Tak, Min Ho Jang, Yongwoo Son, Woo Sung Yang, Young Duk Oh, Uh taek 2024-01-19T19:00:34Z 2024-01-19T19:00:34Z 2022-01-25 2019-11 1226-2560 https://pubs.kist.re.kr/handle/201004/119352 Anoctamin1 (ANO1) also known as TMEM16A is a transmembrane protein that functions as a Ca2+ activated chloride channel. Recently, the structure determination of a fungal Nectria haematococca TMEM16 (nhTMEM16) scramblase by X-ray crystallography and a mouse ANO1 by cryo-electron microscopy has provided the insight in molecular architecture underlying phospholipid scrambling and Ca2+ binding. Because the Ca2+ binding motif is embedded inside channel protein according to defined structure, it is still unclear how intracellular Ca2+ moves to its deep binding pocket effectively. Here we show that EF-hand like region containing multiple acidic amino acids at the N-terminus of ANO1 is a putative site regulating the activity of ANO1 by Ca2+ and voltage. The EF-hand like region of ANO1 is highly homologous to the canonical EF hand loop in calmodulin that contains acidic residues in key Ca2+-coordinating positions in the canonical EF hand. Indeed, deletion and Ala-substituted mutation of this region resulted in a significant reduction in the response to Ca2+ and changes in its key biophysical properties evoked by voltage pulses. Furthermore, only ANO1 and ANO2, and not the other TMEM16 isoforms, contain the EF-hand like region and are activated by Ca2+. Moreover, the molecular modeling analysis supports that EF-hand like region could play a key role during Ca2+ transfer. Therefore, these findings suggest that EF-hand like region in ANO1 coordinates with Ca2+ and modulate the activation by Ca2+ and voltage. English KOREAN SOC BRAIN & NEURAL SCIENCE, KOREAN SOC NEURODEGENERATIVE DISEASE EF-hand like Region in the N-terminus of Anoctamin 1 Modulates Channel Activity by Ca2+ and Voltage Article 10.5607/en.2019.28.6.658 1 EXPERIMENTAL NEUROBIOLOGY, v.28, no.6, pp.658 - 669 EXPERIMENTAL NEUROBIOLOGY 28 6 658 669 N scie scopus kci ART002547697 000505803500002 2-s2.0-85078014390 Medicine, Research & Experimental Neurosciences Research & Experimental Medicine Neurosciences & Neurology Article CHLORIDE CHANNELS TMEM16A ACTIVATION AMBER Anoctamin-1 Chloride channels Calcium Mutagenesis Site-directed