Use of optical biosensors to detect modulation of Slack potassium channels by G protein-coupled receptors

Fleming, Matthew R; Kaczmarek, Leonard K.

doi:10.1080/10799890903056883

Cited by 18 publications

(14 citation statements)

References 36 publications

(51 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The characteristic change in mass that normally follows activation of native receptors in HEK-293 cells is significantly modified in amplitude and timing by the coexpression of Slack channels, further supporting the finding of modulation of K Na current by these receptors [61]. …”

Section: Cellular Regulation Of Kna Channelssupporting

confidence: 56%

Slack, Slick, and Sodium-Activated Potassium Channels

2013

Self Cite

View full text Add to dashboard Cite

The Slack and Slick genes encode potassium channels that are very widely expressed in the central nervous system. These channels are activated by elevations in intracellular sodium, such as those that occur during trains of one or more action potentials, or following activation of nonselective cationic neurotransmitter receptors such as AMPA receptors. This review covers the cellular and molecular properties of Slack and Slick channels and compares them with findings on the properties of sodium-activated potassium currents (termed KNa currents) in native neurons. Human mutations in Slack channels produce extremely severe defects in learning and development, suggesting that KNa channels play a central role in neuronal plasticity and intellectual function.

show abstract

Section: Cellular Regulation Of Kna Channelssupporting

confidence: 56%

Slack, Slick, and Sodium-Activated Potassium Channels

2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…This technique uses evanescent waves and resonant waveguide grating (RWG) optical biosensors to monitor changes in mass within the first ~150 nm of the membrane surface in adherent cells (Cunningham et al, 2004) (Fig.S1C). RWG optical biosensors detect changes in the index of refraction resulting from a change in mass, such as the loss of membrane-associated actin filaments, within the detection zone of the biosensor (Fleming and Kaczmarek, 2009). …”

Section: Resultsmentioning

confidence: 99%

“…Cells were plated on poly-l-lysine/laminin coated TiO 2 384-well BIND biosensor plates, which were then transferred to an X-BODY Biosciences BIND Scanner for analysis (Fleming and Kaczmarek, 2009). …”

Section: Methodsmentioning

confidence: 99%

Kv3.3 Channels Bind Hax-1 and Arp2/3 to Assemble a Stable Local Actin Network that Regulates Channel Gating

Zhang

Fleming

et al. 2016

Cell

105

View full text Add to dashboard Cite

Mutations in the Kv3.3 potassium channel (KCNC3) cause cerebellar neurodegeneration and impair auditory processing. The cytoplasmic C-terminus of Kv3.3 contains a proline-rich domain conserved in proteins that activate actin nucleation through Arp2/3. We found that Kv3.3 recruits Arp2/3 to the plasma membrane, resulting in formation of a relatively stable cortical actin filament network resistant to cytochalasin D which inhibits fast barbed end actin assembly. These Kv3.3-associated actin structures are required to prevent very rapid N-type channel inactivation during short depolarizations of the plasma membrane. The effects of Kv3.3 on the actin cytoskeleton are mediated by the binding of the cytoplasmic C-terminus of Kv3.3 to Hax-1, an anti-apoptotic protein that regulates actin nucleation through Arp2/3. A human Kv3.3 mutation within a conserved proline-rich domain produces channels that bind Hax-1 but are impaired in recruiting Arp2/3 to the plasma membrane, resulting in growth cones with deficient actin veils in stem cell-derived neurons.

show abstract

“…To monitor the interactions of Slack channels with its potential cytoplasmic partners in real-time within living cells, we used resonance-wavelength grating (RWG) optical biosensors, a technique that has been used to monitor the activation of G-protein coupled receptors (Fang et al, 2007; Fleming and Kaczmarek, 2009; Lee, 2009). When cells adhere to these optical biosensors, changes in mass within ~150 nm of the biosensor alter the peak intensity of the reflected wavelengths of resonant light.…”

Section: Resultsmentioning

confidence: 99%

Stimulation of Slack K+ Channels Alters Mass at the Plasma Membrane by Triggering Dissociation of a Phosphatase-Regulatory Complex

et al. 2016

View full text Add to dashboard Cite

Summary Human mutations in the cytoplasmic C-terminal domain of Slack sodium-activated potassium (KNa) channels result in childhood epilepsy with severe intellectual disability. Slack currents can be increased by pharmacological activators or by phosphorylation of a Slack C-terminal residue by protein kinase C. Using an optical biosensor assay, we find that Slack channel stimulation in neurons or transfected cells produces loss of mass near the plasma membrane. Slack mutants associated with intellectual disability fail to trigger any change in mass. The loss of mass results from the dissociation of the protein phosphatase 1 (PP1) targeting protein, Phactr-1, from the channel. Phactr1 dissociation is specific to wild-type Slack channels and is not observed when related potassium channels are stimulated. Our findings suggest that Slack channels are coupled to cytoplasmic signaling pathways, and that dysregulation of this coupling may trigger the aberrant intellectual development associated with specific childhood epilepsies.

show abstract

Use of optical biosensors to detect modulation of Slack potassium channels by G protein-coupled receptors

Cited by 18 publications

References 36 publications

Slack, Slick, and Sodium-Activated Potassium Channels

Slack, Slick, and Sodium-Activated Potassium Channels

Kv3.3 Channels Bind Hax-1 and Arp2/3 to Assemble a Stable Local Actin Network that Regulates Channel Gating

Stimulation of Slack K+ Channels Alters Mass at the Plasma Membrane by Triggering Dissociation of a Phosphatase-Regulatory Complex

Contact Info

Product

Resources

About