title: Orange-spotted grouper (Epinephelus coioides) adiponectin receptors: molecular characterization, mRNA expression, and subcellular location.
abstract: Adiponectin is an abundantly secreted adipokine from adipose tissue in mammals, which plays important roles in the regulation of glucose and lipid metabolism. The biological function of adiponectin is mediated by at least two receptors (AdipoR1 and AdipoR2). Although both of them were identified in mammals, there are few researches about adiponectin and its receptors in teleosts. In this study, two types of adiponectin receptors have been isolated and characterized in the orange-spotted grouper (Epinephelus coioides). The cDNAs of grouper AdipoR1 and AdipoR2 are 1444 and 2034 bp in length, encoding proteins of 376 amino acids and 375 amino acids, respectively. Multiple alignment results showed that there was a variable region at the N-terminal of AdipoR1/R2, which has never been reported. Both AdipoR1 and AdipoR2 were found to be widely expressed in various tissues of grouper. Compared to AdipoR2, AdipoR1 expressed at higher levels in the nervous system and pituitary gland, but at lower levels in some peripheral tissues, including heart, liver, adipose tissue, stomach, intestine and especially gonad. Fasting and refeeding experiments showed that the mRNA expressions of AdipoR1/R2 were up-regulated by fasting in the muscle and adipose tissue of grouper, and restored rapidly to normal levels after refeeding. However, the mRNA expressions of AdipoR1/R2 in the hypothalamus and liver of grouper were insensitive to fasting. By indirect immunofluorescence, we demonstrated that grouper AdipoR1/R2 were integral membrane proteins; the C-terminals were extracellular, while the N-terminals were intracellular.
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou, PR China.
authors.forename: Chaobin
authors.initials: C
authors.lastname: Qin
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou, PR China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou, PR China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou, PR China.
authors.forename: Jirong
authors.initials: J
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, No. 135, Xingang Xi Road, Guangzhou, PR China. Electronic address: lsslws@mail.sysu.edu.cn.
authors.forename: Wensheng
authors.initials: W
authors.lastname: Li
mesh_terms: D052242:Adiponectin / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001492:Bass / Q000254:growth & development / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005215:Fasting; D005455:Fluorescent Antibody Technique; D057809:HEK293 Cells; D006801:Humans; D050356:Lipid Metabolism; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D054419:Receptors, Adiponectin / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions
chemical_list: D052242:Adiponectin; D018076:DNA, Complementary; D012333:RNA, Messenger; D054419:Receptors, Adiponectin
keywords: Adiponectin receptors; Fasting; Subcellular location; Tissue distribution