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Wang Y, Liu X, Zheng Y, Yang Y, Chen M. Endocrine regulation of reproductive biology in echinoderms: An evolutionary perspective from closest marine invertebrate relatives to chordates. Mol Cell Endocrinol 2024; 580:112105. [PMID: 37952726 DOI: 10.1016/j.mce.2023.112105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/27/2023] [Accepted: 10/29/2023] [Indexed: 11/14/2023]
Abstract
Echinoderms are a phylum of invertebrate deuterostomes, which contain echinoids, asteroids, holothuroids, crinoids, and ophiuroids. Echinoderms have special evolutionary position and unique characteristics, including pentamerous radial body structure, elaborate calcareous endoskeletons, and versatile water vascular system. Echinoderms exhibit extraordinarily diverse reproductive modes: asexual reproduction, sexual reproduction, sexual reversal, etc. Endocrine regulation plays important well-known roles in sex differentiation, gonadal development and maturation, gametogenesis, and reproductive behavior in vertebrates. However, the entire picture of reproductive endocrinology in echinoderms as an evolutionary model of the closest marine invertebrate relatives to chordates has not been revealed. Here, we reviewed previous and recent research progress on reproductive endocrinology in echinoderms, mainly including two sections: Sex steroids in echinoderms and neuropeptide regulation in echinoderm reproduction. This review introduces a variety of endocrine regulatory mechanisms in reproductive biology of echinoderms. It discusses the vertebrate-like sex steroids, putative steroidogenic pathway and metabolism, and reproduction-related neuropeptides. The review will provide a deeper understanding about endocrine regulatory mechanisms of gonadal development in lower deuterostomes and the application of endocrine control in economic echinoderm species in aquaculture.
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Affiliation(s)
- Yixin Wang
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Xinghai Liu
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Yingqiu Zheng
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China
| | - Yujia Yang
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China.
| | - Muyan Chen
- The Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, China.
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2
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Mita M. Relaxin-like Gonad-Stimulating Peptides in Asteroidea. Biomolecules 2023; 13:biom13050781. [PMID: 37238650 DOI: 10.3390/biom13050781] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Starfish relaxin-like gonad-stimulating peptide (RGP) is the first identified peptide hormone with gonadotropin-like activity in invertebrates. RGP is a heterodimeric peptide, comprising A and B chains with disulfide cross-linkages. Although RGP had been named a gonad-stimulating substance (GSS), the purified peptide is a member of relaxin-type peptide family. Thus, GSS was renamed as RGP. The cDNA of RGP encodes not only the A and B chains, but also signal and C-peptides. After the rgp gene is translated as a precursor, mature RGP is produced by eliminating the signal and C-peptides. Hitherto, twenty-four RGP orthologs have been identified or predicted from starfish in the orders Valvatida, Forcipulatida, Paxillosida, Spinulosida, and Velatida. The molecular evolution of the RGP family is in good accordance with the phylogenetic taxonomy in Asteroidea. Recently, another relaxin-like peptide with gonadotropin-like activity, RLP2, was found in starfish. RGP is mainly present in the radial nerve cords and circumoral nerve rings, but also in the arm tips, the gonoducts, and the coelomocytes. RGP acts on ovarian follicle cells and testicular interstitial cells to induce the production of 1-methyladenine (1-MeAde), a starfish maturation-inducing hormone. RGP-induced 1-MeAde production is accompanied by an increase in intracellular cyclic AMP levels. This suggests that the receptor for RGP (RGPR) is a G protein-coupled receptor (GPCR). Two types of GPCRs, RGPR1 and RGPR2, have been postulated as candidates. Furthermore, 1-MeAde produced by RGP not only induces oocyte maturation, but also induces gamete shedding, possibly by stimulating the secretion of acetylcholine in the ovaries and testes. Thus, RGP plays an important role in starfish reproduction, but its secretion mechanism is still unknown. It has also been revealed that RGP is found in the peripheral adhesive papillae of the brachiolaria arms. However, gonads are not developed in the larvae before metamorphosis. It may be possible to discover new physiological functions of RGP other than gonadotropin-like activity.
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Affiliation(s)
- Masatoshi Mita
- Department of Biochemistry, Showa University School of Medicine, Hatanodai 8-5-1, Shinagawa-ku, Tokyo 142-8555, Japan
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Katayama H, Mita M. The C-terminally amidated relaxin-like gonad-stimulating peptide in the starfish Astropecten scoparius. Gen Comp Endocrinol 2023; 334:114226. [PMID: 36731602 DOI: 10.1016/j.ygcen.2023.114226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/26/2023] [Accepted: 01/28/2023] [Indexed: 02/03/2023]
Abstract
A relaxin-like gonad-stimulating peptide (RGP) in starfish was the first identified invertebrate gonadotropin, consisting of A- and B-chain. Recently, an RGP ortholog (Asc-RGP) from Astropecten scoparius in the order Paxillosida was found to harbor an amidation signal (Gly-Arg) at the C-terminus of the B-chain (Mita et al., 2020a). Two cleavage sites were also predicted within the signal peptide of the Asc-RGP precursor. Thus, four kinds of analogs (Asc-RGP-NH2(S), Asc-RGP-GR(S), Asc-RGP- NH2(L), Asc-RGP-GR(L) were hypothesized as natural Asc-RGPs. To identify the natural Asc-RGP, an extract of radial nerve cords from A. scoparius was analyzed using reverse-phase high-performance liquid chromatography and MALDI-TOF-mass spectrometry. The molecular weight of Asc-RGP was 4585.3, and those of A- and B-chains were 2511.8 and 2079.8, respectively. This strongly suggests that natural RGP in A. scoparius is Asc-RGP-NH2(S). Asc-RGP-NH2(S) stimulated 1-methyladenine and cyclic AMP production in isolated ovarian follicle cells of A. scoparius. On the other hand, the concentrations of four synthetic Asc-RGP analogs required for the induction of spawning in 50% of ovarian fragments were almost the same. The size and C-terminal amidation of the B-chain might not be important for spawning-inducing activity. C-terminally amidated RGPs in the B-chain were also observed in other species of starfish belonging to the order Paxillosida, particularly the family Astropectinidae, but not the family Luidiidae.
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Affiliation(s)
- Hidekazu Katayama
- Department of Bioengineering, School of Engineering, Tokai University, 4-1-1, Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
| | - Masatoshi Mita
- Department of Biochemistry, Showa University School of Medicine, 1-5-8, Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
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Mita M, Elphick MR, Katayama H. A specific and sensitive enzyme-linked immunosorbent assay for measurement of relaxin-like gonad-stimulating peptide in the starfish Asterias rubens. Gen Comp Endocrinol 2021; 310:113831. [PMID: 34089706 DOI: 10.1016/j.ygcen.2021.113831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 03/10/2021] [Accepted: 06/01/2021] [Indexed: 11/22/2022]
Abstract
A relaxin-like gonad-stimulating peptide (RGP) acts as a gonadotropic hormone in starfish. In this study, antibodies to Asterias rubens RGP (AruRGP) were used for the development of a specific and sensitive enzyme-linked immunosorbent assay (ELISA) to measure AruRGP. Biotin-conjugated RGP (biotin-AruRGP) that binds to peroxidase-conjugated streptavidin was synthesized chemically so that it could be specifically detected using 3, 3', 5, 5'-tetramethylbenzidine (TMB)/hydrogen peroxide as a substrate. Similar to AruRGP, biotin-AruRGP bound to AruRGP antibodies. In binding experiments with biotin-AruRGP using wells coated with AruRGP antibodies, a displacement curve was obtained using serial dilutions of AruRGP. Using this ELISA system, AruRGP could be measured in the range 0.01-5.0 pmol per 50 µl test solution. Furthermore, 0.22 ± 0.03 and 0.20 ± 0.04 pmol AruRGP/mg wet weight tissue were detected in the radial nerve cords and circumoral nerve-rings of A. rubens, respectively. Smaller amounts of AruRGP were detected in tube feet, pyloric stomach and cardiac stomach but AruRGP was not detected in pyloric caeca, ovaries and testes. Analysis of the specificity of the AruRGP antibodies revealed that the A- and B-chains of AruRGP, Patiria pectinifera RGP, Aphelasterias japonica RGP, and human relaxin exhibit little or no cross-reactivity in the ELISA. We conclude, therefore, that we have successfully generated an ELISA system that is highly sensitive and specific for detection of AruRGP.
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Affiliation(s)
- Masatoshi Mita
- Department of Biochemistry, Showa University School of Medicine, Hatanodai 8-5-1, Shinagawa-ku, Tokyo 142-8555, Japan.
| | - Maurice R Elphick
- Queen Mary University of London, School of Biological & Chemical Sciences, Mile End Road, London E1 4NS, UK
| | - Hidekazu Katayama
- Department of Applied Biochemistry, School of Engineering, Tokai University, 4-1-1, Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
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Mita M, Osugi T, Matsubara S, Kawada T, Satake H, Katayama H. A relaxin-like gonad-stimulating peptide identified from the starfish Astropecten scoparius. Mol Reprod Dev 2020; 88:34-42. [PMID: 33244845 DOI: 10.1002/mrd.23444] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 11/12/2022]
Abstract
A relaxin-like gonad-stimulating peptide (RGP) in starfish was the first identified invertebrate gonadotropin responsible for final gamete maturation. An RGP ortholog was newly identified from Astropecten scoparius of the order Paxillosida. The A. scoparius RGP (AscRGP) precursor is encoded by a 354 base pair open reading frame and is a 118 amino acid (aa) protein consisting of a signal peptide (26 aa), B-chain (21 aa), C-peptide (47 aa), and A-chain (24 aa). There are three putative processing sites (Lys-Arg) between the B-chain and C-peptide, between the C-peptide and A-chain, and within the C-peptide. This structural organization revealed that the mature AscRGP is composed of A- and B-chains with two interchain disulfide bonds and one intrachain disulfide bond. The C-terminal residues of the B-chain are Gln-Gly-Arg, which is a potential substrate for formation of an amidated C-terminal Gln residue. Non-amidated (AscRGP-GR) and amidated (AscRGP-NH2 ) peptides were chemically synthesized and their effect on gamete shedding activity was examined using A. scoparius ovaries. Both AscRGP-GR and AscRGP-NH2 induced oocyte maturation and ovulation in similar dose-dependent manners. This is the first report on a C-terminally amidated functional RGP. Collectively, these results suggest that AscRGP-GR and AscRGP-NH2 act as a natural gonadotropic hormone in A. scoparius.
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Affiliation(s)
- Masatoshi Mita
- Department of Biochemistry, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan
| | - Tomohiro Osugi
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Soraku-gun, Kyoto, Japan
| | - Shin Matsubara
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Soraku-gun, Kyoto, Japan
| | - Tsuyoshi Kawada
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Soraku-gun, Kyoto, Japan
| | - Honoo Satake
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Soraku-gun, Kyoto, Japan
| | - Hidekazu Katayama
- Department of Applied Biochemistry, Tokai University, Hiratsuka, Kanagawa, Japan
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Mita M, Elphick MR, Katayama H. Effect of chimeric relaxin-like gonad-stimulating peptides on oocyte maturation and ovulation in the starfish Asterias rubens and Aphelasterias japonica. Gen Comp Endocrinol 2020; 287:113351. [PMID: 31805285 DOI: 10.1016/j.ygcen.2019.113351] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 10/15/2019] [Accepted: 11/29/2019] [Indexed: 12/14/2022]
Abstract
A relaxin-like gonad-stimulating peptide (RGP), comprising two peptide chains (A- and B-chains) linked by two interchain bonds and one intrachain disulfide bond, acts as a gonadotropin in starfish. RGP orthologs have been identified in several starfish species, including Patiria pectinifera (PpeRGP), Asterias rubens (AruRGP) and Aphelasterias japonica (AjaRGP). To analyze species-specificity, this study examined the effects on oocyte maturation and ovulation in ovaries of A. rubens and A. japonica of nine RGP derivatives comprising different combinations of A- and B-chains from the three species. All nine RGP derivatives induced spawning in A. rubens and A. japonica ovaries. However, AruRGP, AjaRGP and their chimeric derivatives were more potent than peptides containing the A- or B-chain of PpeRGP. Three-dimensional models of the structures of the RGP derivatives revealed that residues in the B-chains, such as AspB6, MetB10 and PheB13 in PpeRGP and GluB7, MetB11, and TyrB14 in AruRGP and AjaRGP, respectively, are likely to be involved in receptor binding. Conversely, it is likely that ArgA18 in the A-chain of AruRGP and AjaRGP impairs binding of these peptides to the PpeRGP receptor in P. pectinifera. In conclusion, this study provides new insights into the structural basis of RGP bioactivity and RGP receptor activation in starfish.
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Affiliation(s)
- Masatoshi Mita
- Department of Biochemistry, Showa University School of Medicine, Hatanodai 8-5-1, Shinagawa-ku, Tokyo 142-8555, Japan; Center for Advanced Biomedical Sciences, Waseda University, 2-2, Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
| | - Maurice R Elphick
- Queen Mary University of London, School of Biological & Chemical Sciences, Mile End Road, London E1 4NS, UK
| | - Hidekazu Katayama
- Department of Applied Biochemistry, School of Engineering, Tokai University, 4-1-1, Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan
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Mita M. Inhibitory mechanism of l
-glutamic acid on spawning of the starfish Patiria
(Asterina
) pectinifera. Mol Reprod Dev 2017; 84:246-256. [DOI: 10.1002/mrd.22769] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/17/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Masatoshi Mita
- Department of Biology; Faculty of Education; Tokyo Gakugei University; Koganei Tokyo Japan
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Mita M. Starfish gonadotropic hormone: Relaxin-like gonad-stimulating peptides. Gen Comp Endocrinol 2016; 230-231:166-9. [PMID: 27102940 DOI: 10.1016/j.ygcen.2016.04.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 04/14/2016] [Accepted: 04/16/2016] [Indexed: 11/19/2022]
Abstract
Relaxin-like gonad-stimulating peptide (RGP) of starfish Patiria (= Asterina) pectinifera is the first identified invertebrate gonadotropin to trigger final gamete maturation. Recently, chemical structures of RGP were identified in several species of starfish. Three kinds of RGP molecules are found in the class Asteroidea. The chemical structure of P. pectinifera RGP (PpeRGP) is conserved among starfish of the order Valvatida beyond species. In contrast, the chemical structures of RGP identified in Asterias amurensis and Aphelasterias japonica of the order Forcipulatida are quite different from that of PpeRGP. The chemical structure of RGP in A. amurensis (AamRGP) is exactly the same as that in Asterias rubens (the order Forcipulatida), Astropecten scoparius (the order Paxillosida), Astropecten polyacanthus (the order Paxillosida), and Echinaster luzonicus (the order Spinulosida). The chemical structure of Coscinasterias acutispina RGP (the order Forcipulatida) is consistent with that of A. japonica RGP (AjaRGP). In cross-experiments using P. pectinifera, A. amurensis, and A. japonica ovaries, AamRGP and AjaRGP can induce each species of ovaries. Neither AamRGP nor AjaRGP induce oocyte maturation and ovulation in the ovary of P. pectinifera, although the PpeRGP is active in ovaries of A. amurensis and A. japonica. This suggests that the AamRGP and AjaRGP partly act species specificity.
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Affiliation(s)
- Masatoshi Mita
- Department of Biology, Faculty of Education, Tokyo Gakugei University, Nukuikita-machi 4-1-1, Koganei-shi, Tokyo 184-8501, Japan.
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