scholarly journals Structures and gating mechanism of human TRPM2

Science ◽  
2018 ◽  
Vol 362 (6421) ◽  
pp. eaav4809 ◽  
Author(s):  
Longfei Wang ◽  
Tian-Min Fu ◽  
Yiming Zhou ◽  
Shiyu Xia ◽  
Anna Greka ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Adenosine Diphosphate ◽  
Transmembrane Helices ◽  
Gating Mechanism ◽  
Channel Opening ◽  
Transient Receptor ◽  
Intersubunit Interactions

Transient receptor potential (TRP) melastatin 2 (TRPM2) is a cation channel associated with numerous diseases. It has a C-terminal NUDT9 homology (NUDT9H) domain responsible for binding adenosine diphosphate (ADP)–ribose (ADPR), and both ADPR and calcium (Ca2+) are required for TRPM2 activation. Here we report cryo–electron microscopy structures of human TRPM2 alone, with ADPR, and with ADPR and Ca2+. NUDT9H forms both intra- and intersubunit interactions with the N-terminal TRPM homology region (MHR1/2/3) in the apo state but undergoes conformational changes upon ADPR binding, resulting in rotation of MHR1/2 and disruption of the intersubunit interaction. The binding of Ca2+ further engages transmembrane helices and the conserved TRP helix to cause conformational changes at the MHR arm and the lower gating pore to potentiate channel opening. These findings explain the molecular mechanism of concerted TRPM2 gating by ADPR and Ca2+ and provide insights into the gating mechanism of other TRP channels.

scholarly journals Structure of the human TRPM4 ion channel in a lipid nanodisc

Science ◽  
2017 ◽  
Vol 359 (6372) ◽  
pp. 228-232 ◽  
Author(s):  
Henriette E. Autzen ◽  
Alexander G. Myasnikov ◽  
Melody G. Campbell ◽  
Daniel Asarnow ◽  
David Julius ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Calcium Binding ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Dependent Manner ◽  
Calcium Binding Site ◽  
Voltage Dependent ◽  
Transient Receptor ◽  
Lipid Nanodiscs

Transient receptor potential (TRP) melastatin 4 (TRPM4) is a widely expressed cation channel associated with a variety of cardiovascular disorders. TRPM4 is activated by increased intracellular calcium in a voltage-dependent manner but, unlike many other TRP channels, is permeable to monovalent cations only. Here we present two structures of full-length human TRPM4 embedded in lipid nanodiscs at ~3-angstrom resolution, as determined by single-particle cryo–electron microscopy. These structures, with and without calcium bound, reveal a general architecture for this major subfamily of TRP channels and a well-defined calcium-binding site within the intracellular side of the S1-S4 domain. The structures correspond to two distinct closed states. Calcium binding induces conformational changes that likely prime the channel for voltage-dependent opening.

scholarly journals Structural insights into TRPM8 inhibition and desensitization

Science ◽  
2019 ◽  
Vol 365 (6460) ◽  
pp. 1434-1440 ◽  
Author(s):  
Melinda M. Diver ◽  
Yifan Cheng ◽  
David Julius
Keyword(s):  
Conformational Changes ◽  
Calcium Binding ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Binding Pocket ◽  
Chemical Structures ◽  
Transient Receptor Potential Melastatin ◽  
Transient Receptor ◽  
Large Rearrangements

The transient receptor potential melastatin 8 (TRPM8) ion channel is the primary detector of environmental cold and an important target for treating pathological cold hypersensitivity. Here, we present cryo–electron microscopy structures of TRPM8 in ligand-free, antagonist-bound, or calcium-bound forms, revealing how robust conformational changes give rise to two nonconducting states, closed and desensitized. We describe a malleable ligand-binding pocket that accommodates drugs of diverse chemical structures, and we delineate the ion permeation pathway, including the contribution of lipids to pore architecture. Furthermore, we show that direct calcium binding mediates stimulus-evoked desensitization, clarifying this important mechanism of sensory adaptation. We observe large rearrangements within the S4-S5 linker that reposition the S1-S4 and pore domains relative to the TRP helix, leading us to propose a distinct model for modulation of TRPM8 and possibly other TRP channels.

scholarly journals The push-to-open mechanism of the tethered mechanosensitive ion channel NompC

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Yang Wang ◽  
Yifeng Guo ◽  
Guanluan Li ◽  
Chunhong Liu ◽  
Lei Wang ◽  
...  
Keyword(s):  
Ion Channel ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Ankyrin Repeat ◽  
Gating Mechanism ◽  
Repeat Domain ◽  
Mechanosensitive Ion Channel ◽  
Transient Receptor ◽  
Dynamics Simulations

NompC is a mechanosensitive ion channel responsible for the sensation of touch and balance in Drosophila melanogaster. Based on a resolved cryo-EM structure, we performed all-atom molecular dynamics simulations and electrophysiological experiments to study the atomistic details of NompC gating. Our results showed that NompC could be opened by compression of the intracellular ankyrin repeat domain but not by a stretch, and a number of hydrogen bonds along the force convey pathway are important for the mechanosensitivity. Under intracellular compression, the bundled ankyrin repeat region acts like a spring with a spring constant of ~13 pN nm−1 by transferring forces at a rate of ~1.8 nm ps−1. The linker helix region acts as a bridge between the ankyrin repeats and the transient receptor potential (TRP) domain, which passes on the pushing force to the TRP domain to undergo a clockwise rotation, resulting in the opening of the channel. This could be the universal gating mechanism of similar tethered mechanosensitive TRP channels, which enable cells to feel compression and shrinkage.

scholarly journals Structure–function analyses of the ion channel TRPC3 reveal that its cytoplasmic domain allosterically modulates channel gating

2018 ◽  
Vol 293 (41) ◽  
pp. 16102-16114 ◽  
Author(s):  
Francisco Sierra-Valdez ◽  
Caleigh M. Azumaya ◽  
Luis O. Romero ◽  
Terunaga Nakagawa ◽  
Julio F. Cordero-Morales
Keyword(s):  
Conformational Changes ◽  
Transient Receptor Potential ◽  
Transmembrane Domain ◽  
Trp Channels ◽  
Channel Gating ◽  
Memory Loss ◽  
Receptor Potential ◽  
Cytoplasmic Domain ◽  
Terminal Loop ◽  
Transient Receptor

The transient receptor potential ion channels support Ca2+ permeation in many organs, including the heart, brain, and kidney. Genetic mutations in transient receptor potential cation channel subfamily C member 3 (TRPC3) are associated with neurodegenerative diseases, memory loss, and hypertension. To better understand the conformational changes that regulate TRPC3 function, we solved the cryo-EM structures for the full-length human TRPC3 and its cytoplasmic domain (CPD) in the apo state at 5.8- and 4.0-Å resolution, respectively. These structures revealed that the TRPC3 transmembrane domain resembles those of other TRP channels and that the CPD is a stable module involved in channel assembly and gating. We observed the presence of a C-terminal domain swap at the center of the CPD where horizontal helices (HHs) transition into a coiled-coil bundle. Comparison of TRPC3 structures revealed that the HHs can reside in two distinct positions. Electrophysiological analyses disclosed that shortening the length of the C-terminal loop connecting the HH with the TRP helices increases TRPC3 activity and that elongating the length of the loop has the opposite effect. Our findings indicate that the C-terminal loop affects channel gating by altering the allosteric coupling between the cytoplasmic and transmembrane domains. We propose that molecules that target the HH may represent a promising strategy for controlling TRPC3-associated neurological disorders and hypertension.

scholarly journals Extracellular cap domain is an essential component of the TRPV1 gating mechanism

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kirill D. Nadezhdin ◽  
Arthur Neuberger ◽  
Yury A. Nikolaev ◽  
Lyle A. Murphy ◽  
Elena O. Gracheva ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Trp Channels ◽  
Ion Selectivity ◽  
Receptor Potential ◽  
Open Probability ◽  
Ion Conductance ◽  
Molecular Sensors ◽  
Gating Mechanism ◽  
C Terminus ◽  
Transient Receptor

AbstractTransient receptor potential (TRP) channels are polymodal molecular sensors involved in numerous physiological processes and implicated in a variety of human diseases. Several structures of the founding member of the TRP channel family, TRPV1, are available, all of which were determined for the protein missing the N- and C-termini and the extracellular S5-P-loop. Here, we present structures of the full-length thirteen-lined ground squirrel TRPV1 solved by cryo-EM. Our structures resolve the extracellular cap domain formed by the S5-P-loops and the C-terminus that wraps around the three-stranded β-sheet connecting elements of the TRPV1 intracellular skirt. The cap domain forms a dome above the pore’s extracellular entrance, with four portals leading to the ion conductance pathway. Deletion of the cap increases the TRPV1 average conductance, reduces the open probability and affects ion selectivity. Our data show that both the termini and the cap domain are critical determinants of TRPV1 function.

Intragastric administration of capsiate, a transient receptor potential channel agonist, triggers thermogenic sympathetic responses

2011 ◽  
Vol 110 (3) ◽  
pp. 789-798 ◽  
Author(s):  
Kaori Ono ◽  
Masako Tsukamoto-Yasui ◽  
Yoshiko Hara-Kimura ◽  
Naohiko Inoue ◽  
Yoshihito Nogusa ◽  
...  
Keyword(s):  
Sympathetic Nerve ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Low Frequency ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Intragastric Administration ◽  
Brown Adipose ◽  
Reflex Arc ◽  
Transient Receptor

The sympathetic thermoregulatory system controls the magnitude of adaptive thermogenesis in correspondence with the environmental temperature or the state of energy intake and plays a key role in determining the resultant energy storage. However, the nature of the trigger initiating this reflex arc remains to be determined. Here, using capsiate, a digestion-vulnerable capsaicin analog, we examined the involvement of specific activation of transient receptor potential (TRP) channels within the gastrointestinal tract in the thermogenic sympathetic system by measuring the efferent activity of the postganglionic sympathetic nerve innervating brown adipose tissue (BAT) in anesthetized rats. Intragastric administration of capsiate resulted in a time- and dose-dependent increase in integrated BAT sympathetic nerve activity (SNA) over 180 min, which was characterized by an emergence of sporadic high-activity phases composed of low-frequency bursts. This increase in BAT SNA was abolished by blockade of TRP channels as well as of sympathetic ganglionic transmission and was inhibited by ablation of the gastrointestinal vagus nerve. The activation of SNA was delimited to BAT and did not occur in the heart or pancreas. These results point to a neural pathway enabling the selective activation of the central network regulating the BAT SNA in response to a specific stimulation of gastrointestinal TRP channels and offer important implications for understanding the dietary-dependent regulation of energy metabolism and control of obesity.

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