The small neurotoxin apamin blocks not only small conductance Ca2+ activated K+ channels (SK type) but also the voltage dependent Kv1.3 channel

Voos, Patrick; Yazar, Mehtap; Lautenschläger, René; Rauh, Oliver; Moroni, Anna; Thiel, Gerhard

doi:10.1007/s00249-016-1196-0

Cited by 17 publications

(13 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although apamin has long been used to study K Ca 2 channels, a recent study has demonstrated that it also blocksK v 1.3 channels (22). As K v 1 channels are present on the AIS, we wanted to ensure that the unbinding forces that we detected were indeed between apamin and K Ca 2 channels.…”

Section: Resultsmentioning

confidence: 99%

K _Ca 2 channel localization and regulation in the axon initial segment

Abiraman¹,

Tzingounis²,

Lykotrafitis³

2018

FASEB j.

View full text Add to dashboard Cite

Small conductance calcium-activated potassium (K2) channels are expressed throughout the CNS and play a critical role in synaptic and neuronal excitability. K2 channels have a somatodendritic distribution with their highest expression in distal dendrites. It is unclear whether K2 channels are specifically present on the axon initial segment (AIS), the site at which action potentials are initiated in neurons. Through a powerful combination of toxin pharmacology, single-molecule atomic force microscopy, and dual-color fluorescence microscopy, we report here that K2 channels-predominantly the K2.3 subtype-are indeed present on the AIS. We also report that cAMP-PKA controls the axonal K2 channel surface expression. Surprisingly, and in contrast to K2 channels that were observed in the soma and dendrites, the inhibition of cAMP-PKA increased the surface expression of K2 channels without promoting nanoclustering. Lastly, we found that axonal K2 channels seem to undergo endocytosis in a dynamin-independent manner, unlike K2 channels in the soma and dendrites. Together, these novel results demonstrate that the distribution and membrane recycling of K2 channels differs among various neuronal subcompartments.-Abiraman, K., Tzingounis, A. V., Lykotrafitis, G. K2 channel localization and regulation in the axon initial segment.

show abstract

Section: Resultsmentioning

confidence: 99%

K _Ca 2 channel localization and regulation in the axon initial segment

Abiraman¹,

Tzingounis²,

Lykotrafitis³

2018

FASEB j.

View full text Add to dashboard Cite

show abstract

“…Apamin, a highly selective SK channel blocker, does not affect human cardiac Na + , l -type Ca 2+ , or major K + currents 20 . The family of SK channels consists of three members that exhibit differential sensitivity to apamin: SK1 (also known as K Ca 2.1, encoded by the KCNN1 gene), which has the least sensitivity (EC 50 for hSK 1–10 nM), SK2 (also known as K Ca 2.2, encoded by the KCNN2 gene), which has the highest sensitivity (EC 50 ~40 pM), and SK3 (also known as K Ca 2.3, encoded by the KCNN3 gene), which has intermediate sensitivity (EC 50 ~1 nM) (Table 1 ).…”

Section: Structure and Function Of Sk Channels In The Heartmentioning

confidence: 97%

Small-conductance Ca2+-activated K+ channels: insights into their roles in cardiovascular disease

Zhu

Xi³

et al. 2018

Exp Mol Med

View full text Add to dashboard Cite

Life-threatening malignant arrhythmias in pathophysiological conditions can increase the mortality and morbidity of patients with cardiovascular diseases. Cardiac electrical activity depends on the coordinated propagation of excitatory stimuli and the generation of action potentials in cardiomyocytes. Action potential formation results from the opening and closing of ion channels. Recent studies have indicated that small-conductance calcium-activated potassium (SK) channels play a critical role in cardiac repolarization in pathophysiological but not normal physiological conditions. The aim of this review is to describe the role of SK channels in healthy and diseased hearts, to suggest cardiovascular pathophysiologic targets for intervention, and to discuss studies of agents that target SK channels for the treatment of cardiovascular diseases.

show abstract

“…This peptide is a specific inhibitor of small-conductance Ca 2+ -activated K + (SK) channels in the central nervous system ( 13 , 15 ) and activates the M 2 inhibitory muscarinic receptors of the peripheral nervous system ( 10 , 14 , 15 ). Another activity is blockage of the Kv1.3 channel, a potassium channel type found in immune cells ( 24 ). Pharmacologically, apamin has antibacterial, antifungal, anti-inflammatory, anti-atherosclerotic, and antitumoral effects ( 13 ) and has been tested for treating neurological disturbances, including Parkinson's disease and learning deficit disorder ( 15 ).…”

Section: The Honeybee Venommentioning

confidence: 99%

Toxicological Risk Assessment of the Accidental Ingestion of a Honeybee (Apis mellifera L.) Present in Food

Marinho

Soto-Blanco

2020

Front. Vet. Sci.

View full text Add to dashboard Cite

The aim of the present work was to evaluate the possible risk of toxic effects due to the ingestion of a honeybee ( Apis mellifera L.) accidentally present in food. The methodology used in this study was a bibliographic survey of studies on the toxic effects related to honeybees, with a critical analysis of the possible risks of accidental ingestion of these insects. The amount of venom present in a bee is considered insufficient to induce detectable toxic effects in a person who ingests it by accident, and various components of the venom are destroyed by gastric secretions. However, despite the rare frequency, there is a risk of the ingestion of a bee, causing an allergic reaction to some components of the venom in sensitized individuals. In addition, pollen carried by a bee may cause an allergic reaction in a sensitive individual. Thus, the accidental ingestion of a bee present in a food does not pose the risk of toxic effects for the majority of the population but may promote allergic reactions in susceptible individuals.

show abstract

The small neurotoxin apamin blocks not only small conductance Ca2+ activated K+ channels (SK type) but also the voltage dependent Kv1.3 channel

Cited by 17 publications

References 24 publications

K _Ca 2 channel localization and regulation in the axon initial segment

K _Ca 2 channel localization and regulation in the axon initial segment

Small-conductance Ca2+-activated K+ channels: insights into their roles in cardiovascular disease

Toxicological Risk Assessment of the Accidental Ingestion of a Honeybee (Apis mellifera L.) Present in Food

Contact Info

Product

Resources

About

The small neurotoxin apamin blocks not only small conductance Ca2+ activated K+ channels (SK type) but also the voltage dependent Kv1.3 channel

Cited by 17 publications

References 24 publications

K Ca 2 channel localization and regulation in the axon initial segment

K Ca 2 channel localization and regulation in the axon initial segment

Small-conductance Ca2+-activated K+ channels: insights into their roles in cardiovascular disease

Toxicological Risk Assessment of the Accidental Ingestion of a Honeybee (Apis mellifera L.) Present in Food

Contact Info

Product

Resources

About

K _Ca 2 channel localization and regulation in the axon initial segment

K _Ca 2 channel localization and regulation in the axon initial segment