NIH VideoCast - Molecular Mechanism of Gating in Cyclic Nucleotide-gated Ion Channels

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Molecular Mechanism of Gating in Cyclic Nucleotide-gated Ion Channels

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Air date:	Monday, January 28, 2008, 12:00:00 PM Time displayed is Eastern Time, Washington DC Local
Views:	Total views: 137 * This only includes stats from October 2011 and forward.
Category:	Neuroscience
Runtime:	01:01:42
Closed captioning:	Check box to display CC outside of the video Note: You can drag the captioning window around and resize it
Description:	Cyclic nucleotide-regulated channels, such as CNG channels and HCN channels, underlie the primary electrical signals in phototransduction and olfactory transduction and control the repetitive firing activity of cardiac and neuronal cells. Activation of these channels involves the direct binding of cyclic nucleotide to an intracellular domain of the channel. Dr. Zagotta's lab has been interested in understanding the molecular mechanism for this allostery. To do this, they have employed a number of fluorescence approaches combined with patch-clamp fluorometry, a technique for simultaneously recording electrical current and fluorescence from excised inside-out patches. They explored the structure and conformational rearrangements of the C-terminal gating ring of the cyclic nucleotide-gated channel CNGA1 during activation by cyclic nucleotides. By monitoring fluorescent resonance energy transfer (FRET) between membrane-resident quenchers and fluorophores attached to the channel, Dr. Zagotta's lab detected no movement orthogonal to the membrane during channel activation. By monitoring FRET between fluorophores within the C-terminal region, they determined that the C-terminal end of the C-linker and the end of the C-helix move apart when channels open. They conclude that during channel activation, a portion of the gating ring moves parallel to the plasma membrane, hinging toward the central axis of the channel. NIH Neuroscience Seminar Series

NLM Title:	Molecular mechanism of gating in cyclic nucleotide-gated ion channels / William N. Zagotta.
Author:	Zagotta, William N. National Institutes of Health (U.S.)
Publisher:
Abstract:	(CIT): Cyclic nucleotide-regulated channels, such as CNG channels and HCN channels, underlie the primary electrical signals in phototransduction and olfactory transduction and control the repetitive firing activity of cardiac and neuronal cells. Activation of these channels involves the direct binding of cyclic nucleotide to an intracellular domain of the channel. Dr. Zagotta's lab has been interested in understanding the molecular mechanism for this allostery. To do this, they have employed a number of fluorescence approaches combined with patch-clamp fluorometry, a technique for simultaneously recording electrical current and fluorescence from excised inside-out patches. They explored the structure and conformational rearrangements of the C-terminal gating ring of the cyclic nucleotide-gated channel CNGA1 during activation by cyclic nucleotides. By monitoring fluorescent resonance energy transfer (FRET) between membrane-resident quenchers and fluorophores attached to the channel, Dr. Zagotta's lab detected no movement orthogonal to the membrane during channel activation. By monitoring FRET between fluorophores within the C-terminal region, they determined that the C-terminal end of the C-linker and the end of the C-helix move apart when channels open. They conclude that during channel activation, a portion of the gating ring moves parallel to the plasma membrane, hinging toward the central axis of the channel. NIH Neuroscience Seminar Series.
Subjects:	Ion Channel Gating--genetics Nucleotides, Cyclic--genetics
Publication Types:	Lecture Webcast
NLM Classification:	QU 57
NLM ID:	101465448
CIT Live ID:	6176
Permanent link:	https://videocast.nih.gov/watch=6176

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