Yutaka Amemiya's research while affiliated with Kitasato University and other places

Publications (27)

Article
Three peptides containing the melanotropin-core amino-acid sequence, YXMXHFRWG, were isolated from the pituitary glands of a modern representative of the most primitive vertebrates, the sea lamprey, Petromyzon marinus. MSH-A, a nonadecapeptide (NPELYQMNHFRWGQPPTHF), is free at both ends. MSH-B, an eicosapeptide (VQESADGYRMQHFRWGQPLP), is free at th...
Article
Melanophore-stimulating hormone (MSH) has been shown to be associated with food intake in addition to body color change in teleosts. MSH is encoded by a proopiomelanocortin (POMC) gene together with endorphin (END). To assess the significance of MSH to biological activities, we determined the structure and evaluated the expression of POMC mRNA in b...
Article
Proopiomelanocortin (POMC) is a precursor for several pituitary hormones including adrenocorticotropin (ACTH), melanocyte-stimulating hormone (MSH) and endorphin (END). Fish POMCs in four taxonomic classes, Cephalaspidomorphi (lampreys), Chondrichthyes (cartilaginous fish), Sarcopterygii (lobe-finned fish), and Actinopterygii (ray-finned fish) have...
Chapter
Proopiomelanocortin (POMC) is a common precursor protein for several hormonal peptides, such as adrenocorticotropin, β-lipotropin, α-, β-, γ -melanotropins (MSHs), and β-endorphin secreted from the pituitary gland of vertebrates. These POMC products exhibit a variety of physiological functions, which are associated with stress response and environm...
Article
Several pituitary hormones, including adrenocorticotropin (ACTH), melanotropin (MSH) and β-endorphin, are generated from a common precursor protein, proopiomelanocortin (POMC). In fish, in addition to steroidogenesis of ACTH and melanogenesis of MSH, immunomodulating activity has been found in some POMC-related peptides. To investigate the function...
Article
In an attempt to understand growth regulation in milkfish, the milkfish growth hormone (GH) and its cDNA were characterized and the expression of GH mRNA in embryos and larvae was examined by RT-PCR. The milkfish GH was purified from an alkaline extract of the pituitary by reverse-phase high-performance liquid chromatography and detected as an immu...
Article
Recently, we have characterized a new MSH (named delta-MSH) which joins the group of MSHs (alpha, beta, gamma) in dogfish proopiomelanocortin (POMC). The present study has confirmed the presence of delta-MSH in POMC of another member of the elasmobranchian order, the stingray, Dasyatis akajei, by cDNA cloning from pituitary mRNAs. Overlapping parti...
Article
We report the immunomodulating effects of proopiomelanocortin (POMC)-related peptides on phagocytic cells in carp. The complete amino acid sequences of two carp POMCs (I and II) were deduced from the nucleotide sequences after cDNA cloning. Both POMCs consist of 194 amino acids (91% sequence identity) including identical α-melanotropin (MSH) and β-...
Article
We report the isolation, cDNA cloning, and growth promoting activity of rabbitfish (Siganus guttatus; Teleostei; Perciformes; Siganidae) growth hormone (GH). Rabbitfish GH was extracted from pituitary glands under alkaline conditions, fractionated by gel filtration chromatography on Sephadex G-100, and purified by high-performance liquid chromatogr...
Article
To investigate the evolution of proopiomelanocortin (POMC) from fish to tetrapods, nucleotide sequence of POMC cDNA from a lobe-finned fish, the African lungfish, was determined. POMC cDNA was prepared from lungfish pituitary glands. The POMC cDNA is composed of 1114 bp, excluding a poly-A tail, and encodes 255 amino acids (aa) including a signal p...
Article
We report the isolation and cDNA cloning of somatolactin (SL) from rabbitfish, Siganus guttatus. Rabbitfish SL was isolated from an alkaline extract of the pituitary glands by gel filtration chromatography on Sephadex G-100 and reversed-phase high-performance liquid chromatography. SL was monitored by immunoblotting with flounder SL antiserum. The...
Article
Proopiomelanocortin (POMC) is a precursor for corticotropin (ACTH), three or fewer molecular types of melanotropin (MSH), and beta-endorphin. This protein is thought to have evolved by duplication of MSH genomic segments. Here we report that the POMC in the dogfish, an elasmobranch, contains a fourth type of MSH in addition to classical alpha-, bet...
Article
Somatolactin (SL) is a newly characterized pituitary hormone belonging to the growth hormone-prolactin family. Until now SL has been identified only in teleosts, the most highly derived ray-finned fishes. We report here the cloning of SL cDNAs from two species of bony fish, the white sturgeon (Acipenser transmontanus) and the African lungfish (Prot...
Article
Insulin was isolated from the pancreas of Chondrostean fish, the Russian sturgeon, Acipenser guldenstaedti, by acid-ethanol extraction followed by ion-exchange and reverse-phase high-performance liquid chromatographies. The amino acid sequence determined by automated Edman degradation is as follows: A-chain (21-amino-acid peptide), H-Gly-Ile-Val-Gl...
Article
For the investigation of the evolution of the proopiomelanocortin (POMC) gene in early ray-finned fishes, nucleotide sequence of POMC cDNA from a chondrostean fish, the sturgeon has been determined. POMC cDNA was amplified by PCR from double-strand cDNA prepared from sturgeon pituitary and ligated with lambdaZAP II. The POMC cDNA consists of 1079 b...
Article
For the investigation of the evolution of the proopiomelanocortin (POMC) gene in early ray-finned fishes, nucleotide sequence of POMC cDNA from a chondrostean fish, the sturgeon has been determined. POMC cDNA was amplified by PCR from double-strand cDNA prepared from sturgeon pituitary and ligated with λZAP II. The POMC cDNA consists of 1079 bp wit...
Article
In the lamprey, which is a member of the oldest extant class of vertebrates, the agnathans, melanotropins (MSH) and corticotropin (ACTH) were found to be encoded on two distinct genes. In all other vertebrates, a single precursor gene, proopiomelanocortin (POMC), encodes MSH and ACTH, as well as beta-endorphin (END). Two different cDNAs were cloned...
Article
Three peptides containing the melanotropin (MSH)-core sequence, YXMXHFRWG, have been isolated recently from the pituitary glands of adult sea lampreys (Petromyzon marinus) and were tentatively assigned as lamprey adrenocorticotropin (ACTH), MSH-A, and MSH-B, respectively. Both MSHs differed significantly from gnathostome MSHs and cannot be assigned...

Citations

... It is likely that MC3R has evolved to have a preference for c-MSH in mammals; however, c-MSH has weak functional constraint in fish, as shown by its low affinity with MC3R in dogfish (Haitina et al., 2007), and critical mutation in the essential sequence in lungfish and basal ray-finned fish such as sturgeon Amemiya et al., 1997), paddlefish , bichir (Bagrosky et al., 2003) and gar . The c-MSH segment is completely absent from the teleost lineage, which may be due to secondary deletion from ancestral POMC (Takahashi and Kawauchi, 2006a,b;Takahashi et al., 2001Takahashi et al., , 2003. It is possible that selection pressure may have resulted in the deletion of c-MSH, and finally, the corresponding MC3R disappeared from the most derived teleosts, Tetradontiformes, fugu. ...
... This further supports the notion that CRF2 and UCN2 were lost within teleosts. Additionally, γ-MSH is coded for in the POMC gene in the longnose gar, Lepisosteus osseus , white sturgeon, Acipenser transmontanus (Amemiya et al., 1997), and bichir, Polypterus senegalus (Bagrosky et al., 2003); spotted gar also express MC3R (Wolverton et al., 2019). However, while MC2R is ACTH-specific at physiological concentrations in spotted gar, MC2R was also found to be activated by α-MSH when expressed with MRAP1, but only above physiologically relevant concentrations (Wolverton et al., 2019). ...
... These extracts were separated by chromatography, and then the mass value of each peptide was measured by mass spectrometry, and finally the mass value was assigned to an amino acid sequence deduced from the POMC cDNA sequence. Using these methods for carp (44), tuna (45), and flounder POMC (46), most of the peptides predicted from the location of processing signals in the cDNA sequences were identified. However, no PD-specific peptides, such as ACTH and β-END, were detected. ...
... In fishes, the growth of larvae immediately after hatching is critical for survival. The expression of the gh gene in early larval stages has been confirmed in tilapia Oreochromis mossambicus (Ayson et al., 1994), rainbow trout Oncorhynchus mykiss (Yang et al., 1999), milk fish Chanos chanos (de Jesus et al., 2002), Chinese sturgeon Acipenser sinensis (Cao et al., 2011), and Japanese eel Anguilla japonica (Ozaki et al., 2006a). In addition, zebrafish (Danio rerio) mutant lines using CRISPER/CAS9 exhibited very low survival rate (Hu et al. 2019). ...
... Evidence that the melanocortin system plays a role in the immune response of fish is scarce. In vitro assays have shown that α-MSH is able to stimulate phagocytic and respiratory burst activity of rainbow trout and carp head kidney phagocytes [23][24][25][26][27][28]. Our recent studies using a zebrafish strain overexpressing asip1 [10] have demonstrated the involvement of the melanocortin system in the regulation of skin physiology. ...
... This is unlike the single common precursor proopiomelanocortin gene present in most gnathostomes, except in various teleosts in which this gene is duplicated (Alsop & Vijayan, 2009). In the sea lamprey and other lamprey species, these precursors, as their derived peptides MSH and ACTH, are expressed in cells of different parts of the adenohypophysis (pars intermedia and pars proximalis), both in larvae and adults, although with high quantitative variation between larvae, transforming lampreys and different adult phases (Ficele et al., 1998;Nozaki et al., 1995Nozaki et al., , 2008Takahashi et al., 2006). Older studies revealed that both stress and ACTH injection affect cells of the interrenal tissue (adrenocortical homologue) of sea lampreys (Hardisty, 1972;Youson, 1972). ...
... In addition, MCRs bind the agouti signaling peptide (ASIP) and agoutirelated protein (AGPR), which are endogenous antagonists that regulate pigmentation and food intake through the MCR1 and MCR4 receptors, respectively. In lampreys, unlike other vertebrates, melanotropins (MSHs) and corticotropin (ACTH) are encoded by two different genes: proopiocortin (POC encoding ACTH and a form of β-EP) and proopiomelanotropin (POM encoding two MSHs, MSH-A and MSH-B, and a different β-EP) (Heinig et al., 1995;Takahashi et al., 2006;Takahashi, Amemiya, Sarashi, et al., 1995). The two melanotropins identified in the sea lamprey, MSH-A and MSH-B, differ significantly from the MSHs of gnathostome and, therefore, cannot be assigned as α-MSH, β-MSH, γ-MSH, or δ-MSH based on sequence similarity . ...
... In lampreys, unlike other vertebrates, melanotropins (MSHs) and corticotropin (ACTH) are encoded by two different genes: proopiocortin (POC encoding ACTH and a form of β-EP) and proopiomelanotropin (POM encoding two MSHs, MSH-A and MSH-B, and a different β-EP) (Heinig et al., 1995;Takahashi et al., 1995b;Takahashi et al., 2006). The two melanotropins identified in the sea lamprey, MSH-A and MSH-B, differ significantly from the MSHs of gnathostome and, therefore, cannot be assigned as α-MSH, β-MSH, γ-MSH or δ-MSH based on sequence similarity (Takahashi et al., 1995a). POM mRNA was expressed in the lamprey pars intermedia (Ficele et al., 1998), and immunoreactivity for both melanotropins, MSH-A and MSH-B, was also found in the pars intermedia (Dores et al., 1984;Nozaki et al., 1995). ...
... In sarcopterygian fish (lobe-finned fish), the POMC precursor exhibits the same three MSH domains (Amemiya et al., 1999a;Dores et al., 1999). The c-MSH domain occurs only as a remnant in non-teleost actinopterygians, including sturgeons (Amemiya et al., 1997;Alrubaian et al., 1999), and is absent in the most derived group, the teleosts (Salbert et al., 1992;Arends et al., 1998;Cerdá-Reverter et al., 2003). In contrast, elasmobranch fish have an additional fourth MSH domain, termed d-MSH, which probably arose as a duplication from the b-MSH-b-endorphin segment. ...
... Russian sturgeon (Acipenser gueldenstaedtii) is one of the oldest fish species along the course of fish evolution and is reputed for its long evolution history, large body size, delicious flesh and nutritional eggs. The life cycle of this species was closed in 1969 and most studies have focused on its systematics and general biology in the last half-century, but the rearing trial of sturgeons for meat production on farm is in infancy (Rusakov et al. 1998;Memis ß et al. 2009). Since the 1990s, there has been a growing interest in developing sturgeons for commercial production on farms in China. ...