Original Research ARTICLE
Characterization of the Apelin/Elabela Receptors (APLNR) in Chickens, Turtles and Zebrafish: Identification of a Novel Apelin-specific Receptor in Teleosts
- 1Sichuan University, China
Apelin receptor(s) (APLNR) are suggested to mediate the actions of apelin and Elabela (ELA) peptides in many physiological processes, including cardiovascular development and food intake in vertebrates. However, the functionality of APLNR has not been examined in most vertebrate groups. Here, we characterized two APLNRs (APLNR1, APLNR2) in chickens and red-eared sliders, and three APLNRs in zebrafish (APLNR2a, APLNR2b, APLNR3a), which are homologous to human APLNR. Using luciferase-reporter assays or Western blot, we demonstrated that in chickens, APLNR1 (not APLNR2) expressed in HEK293 cells was potently activated by chicken apelin-36 and ELA-32 and coupled to Gi-cAMP and MAPK/ERK signaling pathways, indicating a crucial role of APLNR1 in mediating apelin/ELA actions; in red-eared sliders, APLNR2 (not APLNR1) was potently activated by apelin-36/ELA-32, suggesting that APLNR2 may mediate apelin/ELA actions; in zebrafish, both APLNR2a and APLNR2b were potently activated by apelin-36/ELA-32 and coupled to Gi-cAMP signaling pathway, as previously proposed, whereas the novel APLNR3a was specifically and potently activated by apelin. Similarly, an apelin-specific receptor (APLNR3b) sharing 57% sequence identity with zebrafish APLNR3a was identified in Nile tilapia. Collectively, our data facilitates the uncovering of the roles of APLNR signaling in different vertebrate groups and suggests a key functional switch between APLNR1 and APLNR2/3 in mediating the actions of ELA and apelin during vertebrate evolution.
Keywords: chicken, turtle, Zebrafish, Apelin, Elabela, APLNR
Received: 08 Oct 2018;
Accepted: 29 Nov 2018.
Edited by:Honoo Satake, Suntory Foundation for Life Sciences, Japan
Reviewed by:Taisen Iguchi, National Institute for Basic Biology, Japan
Satoshi Ogawa, Monash University Malaysia, Malaysia
Copyright: © 2018 Zhang, Zhou, Wu, Wan, Fang, Li, Fang, Yi, Zhu, Li and Wang. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Prof. Juan Li, Sichuan University, Chengdu, China, firstname.lastname@example.org
Prof. Yajun Wang, Sichuan University, Chengdu, China, email@example.com