To solve the first structures of TRPV3, we used cryo-electron microscopy. We imaged mouse TRPV3 both in the presence and absence of 2-APB, a small activating molecule with anti-cancer properties, and were able to capture 3D structures of both open and closed states of TRPV3.

We determined the structures of calcium-permeable GluA2 AMPA receptor complexes with the auxiliary subunit stargazin bound to channel blockers, including the orb weaver spider toxin AgTx-636, the spider toxin analog NASPM, and the adamantane derivative IEM-1460. Our structures provide insights into the architecture of the blocker binding site and the mechanism of trapping block.

We determined the structures of human and rat TRPV6 in complex with Calmodulin (CaM) using cryo-electron microscopy (cryo-EM). The TRPV6-CaM complexes exhibit 1:1 stoichiometry; one TRPV6 tetramer binds both CaM lobes, which adopt a distinct head-to-tail arrangement.

Using a combination of X-ray crystallography, cryo-electron microscopy, and functional recordings of calcium flux through TRPV6 and other TRPV ion channels, we have identified a new ligand binding site by which these ion channels can be regulated.

Transient receptor potential (TRP) ion channels are molecular sensors of a large variety of stimuli including temperature, mechanical stress, voltage, small molecules including capsaicin and menthol, and lipids such as phosphatidylinositol 4,5-bisphosphate (PIP2). Since the same TRP channels may respond to different physical and chemical stimuli, they can serve as signal integrators.

At low Ca²⁺ concentrations, only a single calcium ion binds at the narrow constriction of the TRPV6 selectivity filter formed by aspartates D541 and allows Na⁺ permeation. During ion permeation, no water crosses the channel pore narrow constriction. At high Ca²⁺ concentrations, calcium permeates the pore according to the knock-off mechanism that includes formation of a short-lived transition state with three calcium ions bound near D541.

At pH 7.4 or higher, LIN activated a sustained, proton-independent, current through rat and human ASIC3 channels, but not rat ASIC1a or ASIC2a channels. LIN also potentiated proton-induced transient currents and promoted recovery from desensitization in human, but not rat, ASIC3 channels.

Here we present cryo-electron microscopy structures of human TRPV6 in the open and closed states. The channel selectivity filter adopts similar conformations in both states, consistent with its explicit role in ion permeation. The iris-like channel opening is accompanied by an α-to-π-helical transition in the pore-lining transmembrane helix S6 at an alanine hinge just below the selectivity filter.

Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that mediate the majority of excitatory neurotransmission in the central nervous system. iGluRs open their ion channels in response to binding of the neurotransmitter glutamate, rapidly depolarize the postsynaptic neuronal membrane, and initiate signal transduction.

Here we show that mutations in the transmembrane domain of TRPV6 can result in conversion from a domain-swapped to non-swapped fold. These results reveal structural determinants of domain swapping and raise the possibility that a single ion channel subtype can fold into either arrangement in vivo, affecting its function in normal or disease states.

Here we use cryo-electron microscopy to solve the structures of AMPA receptor–auxiliary subunit complexes in the apo, antagonist- and agonist-bound states and determine the iris-like mechanism of ion channel opening.

The concept of signal transduction is now long established as a central tenet of biological sciences. Since the inception of the field close to 50 years ago, the number and variety of signal transduction pathways, cascades, and networks have steadily increased and now constitute what is often regarded as a bewildering array of mechanisms by which cells sense and respond to extracellular and intracellular environmental stimuli.

Here, we report cryo-EM structures of an AMPAR in complex with the auxiliary subunit GSG1L in the closed and desensitized states. GSG1L favors the AMPAR desensitized state, where channel closure is facilitated by profound structural rearrangements in the AMPAR extracellular domain, with ligand-binding domain dimers losing their local 2-fold rotational symmetry.

We used site-directed mutagenesis and patch-clamp recordings to probe the ion channel extracellular collar, the binding region for noncompetitive allosteric inhibitors. We found position and substitution-dependent effects for introduced mutations at this region on AMPA receptor gating.

Here, we report crystal structures of the rat AMPA-subtype GluA2 receptor in complex with three noncompetitive inhibitors. The inhibitors bind to a novel binding site, completely conserved between rat and human, at the interface between the ion channel and linkers connecting it to the ligand-binding domains. We propose that the inhibitors stabilize the AMPA receptor closed state.

Here, we used cryo-electron microscopy to elucidate the structural basis of AMPAR regulation by one of these auxiliary proteins, TARP γ2, or stargazin (STZ). Our structures illuminate the variable interaction stoichiometry of the AMPAR-TARP complex, with one or two TARP molecules binding one tetrameric AMPAR.

Here we report the crystal structure of rat TRPV6 at 3.25 Å resolution. The overall architecture of TRPV6 reveals shared and unique features compared with other TRP channels.

The functional consequence of intersubunit crosslinks was assessed by recording GluA2-mediated currents in reducing and non-reducing conditions.

Despite physiological and pathophysiological importance, obtaining structural information about full-length iGluRs has proven to be a difficult task. To facilitate further structural/functional studies, we describe a detailed protocol of the full-length iGluR expression, purification, and crystallization.

Here, we report a structure of a homotetrameric rat GluA2 receptor in complex with partial agonist (S)-5-nitrowillardiine. Comparison of this structure with the closed-state structure in complex with competitive antagonist ZK 200775 suggests conformational changes that occur during iGluR gating.

This article reviews the recent structural and functional advances in the iGluR field and summarizes them in a simplified model of full-length iGluR gating.

Based in the Department of Biochemistry and Molecular Biophysics at Columbia University Medical Center, we study ion channel signaling using cryo-electron microscopy, X-ray crystallography, electrophysiology and biophysical techniques.