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Zoidl GR, Spray DC. The Roles of Calmodulin and CaMKII in Cx36 Plasticity. Int J Mol Sci 2021; 22:4473. [PMID: 33922931 PMCID: PMC8123330 DOI: 10.3390/ijms22094473] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/17/2021] [Accepted: 04/20/2021] [Indexed: 01/07/2023] Open
Abstract
Anatomical and electrophysiological evidence that gap junctions and electrical coupling occur between neurons was initially confined to invertebrates and nonmammals and was thought to be a primitive form of synaptic transmission. More recent studies revealed that electrical communication is common in the mammalian central nervous system (CNS), often coexisting with chemical synaptic transmission. The subsequent progress indicated that electrical synapses formed by the gap junction protein connexin-36 (Cx36) and its paralogs in nonmammals constitute vital elements in mammalian and fish synaptic circuitry. They govern the collective activity of ensembles of coupled neurons, and Cx36 gap junctions endow them with enormous adaptive plasticity, like that seen at chemical synapses. Moreover, they orchestrate the synchronized neuronal network activity and rhythmic oscillations that underlie the fundamental integrative processes, such as memory and learning. Here, we review the available mechanistic evidence and models that argue for the essential roles of calcium, calmodulin, and the Ca2+/calmodulin-dependent protein kinase II in integrating calcium signals to modulate the strength of electrical synapses through interactions with the gap junction protein Cx36.
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Affiliation(s)
- Georg R. Zoidl
- Department of Biology & Center for Vision Research (CVR), York University, Toronto, ON M3J 1P3, Canada
| | - David C. Spray
- Dominick P. Purpura Department of Neuroscience & Department of Medicine (Cardiology), Albert Einstein College of Medicine, New York, NY 10461, USA;
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Marks CR, Shonesy BC, Wang X, Stephenson JR, Niswender CM, Colbran RJ. Activated CaMKII α Binds to the mGlu 5 Metabotropic Glutamate Receptor and Modulates Calcium Mobilization. Mol Pharmacol 2018; 94:1352-1362. [PMID: 30282777 DOI: 10.1124/mol.118.113142] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/19/2018] [Indexed: 01/03/2023] Open
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) and metabotropic glutamate receptor 5 (mGlu5) are critical signaling molecules in synaptic plasticity and learning/memory. Here, we demonstrate that mGlu5 is present in CaMKIIα complexes isolated from mouse forebrain. Further in vitro characterization showed that the membrane-proximal region of the C-terminal domain (CTD) of mGlu5a directly interacts with purified Thr286-autophosphorylated (activated) CaMKIIα However, the binding of CaMKIIα to this CTD fragment is reduced by the addition of excess Ca2+/calmodulin or by additional CaMKIIα autophosphorylation at non-Thr286 sites. Furthermore, in vitro binding of CaMKIIα is dependent on a tribasic residue motif Lys-Arg-Arg (KRR) at residues 866-868 of the mGlu5a-CTD, and mutation of this motif decreases the coimmunoprecipitation of CaMKIIα with full-length mGlu5a expressed in heterologous cells by about 50%. The KRR motif is required for two novel functional effects of coexpressing constitutively active CaMKIIα with mGlu5a in heterologous cells. First, cell-surface biotinylation studies showed that CaMKIIα increases the surface expression of mGlu5a Second, using Ca2+ fluorimetry and single-cell Ca2+ imaging, we found that CaMKIIα reduces the initial peak of mGlu5a-mediated Ca2+ mobilization by about 25% while doubling the relative duration of the Ca2+ signal. These findings provide new insights into the physical and functional coupling of these key regulators of postsynaptic signaling.
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Affiliation(s)
- Christian R Marks
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Brian C Shonesy
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Xiaohan Wang
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jason R Stephenson
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Colleen M Niswender
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Roger J Colbran
- Departments of Molecular Physiology and Biophysics (C.R.M., B.C.S., J.R.S., R.J.C.) and Pharmacology (C.M.N.), Vanderbilt Brain Institute (X.W., R.J.C.), Vanderbilt Kennedy Center for Research on Human Development (C.M.N., R.J.C.), and Vanderbilt Center for Neuroscience Drug Discovery (C.M.N.), Vanderbilt University School of Medicine, Nashville, Tennessee
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Tao L, Xie Q, Ding YH, Li ST, Peng S, Zhang YP, Tan D, Yuan Z, Dong MQ. CAMKII and calcineurin regulate the lifespan of Caenorhabditis elegans through the FOXO transcription factor DAF-16. eLife 2013; 2:e00518. [PMID: 23805378 PMCID: PMC3691573 DOI: 10.7554/elife.00518] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 05/24/2013] [Indexed: 01/03/2023] Open
Abstract
The insulin-like signaling pathway maintains a relatively short wild-type lifespan in Caenorhabditis elegans by phosphorylating and inactivating DAF-16, the ortholog of the FOXO transcription factors of mammalian cells. DAF-16 is phosphorylated by the AKT kinases, preventing its nuclear translocation. Calcineurin (PP2B phosphatase) also limits the lifespan of C. elegans, but the mechanism through which it does so is unknown. Herein, we show that TAX-6•CNB-1 and UNC-43, the C. elegans Calcineurin and Ca(2+)/calmodulin-dependent kinase type II (CAMKII) orthologs, respectively, also regulate lifespan through DAF-16. Moreover, UNC-43 regulates DAF-16 in response to various stress conditions, including starvation, heat or oxidative stress, and cooperatively contributes to lifespan regulation by insulin signaling. However, unlike insulin signaling, UNC-43 phosphorylates and activates DAF-16, thus promoting its nuclear localization. The phosphorylation of DAF-16 at S286 by UNC-43 is removed by TAX-6•CNB-1, leading to DAF-16 inactivation. Mammalian FOXO3 is also regulated by CAMKIIA and Calcineurin. DOI:http://dx.doi.org/10.7554/eLife.00518.001.
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Affiliation(s)
- Li Tao
- Graduate Program in Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing , China ; National Institute of Biological Sciences, Beijing , Beijing , China
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Patel AK, Yadav RP, Majava V, Kursula I, Kursula P. Structure of the dimeric autoinhibited conformation of DAPK2, a pro-apoptotic protein kinase. J Mol Biol 2011; 409:369-83. [PMID: 21497605 DOI: 10.1016/j.jmb.2011.03.065] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 03/24/2011] [Accepted: 03/28/2011] [Indexed: 11/27/2022]
Abstract
The death-associated protein kinase (DAPK) family has been characterized as a group of pro-apoptotic serine/threonine kinases that share specific structural features in their catalytic kinase domain. Two of the DAPK family members, DAPK1 and DAPK2, are calmodulin-dependent protein kinases that are regulated by oligomerization, calmodulin binding, and autophosphorylation. In this study, we have determined the crystal and solution structures of murine DAPK2 in the presence of the autoinhibitory domain, with and without bound nucleotides in the active site. The crystal structure shows dimers of DAPK2 in a conformation that is not permissible for protein substrate binding. Two different conformations were seen in the active site upon the introduction of nucleotide ligands. The monomeric and dimeric forms of DAPK2 were further analyzed for solution structure, and the results indicate that the dimers of DAPK2 are indeed formed through the association of two apposed catalytic domains, as seen in the crystal structure. The structures can be further used to build a model for DAPK2 autophosphorylation and to compare with closely related kinases, of which especially DAPK1 is an actively studied drug target. Our structures also provide a model for both homodimerization and heterodimerization of the catalytic domain between members of the DAPK family. The fingerprint of the DAPK family, the basic loop, plays a central role in the dimerization of the kinase domain.
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Affiliation(s)
- Ashok K Patel
- Department of Biochemistry, University of Oulu, Finland
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Gagnon KB, Delpire E. On the substrate recognition and negative regulation of SPAK, a kinase modulating Na+-K+-2Cl- cotransport activity. Am J Physiol Cell Physiol 2010; 299:C614-20. [PMID: 20463172 DOI: 10.1152/ajpcell.00074.2010] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Threonines targeted by Ste20-related proline-alanine-rich kinase (SPAK) for phosphorylation have been identified in Na+-K+-2Cl(-) cotransporter type 1 (NKCC1), NKCC2, and Na+-Cl(-) cotransporter (NCC). However, what constitutes the substrate recognition of the kinase is still unknown. Using site-directed mutagenesis and functional measurement of NKCC1 activity in Xenopus laevis oocytes, we determined that SPAK recognizes two threonine residues separated by four amino acids. Addition or removal of a single residue abrogated SPAK activation of NKCC1. Although both threonines are followed by hydrophobic residues, in vivo experiments have determined that SPAK activation of the cotransporter only requires a hydrophobic residue after the first threonine. Interestingly, downstream of the second threonine residue, we have identified a conserved aspartic acid residue which is critical for NKCC1 function. Mouse SPAK activity requires phosphorylation of two specific residues by WNK [with no lysine (K)] kinases: a threonine (T243) in the catalytic domain and a serine (S383) in the regulatory domain. We found that mutating the threonine residue into a glutamic acid (T243E) combined with mutation of the serine into an aspartic acid (S383D) rendered SPAK constitutively active. Surprisingly, alanine substitution of S383 or mutation of residues surrounding this residue also resulted in a constitutively active kinase. Interestingly, deletion of amino acids 356-398 identified another serine residue in the catalytic domain (S321) as another putative target of WNK phosphorylation. We found that WNK4 is capable of stimulating the deletion mutant when S321 is present, but not when S321 is mutated into an alanine.
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Affiliation(s)
- Kenneth B Gagnon
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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CaMKIIbeta binding to stable F-actin in vivo regulates F-actin filament stability. Proc Natl Acad Sci U S A 2008; 105:15791-6. [PMID: 18840684 DOI: 10.1073/pnas.0804399105] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ca2(+)/calmodulin-dependent protein kinase II (CaMKII) is a serine/threonine kinase that is best known for its role in synaptic plasticity and memory. Multiple roles of CaMKII have been identified in the hippocampus, yet its role in developing neurons is less well understood. We show here that endogenous CaMKIIbeta, but not CaMKIIalpha, localized to prominent F-actin-rich structures at the soma in embryonic cortical neurons. Fluorescence recovery after photobleaching analyses of GFP-CaMKIIbeta binding interactions with F-actin in this CaMKIIalpha-free system indicated CaMKIIbeta binding depended upon a putative F-actin binding domain in the variable region of CaMKIIbeta. Furthermore, CaMKIIalpha decreased CaMKIIbeta binding to F-actin. We examined the interaction of CaMKIIbeta with stable and dynamic actin and show that CaMKIIbeta binding to F-actin was dramatically prolonged when F-actin was stabilized. CaMKIIbeta binding to stable F-actin was disrupted when it was bound by Ca2(+)/calmodulin or when it was highly phosphorylated, but not by kinase inactivity. Whereas CaMKIIbeta over-expression increased the prevalence of the F-actin-rich structures, disruption of CaMKIIbeta binding to F-actin reduced them. Taken together, these data suggest that CaMKIIbeta binding to stable F-actin is important for the in vivo maintenance of polymerized F-actin.
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Gurd JW, Rawof S, Zhen Huo J, Dykstra C, Bissoon N, Teves L, Wallace MC, Rostas JAP. Ischemia and status epilepitcus result in enhanced phosphorylation of calcium and calmodulin-stimulated protein kinase II on threonine 253. Brain Res 2008; 1218:158-65. [PMID: 18514171 DOI: 10.1016/j.brainres.2008.04.040] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 04/15/2008] [Accepted: 04/20/2008] [Indexed: 10/22/2022]
Abstract
Ca2+-stimulated protein kinase II (CaMKII) is critically involved in the regulation of synaptic function and is implicated in the neuropathology associated with ischemia and status epilepticus (SE). The activity and localization of CaMKII is regulated by multi-site phosphorylation. In the present study we investigated the effects of global ischemia followed by reperfusion and of SE on the phosphorylation of CaMKII on T253 in rat forebrains and compared this to the phosphorylation of T286. Both ischemia and SE resulted in marked increases in the phosphorylation of T253, and this was particularly marked in the postsynaptic density (PSD). Phosphorylation of T286 decreased rapidly towards basal levels following ischemia whereas phosphorylation of T253 remained elevated for between 1 and 6 h before decreasing to control values. Following SE, phosphorylation of T253 remained elevated for between 1 and 3 h before decreasing to control levels. In contrast, phosphorylation of T286 remained elevated for at least 24 h following the termination of SE. Total CaMKII associated with PSDs transiently increased 10 min following ischemia, but only several hours following SE. The results demonstrate that phoshorylation of CaMKII on T253 is enhanced following both ischemia/reperfusion and SE and indicate that the phosphorylation of T253 and T286 are differentially regulated.
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Affiliation(s)
- James W Gurd
- Centre for the Neurobiology of Stress, University of Toronto Scarborough, Toronto, Canada ON M1C 1A4.
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Migues PV, Lehmann IT, Fluechter L, Cammarota M, Gurd JW, Sim ATR, Dickson PW, Rostas JAP. Phosphorylation of CaMKII at Thr253 occurs in vivo and enhances binding to isolated postsynaptic densities. J Neurochem 2006; 98:289-99. [PMID: 16805815 DOI: 10.1111/j.1471-4159.2006.03876.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Autophosphorylation of Ca(2+)-calmodulin stimulated protein kinase II (CaMKII) at two sites (Thr286 and Thr305/306) is known to regulate the subcellular location and activity of this enzyme in vivo. CaMKII is also known to be autophosphorylated at Thr253 in vitro but the functional effect of phosphorylation at this site and whether it occurs in vivo, is not known. Using antibodies that specifically recognize CaMKII phosphorylated at Thr253 together with FLAG-tagged wild type and phospho- and dephospho-mimic mutants of alpha-CaMKII, we have shown that Thr253 phosphorylation has no effect on either the Ca(2+)-calmodulin dependent or autonomous kinase activity of recombinant alpha-CaMKII in vitro. However, the Thr253Asp phosphomimic mutation increased alpha-CaMKII binding to subcellular fractions enriched in post-synaptic densities (PSDs). The increase in binding was similar in extent, and additive, to that produced by phosphorylation of Thr286. Thr253 phosphorylation was dynamically regulated in intact hippocampal slices. KCl induced depolarisation increased Thr253 phosphorylation and the phospho-Thr253-CaMKII was specifically recovered in the subcellular fraction enriched in PSDs. These results identify Thr253 as an additional site at which CaMKII is phosphorylated in vivo and suggest that this dynamic phosphorylation may regulate CaMKII function by altering its distribution within the cell.
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Affiliation(s)
- Paola V Migues
- School of Biomedical Sciences and Hunter Medical Research Institute, Faculty of Health, The University of Newcastle, Callaghan, New South Wales, Australia
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Umemura T, Rapp P, Rongo C. The role of regulatory domain interactions in UNC-43 CaMKII localization and trafficking. J Cell Sci 2005; 118:3327-38. [PMID: 16079277 DOI: 10.1242/jcs.02457] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Calcium and calmodulin-dependent protein kinase II (CaMKII) plays a fundamental role in the synaptic plasticity events that underlie learning and memory. Regulation of CaMKII kinase activity occurs through an autoinhibitory mechanism in which a regulatory domain of the kinase occupies the catalytic site and calcium/calmodulin activates the kinase by binding to and displacing this regulatory domain. A single putative ortholog of CaMKII, encoded by unc-43, is present in the Caenorhabditis elegans nervous system. Here we examined UNC-43 subcellular localization in the neurons of intact animals and show that UNC-43 is localized to clusters in ventral cord neurites, as well as to an unlocalized pool within these neurites. A mutation that mimics autophosphorylation within the regulatory domain results in an increase in the levels of UNC-43 in the unlocalized neurite pool. Multiple residues of CaMKII facilitate the interaction between the catalytic domain and the regulatory domain, thereby keeping the kinase inactive. Whereas most mutations in these residues result in an increased neurite pool of UNC-43, we have identified two residues that result in the opposite effect when mutated: a decreased neurite pool of UNC-43. The activity of UNC-2, a voltage-dependent calcium channel, is also required for UNC-43 to accumulate in the neurites, suggesting that neural activity regulates the localization of UNC-43. Our results suggest that the activation of UNC-43 by calcium/calmodulin displaces the autoinhibitory domain, thereby exposing key residues of the catalytic domain that allow for protein translocation to the neurites.
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Affiliation(s)
- Tohru Umemura
- The Waksman Institute, Department of Genetics, Rutgers University, Piscataway, NJ 08854, USA
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Robison AJ, Bartlett RK, Bass MA, Colbran RJ. Differential modulation of Ca2+/calmodulin-dependent protein kinase II activity by regulated interactions with N-methyl-D-aspartate receptor NR2B subunits and alpha-actinin. J Biol Chem 2005; 280:39316-23. [PMID: 16172120 DOI: 10.1074/jbc.m508189200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neuronal Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) interacts with several prominent dendritic spine proteins, which have been termed CaMKII-associated proteins. The NR2B subunit of N-methyl-d-aspartate (NMDA)-type glutamate receptor, densin-180, and alpha-actinin bind comparable, approximately stoichiometric amounts of Thr(286)-autophosphorylated CaMKIIalpha, forming a ternary complex (Robison, A. J., Bass, M. A., Jiao, Y., Macmillan, L. B., Carmody, L. C., Bartlett, R. K., and Colbran, R. J. (2005) J. Biol. Chem. 280, 35329-35336), but their impacts on CaMKII function are poorly understood. Here we show that these interactions are differentially regulated and exert distinct effects on CaMKII activity. Nonphosphorylated and Thr(286)-autophosphorylated CaMKII bind to alpha-actinin with similar efficacy, but autophosphorylation at Thr(305/306) or Ca(2+)/calmodulin binding significantly reduce this binding. Moreover, alpha-actinin antagonizes CaMKII activation by Ca(2+)/calmodulin, as assessed by autophosphorylation and phosphorylation of a peptide substrate. CaMKII binding to densin (1247-1542) is partially independent of Thr(286) autophosphorylation and is unaffected by Ca(2+)-independent autophosphorylation or Ca(2+)/calmodulin. In addition, the CaMKII binding domain of densin-180 has little effect on CaMKII activity. In contrast, the interaction of CaMKIIalpha with NR2B requires either Thr(286) autophosphorylation or the binding of both Ca(2+)/calmodulin and adenine nucleotides. NR2B inhibits both the Ca(2+)/calmodulin-dependent and autonomous activities of CaMKII by a mechanism that is competitive with autocamtide-2 substrate, non-competitive with syntide-2 substrate, and uncompetitive with respect to ATP. In combination, these data suggest that dynamically regulated interactions with CaMKII-associated proteins could play pleiotropic roles in finetuning CaMKII signaling in defined subcellular compartments.
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Affiliation(s)
- A J Robison
- Department of Molecular Physiology and Biophysics, Center for Molecular Neurosciences and The Vanderbilt-Kennedy Center for Research on Human Development, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA
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Runyan JD, Moore AN, Dash PK. A role for prefrontal calcium-sensitive protein phosphatase and kinase activities in working memory. Learn Mem 2005; 12:103-10. [PMID: 15805309 PMCID: PMC1074327 DOI: 10.1101/lm.89405] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The prefrontal cortex is involved in the integration and interpretation of information for directing thoughts and planning action. Working memory is defined as the active maintenance of information in mind and is thought to lie at the core of many prefrontal functions. Although dopamine and other neurotransmitters have been implicated, the intracellular events activated by their receptors that influence working memory are poorly understood. We demonstrate that working memory involves transient changes in prefrontal G(q/11)-signaling and in calcium-dependent intracellular protein phosphatase and kinase activity. Interestingly, inhibition of the calcium activated phosphatase calcineurin impaired, while calcium/calmodulin dependent kinase II (CaMKII) and calcium-dependent protein kinase C (PKC) enhanced, working memory. Our findings suggest that the active maintenance of information required for working memory involves transient changes in the balance of these enzymes' activities.
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Affiliation(s)
- Jason D Runyan
- The Vivian L. Smith Center for Neurological Research, Department of Neurobiology and Anatomy, The University of Texas Medical School, Houston, Texas 77225, USA
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Hudmon A, Schulman H. Neuronal CA2+/calmodulin-dependent protein kinase II: the role of structure and autoregulation in cellular function. Annu Rev Biochem 2002; 71:473-510. [PMID: 12045104 DOI: 10.1146/annurev.biochem.71.110601.135410] [Citation(s) in RCA: 506] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Highly enriched in brain tissue and present throughout the body, Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) is central to the coordination and execution of Ca(2+) signal transduction. The substrates phosphorylated by CaMKII are implicated in homeostatic regulation of the cell, as well as in activity-dependent changes in neuronal function that appear to underlie complex cognitive and behavioral responses, including learning and memory. The architecture of CaMKII holoenzymes is unique in nature. The kinase functional domains (12 per holoenzyme) are attached by stalklike appendages to a gear-shaped core, grouped into two clusters of six. Each subunit contains a catalytic, an autoregulatory, and an association domain. Ca(2+)/calmodulin (CaM) binding disinhibits the autoregulatory domain, allowing autophosphorylation and complex changes in the enzyme's sensitivity to Ca(2+)/CaM, including the generation of Ca(2+)/CaM-independent activity, CaM trapping, and CaM capping. These processes confer a type of molecular memory to the autoregulation and activity of CaMKII. Its function is intimately shaped by its multimeric structure, autoregulation, isozymic type, and subcellular localization; these features and processes are discussed as they relate to known and potential cellular functions of this multifunctional protein kinase.
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Affiliation(s)
- Andy Hudmon
- Department of Neurobiology, Stanford University School of Medicine, 299 Campus Drive, Stanford, California 94305, USA.
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Corcoran EE, Means AR. Defining Ca2+/calmodulin-dependent protein kinase cascades in transcriptional regulation. J Biol Chem 2001; 276:2975-8. [PMID: 11096122 DOI: 10.1074/jbc.r000027200] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- E E Corcoran
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
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15
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Padre RC, Stull JT. Conformational requirements for Ca(2+)/calmodulin binding and activation of myosin light chain kinase. FEBS Lett 2000; 472:148-52. [PMID: 10781823 DOI: 10.1016/s0014-5793(00)01434-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Myosin light chain kinase contains a regulatory segment consisting of an autoinhibitory region and a calmodulin-binding sequence that folds back on its catalytic core to inhibit kinase activity. It has been proposed that alpha-helix formation may be involved in displacement of the regulatory segment and activation of the kinase by Ca(2+)/calmodulin. Proline mutations were introduced at putative non-interacting residues in the regulatory segment to disrupt helix formation. Substitution of proline residues immediately N-terminal of the Trp in the calmodulin-binding sequence had most significant effects on Ca(2+)/calmodulin binding and activation. Formation of an alpha-helix in this region upon Ca(2+)/calmodulin binding may be necessary for displacement of the regulatory segment allowing phosphorylation of myosin regulatory light chain.
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Affiliation(s)
- R C Padre
- Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA
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16
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Abstract
Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) undergoes Ca(2+)/calmodulin-dependent autophosphorylation of threonine-286/287 (Thr(286/287)). Extremely high concentration of CaMKII in the postsynaptic spine indicates that increase in the Ca(2+) concentration in the spine induced by synaptic activation results in Thr(286/287) autophosphorylation of this enzyme. It has recently been shown that the K(d) value of CaMKII for Ca(2+)/calmodulin (Ca(2+)/CaM) drastically decreases after Thr(286/287) autophosphorylation. Therefore, Ca(2+)/CaM associated with CaMKII becomes tightly bound to this kinase after Thr(286/287) autophosphorylation. This has been called 'Ca(2+)/CaM trapping'. We discussed the functional significance of Ca(2+)/CaM trapping in the neuronal system by a mathematical-modelling approach. We considered neighbouring synapses formed on the same dendrite and different increase in the Ca(2+) concentration in each spine. CaMKII undergoing Thr(286/287) autophosphorylation in each spine is eager to recruit nearby calmodulin in the dendrite for Ca(2+)/CaM trapping. Since the amount of calmodulin is limited, recruiting calmodulin to each spine causes competition among synapses for this finite resource. The results of our computer simulation show that this competition leads to 'winner-take-all': almost all calmodulin is taken by a few synapses to which relatively large increases in the Ca(2+) concentration are assigned. These results suggest a novel form of synaptic encoding of information.
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Affiliation(s)
- H Okamoto
- Corporate Research Labs., Fuji Xerox Co. Ltd., 430 Sakai, Nakai-machi, Ashigarakami-gun, Kanagawa, Japan.
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17
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Yang E, Schulman H. Structural examination of autoregulation of multifunctional calcium/calmodulin-dependent protein kinase II. J Biol Chem 1999; 274:26199-208. [PMID: 10473573 DOI: 10.1074/jbc.274.37.26199] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Regulation of Ca(2+)/calmodulin-dependent protein kinase II is likely based on an auto-inhibitory mechanism in which a segment of the kinase occupies the catalytic site in the absence of calmodulin. We analyze potential auto-inhibitory associations by employing charge reversal and hydrophobic-to-charged residue mutagenesis. We identify interacting amino acid pairs by using double mutants to test which modification in the catalytic domain complements a given change in the auto-inhibitory domain. Our studies identify the core pseudosubstrate sequence (residues 297-300) but reveal that distinct sequences centered about the autophosphorylation site at Thr-286 are involved in the critical auto-inhibitory interactions. Individual changes in any of the residues Arg-274, His-282, Arg-283, Lys-291, Arg-297, Phe-293, and Asn-294 in the auto-inhibitory domain or their interacting partners in the catalytic domain produces an enhanced affinity for calmodulin or generates a constitutively active enzyme. A structural model of Ca(2+)/calmodulin-dependent protein kinase II that incorporates these interactions shows that Thr-286 is oriented inwardly into a hydrophobic channel. The model explains why calmodulin must bind to the auto-inhibitory domain in order for Thr-286 in that domain to be phosphorylated and why introduction of phospho-Thr-286 produces the important Ca(2+)-independent state of the enzyme.
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Affiliation(s)
- E Yang
- Department of Neurobiology, Stanford University School of Medicine, Stanford, California 94305-5125, USA
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18
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Rich RC, Schulman H. Substrate-directed function of calmodulin in autophosphorylation of Ca2+/calmodulin-dependent protein kinase II. J Biol Chem 1998; 273:28424-9. [PMID: 9774470 DOI: 10.1074/jbc.273.43.28424] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Autophosphorylation of Thr286 in Ca2+/calmodulin-dependent protein kinase II occurs within each holoenzyme by an intersubunit reaction and is essential for kinase function in vivo. In addition to a kinase-directed function of calmodulin to activate the kinase, a second calmodulin is required for the autophosphorylation of each Thr286 (Hanson, P. I., Meyer, T., Stryer, L., and Schulman, H. (1994) Neuron 12, 943-956). We have engineered heteromeric holoenzymes comprising distinct "kinase" and "substrate" subunits to test for kinase- and substrate-directed functions of calmodulin. The obligate kinase subunits have aspartate residues substituted for threonine at positions 286, 305, and 306 (the autophosphorylation and calmodulin-binding sites), making it constitutively active but unable to bind calmodulin. Obligate substrate subunits are catalytically inactive (K42M mutation) but are able to bind calmodulin. Phosphorylation of substrate subunits occurs specifically at Thr286 and is completely dependent upon the presence of calmodulin. Blocking the ability of the substrate subunit to bind calmodulin, either with inhibitor KN-93 or by mutagenesis of the calmodulin-binding domain of the substrate subunit, prevents its phosphorylation, consistent with a substrate-directed function of calmodulin that requires its direct binding to the subunit being phosphorylated.
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Affiliation(s)
- R C Rich
- Department of Neurobiology, Stanford University School of Medicine, Stanford, California 94305-5125, USA
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19
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Gotter AL, Kaetzel MA, Dedman JR. A major second messenger mediator of Electrophorus electricus electric tissue is CaM kinase II. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART A, PHYSIOLOGY 1997; 118:81-91. [PMID: 9243814 DOI: 10.1016/s0300-9629(96)00411-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Electric tissue of the electric eel, Electrophorus electricus, has been used extensively as a model system for the study of excitable membrane biochemistry and electrophysiology. Membrane receptors, ion channels, and ATPases utilized by electrocytes are conserved in mammalian neurons and myocytes. In this study, we show that Ca2+ predominates as the major mediator of electric tissue phosphorylation relative to cyclic AMP and cyclic GMP-induced phosphorylation. Mastoparan, a calmodulin inhibitor peptide, and a peptide corresponding to the pseudosubstrate region of mammalian calmodulin-dependent protein kinase II (CaMKII (281-302)) attenuated Ca(2+)-dependent phosphorylation in a dose-dependent manner. These experiments demonstrated that calmodulin-dependent protein kinase II activity predominates in electric tissue. The Electrophorus kinase was purified by a novel affinity chromatography procedure utilizing Ca2+/calmodulin-dependent binding to the CaMKII (281-302) peptide coupled to Sepharose. The purified 51 kDa calmodulin-dependent protein kinase II demonstrated extensive autophosphorylation and exhibited a 3- to 4-fold increase in Ca(2+)-independent activity following autophosphorylation. Immunofluorescent localization experiments demonstrated calmodulin to be abundant in electrocytes, particularly subjacent to the plasma membrane. Calmodulin-dependent protein kinase II had a punctate distribution indicating that it may be compartmentalized by association with vesicles or the cytoskeleton. As the primary mediator of phosphorylation within electric tissue, CaM kinase II may be critical for the regulation of the specialized electrophysiological function of electrocytes.
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Affiliation(s)
- A L Gotter
- Department of Molecular and Cellular Physiology, University of Cincinnati College of Medicine, Ohio 45267-0576, USA
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20
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Soderling TR. Structure and regulation of calcium/calmodulin-dependent protein kinases II and IV. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1297:131-8. [PMID: 8917614 DOI: 10.1016/s0167-4838(96)00105-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- T R Soderling
- Vollum Institute, Oregon Health Sciences University, Portland 97225, USA
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21
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Petersen JM, Skalicky JJ, Donaldson LW, McIntosh LP, Alber T, Graves BJ. Modulation of transcription factor Ets-1 DNA binding: DNA-induced unfolding of an alpha helix. Science 1995; 269:1866-9. [PMID: 7569926 DOI: 10.1126/science.7569926] [Citation(s) in RCA: 153] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Conformational changes, including local protein folding, play important roles in protein-DNA interactions. Here, studies of the transcription factor Ets-1 provided evidence that local protein unfolding also can accompany DNA binding. Circular dichroism and partial proteolysis showed that the secondary structure of the Ets-1 DNA-binding domain is unchanged in the presence of DNA. In contrast, DNA allosterically induced the unfolding of an alpha helix that lies within a flanking region involved in the negative regulation of DNA binding. These findings suggest a structural basis for the intramolecular inhibition of DNA binding and a mechanism for the cooperative partnerships that are common features of many eukaryotic transcription factors.
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Affiliation(s)
- J M Petersen
- Department of Oncological Sciences, University of Utah School of Medicine, Salt Lake City 84132, USA
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22
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Mukherji S, Soderling TR. Mutational analysis of Ca(2+)-independent autophosphorylation of calcium/calmodulin-dependent protein kinase II. J Biol Chem 1995; 270:14062-7. [PMID: 7775466 DOI: 10.1074/jbc.270.23.14062] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Previous studies with synthetic peptides indicate that residues 290-309, corresponding to the calmodulin (CaM)-binding domain of Ca2+/CaM-dependent protein kinase II interact with the catalytic core of the enzyme as a pseudosubstrate (Colbran, R. J., Smith, M. K., Schworer, C. M., Fong, Y. L., and Soderling, T. R. (1989) J. Biol. Chem. 264, 4800-4804). In the present study, we attempted to locate the pseudosubstrate motif by generation or removal of potential substrate recognition sequences (RXXS/T) at selected positions using site-directed mutagenesis. Based on previous results, Arg297, Thr305/306, and Ser314 were selected as key residues. Single mutations such as N294S, K300S, A302R, A309R, and R311A were expressed, purified, and characterized. Several of the mutants exhibited decreased binding of and activation by CaM, not surprising since the mutations were within the CaM-binding domain. None of the mutants exhibited enhanced Ca(2+)-independent kinase activity toward exogenous substrate, but the K300S and N294S mutants showed a significant enhancement in the rate and stoichiometry of 32P incorporation during Ca(2+)-independent autophosphorylation. Using two-dimensional peptide mapping and phosphoamino acid analyses, enhanced phosphorylation of the introduced Ser residue was demonstrated in the K300S mutant but not in the N294S mutant. This specific Ca(2+)-independent autophosphorylation of Ser300 is consistent with the hypothesis that Arg297 may occupy the P (-3) position in a pseudosubstrate autoinhibitory interaction with the catalytic core in the nonactivated state of the kinase.
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Affiliation(s)
- S Mukherji
- Vollum Institute, Oregon Health Sciences University, Portland 97201, USA
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23
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McNeill RB, Colbran RJ. Interaction of autophosphorylated Ca2+/calmodulin-dependent protein kinase II with neuronal cytoskeletal proteins. Characterization of binding to a 190-kDa postsynaptic density protein. J Biol Chem 1995; 270:10043-9. [PMID: 7730306 DOI: 10.1074/jbc.270.17.10043] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Subcellular localization of Ca2+/calmodulin-dependent protein kinase II (CaMKII) by interaction with specific anchoring proteins may be an important mechanism contributing to the regulation of CaMKII. Proteins capable of binding CaMKII were identified by the use of a gel overlay assay with recombinant mouse CaMKII alpha (mCaMKII alpha) or Xenopus CaMKII beta (xCaMKII beta) 32P-autophosphorylated at Thr286/287 as a probe. Numerous [32P]CaMKII-binding proteins were identified in various whole rat tissue extracts, but binding was most prominent to forebrain proteins of 190 kDa (p190) and 140 kDa (p140). Fractionation of forebrain extracts localized p190 and p140 to a crude particulate/cytoskeletal fraction and isolated postsynaptic densities. [32P]m-CaMKII alpha-bound to p190 with an apparent Kd of 609 nM (subunit concentration) and a Bmax of 7.0 pmol of mCaMKII alpha subunit bound per mg of P2 protein, as measured using the overlay assay. Binding of 100 nM [32P]m-CaMKII alpha to p190 was competed by nonradioactive mCaMKII alpha autophosphorylated on Thr286 (EC50% = 200 nM), but to a much lesser extent by nonradioactive mCaMKII alpha autophosphorylated on Thr306 (EC50% > 2000 nM). In addition, nonphosphorylated mCaMKII alpha was a poor competitor for [32P]mCaMKII alpha binding to p190. The competition data indicate that Ca2+/CaM-dependent autophosphorylation at Thr286 promotes binding to p190, whereas, Ca2+/CaM-independent autophosphorylation at Thr306 does not enhance binding. Therefore, CaMKII may become localized to postsynaptic densities by p190 following its activation by an increase of dendritic Ca2+ concentration.
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Affiliation(s)
- R B McNeill
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA
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Brickey DA, Bann JG, Fong YL, Perrino L, Brennan RG, Soderling TR. Mutational analysis of the autoinhibitory domain of calmodulin kinase II. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)62011-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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