BK Channels and the Control of the Pituitary

Duncan, Peter J.; Shipston, Michael J.

doi:10.1016/bs.irn.2016.03.004

Cited by 12 publications

(8 citation statements)

References 80 publications

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“…BK channels, encoded by a single KCa1.1 gene (also called Kcnma1 or Slo1 ), are also expressed in an unusually broad range of cell types, including both excitable and inexcitable cells (1–3). In fact, it is possible that, among cation channels, KCa1.1 -encoded BK channels are found in a larger range of cell types than any other plasma membrane ion channel, including neurons with a variety of diverse firing behaviors (4–6), neuroendocrine cells (7, 8), glia cells (9), skeletal muscle cells (10), smooth muscle cells (SMCs) of all types (11–13), principal cells (PCs), and intercalated cells (ICs) in collecting ducts of the kidney (14–16), and a variety of epithelial cells (17–20). There is also a growing literature on BK channels in membranes of intracellular organelles, including nuclei (21), mitochondria (22), and lysosomes (23).…”

Section: Introductionmentioning

confidence: 99%

Regulation of BK Channels by Beta and Gamma Subunits

González-Pérez

Lingle

2019

Annu. Rev. Physiol.

104

110

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Ca2+- and voltage-gated K+ channels of large conductance (BK channels) are expressed in a diverse variety of both excitable and inexcitable cells, with functional properties presumably uniquely calibrated for the cells in which they are found. Although some diversity in BK channel function, localization, and regulation apparently arises from cell-specific alternative splice variants of the single pore–forming α subunit (KCa1.1, Kcnma1, Slo1) gene, two families of regulatory subunits, β and γ, define BK channels that span a diverse range of functional properties. We are just beginning to unravel the cell-specific, physiological roles served by BK channels of different subunit composition.

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Section: Introductionmentioning

confidence: 99%

Regulation of BK Channels by Beta and Gamma Subunits

González-Pérez

Lingle

2019

Annu. Rev. Physiol.

104

110

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“…However, in some pituitary cell types, these channels paradoxically cause bursting activity [9]. We and others have shown, both experimentally with dynamic clamp and from mathematical modelling, that gradually increasing the total BK channel conductance in such cells can cause a transition from spiking to bursting [16,17].…”

Section: Introductionmentioning

confidence: 93%

Ion channel noise shapes the electrical activity of endocrine cells

2020

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Endocrine cells in the pituitary gland typically display either spiking or bursting electrical activity, which is related to the level of hormone secretion. Recent work, which combines mathematical modelling with dynamic clamp experiments, suggests the difference is due to the presence or absence of a few large-conductance potassium channels. Since endocrine cells only contain a handful of these channels, it is likely that stochastic effects play an important role in the pattern of electrical activity. Here, for the first time, we explicitly determine the effect of such noise by studying a mathematical model that includes the realistic noisy opening and closing of ion channels. This allows us to investigate how noise affects the electrical activity, examine the origin of spiking and bursting, and determine which channel types are responsible for the greatest noise. Further, for the first time, we address the role of cell size in endocrine cell electrical activity, finding that larger cells typically display more bursting, while the smallest cells almost always only exhibit spiking behaviour.

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Section: Introductionmentioning

confidence: 99%

“…BK channels are ubiquitously expressed in many different tissues and are critical to numerous physiological processes, including regulation of vascular tone, neuronal excitability, synaptic transmission and hormone secretion (Burdyga & Wray, 2005;Wang, 2008;Sachse et al 2014;Duncan & Shipston, 2016;Whitt et al 2016). Allosteric activation of BK occurs in response to elevated intracellular [Ca 2+ ] as well as membrane depolarization, the only K + channel that possess both characteristics.…”

Section: Introductionmentioning

confidence: 99%

Large‐conductance Ca²⁺‐activated K⁺ channel activation by apical P2Y receptor agonists requires hydrocortisone in differentiated airway epithelium

Zaidman

Panoskaltsis‐Mortari

O’Grady

2017

The Journal of Physiology

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In the present study we investigated the role of hydrocortisone (HC) on uridine-5'-triphosphate (UTP)-stimulated ion transport in differentiated, pseudostratified epithelia derived from normal human bronchial basal cells. The presence of a UTP-stimulated, paxilline-sensitive large-conductance Ca -activated K (BK) current was demonstrated in control epithelia but was not stimulated in epithelia differentiated in the absence of HC (HC0). Addition of the BK channel opener NS11021 directly activated channels in control epithelia; however, under HC0 conditions, activation only occurred when UTP was added after NS11021. The PKC inhibitors GF109203x and Gö6983 blocked BK activation by UTP in control epithelia, suggesting that PKC-mediated phosphorylation plays a permissive role in purinoceptor-stimulated BK activation. Moreover, HC0 epithelia expressed significantly more KCNMA1 containing the stress-regulated exon (STREX), a splice-variant of the α-subunit that displays altered channel regulation by phosphorylation, compared to control epithelia. Furthermore, BK channels as well as purinergic receptors were shown to localize in unique and overlapping domains at the apical membrane of ciliated surface cells. These results establish a previously unrecognized role for glucocorticoids in regulation of BK channels in airway epithelial cells.

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BK Channels and the Control of the Pituitary

Cited by 12 publications

References 80 publications

Regulation of BK Channels by Beta and Gamma Subunits

Regulation of BK Channels by Beta and Gamma Subunits

Ion channel noise shapes the electrical activity of endocrine cells

Large‐conductance Ca²⁺‐activated K⁺ channel activation by apical P2Y receptor agonists requires hydrocortisone in differentiated airway epithelium

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BK Channels and the Control of the Pituitary

Cited by 12 publications

References 80 publications

Regulation of BK Channels by Beta and Gamma Subunits

Regulation of BK Channels by Beta and Gamma Subunits

Ion channel noise shapes the electrical activity of endocrine cells

Large‐conductance Ca2+‐activated K+ channel activation by apical P2Y receptor agonists requires hydrocortisone in differentiated airway epithelium

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Large‐conductance Ca²⁺‐activated K⁺ channel activation by apical P2Y receptor agonists requires hydrocortisone in differentiated airway epithelium