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Alba-González A, Yáñez J, Anadón R, Folgueira M. Neurogranin-like immunoreactivity in the zebrafish brain during development. Brain Struct Funct 2022; 227:2593-2607. [PMID: 36018391 PMCID: PMC9618489 DOI: 10.1007/s00429-022-02550-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 08/03/2022] [Indexed: 11/30/2022]
Abstract
Neurogranin (Nrgn) is a neural protein that is enriched in the cerebral cortex and is involved in synaptic plasticity via its interaction with calmodulin. Recently we reported its expression in the brain of the adult zebrafish (Alba-González et al. J Comp Neurol 530:1569–1587, 2022). In this study we analyze the development of Nrgn-like immunoreactivity (Nrgn-like-ir) in the brain and sensory structures of zebrafish embryos and larvae, using whole mounts and sections. First Nrgn-like positive neurons appeared by 2 day post-fertilization (dpf) in restricted areas of the brain, mostly in the pallium, epiphysis and hindbrain. Nrgn-like populations increased noticeably by 3 dpf, reaching an adult-like pattern in 6 dpf. Most Nrgn-like positive neurons were observed in the olfactory organ, retina (most ganglion cells, some amacrine and bipolar cells), pallium, lateral hypothalamus, thalamus, optic tectum, torus semicircularis, octavolateralis area, and viscerosensory column. Immunoreactivity was also observed in axonal tracts originating in Nrgn-like neuronal populations, namely, the projection of Nrgn-like immunopositive primary olfactory fibers to olfactory glomeruli, that of Nrgn-like positive pallial cells to the hypothalamus, the Nrgn-like-ir optic nerve to the pretectum and optic tectum, the Nrgn-like immunolabeled lateral hypothalamus to the contralateral region via the horizontal commissure, the octavolateralis area to the midbrain via the lateral lemniscus, and the viscerosensory column to the dorsal isthmus via the secondary gustatory tract. The late expression of Nrgn in zebrafish neurons is probably related to functional maturation of higher brain centers, as reported in the mammalian telencephalon. The analysis of Nrgn expression in the zebrafish brain suggests that it may be a useful marker for specific neuronal circuitries.
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Affiliation(s)
- Anabel Alba-González
- Department of Biology, Faculty of Sciences, University of A Coruña, Campus da Zapateira, 15008-A, Coruña, Spain.,Centro de Investigaciones Científicas Avanzadas (CICA), University of A Coruña, 15071-A, Coruña, Spain
| | - Julián Yáñez
- Department of Biology, Faculty of Sciences, University of A Coruña, Campus da Zapateira, 15008-A, Coruña, Spain. .,Centro de Investigaciones Científicas Avanzadas (CICA), University of A Coruña, 15071-A, Coruña, Spain.
| | - Ramón Anadón
- Department of Functional Biology, Faculty of Biology, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Mónica Folgueira
- Department of Biology, Faculty of Sciences, University of A Coruña, Campus da Zapateira, 15008-A, Coruña, Spain. .,Centro de Investigaciones Científicas Avanzadas (CICA), University of A Coruña, 15071-A, Coruña, Spain.
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Alba‐González A, Folgueira M, Castro A, Anadón R, Yáñez J. Distribution of neurogranin-like immunoreactivity in the brain and sensory organs of the adult zebrafish. J Comp Neurol 2022; 530:1569-1587. [PMID: 35015905 PMCID: PMC9415131 DOI: 10.1002/cne.25297] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 11/11/2022]
Abstract
We studied the expression of neurogranin in the brain and some sensory organs (barbel taste buds, olfactory organs, and retina) of adult zebrafish. Database analysis shows zebrafish has two paralog neurogranin genes (nrgna and nrgnb) that translate into three peptides with a conserved IQ domain, as in mammals. Western blots of zebrafish brain extracts using an anti-neurogranin antiserum revealed three separate bands, confirming the presence of three neurogranin peptides. Immunohistochemistry shows neurogranin-like expression in the brain and sensory organs (taste buds, neuromasts and olfactory epithelium), not being able to discern its three different peptides. In the retina, the most conspicuous positive cells were bipolar neurons. In the brain, immunopositive neurons were observed in all major regions (pallium, subpallium, preoptic area, hypothalamus, diencephalon, mesencephalon and rhombencephalon, including the cerebellum), a more extended distribution than in mammals. Interestingly, dendrites, cell bodies and axon terminals of some neurons were immunopositive, thus zebrafish neurogranins may play presynaptic and postsynaptic roles. Most positive neurons were found in primary sensory centers (viscerosensory column and medial octavolateral nucleus) and integrative centers (pallium, subpallium, optic tectum and cerebellum), which have complex synaptic circuitry. However, we also observed expression in areas not related to sensory or integrative functions, such as in cerebrospinal fluid-contacting cells associated with the hypothalamic recesses, which exhibited high neurogranin-like immunoreactivity. Together, these results reveal important differences with the patterns reported in mammals, suggesting divergent evolution from the common ancestor.
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Affiliation(s)
- Anabel Alba‐González
- Department of Biology, Faculty of SciencesUniversity of A CoruñaA CoruñaSpain,Centro de Investigaciones Científicas Avanzadas (CICA)University of A CoruñaA CoruñaSpain
| | - Mónica Folgueira
- Department of Biology, Faculty of SciencesUniversity of A CoruñaA CoruñaSpain,Centro de Investigaciones Científicas Avanzadas (CICA)University of A CoruñaA CoruñaSpain
| | - Antonio Castro
- Department of Biology, Faculty of SciencesUniversity of A CoruñaA CoruñaSpain,Centro de Investigaciones Científicas Avanzadas (CICA)University of A CoruñaA CoruñaSpain
| | - Ramón Anadón
- Department of Functional Biology, Faculty of BiologyUniversity of Santiago de CompostelaSantiago de CompostelaSpain
| | - Julián Yáñez
- Department of Biology, Faculty of SciencesUniversity of A CoruñaA CoruñaSpain,Centro de Investigaciones Científicas Avanzadas (CICA)University of A CoruñaA CoruñaSpain
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3
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Çevik S, Özgenç MM, Güneyk A, Evran Ş, Akkaya E, Çalış F, Katar S, Soyalp C, Hanımoğlu H, Kaynar MY. NRGN, S100B and GFAP levels are significantly increased in patients with structural lesions resulting from mild traumatic brain injuries. Clin Neurol Neurosurg 2019; 183:105380. [PMID: 31234132 DOI: 10.1016/j.clineuro.2019.105380] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 05/19/2019] [Accepted: 06/01/2019] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To determine whether serum neurogranin (NRGN), glial fibrillary acidic protein (GFAP), and calcium-binding protein S100 beta (S100B) levels are associated with traumatic intracranial lesions compared to computed tomography (CT) findings of patients with mild traumatic brain injury (mTBI). PATIENTS AND METHODS The cross-sectional study cohort included 48 patients who were admitted to the Emergency Department with a complaint of mTBI, a Glasgow Coma Scale score of 14-15, and at least one symptom of head trauma (i.e., post-traumatic amnesia, nausea or vomiting, post-traumatic seizures, persistent headache, and transient loss of consciousness). Blood samples and CT scans were obtained for all patients within 4 h of injury. Age-matched patients without intracranial traumatic pathology (CT-) were recruited as a control group. Blood samples were measured for NRGN, GFAP, and S100B levels. RESULTS Of 48 patients, 24 were CT + and had significantly higher serum NRGN (5.79 vs. 2.95 ng/mL), GFAP (0.59 vs.0.36 ng/mL), and S100B (1.72 vs.0.73 μg/L) levels than those who were CT- (p = 0.001, p = 0.026, and p < 0.001, respectively). ROC curves showed that NRGN, GFAP, and S100B levels were sufficient to distinguish traumatic brain injury in patients with mTBI. At the cut-off value for NRGN of 1.87 ng/mL, sensivity was 83.3%, and specificity was 58.3%. At the cut-off value for GFAP of 0.23 ng/mL, sensivity was 75% and specificity was 62.5%. The optimal cut-off value for S100B was 0.47 μg/L (95.8% sensitivity and 62.5% specificity). CONCLUSION This is the first study to evaluate NRGN in human serum after mTBI. We confirmed that NRGN levels were significantly higher in CT + patients than CT- patients in the mTBI patient population. Future studies of larger populations and different age groups (especially pediatric) can help reduce the number of CT scans as a reliable and noninvasive diagnostic tool for evaluating NRGN protein levels in mTBI patients with a low probability of intracranial lesions.
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Affiliation(s)
- Serdar Çevik
- Department of Neurosurgery, Bezmialem Vakıf University, Adnan Menderes Bulvarı, Vatan caddesi 34093, Fatih, Istanbul, Turkey.
| | | | - Ahmet Güneyk
- Department of Biochemstry, Ağrı State Hospital, Ağrı, Turkey
| | - Şevket Evran
- Department of Neurosurgery, Bahçelievler State Hospital, İstanbul, Turkey
| | - Enes Akkaya
- Department of Neurosurgery, University of Health Sciences, Sisli Hamidiye Etfal Training and Research Hospital, Istanbul, Turkey
| | - Fatih Çalış
- Deparrment of Neurosurgery, Medeniyet University, Göztepe Training and Research Hospital, Istanbul, Turkey
| | - Salim Katar
- Department of Neurosurgery, Selahaddin Eyyübi State Hospital, Diyarbakır, Turkey
| | - Celaleddin Soyalp
- Department of Anesthesiology and Intensive Care, Yüzüncü Yıl University School of Medicine, Van, Turkey
| | - Hakan Hanımoğlu
- Department of Neurosurgery, Biruni University, İstanbul, Turkey
| | - Mehmet Yaşar Kaynar
- Department of Neurosurgery, Istanbul University Cerrahpasa School of Medicine, İstanbul, Turkey
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Yang J, Korley FK, Dai M, Everett AD. Serum neurogranin measurement as a biomarker of acute traumatic brain injury. Clin Biochem 2015; 48:843-8. [PMID: 26025774 DOI: 10.1016/j.clinbiochem.2015.05.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/15/2015] [Accepted: 05/16/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Neurogranin (NRGN) is a small neuronal protein that plays an important role in synaptic signaling by regulating calmodulin (CaM) availability. In this study, we developed an ELISA to measure NRGN quantitatively in serum samples from a cohort of acute traumatic brain injury (TBI) patients and a non-TBI control cohort, and explored the potential value of NRGN as a circulating biomarker for TBI. DESIGN AND METHODS Recombinant His-NRGN protein was used to develop mouse monoclonal capture and rabbit polyclonal detection antibodies, and they were used to develop a sandwich ELISA. After validation, we used this ELISA to measure serum samples from a cohort of typical adult acute TBI patients (N=76 TBI cases) and non-TBI control patients (N=150 controls). RESULTS The NRGN ELISA lower limit of detection was 0.055ng/mL, lower limit of quantification was 0.2ng/mL, and interassay CVs were ≤10.7%. The average recovery was 99.9% (range from 97.2-102%). Serum NRGN concentrations in TBI cases were significantly higher than in controls (median values were 0.18ng/mL vs. 0.02ng/mL, p<0.0001), but did not discriminate TBI cases with intracranial hemorrhage (p=0.09). CONCLUSIONS We have developed a highly sensitive and reproducible ELISA for measuring circulating NRGN in blood samples. Serum NRGN concentrations in acute TBI patients were significantly higher than in controls, indicating that NRGN could have utility as a circulating biomarker for acute TBI. This report provides evidence to support larger and controlled TBI clinical studies for NRGN validation and prediction of outcomes.
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Affiliation(s)
- Jun Yang
- Department of Pediatrics, Division of Pediatric Cardiology, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Frederick K Korley
- Department of Emergency Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Min Dai
- Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD, United States
| | - Allen D Everett
- Department of Pediatrics, Division of Pediatric Cardiology, Johns Hopkins University, School of Medicine, Baltimore, MD, United States.
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Zhong L, Cherry T, Bies CE, Florence MA, Gerges NZ. Neurogranin enhances synaptic strength through its interaction with calmodulin. EMBO J 2009; 28:3027-39. [PMID: 19713936 PMCID: PMC2736013 DOI: 10.1038/emboj.2009.236] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Accepted: 07/23/2009] [Indexed: 11/09/2022] Open
Abstract
Learning-correlated plasticity at CA1 hippocampal excitatory synapses is dependent on neuronal activity and NMDA receptor (NMDAR) activation. However, the molecular mechanisms that transduce plasticity stimuli to postsynaptic potentiation are poorly understood. Here, we report that neurogranin (Ng), a neuron-specific and postsynaptic protein, enhances postsynaptic sensitivity and increases synaptic strength in an activity- and NMDAR-dependent manner. In addition, Ng-mediated potentiation of synaptic transmission mimics and occludes long-term potentiation (LTP). Expression of Ng mutants that lack the ability to bind to, or dissociate from, calmodulin (CaM) fails to potentiate synaptic transmission, strongly suggesting that regulated Ng-CaM binding is necessary for Ng-mediated potentiation. Moreover, knocking-down Ng blocked LTP induction. Thus, Ng-CaM interaction can provide a mechanistic link between induction and expression of postsynaptic potentiation.
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Affiliation(s)
- Ling Zhong
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Tiffani Cherry
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christine E Bies
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Matthew A Florence
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Nashaat Z Gerges
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
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Clayton DF, George JM, Mello CV, Siepka SM. Conservation and expression of IQ-domain-containing calpacitin gene products (neuromodulin/GAP-43, neurogranin/RC3) in the adult and developing oscine song control system. Dev Neurobiol 2009; 69:124-40. [PMID: 19023859 DOI: 10.1002/dneu.20686] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Songbirds are appreciated for the insights they provide into regulated neural plasticity. Here, we describe the comparative analysis and brain expression of two gene sequences encoding probable regulators of synaptic plasticity in songbirds: neuromodulin (GAP-43) and neurogranin (RC3). Both are members of the calpacitin family and share a distinctive conserved core domain that mediates interactions between calcium, calmodulin, and protein kinase C signaling pathways. Comparative sequence analysis is consistent with known phylogenetic relationships, with songbirds most closely related to chicken and progressively more distant from mammals and fish. The C-terminus of neurogranin is different in birds and mammals, and antibodies to the protein reveal high expression in adult zebra finches in cerebellar Purkinje cells, which has not been observed in other species. RNAs for both proteins are generally abundant in the telencephalon yet markedly reduced in certain nuclei of the song control system in adult canaries and zebra finches: neuromodulin RNA is very low in RA and HVC (relative to the surrounding pallial areas), whereas neurogranin RNA is conspicuously low in Area X (relative to surrounding striatum). In both cases, this selective downregulation develops in the zebra finch during the juvenile song learning period, 25-45 days after hatching. These results suggest molecular parallels to the robust stability of the adult avian song control circuit.
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Affiliation(s)
- David F Clayton
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Illinois 61801, USA.
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Abstract
A number of neuronal functions, including synaptic plasticity, depend on proper regulation of synaptic proteins, many of which can be rapidly regulated by phosphorylation. Neuronal activity controls the function of these synaptic proteins by exquisitely regulating the balance of various protein kinase and protein phosphatase activity. Recent understanding of synaptic plasticity mechanisms underscores important roles that these synaptic phosphoproteins play in regulating both pre- and post-synaptic functions. This review will focus on key postsynaptic phosphoproteins that have been implicated to play a role in synaptic plasticity.
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Affiliation(s)
- Hey-Kyoung Lee
- Department of Biology, Neuroscience and Cognitive Science (NACS) Program, University of Maryland, College Park, MD 20742, USA.
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9
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Prichard L, Deloulme JC, Storm DR. Interactions between neurogranin and calmodulin in vivo. J Biol Chem 1999; 274:7689-94. [PMID: 10075657 DOI: 10.1074/jbc.274.12.7689] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neurogranin is a neural-specific, calmodulin (CaM)-binding protein that is phosphorylated by protein kinase C (PKC) within its IQ domain at serine 36. Since CaM binds to neurogranin through the IQ domain, PKC phosphorylation and CaM binding are mutually exclusive. Consequently, we hypothesize that neurogranin may function to concentrate CaM at specific sites in neurons and release free CaM in response to increased Ca2+ and PKC activation. However, it has not been established that neurogranin interacts with CaM in vivo. In this study, we examined this question using yeast two-hybrid methodology. We also searched for additional proteins that might interact with neurogranin by screening brain cDNA libraries. Our data illustrate that CaM binds to neurogranin in vivo and that CaM is the only neurogranin-interacting protein isolated from brain cDNA libraries. Single amino acid mutagenesis indicated that residues within the IQ domain are important for CaM binding to neurogranin in vivo. The Ile-33 --> Gln point mutant completely inhibited and Arg-38 --> Gln and Ser-36 --> Asp point mutants reduced neurogranin/CaM interactions. These data demonstrate that CaM is the major protein that interacts with neurogranin in vivo and support the hypothesis that phosphorylation of neurogranin at Ser-36 regulates its binding to CaM.
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Affiliation(s)
- L Prichard
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA
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10
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Gerendasy DD, Sutcliffe JG. RC3/neurogranin, a postsynaptic calpacitin for setting the response threshold to calcium influxes. Mol Neurobiol 1997; 15:131-63. [PMID: 9396008 DOI: 10.1007/bf02740632] [Citation(s) in RCA: 163] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this review, we attempt to cover the descriptive, biochemical and molecular biological work that has contributed to our current knowledge about RC3/neurogranin function and its role in dendritic spine development, long-term potentiation, long-term depression, learning, and memory. Based on the data reviewed here, we propose that RC3, GAP-43, and the small cerebellum-enriched peptide, PEP-19, belong to a protein family that we have named the calpacitins. Membership in this family is based on sequence homology and, we believe, a common biochemical function. We propose a model wherein RC3 and GAP-43 regulate calmodulin availability in dendritic spines and axons, respectively, and calmodulin regulates their ability to amplify the mobilization of Ca2+ in response to metabotropic glutamate receptor stimulation. PEP-19 may serve a similar function in the cerebellum, although biochemical characterization of this molecule has lagged behind that of RC3 and GAP-43. We suggest that these molecules release CaM rapidly in response to large influxes of Ca2+ and slowly in response to small increases. This nonlinear response is analogous to the behavior of a capacitor, hence the name calpacitin. Since CaM regulates the ability of RC3 to amplify the effects of metabotropic glutamate receptor agonists, this activity must, necessarily, exhibit nonlinear kinetics as well. The capacitance of the system is regulated by phosphorylation by protein kinase C, which abrogates interactions between calmodulin and RC3 or GAP-43. We further propose that the ratio of phosphorylated to unphosphorylated RC3 determines the sliding LTP/LTD threshold in concept with Ca2+/ calmodulin-dependent kinase II. Finally, we suggest that the close association between RC3 and a subset of mitochondria serves to couple energy production with the synthetic events that accompany dendritic spine development and remodeling.
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Affiliation(s)
- D D Gerendasy
- Department of Molecular Biology, Scripps Research Institute
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11
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Chen SJ, Sweatt JD, Klann E. Enhanced phosphorylation of the postsynaptic protein kinase C substrate RC3/neurogranin during long-term potentiation. Brain Res 1997; 749:181-7. [PMID: 9138717 DOI: 10.1016/s0006-8993(96)01159-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Long-term potentiation (LTP) is a sustained strengthening of synaptic connections that occurs in the mammalian hippocampus, and is a cellular mechanism likely to contribute to memory formation. One question of current interest is whether the biochemical mechanisms responsible for the maintenance of LTP have a presynaptic or postsynaptic locus. We have determined that the phosphorylation of the postsynaptic protein kinase (PKC) substrate RC3/neurogranin is increased in the maintenance phase of LTP, and that the induction of this effect is dependent on activation of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors. The sustained increase in RC3/neurogranin phosphorylation requires ongoing protein kinase activity, as application of the protein kinase inhibitor H-7 after LTP induction can reverse the increased RC3/neurogranin phosphorylation. Overall, these data are evidence for postsynaptic biochemical changes in the maintenance of LTP. They also implicate RC3/neurogranin as a downstream effector of PKC activity in LTP that could contribute to physiologic expression of LTP.
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Affiliation(s)
- S J Chen
- Division of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
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12
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Di Luca M, Pastorino L, Raverdino V, De Graan PN, Caputi A, Gispen WH, Cattabeni F. Determination of the endogenous phosphorylation state of B-50/GAP-43 and neurogranin in different brain regions by electrospray mass spectrometry. FEBS Lett 1996; 389:309-13. [PMID: 8766722 DOI: 10.1016/0014-5793(96)00612-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Electrospray mass spectrometry coupled to liquid chromatography was utilized to measure two PKC neuronal substrates, B-50/GAP-43 and neurogranin, in single rat brain areas. Aliquots of perchloric acid extracts were directly injected and mass spectra recorded. At elution times of 14.2 and 27.0 min two molecular species of MW 7450 and 23 602 Da were observed. These values are in excellent agreement for the expected MW for rat neurogranin and B-50/GAP-43. The presence of molecular species shifted by 80 mass units in both cases indicates that these proteins are present in phosphorylated forms in cortical and hippocampal extracts.
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Affiliation(s)
- M Di Luca
- Institute of Pharmacological Sciences, University of Milano, Italy
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13
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Pasinelli P, Ramakers GM, Urban IJ, Hens JJ, Oestreicher AB, de Graan PN, Gispen WH. Long-term potentiation and synaptic protein phosphorylation. Behav Brain Res 1995; 66:53-9. [PMID: 7755899 DOI: 10.1016/0166-4328(94)00124-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Long-term potentiation (LTP) is a well known experimental model for studying the activity-dependent enhancement of synaptic plasticity, and because of its long duration and its associative properties, it has been proposed as a system to investigate the molecular mechanisms of memory formation. At present, there are several lines of evidence that indicate that pre- and postsynaptic kinases and their specific substrates are involved in molecular mechanisms underlying LTP. Many studies focus on the involvement of protein kinase C (PKC). One way to investigate the role of PKC in long-term potentiation is to determine the degree of phosphorylation of its substrates after in situ phosphorylation in hippocampal slices. Two possible targets are the presynaptic membrane-associated protein B-50 (a.k.a. GAP 43, neuromodulin and F1), which has been implicated in different forms of synaptical plasticity in the brain such as neurite outgrowth, hippocampal LTP and neurotransmitter release, and the postsynaptic protein neurogranin (a.k.a. RC3, BICKS and p17) which function remains to be determined. This review will focus on the protein kinase C activity in pre- and postsynaptic compartment during the early phase of LTP and the possible involvement of its substrates B-50 and neurogranin.
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Affiliation(s)
- P Pasinelli
- Department of Medical Pharmacology, Rudolf Magnus Institute for Neuroscience, Utrecht University, The Netherlands
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14
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Gerendasy DD, Herron SR, Wong KK, Watson JB, Sutcliffe JG. Rapid purification, site-directed mutagenesis, and initial characterization of recombinant RC3/neurogranin. J Mol Neurosci 1994; 5:133-48. [PMID: 7654517 DOI: 10.1007/bf02736729] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
RC3/Neurogranin is a postnatal-onset, forebrain-specific, thyroid hormone-regulated, protein kinase C (PKC) substrate that binds calmodulin (CaM) and accumulates in dendritic spines. We bacterially expressed and purified RC3 and, for comparison, GAP-43/neuromodulin to near homogeneity using relatively simple procedures. We then raised antisera against recombinant RC3 that does not crossreact with GAP-43 and is suitable for immunohistochemical analysis of brain slices. We also constructed over 30 RC3 sequence variants by PCR-mediated, site-directed mutagenesis, and purified four of these to near homogeneity. The elution profiles displayed by RC3 and sequence variants during purification on CaM-Sepharose columns suggest that two different affinity forms of the RC3.CaM complex coexist when Ca2+ is absent and that GAP-43.CaM interactions are far more sensitive to salt than those that occur between recombinant RC3 and CaM. Variant proteins in which serine 36 was changed failed to serve as a substrate for PKC, implicating this as the target residue.
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Affiliation(s)
- D D Gerendasy
- Department of Molecular Biology, Scripps Research Institute, La Jolla, CA 92037, USA
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15
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Suzuki T, Okumura-Noji K, Tanaka R, Ogura A, Nakamura K, Kudo Y, Tada T. Characterization of protein kinase C activities in postsynaptic density fractions prepared from cerebral cortex, hippocampus, and cerebellum. Brain Res 1993; 619:69-75. [PMID: 8374793 DOI: 10.1016/0006-8993(93)91596-k] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Protein kinase C (PKC) activities, especially, substrates and PKC isozymes, associated with postsynaptic density (PSD) fractions isolated from rat cerebral cortex, hippocampus, or cerebellum were investigated. The 17k M(r) major substrate for PKC was associated with PSD fractions prepared from cerebral cortex and hippocampus, and several substrates including 18k M(r) protein were associated with PSD fraction isolated from cerebellum. The content of 17k M(r) substrate was extremely low in the PSD fraction prepared from cerebellum. PKCs-beta and gamma were associated with PSD fractions and PKC-alpha was virtually absent in the fraction prepared from the three different regions of the brain. All of PKCs-alpha, beta, and gamma were associated with synaptosome fractions. The 36k M(r) bands immunoreactive with anti-PKC-beta antibody, probably degradation products of native PKC-beta, were detected in both the PSD and synaptosome fractions from the three regions, and the ratio of the degradation fragments to native PKC molecule was higher in PSD fractions than in synaptosome fractions. The results suggest postsynaptic roles of PKCs-beta and gamma and involvement of proteolytic activation of PKC-beta in the postsynaptic signal processing.
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Affiliation(s)
- T Suzuki
- Department of Biochemistry, Nagoya City University, Medical School, Japan
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