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Chen X, Cai Q, Zhou J, Pleasure SJ, Schulman H, Zhang M, Nicoll RA. CaMKII autophosphorylation is the only enzymatic event required for synaptic memory. Proc Natl Acad Sci U S A 2024; 121:e2402783121. [PMID: 38889145 PMCID: PMC11214084 DOI: 10.1073/pnas.2402783121] [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: 02/09/2024] [Accepted: 05/15/2024] [Indexed: 06/20/2024] Open
Abstract
Ca2+/calmodulin (CaM)-dependent kinase II (CaMKII) plays a critical role in long-term potentiation (LTP), a well-established model for learning and memory through the enhancement of synaptic transmission. Biochemical studies indicate that CaMKII catalyzes a phosphotransferase (kinase) reaction of both itself (autophosphorylation) and of multiple downstream target proteins. However, whether either type of phosphorylation plays any role in the synaptic enhancing action of CaMKII remains hotly contested. We have designed a series of experiments to define the minimal requirements for the synaptic enhancement by CaMKII. We find that autophosphorylation of T286 and further binding of CaMKII to the GluN2B subunit are required both for initiating LTP and for its maintenance (synaptic memory). Once bound to the NMDA receptor, the synaptic action of CaMKII occurs in the absence of target protein phosphorylation. Thus, autophosphorylation and binding to the GluN2B subunit are the only two requirements for CaMKII in synaptic memory.
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Affiliation(s)
- Xiumin Chen
- Department of Neurology and Institute of Neuroscience of Soochow University, Second Affiliated Hospital of Soochow University, Suzhou215004, China
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA94158
| | - Qixu Cai
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- Department of Laboratory Medicine, State Key Laboratory of Vaccines for Infectious Diseases,School of Public Heath, Xiamen University, Xiamen, Fujian361102, China
| | - Jing Zhou
- Department of Neurology, University of California, San Francisco, CA94158
| | - Samuel J. Pleasure
- Department of Neurology, University of California, San Francisco, CA94158
| | - Howard Schulman
- Department of Pharmacology, Stanford University School of Medicine, Stanford, CA
- Department of Pharmacology, Panorama Research Institute, Sunnyvale, CA
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- Department of Laboratory Medicine, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong518055, China
| | - Roger A. Nicoll
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA94158
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Nguyen BV, Özden C, Dong K, Torres-Ocampo AP, Dziedzic N, Flaherty D, Huang J, Sankura S, Abromson NL, Tomchick DR, Chen J, Garman SC, Stratton MM. A domain-swapped CaMKII conformation facilitates linker-mediated allosteric regulation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.24.586494. [PMID: 38585726 PMCID: PMC10996533 DOI: 10.1101/2024.03.24.586494] [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
Ca2+ signaling plays a key role in physiological processes such as memory formation and cardiac function. Ca2+/calmodulin-dependent protein kinase II (CaMKII) is the primary kinase that responds to Ca2+ inputs in these cells. There are four CaMKII paralogs in mammals which are alternatively spliced in the variable linker region to create upwards of 70 different variants. In this study, we systematically studied different linker regions and determined that the position of charged residues within the linker region modulates the Ca2+/CaM sensitivity of the holoenzyme. We present an X-ray crystal structure of full-length CaMKIIδ that shows a domain-swapped conformation of the subunits within the dodecameric holoenzyme. In this structure, the kinase domain of one subunit is docked onto the hub domain of a different subunit, providing an additional interface within the holoenzyme. Mutations at the equatorial and lateral interfaces revealed that the kinase-hub interaction dissociates as the hub-hub interfaces are disturbed, which led alterations in the stoichiometry of CaMKII holoenzyme and Ca2+/CaM sensitivity. Molecular dynamics simulations of linker-containing domain-swapped and non-domain-swapped CaMKIIs reveal that the domain-swapped configuration facilitates an interaction between the calmodulin binding domain and the variable linker region, such that dynamic electrostatic forces between charges on these segments can modulate the equilibrium between the compact and extended conformational states of the holoenzyme. Small angle X-ray scattering data confirms that a negatively charged linker CaMKII holoenzyme adopts a more compact conformation compared to a positively charged linker. These data support a model where patches of charged linker residues interact with the calmodulin binding domain to allosterically regulate sensitivity to Ca2+/CaM. Our findings provide a new framework for understanding CaMKII structure and allosteric regulation by the variable linker region in Ca2+-sensitive cells.
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Affiliation(s)
- Bao V. Nguyen
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
- Chemistry-Biology Interface Training Program, University of Massachusetts, Amherst, MA 01003, USA
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Can Özden
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Kairong Dong
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Ana P. Torres-Ocampo
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
- Chemistry-Biology Interface Training Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Noelle Dziedzic
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, USA
- Chemistry-Biology Interface Training Program, University of Massachusetts, Amherst, MA 01003, USA
| | - Daniel Flaherty
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Jian Huang
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Saketh Sankura
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Nikki Lyn Abromson
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Diana R. Tomchick
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA
| | - Scott C Garman
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Margaret M Stratton
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
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Anjum R, Clarke VRJ, Nagasawa Y, Murakoshi H, Paradis S. Rem2 interacts with CaMKII at synapses and restricts long-term potentiation in hippocampus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.11.584540. [PMID: 38558974 PMCID: PMC10979978 DOI: 10.1101/2024.03.11.584540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Synaptic plasticity, the process whereby neuronal connections are either strengthened or weakened in response to stereotyped forms of stimulation, is widely believed to represent the molecular mechanism that underlies learning and memory. The holoenzyme CaMKII plays a well-established and critical role in the induction of a variety of forms of synaptic plasticity such as long-term potentiation (LTP), long-term depression (LTD) and depotentiation. Previously, we identified the GTPase Rem2 as a potent, endogenous inhibitor of CaMKII. Here, we report that knock out of Rem2 enhances LTP at the Schaffer collateral to CA1 synapse in hippocampus, consistent with an inhibitory action of Rem2 on CaMKII in vivo. Further, re-expression of WT Rem2 rescues the enhanced LTP observed in slices obtained from Rem2 conditional knock out (cKO) mice, while expression of a mutant Rem2 construct that is unable to inhibit CaMKII in vitro fails to rescue increased LTP. In addition, we demonstrate that CaMKII and Rem2 interact in dendritic spines using a 2pFLIM-FRET approach. Taken together, our data lead us to propose that Rem2 serves as a brake on runaway synaptic potentiation via inhibition of CaMKII activity. Further, the enhanced LTP phenotype we observe in Rem2 cKO slices reveals a previously unknown role for Rem2 in the negative regulation of CaMKII function.
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Affiliation(s)
- Rabia Anjum
- Department of Biology and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454, United States of America
| | - Vernon R J Clarke
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
| | - Yutaro Nagasawa
- Department of Physiological Sciences, The Graduate University for Advanced Studies; Hayama, Kanagawa 240-0193, Japan
- Supportive Center for Brain Research, National Institute for Physiological Sciences; Okazaki, Aichi 444-8585, Japan
| | - Hideji Murakoshi
- Department of Physiological Sciences, The Graduate University for Advanced Studies; Hayama, Kanagawa 240-0193, Japan
- Supportive Center for Brain Research, National Institute for Physiological Sciences; Okazaki, Aichi 444-8585, Japan
| | - Suzanne Paradis
- Department of Biology and Volen Center for Complex Systems, Brandeis University, Waltham, Massachusetts 02454, United States of America
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Li G, McLaughlin DW, Peskin CS. A biochemical description of postsynaptic plasticity-with timescales ranging from milliseconds to seconds. Proc Natl Acad Sci U S A 2024; 121:e2311709121. [PMID: 38324573 PMCID: PMC10873618 DOI: 10.1073/pnas.2311709121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 12/29/2023] [Indexed: 02/09/2024] Open
Abstract
Synaptic plasticity [long-term potentiation/depression (LTP/D)], is a cellular mechanism underlying learning. Two distinct types of early LTP/D (E-LTP/D), acting on very different time scales, have been observed experimentally-spike timing dependent plasticity (STDP), on time scales of tens of ms; and behavioral time scale synaptic plasticity (BTSP), on time scales of seconds. BTSP is a candidate for a mechanism underlying rapid learning of spatial location by place cells. Here, a computational model of the induction of E-LTP/D at a spine head of a synapse of a hippocampal pyramidal neuron is developed. The single-compartment model represents two interacting biochemical pathways for the activation (phosphorylation) of the kinase (CaMKII) with a phosphatase, with ion inflow through channels (NMDAR, CaV1,Na). The biochemical reactions are represented by a deterministic system of differential equations, with a detailed description of the activation of CaMKII that includes the opening of the compact state of CaMKII. This single model captures realistic responses (temporal profiles with the differing timescales) of STDP and BTSP and their asymmetries. The simulations distinguish several mechanisms underlying STDP vs. BTSP, including i) the flow of [Formula: see text] through NMDAR vs. CaV1 channels, and ii) the origin of several time scales in the activation of CaMKII. The model also realizes a priming mechanism for E-LTP that is induced by [Formula: see text] flow through CaV1.3 channels. Once in the spine head, this small additional [Formula: see text] opens the compact state of CaMKII, placing CaMKII ready for subsequent induction of LTP.
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Affiliation(s)
- Guanchun Li
- Courant Institute and Center for Neural Science, Department of Mathematics, New York University, New York, NY10012
| | - David W. McLaughlin
- Courant Institute and Center for Neural Science, Department of Mathematics, New York University, New York, NY10012
- Center for Neural Science, Department of Neural Science, New York University, New York, NY10012
- Institute of Mathematical Science, Mathematics Department, New York University-Shanghai, Shanghai200122, China
- Neuroscience Institute of New York University Langone Health, New York University, New York, NY10016
| | - Charles S. Peskin
- Courant Institute and Center for Neural Science, Department of Mathematics, New York University, New York, NY10012
- Center for Neural Science, Department of Neural Science, New York University, New York, NY10012
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Lučić I, Jiang P, Franz A, Bursztyn Y, Liu F, Plested AJR. Controlling the interaction between CaMKII and Calmodulin with a photocrosslinking unnatural amino acid. Protein Sci 2023; 32:e4798. [PMID: 37784242 PMCID: PMC10588329 DOI: 10.1002/pro.4798] [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: 11/29/2022] [Revised: 09/08/2023] [Accepted: 09/29/2023] [Indexed: 10/04/2023]
Abstract
Using unnatural amino acid mutagenesis, we made a mutant of CaMKII that forms a covalent linkage to Calmodulin upon illumination by UV light. Like wild-type CaMKII, the L308BzF mutant stoichiometrically binds to Calmodulin, in a calcium-dependent manner. Using this construct, we demonstrate that Calmodulin binding to CaMKII, even under these stochiometric conditions, does not perturb the CaMKII oligomeric state. Furthermore, we were able to achieve activation of CaMKII L308BzF by UV-induced binding of Calmodulin, which, once established, is further insensitive to calcium depletion. In addition to the canonical auto-inhibitory role of the regulatory segment, inter-subunit crosslinking in the absence of CaM indicates that kinase domains and regulatory segments are substantially mobile in basal conditions. Characterization of CaMKIIL308BzF in vitro, and its expression in mammalian cells, suggests it could be a promising candidate for control of CaMKII activity in mammalian cells with light.
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Affiliation(s)
- Iva Lučić
- Institute of Biology, Cellular BiophysicsHumboldt Universität zu BerlinBerlinGermany
- Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Pin‐Lian Jiang
- Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
| | - Andreas Franz
- Freie Universität Berlin, Institute of Chemistry and BiochemistryBerlinGermany
| | - Yuval Bursztyn
- Institute of Biology, Cellular BiophysicsHumboldt Universität zu BerlinBerlinGermany
| | - Fan Liu
- Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
- Charité‐Universitätsmedizin BerlinBerlinGermany
| | - Andrew J. R. Plested
- Institute of Biology, Cellular BiophysicsHumboldt Universität zu BerlinBerlinGermany
- Leibniz Forschungsinstitut für Molekulare Pharmakologie (FMP)BerlinGermany
- NeuroCure, Charité UniversitätsmedizinBerlinGermany
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