Glutamate Permeability of Chicken Best1
- Author:
Jung Moo LEE
1
;
Changdev Gorakshnath GADHE
;
Hyunji KANG
;
Ae Nim PAE
;
C. Justin LEEC
Author Information
- Publication Type:Short Communication
- From:Experimental Neurobiology 2022;31(5):277-288
- CountryRepublic of Korea
- Language:English
- Abstract: Bestrophin-1 (Best1) is a calcium (Ca 2+ )-activated chloride (Cl - ) channel which has a phylogenetically conserved channel structure with an aperture and neck in the ion-conducting pathway. Mammalian mouse Best1 (mBest1) has been known to have a permeability for large organic anions including gluconate, glutamate, and D-serine, in addition to several small monovalent anions, such as Cl - , bromine (Br - ), iodine (I - ), and thiocyanate (SCN - ). However, it is still unclear whether non-mammalian Best1 has a glutamate permeability through the ion-conducting pathway. Here, we report that chicken Best1 (cBest1) is permeable to glutamate in a Ca 2+ -dependent manner. The molecular docking and molecular dynamics simulation showed a glutamate binding at the aperture and neck of cBest1 and a glutamate permeation through the ion-conducting pore, respectively. Moreover, through electrophysiological recordings, we calculated the permeability ratio of glutamate to Cl - (P Glutamate /P Cl ) as 0.28 based on the reversal potential shift by ion substitution from Cl - to glutamate in the internal solution. Finally, we directly detected the Ca 2+ -dependent glutamate release through cBest1 using the ultrasensitive two-cell sniffer patch technique. Our results propose that Best1 homologs from non-mammalian (cBest1) to mammalian (mBest1) have a conserved permeability for glutamate.
