Molecular Mechanism of Gating in Cyclic Nucleotide-gated Ion Channels |
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| Launch in standalone player | |
| Air date: | Monday, January 28, 2008, 12:00:00 PM |
| Category: | Neuroscience |
| 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 |
| Author: | William N. Zagotta, Ph.D., University of Washington |
| Runtime: | 75 minutes |
| Download: | Download
Video How to download a Videocast |
| CIT File ID: | 14264 |
| CIT Live ID: | 6176 |
| Permanent link: | http://videocast.nih.gov/launch.asp?14264 |
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Enhanced Audio Podcast | 1:01:42 |
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Enhanced Video Podcast | 1:01:42 | |