Stimulation of Carbonic Anhydrase Activity and Phosphorylation in Primary Astroglial Cultures by Norepinephrine

Church, George M.; Kimelberg, Harold K.; Sapirstein, Victor S.

doi:10.1111/j.1471-4159.1980.tb09660.x

Cited by 46 publications

(16 citation statements)

References 31 publications

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“…Modulation of enzyme activity and specificity by phosphorylation has been shown for histone deacetylase (Pflum et al , 2001), protein disulphide isomerase (Guthapfel et al , 1996), β-carbonic anhydrase (Church et al , 1980), Rubisco (Aggarwal et al , 1993), RNA helicase (Yang et al , 2005), and ATP synthase (Murtazina et al , 2001). Phosphorylation also reportedly mediates association and assembly of protein complexes of Rubisco (Aggarwal et al , 1993), 60S acidic ribosomal protein P0-2 (Naranda and Ballesta, 1991), endoplasmin (Brunati et al , 2000), tubulins (Blume et al , 2009), proteasome subunits (Umeda et al , 1997), and heat shock proteins (Picard, 2002).…”

Section: Discussionmentioning

confidence: 99%

Early cytokinin response proteins and phosphoproteins of Arabidopsis thaliana identified by proteome and phosphoproteome profiling

Černý

Dyčka

Bobáľová

et al. 2010

Journal of Experimental Botany

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Cytokinins are plant hormones involved in regulation of diverse developmental and physiological processes in plants whose molecular mechanisms of action are being intensely researched. However, most rapid responses to cytokinin signals at the proteomic and phosphoproteomic levels are unknown. Early cytokinin responses were investigated through proteome-wide expression profiling based on image and mass spectrometric analysis of two-dimensionally separated proteins and phosphoproteins. The effects of 15 min treatments of 7-day-old Arabidopsis thaliana seedlings with four main cytokinins representing hydroxyisopentenyl, isopentenyl, aromatic, and urea-derived type cytokinins were compared to help elucidate their common and specific function(s) in regulating plant development. In proteome and phosphoproteome maps, significant differences were reproducibly observed for 53 and 31 protein spots, respectively. In these spots, 96 proteins were identified by matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS), providing a snapshot of early links in cytokinin-regulated signalling circuits and cellular processes, including light signalling and photosynthesis, nitrogen metabolism, the CLAVATA pathway, and protein and gene expression regulation, in accordance with previously described cytokinin functions. Furthermore, they indicate novel links between temperature and cytokinin signalling, and an involvement of calcium ions in cytokinin signalling. Most of the differentially regulated proteins and phosphoproteins are located in chloroplasts, suggesting an as yet uncharacterized direct signalling chain responsible for cytokinin action in chloroplasts. Finally, first insights into the degree of specificity of cytokinin receptors on phosphoproteomic effects were obtained from analyses of cytokinin action in a set of cytokinin receptor double mutants.

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Section: Discussionmentioning

confidence: 99%

Early cytokinin response proteins and phosphoproteins of Arabidopsis thaliana identified by proteome and phosphoproteome profiling

Černý

Dyčka

Bobáľová

et al. 2010

Journal of Experimental Botany

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“…Morphological methods have shown no indication of extracellular enzyme (30)(31)(32), although these techniques often fail to detect CA when present at low levels. For example, in many instances, astrocytes are not stained by histochemical or immunocytochemical methods (30,32,33), although the enzyme is apparently present in these cells (5,34,35). In view of these methodological limitations, impermeant inhibitors of CA remain the only tool that can address whether functional enzyme is present in the extracellular space of the brain.…”

Section: B Aphomentioning

confidence: 99%

“…In the central nervous system, CA is abundant (2) and has been localized predominantly within glia (3)(4)(5) and choroid plexus (6). However, apart from its role in the secretion of cerebral spinal fluid (7,8), the functions of CA in the brain have remained obscure.…”

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confidence: 99%

pH transients evoked by excitatory synaptic transmission are increased by inhibition of extracellular carbonic anhydrase.

Chen

Chesler

1992

Proc. Natl. Acad. Sci. U.S.A.

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December 19, 1991) ABSTRACT Excitatory synaptic transmission has been associated with a rapid alkalinition of the brain extracellular space. These pH shifts are markedly increased by acetazolamide, an inhibitor of carbonic anhydrase. Although this effect can be readily explained by inhibition of extracellular carbonic anhydrase, this enzyme has been considered strictly intracellular in the central nervous system. To determine whether these alkaline shifts are regulated by extracellular carbonic anhydrase, we studied the effects of a membrane impermeant, dextran-bound inhibitor of this enzyme. Extraceflular alkaline transients, measured with pH-sensitive microelectrodes, were generated in the CAl region of rat hippocampal slices by repetitive electrical stimulation of Schaeffer collateral fibers or by local ejection of glutamate. More direct lkalinizations were elicited by focal ejection of NaOH in the vicinity of a pH microelectrode. These pH transients were reversibly enhanced by addition of the dextran-bound inhibitor. We conclude that there is significant carbonic anhydrase activity in the extracellular space of the brain. We postulate that this enzyme functions in the regulation and modulation of extracellular pH transients associated with neuronal activity.The enzyme carbonic anhydrase (CA) catalyzes the reversible hydration of CO2 and plays an important role in the function of erythrocytes and secretory epithelia (1). In the central nervous system, CA is abundant (2) and has been localized predominantly within glia (3-5) and choroid plexus (6). However, apart from its role in the secretion of cerebral spinal fluid (7,8), the functions of CA in the brain have remained obscure.While most forms of CA are intracellular, an extracellular isoform exists in several tissues, including kidney, lung, and muscle (9). Although there is no morphological evidence for extracellular CA in the brain, inhibitors of CA have been shown to have a large effect on the behavior of extracellular pH. Sulfonamide derivatives, such as acetazolamide, greatly increased the alkaline shifts associated with synaptic transmission (10-13). These effects could not be explained by enhancement of electrophysiological responses, since corresponding field potentials were unaffected. However, it remained unclear whether the action of acetazolamide was principally intracellular or extracellular, as this agent can readily penetrate cell membranes (1).It was subsequently noted that the effects of acetazolamide could be simply explained by a decrease in the extracellular buffering capacity (14). Experimental manipulation of the extracellular buffering power supported this view: synaptically evoked alkaline shifts were enhanced when bicarbonatebuffered saline was replaced by poorly buffered solutions containing Hepes (15,16). Although a role of metabolically generated CO2 could not be ruled out, the amplification and persistence of these alkalinizations in Hepes-buffered media suggested that shifts in CO2 and bicarbonate were not immediately respo...

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“…We have previously shown tat CAII may be expressed in the Bergmann :11s of some mutant mice cerebella [1], This nzyme is a normal component of the retinal [filler cells [16]. Moreover, even astrocytes ave been shown to express this protein in ivo [14,15] and in vitro [9,15].…”

Section: Introductionmentioning

confidence: 99%

Early Expression of Carbonic Anhydrase II (CAII) in Transitory Glial Cells of the Developing Murine Nervous System

Benjelloun

Delaunoy²,

Gomès

et al. 1986

Dev Neurosci

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Using immunocytochemical methods carbonic anhydrase II (CAII) has been detected in the embryonic mouse central nervous system as early as in stage E16. In the spinal cord and the brain stem, the enzyme first appeared in transitory cells probably derived from the radial glia. In the cerebrum such transitory cells were never stained with anti-CAII sera. The bodies of CAII-positive cells were never visualized in the ventricular layer. The controversial cellular specificity of CAII made it impossible to specify the glial lineage to which these transitory CAII-positive cells are committed.

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Stimulation of Carbonic Anhydrase Activity and Phosphorylation in Primary Astroglial Cultures by Norepinephrine

Cited by 46 publications

References 31 publications

Early cytokinin response proteins and phosphoproteins of Arabidopsis thaliana identified by proteome and phosphoproteome profiling

Early cytokinin response proteins and phosphoproteins of Arabidopsis thaliana identified by proteome and phosphoproteome profiling

pH transients evoked by excitatory synaptic transmission are increased by inhibition of extracellular carbonic anhydrase.

Early Expression of Carbonic Anhydrase II (CAII) in Transitory Glial Cells of the Developing Murine Nervous System

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