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
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Murakoshi H, Shibata ACE, Nakahata Y, Nabekura J. A dark green fluorescent protein as an acceptor for measurement of Förster resonance energy transfer. Sci Rep 2015; 5:15334. [PMID: 26469148 PMCID: PMC4606784 DOI: 10.1038/srep15334] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 09/23/2015] [Indexed: 01/31/2023] Open
Abstract
Measurement of Förster resonance energy transfer by fluorescence lifetime imaging microscopy (FLIM-FRET) is a powerful method for visualization of intracellular signaling activities such as protein-protein interactions and conformational changes of proteins. Here, we developed a dark green fluorescent protein (ShadowG) that can serve as an acceptor for FLIM-FRET. ShadowG is spectrally similar to monomeric enhanced green fluorescent protein (mEGFP) and has a 120-fold smaller quantum yield. When FRET from mEGFP to ShadowG was measured using an mEGFP-ShadowG tandem construct with 2-photon FLIM-FRET, we observed a strong FRET signal with low cell-to-cell variability. Furthermore, ShadowG was applied to a single-molecule FRET sensor to monitor a conformational change of CaMKII and of the light oxygen voltage (LOV) domain in HeLa cells. These sensors showed reduced cell-to-cell variability of both the basal fluorescence lifetime and response signal. In contrast to mCherry- or dark-YFP-based sensors, our sensor allowed for precise measurement of individual cell responses. When ShadowG was applied to a separate-type Ras FRET sensor, it showed a greater response signal than did the mCherry-based sensor. Furthermore, Ras activation and translocation of its effector ERK2 into the nucleus could be observed simultaneously. Thus, ShadowG is a promising FLIM-FRET acceptor.
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Affiliation(s)
- Hideji Murakoshi
- Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Akihiro C. E. Shibata
- Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Yoshihisa Nakahata
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Junichi Nabekura
- Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
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