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Ancatén-González C, Segura I, Alvarado-Sánchez R, Chávez AE, Latorre R. Ca 2+- and Voltage-Activated K + (BK) Channels in the Nervous System: One Gene, a Myriad of Physiological Functions. Int J Mol Sci 2023; 24:3407. [PMID: 36834817 PMCID: PMC9967218 DOI: 10.3390/ijms24043407] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/18/2023] [Accepted: 01/21/2023] [Indexed: 02/11/2023] Open
Abstract
BK channels are large conductance potassium channels characterized by four pore-forming α subunits, often co-assembled with auxiliary β and γ subunits to regulate Ca2+ sensitivity, voltage dependence and gating properties. BK channels are abundantly expressed throughout the brain and in different compartments within a single neuron, including axons, synaptic terminals, dendritic arbors, and spines. Their activation produces a massive efflux of K+ ions that hyperpolarizes the cellular membrane. Together with their ability to detect changes in intracellular Ca2+ concentration, BK channels control neuronal excitability and synaptic communication through diverse mechanisms. Moreover, increasing evidence indicates that dysfunction of BK channel-mediated effects on neuronal excitability and synaptic function has been implicated in several neurological disorders, including epilepsy, fragile X syndrome, mental retardation, and autism, as well as in motor and cognitive behavior. Here, we discuss current evidence highlighting the physiological importance of this ubiquitous channel in regulating brain function and its role in the pathophysiology of different neurological disorders.
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Affiliation(s)
- Carlos Ancatén-González
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Programa de Doctorado en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Ignacio Segura
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Rosangelina Alvarado-Sánchez
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
- Doctorado en Ciencias Mención Biofísica y Biología Computacional, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Andrés E. Chávez
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso (CINV), Instituto de Neurociencias, Universidad de Valparaíso, Valparaíso 2340000, Chile
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Li B, Jie W, Huang L, Wei P, Li S, Luo Z, Friedman AK, Meredith AL, Han MH, Zhu XH, Gao TM. Nuclear BK channels regulate gene expression via the control of nuclear calcium signaling. Nat Neurosci 2014; 17:1055-63. [PMID: 24952642 PMCID: PMC4115017 DOI: 10.1038/nn.3744] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 05/19/2014] [Indexed: 12/15/2022]
Abstract
Ion channels are essential for the regulation of neuronal functions. The significance of plasma membrane, mitochondrial, endoplasmic reticulum and lysosomal ion channels in the regulation of Ca(2+) is well established. In contrast, surprisingly little is known about the function of ion channels on the nuclear envelope (NE). Here we demonstrate the presence of functional large-conductance, calcium-activated potassium channels (BK channels) on the NE of rodent hippocampal neurons. Functionally, blockade of nuclear BK channels (nBK channels) induces NE-derived Ca(2+) release, nucleoplasmic Ca(2+) elevation and cyclic AMP response element binding protein (CREB)-dependent transcription. More importantly, blockade of nBK channels regulates nuclear Ca(2+)-sensitive gene expression and promotes dendritic arborization in a nuclear Ca(2+)-dependent manner. These results suggest that the nBK channel functions as a molecular link between neuronal activity and nuclear Ca(2+) to convey signals from synapse to nucleus and is a new modulator, operating at the NE, of synaptic activity-dependent neuronal functions.
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Affiliation(s)
- Boxing Li
- 1] State Key Laboratory of Organ Failure Research, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. [2] Key Laboratory of Neuroplasticity of Guangdong Higher Education Institutes, Southern Medical University, Guangzhou, China
| | - Wei Jie
- 1] State Key Laboratory of Organ Failure Research, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. [2] Key Laboratory of Neuroplasticity of Guangdong Higher Education Institutes, Southern Medical University, Guangzhou, China
| | - Lianyan Huang
- School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, China
| | - Peng Wei
- 1] State Key Laboratory of Organ Failure Research, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. [2] Key Laboratory of Neuroplasticity of Guangdong Higher Education Institutes, Southern Medical University, Guangzhou, China
| | - Shuji Li
- 1] State Key Laboratory of Organ Failure Research, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. [2] Key Laboratory of Neuroplasticity of Guangdong Higher Education Institutes, Southern Medical University, Guangzhou, China
| | - Zhengyi Luo
- 1] State Key Laboratory of Organ Failure Research, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. [2] Key Laboratory of Neuroplasticity of Guangdong Higher Education Institutes, Southern Medical University, Guangzhou, China
| | - Allyson K Friedman
- Department of Pharmacology and Systems Therapeutics, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Andrea L Meredith
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ming-Hu Han
- Department of Pharmacology and Systems Therapeutics, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Xin-Hong Zhu
- 1] State Key Laboratory of Organ Failure Research, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. [2] Key Laboratory of Neuroplasticity of Guangdong Higher Education Institutes, Southern Medical University, Guangzhou, China
| | - Tian-Ming Gao
- 1] State Key Laboratory of Organ Failure Research, Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. [2] Key Laboratory of Neuroplasticity of Guangdong Higher Education Institutes, Southern Medical University, Guangzhou, China
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Abstract
Low-frequency depression (LFD) of transmitter release occurs at phasic synapses with stimulation at 0.2 Hz in both isolated crayfish (Procambarus clarkii) neuromuscular junction (NMJ) preparations and in intact animals. LFD is regulated by presynaptic activity of the Ca(2+)-dependent phosphatase calcineurin (Silverman-Gavrila and Charlton, 2009). Since the fast Ca(2+) chelator BAPTA-AM inhibits LFD but the slow chelator EGTA-AM does not, the Ca(2+) sensor for LFD may be close to a Ca(2+) source at active zones. Calcineurin can be activated by the Ca(2+)-activated protease calpain, and immunostaining showed that both proteins are present at nerve terminals. Three calpain inhibitors, calpain inhibitor I, MDL-28170, and PD150606, but not the control compound PD145305, inhibit LFD both in the intact animal as shown by electromyograms and by intracellular recordings at neuromuscular junctions. Analysis of mini-EPSPs indicated that these inhibitors had minimal postsynaptic effects. Proteolytic activity in CNS extract, detected by a fluorescent calpain substrate, was modulated by Ca(2+) and calpain inhibitors. Western blot analysis of CNS extract showed that proteolysis of calcineurin to a fragment consistent with the constitutively active form required Ca(2+) and was blocked by calpain inhibitors. Inhibition of LFD by calpain inhibition blocks the reduction in phosphoactin and the depolymerization of tubulin that normally occurs in LFD, probably by blocking the dephosphorylation of cytoskeletal proteins by calcineurin. In contrast, high-frequency depression does not involve protein phosphorylation- or calpain-dependent mechanisms. LFD may involve a specific pathway in which local Ca(2+) signaling activates presynaptic calpain and calcineurin at active zones and causes changes of tubulin cytoskeleton.
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Kubokawa M, Nakamura K, Komagiri Y. Interaction between Calcineurin and Ca/Calmodulin Kinase-II in Modulating Cellular Functions. Enzyme Res 2011; 2011:587359. [PMID: 21687603 PMCID: PMC3112523 DOI: 10.4061/2011/587359] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 04/01/2011] [Indexed: 12/28/2022] Open
Abstract
Roles of calcineurin (CaN), a Ca2+/calmodulin- (CaM-) dependent protein phosphatase, and Ca2+/CaM-dependent protein kinase-II (CaMKII) in modulating K+ channel activity and the intracellular Ca2+ concentration ([Ca2+]i) have been investigated in renal tubule epithelial cells. The channel current through the cell membrane was recorded with the patch-clamp technique, and [Ca2+]i was monitored using fura-2 imaging. We found that a CaN-inhibitor, cyclosporin A (CyA), lowered the K+ channel activity and elevated [Ca2+]i, suggesting that CyA closes K+ channels and opens Ca2+-release channels of the cytosolic Ca2+-store. Moreover, both of these responses were blocked by KN-62, an inhibitor of CaMKII. It is suggested that the CyA-mediated response results from the activation of CaMKII. Indeed, Western blot analysis revealed that CyA increased phospho-CaMKII, an active form of CaMKII. These findings suggest that CaN-dependent dephosphorylation inhibits CaMKII-mediated phosphorylation, and the inhibition of CaN increases phospho-CaMKII, which results in the stimulation of CaMKII-dependent cellular actions.
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Affiliation(s)
- Manabu Kubokawa
- Department of Physiology, Iwate Medical University School of Medicine, 2-1-1 Nishitokuda, Yahaba, Iwate 028-3694, Japan
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van Welie I, du Lac S. Bidirectional control of BK channel open probability by CAMKII and PKC in medial vestibular nucleus neurons. J Neurophysiol 2011; 105:1651-9. [PMID: 21307321 DOI: 10.1152/jn.00058.2011] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Large conductance K(+) (BK) channels are a key determinant of neuronal excitability. Medial vestibular nucleus (MVN) neurons regulate eye movements to ensure image stabilization during head movement, and changes in their intrinsic excitability may play a critical role in plasticity of the vestibulo-ocular reflex. Plasticity of intrinsic excitability in MVN neurons is mediated by kinases, and BK channels influence excitability, but whether endogenous BK channels are directly modulated by kinases is unknown. Double somatic patch-clamp recordings from MVN neurons revealed large conductance potassium channel openings during spontaneous action potential firing. These channels displayed Ca(2+) and voltage dependence in excised patches, identifying them as BK channels. Recording isolated single channel currents at physiological temperature revealed a novel kinase-mediated bidirectional control in the range of voltages over which BK channels are activated. Application of activated Ca(2+)/calmodulin-dependent kinase II (CAMKII) increased BK channel open probability by shifting the voltage activation range towards more hyperpolarized potentials. An opposite shift in BK channel open probability was revealed by inhibition of phosphatases and was occluded by blockade of protein kinase C (PKC), suggesting that active PKC associated with BK channel complexes in patches was responsible for this effect. Accordingly, direct activation of endogenous PKC by PMA induced a decrease in BK open probability. BK channel activity affects excitability in MVN neurons and bidirectional control of BK channels by CAMKII, and PKC suggests that cellular signaling cascades engaged during plasticity may dynamically control excitability by regulating BK channel open probability.
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Affiliation(s)
- Ingrid van Welie
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, San Diego, CA 92037, USA
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Millership JE, Heard C, Fearon IM, Bruce JIE. Differential Regulation of Calcium-Activated Potassium Channels by Dynamic Intracellular Calcium Signals. J Membr Biol 2010; 235:191-210. [DOI: 10.1007/s00232-010-9266-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Accepted: 05/14/2010] [Indexed: 01/08/2023]
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Fry C, Meng E, Young J. The physiological function of lower urinary tract smooth muscle. Auton Neurosci 2010; 154:3-13. [DOI: 10.1016/j.autneu.2009.10.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Revised: 10/25/2009] [Accepted: 10/27/2009] [Indexed: 11/15/2022]
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Role of calcineurin-mediated dephosphorylation in modulation of an inwardly rectifying K+ channel in human proximal tubule cells. J Membr Biol 2009; 231:79-92. [PMID: 19865787 DOI: 10.1007/s00232-009-9207-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Accepted: 09/23/2009] [Indexed: 01/26/2023]
Abstract
Activity of an inwardly rectifying K(+) channel with inward conductance of about 40 pS in cultured human renal proximal tubule epithelial cells (RPTECs) is regulated at least in part by protein phosphorylation and dephosphorylation. In this study, we examined involvement of calcineurin (CaN), a Ca(2+)/calmodulin (CaM)-dependent phosphatase, in modulating K(+) channel activity. In cell-attached mode of the patch-clamp technique, application of a CaN inhibitor, cyclosporin A (CsA, 5 microM) or FK520 (5 microM), significantly suppressed channel activity. Intracellular Ca(2+) concentration ([Ca(2+)]( i )) estimated by fura-2 imaging was elevated by these inhibitors. Since inhibition of CaN attenuates some dephosphorylation with increase in [Ca(2+)]( i ), we speculated that inhibiting CaN enhances Ca(2+)-dependent phosphorylation, which might result in channel suppression. To verify this hypothesis, we examined effects of inhibitors of PKC and Ca(2+)/CaM-dependent protein kinase-II (CaMKII) on CsA-induced channel suppression. Although the PKC inhibitor GF109203X (500 nM) did not influence the CsA-induced channel suppression, the CaMKII inhibitor KN62 (20 microM) prevented channel suppression, suggesting that the channel suppression resulted from CaMKII-dependent processes. Indeed, Western blot analysis showed that CsA increased phospho-CaMKII (Thr286), an activated CaMKII in inside-out patches, application of CaM (0.6 microM) and CaMKII (0.15 U/ml) to the bath at 10(-6) M Ca(2+) significantly suppressed channel activity, which was reactivated by subsequent application of CaN (800 U/ml). These results suggest that CaN plays an important role in supporting K(+) channel activity in RPTECs by preventing CaMKII-dependent phosphorylation.
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Orie NN, Thomas AM, Perrino BA, Tinker A, Clapp LH. Ca2+/calcineurin regulation of cloned vascular K ATP channels: crosstalk with the protein kinase A pathway. Br J Pharmacol 2009; 157:554-64. [PMID: 19422382 DOI: 10.1111/j.1476-5381.2009.00221.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND AND PURPOSE Vascular ATP-sensitive potassium (K(ATP)) channels are activated by cyclic AMP elevating vasodilators through protein kinase A (PKA). Direct channel phosphorylation is a critical mechanism, though the phosphatase opposing these effects is unknown. Previously, we reported that calcineurin, a Ca(2+)-dependent phosphatase, inhibits K(ATP) channels, though neither the site nor the calcineurin isoform involved is established. Given that the type-2 regulatory (RII) subunit of PKA is a substrate for calcineurin we considered whether calcineurin regulates channel activity through interacting with PKA. EXPERIMENTAL APPROACH Whole-cell recordings were made in HEK-293 cells stably expressing the vascular K(ATP) channel (K(IR)6.1/SUR2B). The effect of intracellular Ca(2+) and modulators of the calcineurin and PKA pathway on glibenclamide-sensitive currents were examined. KEY RESULTS Constitutively active calcineurin A alpha but not A beta significantly attenuated K(ATP) currents activated by low intracellular Ca(2+), whereas calcineurin inhibitors had the opposite effect. PKA inhibitors reduced basal K(ATP) currents and responses to calcineurin inhibitors, consistent with the notion that some calcineurin action involves inhibition of PKA. However, raising intracellular Ca(2+) (equivalent to increasing calcineurin activity), almost completely inhibited K(ATP) channel activation induced by the catalytic subunit of PKA, whose enzymatic activity is independent of the RII subunit. In vitro phosphorylation experiments showed calcineurin could directly dephosphorylate a site in Kir6.1 that was previously phosphorylated by PKA. CONCLUSIONS AND IMPLICATIONS Calcineurin A alpha regulates K(IR)6.1/SUR2B by inhibiting PKA-dependent phosphorylation of the channel as well as PKA itself. Such a mechanism is likely to directly oppose the action of vasodilators on the K(ATP) channel.
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Affiliation(s)
- N N Orie
- BHF Laboratories, Department of Medicine, University College, London, UK
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10
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Abstract
Big-K(+) conductance (BK)-channel mediated fast afterhyperpolarizations (AHPs) following action potentials are reduced after eyeblink conditioning. Blocking BK channels with paxilline increases evoked firing frequency in vitro and spontaneous pyramidal activity in vivo. To examine how increased excitability after BK-channel blockade affects learning, rats received bilateral infusions of paxilline, saline, or nothing into hippocampal CA1 prior to trace eyeblink conditioning. The drug group was slower to acquire the task, but learning was not completely impaired. This suggests that nonspecific increases in excitability and baseline neuronal firing rates caused by in vivo blockade of the BK channel may disrupt correct processing of inputs, thereby impairing hippocampus-dependent learning.
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The BK-mediated fAHP is modulated by learning a hippocampus-dependent task. Proc Natl Acad Sci U S A 2008; 105:15154-9. [PMID: 18799739 DOI: 10.1073/pnas.0805855105] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intrinsic excitability is a plastic property of cells that, along with synaptic changes, can be modulated by learning. Action potential (AP) height, width, and frequency are intrinsically controlled properties which rely on the activation of Na(+), Ca(2+), and K(+) channels in the dendritic, somatic, and axonal membranes. The fast after-hyperpolarization (fAHP) after an AP is partially responsible for determining the half-width and duration of the AP and thus Ca(2+) influx during the depolarization. In CA1 hippocampal pyramidal cells, the fAHP is carried by the voltage- and Ca(2+)-dependent BK channel. In addition to modulating the duration of the AP, the BK-mediated potassium current exerts control over the frequency of AP generation in response to a depolarizing input. These facts position BK-mediated effects to not only modulate immediate intraneuronal communication, but also to control longer-term Ca(2+)-dependent changes in the neuron, such as kinase activation, gene transcription, and synaptic plasticity. We examined how the BK-mediated fAHP was altered in hippocampal neurons after learning trace eyeblink conditioning. By using current clamp methods, it was found that the fAHP is reduced and the AP duration is increased in cells from conditioned animals. Additionally, in vitro and in vivo measures of firing frequency show that BK-channel blockade increases both evoked (in vitro) and spontaneous (in vivo) firing frequency of CA1 neurons, implicating the BK channel in the control of intrinsic excitability. These data indicate that the reduction of the BK-mediated fAHP is an essential part of the total increase of neuronal excitability known to accompany hippocampus-dependent learning.
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Kim BJ, Jeon JH, Kim SJ, So I. Role of calmodulin and myosin light chain kinase in the activation of carbachol-activated cationic current in murine ileal myocytes. Can J Physiol Pharmacol 2008; 85:1254-62. [PMID: 18066127 DOI: 10.1139/y07-118] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the effect of calmodulin (CaM) and myosin light chain kinase (MLCK) on murine ileal myocytes using the whole-cell patch-clamp technique. Under the voltage clamp, at the holding potential of -60 mV, 50 micromol/L carbachol (CCh) induced inward currents (I CCh), and spontaneous decay of I CCh occurred. The peak inward currents induced by the repetitive application of CCh (50 micromol/L) tended to decrease in amplitude. Intracellular application of 0.2 mmol/L guanosine 5'-O-(gamma-thio)triphosphate (GTP gammaS) from the patch electrode induced an inward current at a holding potential of -60m V, and the peak inward currents induced by the repetitive application of Cs tended to decrease slightly in amplitude. The amplitude of I CCh was reduced by pretreatment either with W-7, trifluoroperazine, W-5, and melittin (CaM inhibitors) or with ML-7 and ML-9 (selective MLCK inhibitors), and the inhibitory effects were reversible. However, when we pretreated with 50 micromol/L W-7 or 5 micromol/L ML-7 on GTP gammaS-induced inward currents, almost no inhibition was observed in the inward currents. Application of both Rho kinase inhibitor and MLCK inhibitor inhibited GTP gammaS-induced currents. We conclude that CaM and MLCK modulate the activation process of I CCh in murine ileal myocytes and suggest that the classical type transient receptor potential (TRPC) channel 5 might be a candidate for nonselective cationic currents (NSCC) activated by muscarinic stimulation in gastrointestinal smooth muscle cells.
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Affiliation(s)
- Byung Joo Kim
- Center for Bio-Artificial Muscle and Department of Physiology, Seoul National University College of Medicine, Seoul 110-799, Korea
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13
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Abstract
The large conductance calcium-activated potassium channel, or BKCa channel, plays an important feedback role in a variety of physiological processes, including neurotransmitter release and smooth muscle contraction. Some reports have suggested that this channel forms a stable complex with regulators of its function, including several kinases and phosphatases. To further define such signaling complexes, we used the yeast two-hybrid system to screen a human aorta cDNA library for proteins that bind to the BKCa channel's intracellular, COOH-terminal “tail”. One of the interactors we identified is the protein receptor for activated C kinase 1 (RACK1). RACK1 is a member of the WD40 protein family, which also includes the G protein β-subunits. Consistent with an important role in BKCa-channel regulation, RACK1 has been shown to be a scaffolding protein that interacts with a wide variety of signaling molecules, including cSRC and PKC. We have confirmed the interaction between RACK1 and the BKCa channel biochemically with GST pull-down and coimmunoprecipitation experiments. We have observed some co-localization of RACK1 with the BKCa channel in vascular smooth muscle cells with immunocytochemical experiments, and we have found that RACK1 has effects on the BKCa channel's biophysical properties. Thus RACK1 binds to the BKCa channel and it may form part of a BKCa-channel regulatory complex in vascular smooth muscle.
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Affiliation(s)
- Christina Kaldany Isacson
- Molecular Cardiology Research Institute, Tufts-New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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