TY - JOUR
T1 - Molecular cloning, molecular evolution and gene expression of cDNAs encoding thyrotropin-releasing hormone receptor subtypes in a teleost, the sockeye salmon (Oncorhynchus nerka)
AU - Saito, Yuichi
AU - Mekuchi, Miyuki
AU - Kobayashi, Noriaki
AU - Kimura, Makoto
AU - Aoki, Yasuhiro
AU - Masuda, Tomohiro
AU - Azuma, Teruo
AU - Fukami, Motohiro
AU - Iigo, Masayuki
AU - Yanagisawa, Tadashi
N1 - Funding Information:
We thank Koji Muto, Freshwater Fisheries Research Division, National Research Institute of Fisheries Science, for excellent technical assistance. This study was supported in part by Grants-in-Aid from the Ministry of Education, Science, Sports and Culture of Japan and JSPS to TY and MI, by the Grant for Young Scholar from VBL Department, The Collaboration Center for Research and Development of Utsunomiya University to YS, and by grants from Utsunomiya University to TY, MF and MI. We express our thanks to Dr. Alan Peterkofsky, National Heart, Lung, and Blood Institute, NIH in USA and Dr. G. David Trisler, University of Maryland, School of Medicine, for their encouraging us during this study and kindly reading the manuscript.
PY - 2011/11/1
Y1 - 2011/11/1
N2 - Molecular cloning of thyrotropin-releasing hormone receptors (TRHR) was performed in a teleost, the sockeye salmon (Oncorhynchus nerka). Four different TRHR cDNAs were cloned and named TRHR1, TRHR2a, TRHR2b and TRHR3 based on their similarity to known TRHR subtypes in vertebrates. Important residues for TRH binding were conserved in deduced amino acid sequences of the three TRHR subtypes except for the TRHR2b. Seven transmembrane domains were predicted for TRHR1, TRHR2a and TRHR3 proteins but only five for TRHR2b which appears to be truncated. In silico database analysis identified putative TRHR sequences including invertebrate TRHR and reptilian, avian and mammalian TRHR3. Phylogenetic analyses predicted the molecular evolution of TRHR in vertebrates: from the common ancestral TRHR (i.e. invertebrate TRHR), the TRHR2 subtype diverged first and then TRHR1 and TRHR3 diverged. Reverse transcription-polymerase chain reaction analyses revealed TRHR1 transcripts in the brain (hypothalamus), retina, pituitary gland and large intestine; TRHR2a in the brain (telencephalon and hypothalamus); and TRHR3 in the brain (olfactory bulbs) and retina.
AB - Molecular cloning of thyrotropin-releasing hormone receptors (TRHR) was performed in a teleost, the sockeye salmon (Oncorhynchus nerka). Four different TRHR cDNAs were cloned and named TRHR1, TRHR2a, TRHR2b and TRHR3 based on their similarity to known TRHR subtypes in vertebrates. Important residues for TRH binding were conserved in deduced amino acid sequences of the three TRHR subtypes except for the TRHR2b. Seven transmembrane domains were predicted for TRHR1, TRHR2a and TRHR3 proteins but only five for TRHR2b which appears to be truncated. In silico database analysis identified putative TRHR sequences including invertebrate TRHR and reptilian, avian and mammalian TRHR3. Phylogenetic analyses predicted the molecular evolution of TRHR in vertebrates: from the common ancestral TRHR (i.e. invertebrate TRHR), the TRHR2 subtype diverged first and then TRHR1 and TRHR3 diverged. Reverse transcription-polymerase chain reaction analyses revealed TRHR1 transcripts in the brain (hypothalamus), retina, pituitary gland and large intestine; TRHR2a in the brain (telencephalon and hypothalamus); and TRHR3 in the brain (olfactory bulbs) and retina.
KW - Molecular evolution
KW - Sockeye salmon Oncorhynchus nerka
KW - Teleosts
KW - Thyrotropin-releasing hormone
KW - Thyrotropin-releasing hormone receptor
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U2 - 10.1016/j.ygcen.2011.07.011
DO - 10.1016/j.ygcen.2011.07.011
M3 - Article
C2 - 21827760
AN - SCOPUS:80054095384
SN - 0016-6480
VL - 174
SP - 80
EP - 88
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 2
ER -