Pharmacological modulation of the cAMP signaling of two isoforms of melanocortin-3 receptor by melanocortin receptor accessory proteins in the tetrapod Xenopus laevis

Ying Xu; Lei Li; Jihong Zheng; Meng Wang; Bopei Jiang; Yue Zhai; Liumei Lu; Cong Zhang; Zhe Kuang; Xiaomei Yang; Li-Na Jin; Gufa Lin; Chao Zhang

doi:10.1530/EC-21-0179

Pharmacological modulation of the cAMP signaling of two isoforms of melanocortin-3 receptor by melanocortin receptor accessory proteins in the tetrapod Xenopus laevis

Endocr Connect. 2021 Nov 15;10(11):1477-1488. doi: 10.1530/EC-21-0179.

Authors

Ying Xu¹, Lei Li¹, Jihong Zheng¹, Meng Wang¹, Bopei Jiang¹, Yue Zhai¹, Liumei Lu¹, Cong Zhang¹, Zhe Kuang¹, Xiaomei Yang¹, Li-Na Jin², Gufa Lin^{1

3}, Chao Zhang¹

Affiliations

¹ Translational Medical Center for Stem Cell Therapy and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai, China.
² Department of Hematology, Changzheng Hospital, Naval Medical University, Shanghai, China.
³ Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration of Ministry of Education, Orthopaedic Department of Tongji Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.

Abstract

As a member of the seven-transmembrane rhodopsin-like G protein-coupled receptor superfamily, the melanocortin-3 receptor (MC3R) is vital for the regulation of energy homeostasis and rhythms synchronizing in mammals, and its pharmacological effect could be directly influenced by the presence of melanocortin receptor accessory proteins (MRAPs), MRAP1 and MRAP2. The tetrapod amphibian Xenopus laevis (xl) retains higher duplicated genome than extant teleosts and serves as an ideal model system for embryonic development and physiological studies. However, the melanocortin system of the Xenopus laevis has not yet been thoroughly evaluated. In this work, we performed sequence alignment, phylogenetic tree, and synteny analysis of two xlMC3Rs. Co-immunoprecipitation and immunofluorescence assay further confirmed the co-localization and in vitro interaction of xlMC3Rs with xlMRAPs on the plasma membrane. Our results demonstrated that xlMRAP2.L/S could improve α-MSH-stimulated xlMC3Rs signaling and suppress their surface expression. Moreover, xlMC3R.L showed a similar profile on the ligands and surface expression in the presence of xlMRAP1.L. Overall, the distinct pharmacological modulation of xlMC3R.L and xlMC3R.S by dual MRAP2 proteins elucidated the functional consistency of melanocortin system during genomic duplication of tetrapod vertebrates.

Keywords: MC3R; MRAPs; Xenopus laevis; tetrapod.