- 제목 : Mechanosensitive Piezo Channel, PEZO-1, regulates food deglutition in C. elegans
- 연사 : 김규형 교수님(DGIST 뇌과학과)
- 초정자 : 강봉균 교수님 (서울대학교 생명과학부)
- 일시 : 2023년 5월 4일 (목) 오전 11시
- 장소: 서울대학교 관악캠퍼스 28동 101호 

- 링크: https://snu-ac-kr.zoom.us/j/4676548421
- Abstract :The PIEZO ion channel is an evolutionarily conserved mechanosensitive channel (Coste et al., 2010). Mammalian genomes encode two PIEZO genes, Piezo1 and Piezo2, of which functions have been shown to be involved in mechanosensation (Woo et al., 2014, Nonomura et al., 2017, Li et al., 2014, Rode et al., 2017). C. elegans genome has a single PIEZO gene, pezo-1, which encodes 14 isoforms (Bai et al., 2020). The molecular function of PEZO-1 in C. elegans has yet to be fully determined. To examine pezo-1 function, we grouped 14 isoforms depending on the mRNA length and observed their expression patterns. The promoter region of long isoforms is specifically expressed in the pharyngeal-intestinal valve, which is predicted to mediate food swallowing (Avery and Thomas, 1997). Next, to examine whether pezo-1 has a role in food swallowing, we fed animals with OP50-sized GFP-microsphere and found that pezo-1 mutant animals show excess accumulation of GFP-microsphere in the anterior part of the intestine lumen. Expression of long isoform PEZO-1 or mouse PIEZO1 under the control of valve cell-specific promoter restores the food swallowing defect of pezo-1 mutant animals. We also observed that when GFP-microspheres are fully accumulated at the anterior part of the intestine, the pharynx is pulled posteriorly to push GFP-microspheres down into the posterior intestine. We named this as a pharyngeal plunge. We next found that the pharyngeal-intestinal valve exhibits calcium transient during pharyngeal plunge and the optogenetic activation of valve cells induces the pharyngeal plunge. Moreover, elevated pressure in the anterior part of the intestinal lumen by microinjecting buffer solution causes pharyngeal plunge, not in pezo-1 mutant but wild-type animals. Ectopic expression of PEZO-1 in a C. elegans chemosensory neuron confers head bending-dependent responses. These results demonstrate that the C. elegans PIEZO channel regulates pharyngeal plunge and provides insights to understand the function of the mammalian PIEZO channel shown to be expressed in the esophagus.