ArticleThe Journal of general physiology2005
Long polyamines act as cofactors in PIP2 activation of inward rectifier potassium (Kir2.1) channels.
Article in The Journal of general physiology, 2005. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers.
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Who cites it
17 citing papers in PubMed, 38 citations in OpenAlex.
- A critical residue mediates proper assembly and gating of GIRK2 channels.The Journal of general physiology · 2026Article
- Molecular stratification of arrhythmogenic mechanisms in the Andersen Tawil syndrome.Cardiovascular research · 2023Article
- Simulating PIPFrontiers in molecular biosciences · 2021Article
- Modulation of Actin Filament Dynamics by Inward Rectifying of Potassium Channel Kir2.1.International journal of molecular sciences · 2020Article
- Modulation of Ion Transport Across Plant Membranes by Polyamines: Understanding Specific Modes of Action Under Stress.Frontiers in plant science · 2020Article
- Lipid signaling to membrane proteins: From second messengers to membrane domains and adapter-free endocytosis.The Journal of general physiology · 2018Review
- Inward rectifying potassium currents resolved into components: modeling of complex drug actions.Pflugers Archiv : European journal of physiology · 2018Article
- β3 integrin expression is required for invadopodia-mediated ECM degradation in lung carcinoma cells.PloS one · 2017Article
- Activation of the CaPflugers Archiv : European journal of physiology · 2016Article
- Polyamines control of cation transport across plant membranes: implications for ion homeostasis and abiotic stress signaling.Frontiers in plant science · 2014Review
- Revisiting inward rectification: K ions permeate through Kir2.1 channels during high-affinity block by spermidine.The Journal of general physiology · 2012Article
- Polyamines interact with hydroxyl radicals in activating Ca(2+) and K(+) transport across the root epidermal plasma membranes.Plant physiology · 2011Article
- Phosphatidylinositol 4,5-bisphosphate activates Slo3 currents and its hydrolysis underlies the epidermal growth factor-induced current inhibition.The Journal of biological chemistry · 2010Article
- Phosphatidylinositol-4,5-bisphosphate (PIP2) regulation of strong inward rectifier Kir2.1 channels: multilevel positive cooperativity.The Journal of physiology · 2008Article
- Low-affinity spermine block mediating outward currents through Kir2.1 and Kir2.2 inward rectifier potassium channels.The Journal of physiology · 2007Article
- Inhibition of cardiomyocyte automaticity by electrotonic application of inward rectifier current from Kir2.1 expressing cells.Medical & biological engineering & computing · 2006Article
- Topographical heterogeneity of K(IR) currents in pericyte-containing microvessels of the rat retina: effect of diabetes.The Journal of physiology · 2006Article
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Authors and funding
4 authors at 1 institution in 1 country.
Funding
Abstract
Phosphatidylinosital-4,5-bisphosphate (PIP2) acts as an essential factor regulating the activity of all Kir channels. In most Kir members, the dependence on PIP2 is modulated by other factors, such as protein kinases (in Kir1), G(betagamma) (in Kir3), and the sulfonylurea receptor (in Kir6). So far, however, no regulator has been identified in Kir2 channels. Here we show that polyamines, which cause inward rectification by selectively blocking outward current, also regulate the interaction of PIP2 with Kir2.1 channels to maintain channel availability. Using spermine and diamines as polyamine analogs, we demonstrate that both spontaneous and PIP2 antibody-induced rundown of Kir2.1 channels in excised inside-out patches was markedly slowed by long polyamines; in contrast, polyamines with shorter chain length were ineffective. In K188Q mutant channels, which have a low PIP2 affinity, application PIP2 (10 microM) was unable to activate channel activity in the absence of polyamines, but markedly activated channels in the presence of long diamines. Using neomycin as a measure of PIP2 affinity, we found that long polyamines were capable of strengthening either the wild type or K188Q channels' interaction with PIP2. The negatively charged D172 residue inside the transmembrane pore region was critical for the shift of channel-PIP2 binding affinity by long polyamines. Sustained pore block by polyamines was neither sufficient nor necessary for this effect. We conclude that long polyamines serve a dual role as both blockers and coactivators (with PIP2) of Kir2.1 channels.
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