[대학원 생명과학과 세미나 안내]
연사 : 김규형 교수(대구경북과학기술원)
연제 : Piezo channel PEZO-1 regulates intestinal motility in C. elegans
일시 : 2020년 5월 1일 (금) 오후 5시
장소 : 온라인 화상 강의로 진행됩니다.
초청교수 : 백자현 교수
Abstract
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. The molecular function of PEZO-1 in C. elegans has yet to be determined. To examine the pezo-1 function, we grouped 14 isoforms into short or long isoform depending on the mRNA length and observed their expression patterns. While promoter region of short isoforms is expressed in the several head neurons and intestinal cells, that of long isoforms is specifically expressed in the pharyngeal-intestinal valve, which is predicted to mediate intestinal peristalsis (Avery and Thomas, 1997). Next, to examine whether pezo-1 has a role in intestinal peristalsis, we performed intestinal motility assay by feeding animals with GFP-microsphere and found that pezo-1 mutant animals show excess accumulation of GFP-microsphere in the intestine lumen. Expression of long isoform PEZO-1 under the control of its endogenous promoter restores the peristalsis defect of pezo-1 mutant animals. We also found that the pharyngeal-intestinal valve exhibits calcium transient during peristalsis, and the optogenetic activation of valve cells induce peristalsis by contracting pharynx muscles via gap junctions. Furthermore, the ectopic expression of mouse PIEZO1 is sufficient to restore the defect of pezo-1 mutant animals. Currently, we are investigating whether PEZO-1 is activated upon pressure by performing electrophysiology in a heterologous system. These results demonstrate that C. elegans PIEZO channel pezo-1 is required for intestinal peristalsis, and it provides insights to understand the function of mammalian PIEZO channels, which have shown to be expressed in the intestine.