Carbenoxolone inhibits Pannexin1 channels through interactions in the first extracellular loop
| العنوان: | Carbenoxolone inhibits Pannexin1 channels through interactions in the first extracellular loop |
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| المؤلفون: | Toshimitsu Kawate, Kevin Michalski |
| المصدر: | The Journal of General Physiology |
| بيانات النشر: | The Rockefeller University Press, 2016. |
| سنة النشر: | 2016 |
| مصطلحات موضوعية: | 0301 basic medicine, Physiology, Mutant, Carbenoxolone, Nerve Tissue Proteins, Plasma protein binding, Biology, Connexins, Cell Line, Membrane Potentials, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Adenosine Triphosphate, Extracellular, medicine, Humans, Research Articles, Membrane potential, Voltage-gated ion channel, HEK 293 cells, 3. Good health, Cell biology, 030104 developmental biology, HEK293 Cells, Biochemistry, chemistry, Potassium, Adenosine triphosphate, Ion Channel Gating, 030217 neurology & neurosurgery, medicine.drug, Protein Binding |
| الوصف: | A chimeric approach combined with extensive site-directed mutagenesis reveals new information about the interaction of the toxin carbenoxolone with the ATP release channel Pannexin1 and the role of the first extracellular loop in channel gating. Pannexin1 (Panx1) is an ATP release channel important for controlling immune responses and synaptic strength. Various stimuli including C-terminal cleavage, a high concentration of extracellular potassium, and voltage have been demonstrated to activate Panx1. However, it remains unclear how Panx1 senses and integrates such diverse stimuli to form an open channel. To provide a clue on the mechanism underlying Panx1 channel gating, we investigated the action mechanism of carbenoxolone (CBX), the most commonly used small molecule for attenuating Panx1 function triggered by a wide range of stimuli. Using a chimeric approach, we discovered that CBX reverses its action polarity and potentiates the voltage-gated channel activity of Panx1 when W74 in the first extracellular loop is mutated to a nonaromatic residue. A systematic mutagenesis study revealed that conserved residues in this loop also play important roles in CBX function, potentially by mediating CBX binding. We extended our experiments to other Panx1 inhibitors such as probenecid and ATP, which also potentiate the voltage-gated channel activity of a Panx1 mutant at position 74. Notably, probenecid alone can activate this mutant at a resting membrane potential. These data suggest that CBX and other inhibitors, including probenecid, attenuate Panx1 channel activity through modulation of the first extracellular loop. Our experiments are the first step toward identifying a previously unknown mode of CBX action, which provide insight into the role of the first extracellular loop in Panx1 channel gating. |
| اللغة: | English |
| تدمد: | 1540-7748 0022-1295 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::634dbb7a339a8f7d789056862619a674Test http://europepmc.org/articles/PMC4727946Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....634dbb7a339a8f7d789056862619a674 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15407748 00221295 |
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