8gka
From Proteopedia
Human TRPV3 tetramer structure, closed conformation
Structural highlights
DiseaseTRPV3_HUMAN Mutilating palmoplantar keratoderma with periorificial keratotic plaques. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. FunctionTRPV3_HUMAN Putative receptor-activated non-selective calcium permeant cation channel. It is activated by innocuous (warm) temperatures and shows an increased response at noxious temperatures greater than 39 degrees Celsius. Activation exhibits an outward rectification. May associate with TRPV1 and may modulate its activity. Is a negative regulator of hair growth and cycling: TRPV3-coupled signaling suppresses keratinocyte proliferation in hair follicles and induces apoptosis and premature hair follicle regression (catagen).[1] [2] [3] Publication Abstract from PubMedTransient receptor potential (TRP) channels are a large, eukaryotic ion channel superfamily that control diverse physiological functions, and therefore are attractive drug targets(1-5). More than 210 structures from more than 20 different TRP channels have been determined, and all are tetramers(4). Despite this wealth of structures, many aspects concerning TRPV channels remain poorly understood, including the pore-dilation phenomenon, whereby prolonged activation leads to increased conductance, permeability to large ions and loss of rectification(6,7). Here, we used high-speed atomic force microscopy (HS-AFM) to analyse membrane-embedded TRPV3 at the single-molecule level and discovered a pentameric state. HS-AFM dynamic imaging revealed transience and reversibility of the pentamer in dynamic equilibrium with the canonical tetramer through membrane diffusive protomer exchange. The pentamer population increased upon diphenylboronic anhydride (DPBA) addition, an agonist that has been shown to induce TRPV3 pore dilation. On the basis of these findings, we designed a protein production and data analysis pipeline that resulted in a cryogenic-electron microscopy structure of the TRPV3 pentamer, showing an enlarged pore compared to the tetramer. The slow kinetics to enter and exit the pentameric state, the increased pentamer formation upon DPBA addition and the enlarged pore indicate that the pentamer represents the structural correlate of pore dilation. We thus show membrane diffusive protomer exchange as an additional mechanism for structural changes and conformational variability. Overall, we provide structural evidence for a non-canonical pentameric TRP-channel assembly, laying the foundation for new directions in TRP channel research. A pentameric TRPV3 channel with a dilated pore.,Lansky S, Betancourt JM, Zhang J, Jiang Y, Kim ED, Paknejad N, Nimigean CM, Yuan P, Scheuring S Nature. 2023 Sep;621(7977):206-214. doi: 10.1038/s41586-023-06470-1. Epub 2023 , Aug 30. PMID:37648856[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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