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Nagappan-Chettiar S, Johnson-Venkatesh EM, Umemori H. Tyrosine phosphorylation of the transmembrane protein SIRPα: Sensing synaptic activity and regulating ectodomain cleavage for synapse maturation. J Biol Chem 2018; 293:12026-12042. [PMID: 29914984 DOI: 10.1074/jbc.ra117.001488] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 06/08/2018] [Indexed: 11/06/2022] Open
Abstract
Synapse maturation is a neural activity-dependent process during brain development, in which active synapses preferentially undergo maturation to establish efficient neural circuits in the brain. Defects in this process are implicated in various neuropsychiatric disorders. We have previously reported that a postsynaptic transmembrane protein, signal regulatory protein-α (SIRPα), plays an important role in activity-dependently directing synapse maturation. In the presence of synaptic activity, the ectodomain of SIRPα is cleaved and released and then acts as a retrograde signal to induce presynaptic maturation. However, how SIRPα detects synaptic activity to promote its ectodomain cleavage and synapse maturation is unknown. Here, we show that activity-dependent tyrosine phosphorylation of SIRPα is critical for SIRPα cleavage and synapse maturation. We found that during synapse maturation and in response to neural activity, SIRPα is highly phosphorylated on its tyrosine residues in the hippocampus, a structure critical for learning and memory. Tyrosine phosphorylation of SIRPα was necessary for SIRPα cleavage and presynaptic maturation, as indicated by the fact that a phosphorylation-deficient SIRPα variant underwent much less cleavage and could not drive presynaptic maturation. However, SIRPα phosphorylation did not affect its synaptic localization. Finally, we show that inhibitors of the Src and JAK kinase family suppress neural activity-dependent SIRPα phosphorylation and cleavage. Together, our results indicate that SIRPα phosphorylation serves as a mechanism for detecting synaptic activity and linking it to the ectodomain cleavage of SIRPα, which in turn drives synapse maturation in an activity-dependent manner.
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Affiliation(s)
- Sivapratha Nagappan-Chettiar
- Department of Neurology, F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115; Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02115
| | - Erin M Johnson-Venkatesh
- Department of Neurology, F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115
| | - Hisashi Umemori
- Department of Neurology, F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115; Program in Neuroscience, Harvard Medical School, Boston, Massachusetts 02115.
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Abbasi M, Gupta V, Chitranshi N, You Y, Dheer Y, Mirzaei M, Graham SL. Regulation of Brain-Derived Neurotrophic Factor and Growth Factor Signaling Pathways by Tyrosine Phosphatase Shp2 in the Retina: A Brief Review. Front Cell Neurosci 2018; 12:85. [PMID: 29636665 PMCID: PMC5880906 DOI: 10.3389/fncel.2018.00085] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/09/2018] [Indexed: 01/31/2023] Open
Abstract
SH2 domain-containing tyrosine phosphatase-2 (PTPN11 or Shp2) is a ubiquitously expressed protein that plays a key regulatory role in cell proliferation, differentiation and growth factor (GF) signaling. This enzyme is well expressed in various retinal neurons and has emerged as an important player in regulating survival signaling networks in the neuronal tissues. The non-receptor phosphatase can translocate to lipid rafts in the membrane and has been implicated to regulate several signaling modules including PI3K/Akt, JAK-STAT and Mitogen Activated Protein Kinase (MAPK) pathways in a wide range of biochemical processes in healthy and diseased states. This review focuses on the roles of Shp2 phosphatase in regulating brain-derived neurotrophic factor (BDNF) neurotrophin signaling pathways and discusses its cross-talk with various GF and downstream signaling pathways in the retina.
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Affiliation(s)
- Mojdeh Abbasi
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Vivek Gupta
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Nitin Chitranshi
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Yuyi You
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.,Save Sight Institute, University of Sydney, Sydney, NSW, Australia
| | - Yogita Dheer
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Mehdi Mirzaei
- Australian Proteome Analysis Facility, Macquarie University, Sydney, NSW, Australia.,Department of Molecular Sciences, Macquarie University, Sydney, NSW, Australia
| | - Stuart L Graham
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.,Save Sight Institute, University of Sydney, Sydney, NSW, Australia
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Benon A, Ya C, Martin L, Watrin C, Chounlamountri N, Jaaoini I, Honnorat J, Pellier-Monnin V, Noraz N. The Syk kinases orchestrate cerebellar granule cell tangential migration. Neuroscience 2017; 360:230-239. [DOI: 10.1016/j.neuroscience.2017.07.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 07/21/2017] [Accepted: 07/21/2017] [Indexed: 01/03/2023]
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Noraz N, Jaaoini I, Charoy C, Watrin C, Chounlamountri N, Benon A, Malleval C, Boudin H, Honnorat J, Castellani V, Pellier-Monnin V. Syk kinases are required for spinal commissural axon repulsion at the midline via the ephrin/Eph pathway. Development 2016; 143:2183-93. [PMID: 27122172 DOI: 10.1242/dev.128629] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 04/15/2016] [Indexed: 12/26/2022]
Abstract
In the hematopoietic system, Syk family tyrosine kinases are essential components of immunoreceptor ITAM-based signaling. While there is increasing data indicating the involvement of immunoreceptors in neural functions, the contribution of Syk kinases remains obscure. Previously, we identified phosphorylated forms of Syk kinases in specialized populations of migrating neurons or projecting axons. Moreover, we identified ephrin/Eph as guidance molecules utilizing the ITAM-bearing CD3zeta (Cd247) and associated Syk kinases for the growth cone collapse response induced in vitro Here, we show that in the developing spinal cord, Syk is phosphorylated in navigating commissural axons. By analyzing axon trajectories in open-book preparations of Syk(-/-); Zap70(-/-) mouse embryos, we show that Syk kinases are dispensable for attraction towards the midline but confer growth cone responsiveness to repulsive signals that expel commissural axons from the midline. Known to serve a repulsive function at the midline, ephrin B3/EphB2 are obvious candidates for driving the Syk-dependent repulsive response. Indeed, Syk kinases were found to be required for ephrin B3-induced growth cone collapse in cultured commissural neurons. In fragments of commissural neuron-enriched tissues, Syk is in a constitutively phosphorylated state and ephrin B3 decreased its level of phosphorylation. Direct pharmacological inhibition of Syk kinase activity was sufficient to induce growth cone collapse. In conclusion, Syk kinases act as a molecular switch of growth cone adhesive and repulsive responses.
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Affiliation(s)
- Nelly Noraz
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Iness Jaaoini
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Camille Charoy
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Chantal Watrin
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Naura Chounlamountri
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Aurélien Benon
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Céline Malleval
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Hélène Boudin
- INSERM U1064, Institut de Transplantation Urologie-Néphrologie, Nantes F-44035, France
| | - Jérôme Honnorat
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France Hospices Civils de Lyon, Lyon F-69000, France
| | - Valérie Castellani
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
| | - Véronique Pellier-Monnin
- INSERM U1217, Institut NeuroMyoGène, Lyon F-69000, France CNRS UMR5310, Institut NeuroMyoGène, Lyon F-69000, France University Claude Bernard Lyon 1, Lyon F-69000, France
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Lee KH, Kim SH, Kim DY, Kim S, Kim KT. Internal ribosomal entry site-mediated translation is important for rhythmic PERIOD1 expression. PLoS One 2012; 7:e37936. [PMID: 22662251 PMCID: PMC3360671 DOI: 10.1371/journal.pone.0037936] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 04/26/2012] [Indexed: 01/19/2023] Open
Abstract
The mouse PERIOD1 (mPER1) plays an important role in the maintenance of circadian rhythm. Translation of mPer1 is directed by both a cap-dependent process and cap-independent translation mediated by an internal ribosomal entry site (IRES) in the 5′ untranslated region (UTR). Here, we compared mPer1 IRES activity with other cellular IRESs. We also found critical region in mPer1 5′UTR for heterogeneous nuclear ribonucleoprotein Q (HNRNPQ) binding. Deletion of HNRNPQ binding region markedly decreased IRES activity and disrupted rhythmicity. A mathematical model also suggests that rhythmic IRES-dependent translation is a key process in mPER1 oscillation. The IRES-mediated translation of mPer1 will help define the post-transcriptional regulation of the core clock genes.
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Affiliation(s)
- Kyung-Ha Lee
- Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Sung-Hoon Kim
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Do-Yeon Kim
- Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Seunghwan Kim
- Department of Physics, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Kyong-Tai Kim
- Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
- * E-mail:
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Hatterer E, Benon A, Chounlamountri N, Watrin C, Angibaud J, Jouanneau E, Boudin H, Honnorat J, Pellier-Monnin V, Noraz N. Syk kinase is phosphorylated in specific areas of the developing nervous system. Neurosci Res 2011; 70:172-82. [PMID: 21354221 DOI: 10.1016/j.neures.2011.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 01/31/2011] [Accepted: 02/16/2011] [Indexed: 11/26/2022]
Abstract
An increasing number of data involve immunoreceptors in brain development, synaptic plasticity and behavior. However it has yet to be determined whether these proteins in fact transmit an immunoreceptor-like signal in non-hematopoietic neuronal cells. The recruitment and activation of the Syk family tyrosine kinases, Syk and ZAP-70, being a critical step in this process, we conducted a thorough analysis of Syk/ZAP-70 expression pattern in nervous tissues. Syk/ZAP-70 is present in neurons of different structures including the cerebellum, the hippocampus, the visual system and the olfactory system. During the olfactory system ontogeny the protein is detected from the 16th embryonic day and persists in adulthood. Importantly, Syk was phosphorylated on tyrosine residues representative of an active form of the kinase in specialized neuronal subpopulations comprising rostral migratory stream neuronal progenitor cells, hippocampal pyramidal cells, retinal ganglion cells and cerebellar granular cells. Phospho-Syk staining was also observed in synapse-rich regions such as the olfactory bulb glomeruli and the retina inner plexiform layer. Furthermore, our work on cultured primary hippoccampal neurons indicates that as for hematopoietic cells, Syk phosphorylation is readily induced upon pervanadate treatment. Therefore, Syk appears to be a serious candidate in connecting immunoreceptors to downstream adaptor/effector molecules in neurons.
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Affiliation(s)
- Eric Hatterer
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, Neuro-oncology & Neuro-inflammation Team, University of Lyon 1, Lyon F-69000, France
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Rhodopsin-regulated insulin receptor signaling pathway in rod photoreceptor neurons. Mol Neurobiol 2010; 42:39-47. [PMID: 20407846 DOI: 10.1007/s12035-010-8130-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 04/05/2010] [Indexed: 10/19/2022]
Abstract
The retina is an integral part of the central nervous system and retinal cells are known to express insulin receptors (IR), although their function is not known. This article describes recent studies that link the photoactivation of rhodopsin to tyrosine phosphorylation of the IR and subsequent activation of phosphoinositide 3-kinase, a neuron survival factor. Our studies suggest that the physiological role of this process is to provide neuroprotection of the retina against light damage by activating proteins that protect against stress-induced apoptosis. We focus mainly on our recently identified regulation of the IR pathway through the G-protein-coupled receptor rhodopsin. Various mutant and knockout proteins of phototransduction cascade have been used to study the light-induced activation of the retinal IR. Our studies suggest that rhodopsin may have additional previously uncharacterized signaling functions in photoreceptors.
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Localization of phospho-tyrosine489-β-adducin immunoreactivity in the hypothalamic tanycytes and its involvement in energy homeostasis. Brain Res 2008; 1228:97-106. [DOI: 10.1016/j.brainres.2008.06.093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 04/25/2008] [Accepted: 06/19/2008] [Indexed: 01/17/2023]
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Chae KS, Ko GYP, Dryer SE. Tyrosine phosphorylation of cGMP-gated ion channels is under circadian control in chick retina photoreceptors. Invest Ophthalmol Vis Sci 2007; 48:901-6. [PMID: 17251493 PMCID: PMC2376765 DOI: 10.1167/iovs.06-0824] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate the role of tyrosine phosphorylation in circadian regulation of cGMP-gated cation channels (CNGCs) of chicken cone photoreceptors. METHODS Chick retinas were studied on the second day of constant darkness (DD) after several days of entrainment to 12:12 hr light-dark (LD) cycles in vitro. Inside-out patch recordings were made during the subjective day and subjective night to quantify circadian changes in the sensitivity of CNGCs to activation by cGMP after treatment with various tyrosine kinase and tyrosine phosphatase inhibitors. Immunoprecipitation and immunoblot analysis were also used to examine tyrosine phosphorylation of CNGCs and closely associated proteins after separation by conventional and two-dimensional SDS-PAGE. RESULTS Treatment with tyrosine kinase inhibitors caused a significant decrease in K(1/2) for cGMP activation of CNGCs in patches excised from cones during the subjective day, but had no effect on K(1/2) during the subjective night. Conversely, treatment with a tyrosine phosphatase inhibitor caused a significant increase in the K(1/2) of CNGCs in patches excised during the subjective night but had no effect on channel K(1/2) during the subjective day. Broad spectrum serine-threonine phosphatase inhibitors had no effect. An 85-kDa tyrosine polypeptide that coimmunoprecipitated with CNGC alpha-subunits was detectable at higher levels during the subjective day than during the subjective night. CNGC alpha-subunits were not tyrosine phosphorylated as a function of the time of day. CONCLUSIONS Circadian control of cone CNGCs appears to entail elevated daytime tyrosine phosphorylation of an approximately 85-kDa auxiliary protein or another subunit of the CNGCs.
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Affiliation(s)
- Kwon-Seok Chae
- From the School of Life Sciences and Biotechnology, Korea University, Seoul, Korea; the
| | - Gladys Y.-P. Ko
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas; and the
| | - Stuart E. Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
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Rajala A, Anderson RE, Ma JX, Lem J, Al-Ubaidi MR, Rajala RVS. G-protein-coupled receptor rhodopsin regulates the phosphorylation of retinal insulin receptor. J Biol Chem 2007; 282:9865-9873. [PMID: 17272282 DOI: 10.1074/jbc.m608845200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have shown previously that phosphoinositide 3-kinase in the retina is activated in vivo through light-induced tyrosine phosphorylation of the insulin receptor (IR). The light effect is localized to photoreceptor neurons and is independent of insulin secretion (Rajala, R. V., McClellan, M. E., Ash, J. D., and Anderson, R. E. (2002) J. Biol. Chem. 277, 43319-43326). These results suggest that there exists a cross-talk between phototransduction and other signal transduction pathways. In this study, we examined the stage of phototransduction that is coupled to the activation of the IR. We studied IR phosphorylation in mice lacking the rod-specific alpha-subunit of transducin to determine if phototransduction events are required for IR activation. To confirm that light-induced tyrosine phosphorylation of the IR is signaled through bleachable rhodopsin, we examined IR activation in retinas from RPE65(-/-) mice that are deficient in opsin chromophore. We observed that IR phosphorylation requires the photobleaching of rhodopsin but not transducin signaling. To determine whether the light-dependent activation of IR is mediated through the rod or cone transduction pathway, we studied the IR activation in mice lacking opsin, a mouse model of pure cone function. No light-dependent activation of the IR was found in the retinas of these mice. We provide evidence for the existence of a light-mediated IR pathway in the retina that is different from the known insulin-mediated pathway in nonneuronal tissues. These results suggest that IR phosphorylation in rod photoreceptors is signaled through the G-protein-coupled receptor rhodopsin. This is the first study demonstrating that rhodopsin can initiate signaling pathway(s) in addition to its classical phototransduction.
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Affiliation(s)
- Ammaji Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104; Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Robert E Anderson
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104; Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Jian-Xing Ma
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104; Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Janis Lem
- Department of Ophthalmology, New England Medical Center and Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Muayyad R Al-Ubaidi
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Raju V S Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104; Dean A. McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104.
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Taniguchi H, Tanida M, Okumura N, Hamada J, Sano SI, Nagai K. Regulation of sympathetic and parasympathetic nerve activities by BIT/SHPS-1. Neurosci Lett 2006; 398:102-6. [PMID: 16426751 DOI: 10.1016/j.neulet.2005.12.071] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2005] [Revised: 12/21/2005] [Accepted: 12/22/2005] [Indexed: 11/19/2022]
Abstract
The hypothalamus plays a central role in the homeostatic regulation of internal physiological conditions such as body temperature and energy balance. We have previously shown that cold exposure enhances tyrosine phosphorylation of BIT/SHPS-1 (brain immunoglobulin-like molecule with tyrosine-based activation motifs/SHP substrate-1) in hypothalamic nuclei including the suprachiasmatic nucleus. In order to elucidate the function of BIT/SHPS-1 in the hypothalamus, we stimulated BIT/SHPS-1 in vivo by using the anti-BIT monoclonal antibody (mAb) 1D4, which reacts with the extracellular domain of BIT/SHPS-1 and induces its tyrosine phosphorylation. Administration of mAb 1D4 into the third cerebral ventricle enhanced the electrical activity of the renal sympathetic nerves, while it suppressed that of the gastric parasympathetic nerves. Similarly, blood pressure increased in response to the mAb 1D4 injection, and additionally, temperatures of the abdomen and brown adipose tissue increased. These results indicate that BIT/SHPS-1 is involved in the hypothalamic regulation of thermogenesis via the autonomic nervous system.
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Affiliation(s)
- Hiroyuki Taniguchi
- Laboratory of Proteins Involved in Homeostatic Integration, Division of Integrated Protein Functions, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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Taniguchi H, Okumura N, Hamada J, Inagaki M, Nakahata Y, Sano SI, Nagai K. Cold exposure induces tyrosine phosphorylation of BIT through NMDA receptors in the rat hypothalamus. Biochem Biophys Res Commun 2004; 319:178-84. [PMID: 15158458 DOI: 10.1016/j.bbrc.2004.04.173] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2004] [Indexed: 11/21/2022]
Abstract
The hypothalamus has a central role in maintaining homeostases of physiological conditions including body temperature and energy balance. To examine molecular responses to cold exposure in the hypothalamus, we examined changes in protein tyrosine phosphorylation in the suprachiasmatic nucleus of the hypothalamus after acute cold exposure in rats. It was found that brain immunoglobulin-like molecule with tyrosine-based inhibitory motifs (BIT, also called SHPS-1, SIRPalpha or p84), a transmembrane glycoprotein with two ITIM motifs, showed enhanced tyrosine phosphorylation after cold exposure. Its tyrosine phosphorylation induced by cold exposure was also found in other hypothalamic nuclei including the paraventricular nucleus, lateral hypothalamic area, ventromedial hypothalamus, and arcuate nucleus. This phosphorylation was blocked by AP-5, an NMDA receptor antagonist, indicating that it was mediated by NMDA receptors. These results suggest that BIT is involved in the mechanism of neuronal responses to cold exposure in the hypothalamus.
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Affiliation(s)
- Hiroyuki Taniguchi
- Division of Protein Metabolism, Institute for Protein Research, Osaka University, 3-2, Yamadaoka, Suita, Osaka 565-0871, Japan
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