the cx43-like connexin protein cx40.8 is differentially localized during fin ontogeny and fin regeneration在鳍的cx43-like联接蛋白蛋白质cx40.8不同局部个体发生和鳍再生.pdf

The Cx43-like Connexin Protein Cx40.8 Is Differentially Localized during Fin Ontogeny and Fin Regeneration 1 1 1 1 2 2 Sarah V. Gerhart , Diane M. Eble , R. Michael Burger , Stefan N. Oline , Ana Vacaru , Kirsten C. Sadler , 1 1 Rebecca Jefferis , M. Kathryn Iovine * 1 Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania, United States of America, 2 Department of Medicine-Division of Liver Disease, Department of Regenerative and Developmental Biology, Mount Sinai School of Medicine, New York, New York, United States of America Abstract Connexins (Cx) are the subunits of gap junctions, membraneous protein channels that permit the exchange of small molecules between adjacent cells. Cx43 is required for cell proliferation in the zebrafish caudal fin. Previously, we found that a Cx43-like connexin, cx40.8, is co-expressed with cx43 in the population of proliferating cells during fin regeneration. Here we demonstrate that Cx40.8 exhibits novel differential subcellular localization in vivo, depending on the growth status of the fin. During fin ontogeny, Cx40.8 is found at the plasma membrane, but Cx40.8 is retained in the Golgi apparatus during regeneration. We next identified a 30 amino acid domain of Cx40.8 responsible for its dynamic localization. One possible explanation for the differential localization is that Cx40.8 contributes to the regulation of Cx43 in vivo, perhaps modifying channel activity during ontogenetic growth. However, we find that the voltage-gating properties of Cx40.8 are similar to Cx43. Together our findings reveal that Cx40.8 exhibits differential subcellular localization in vivo, dependent on a discrete domain in its c