| 1. |
- Sundström, Görel, et al.
(författare)
-
Characterization of the neuropeptide Y system in the frog Silurana tropicalis (Pipidae) : three peptides and six receptor subtypes
- 2012
-
Ingår i: General and Comparative Endocrinology. - : Elsevier BV. - 0016-6480 .- 1095-6840. ; 177:3, s. 322-331
-
Tidskriftsartikel (refereegranskat)abstract
- Neuropeptide Y and its related peptides PYY and PP (pancreatic polypeptide) are involved in feeding behavior, regulation of the pituitary and the gastrointestinal tract, and numerous other functions. The peptides act on a family of G-protein coupled receptors with 4-7 members in jawed vertebrates. We describe here the NPY system of the Western clawed frog Silurana (Xenopus) tropicalis. Three peptides, NPY, PYY and PP, were identified together with six receptors, namely subtypes Y1, Y2, Y4, Y5, Y7 and Y8. Thus, this frog has all but one of the ancestral seven gnathostome NPY-family receptors, in contrast to mammals which have lost 2-3 of the receptors. Expression levels of mRNA for the peptide and receptor genes were analyzed in a panel of 19 frog tissues using reverse transcriptase quantitative PCR. The peptide mRNAs had broad distribution with highest expression in skin, blood and small intestine. NPY mRNA was present in the three brain regions investigated, but PYY and PP mRNAs were not detectable in any of these. All receptor mRNAs had similar expression profiles with high expression in skin, blood, muscle and heart. Three of the receptors, Y5, Y7 and Y8, could be functionally expressed in HEK-293 cells and characterized with binding studies using the three frog peptides. PYY had the highest affinity for all three receptors (K(i) 0.042-0.34 nM). Also NPY and PP bound to the Y8 receptor with high affinity (0.14 and 0.50 nM). The low affinity of NPY for the Y5 receptor (100-fold lower than PYY) differs from mammals and chicken. This may suggest a less important role of NPY on Y5 in appetite stimulation in the frog compared with amniotes. In conclusion, our characterization of the NPY system in S. tropicalis with its six receptors demonstrates not only greater complexity than in mammals but also some interesting differences in ligand-receptor preferences.
|
|
| 2. |
- Cardoso, Joao C. R., et al.
(författare)
-
Corticotropin-releasing hormone family evolution : five ancestral genes remain in some lineages
- 2016
-
Ingår i: Journal of Molecular Endocrinology. - 0952-5041 .- 1479-6813. ; 57:1, s. 73-86
-
Tidskriftsartikel (refereegranskat)abstract
- The evolution of the peptide family consisting of corticotropin-releasing hormone ( CRH) and the three urocortins ( UCN1-3) has been puzzling due to uneven evolutionary rates. Distinct gene duplication scenarios have been proposed in relation to the two basal rounds of vertebrate genome doubling ( 2R) and the teleost fish-specific genome doubling ( 3R). By analyses of sequences and chromosomal regions, including many neighboring gene families, we show here that the vertebrate progenitor had two peptide genes that served as the founders of separate subfamilies. Then, 2R resulted in a total of five members: one subfamily consists of CRH1, CRH2, and UCN1. The other subfamily contains UCN2 and UCN3. All five peptide genes are present in the slowly evolving genomes of the coelacanth Latimeria chalumnae ( a lobe-finned fish), the spotted gar Lepisosteus oculatus ( a basal ray-finned fish), and the elephant shark Callorhinchus milii ( a cartilaginous fish). The CRH2 gene has been lost independently in placental mammals and in teleost fish, but is present in birds ( except chicken), anole lizard, and the nonplacental mammals platypus and opossum. Teleost 3R resulted in an additional surviving duplicate only for crh1 in some teleosts including zebrafish ( crh1a and crh1b). We have previously reported that the two vertebrate CRH/UCN receptors arose in 2R and that CRHR1 was duplicated in 3R. Thus, we can now conclude that this peptide-receptor system was quite complex in the ancestor of the jawed vertebrates with five CRH/UCN peptides and two receptors, and that crh and crhr1 were duplicated in the teleost fish tetraploidization.
|
|
| 3. |
- Cardoso, João C R, et al.
(författare)
-
New insights into the evolution of vertebrate CRH (corticotropin-releasing hormone) and invertebrate DH44 (diuretic hormone 44) receptors in metazoans
- 2014
-
Ingår i: General and Comparative Endocrinology. - : Elsevier BV. - 0016-6480 .- 1095-6840. ; 209:SI, s. 162-170
-
Tidskriftsartikel (refereegranskat)abstract
- The corticotropin releasing hormone receptors (CRHR) and the arthropod diuretic hormone 44 receptors (DH44R) are structurally and functionally related members of the G protein-coupled receptors (GPCR) of the secretin-like receptor superfamily. We show here that they derive from a bilaterian predecessor. In protostomes, the receptor became DH44R that has been identified and functionally characterised in several arthropods but the gene seems to be absent from nematode genomes. Duplicate DH44R genes (DH44 R1 and DH44R2) have been described in some arthropods resulting from lineage-specific duplications. Recently, CRHR-DH44R-like receptors have been identified in the genomes of some lophotrochozoans (molluscs, which have a lineage-specific gene duplication, and annelids) as well as representatives of early diverging deuterostomes. Vertebrates have previously been reported to have two CRHR receptors that were named CRHR1 and CRHR2. To resolve their origin we have analysed recently assembled genomes from representatives of early vertebrate divergencies including elephant shark, spotted gar and coelacanth. We show here by analysis of synteny conservation that the two CRHR genes arose from a common ancestral gene in the early vertebrate tetraploidizations (2R) approximately 500 million years ago. Subsequently, the teleost-specific tetraploidization (3R) resulted in a duplicate of CRHR1 that has been lost in some teleost lineages. These results help distinguish orthology and paralogy relationships and will allow studies of functional conservation and changes during evolution of the individual members of the receptor family and their multiple native peptide agonists.
|
|
| 4. |
- Holmberg, Sara K S, et al.
(författare)
-
Localization of neuropeptide Y receptor Y5 mRNA in the guinea pig brain
- 2004
-
Ingår i: Regulatory Peptides. - : Elsevier BV. - 0167-0115 .- 1873-1686. ; 117, s. 61-67
-
Tidskriftsartikel (refereegranskat)abstract
- Neuropeptide Y (NPY) has prominent stimulatory effects on food intake in virtually all animals that have been studied. In mammals, the effect is primarily mediated by receptors Y1 and Y5, which seem to contribute to different aspects of feeding behavior in guinea pigs and rats/mice. Interestingly, differences in receptor distribution among mammalian species have been reported. To get a broader perspective on the role of Y5, we describe here studies of guinea pig (Cavia porcellus), a species which due to its phylogenetic position in the mammalian radiation is an interesting complement to previous studies in rat and mouse. Guinea pig brain sections were hybridized with two 35S-labeled oligonucleotides complementary to Y5 mRNA. The highest expression levels of Y5 mRNA were observed in the hippocampus and several hypothalamic and brain stem nuclei implicated in the regulation of feeding, such as the paraventricular, arcuate and ventromedial hypothalamic nuclei. This contrasts with autoradiography studies that detected low Y5-like binding in these areas, a discrepancy observed also in rat and human. Y5 mRNA expression was also seen in the striatum, in great contrast to mouse and rat. Taken together, these data show that Y5 mRNA distribution displays some interesting species differences, but that its expression in feeding centers seems to be essentially conserved among mammals, adding further support for an important role in food intake.
|
|
| 5. |
- Larhammar, Dan, 1956-, et al.
(författare)
-
Ancestral vertebrate complexity of the opioid system
- 2015
-
Ingår i: Nociceptin Opioid. - : Academic Press. - 9780128024430
-
Bokkapitel (refereegranskat)abstract
- The evolution of the opioid peptides and nociceptin/orphanin as well as their receptors has been difficult to resolve due to variable evolutionary rates. By combining sequence comparisons with information on the chromosomal locations of the genes, we have deduced the following evolutionary scenario: The vertebrate predecessor had one opi- oid precursor gene and one receptor gene. The two genome doublings before the ver- tebrate radiation resulted in three peptide precursor genes whereupon a fourth copy arose by a local gene duplication. These four precursors diverged to become the pre- propeptides for endorphin (POMC), enkephalins, dynorphins, and nociceptin, respec- tively. The ancestral receptor gene was quadrupled in the genome doublings leading to delta, kappa, and mu and the nociceptin/orphanin receptor. This scenario is corroborated by new data presented here for coelacanth and spotted gar, rep- resenting two basal branches in the vertebrate tree. A third genome doubling in the ancestor of teleost fishes generated additional gene copies. These results show that the opioid system was quite complex already in the first vertebrates and that it has more components in teleost fishes than in mammals. From an evolutionary point of view, nociceptin and its receptor can be considered full-fledged members of the opioid system.
|
|
| 6. |
- Larhammar, Dan, et al.
(författare)
-
Ancient Grandeur of the Vertebrate Neuropeptide Y System Shown by the Coelacanth Latimeria chalumnae
- 2013
-
Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- The neuropeptide Y (NPY) family receptors and peptides have previously been characterized in several tetrapods, teleost fishes, and in a holocephalan cartilaginous fish. This has shown that the ancestral NPY system in the jawed vertebrates consisted of the peptides NPY and peptide YY (PYY) and seven G-protein-coupled receptors named Y1-Y8 (Y3 does not exist). The different vertebrate lineages have subsequently lost or gained a few receptor genes. For instance, the human genome has lost three of the seven receptors while the zebrafish has lost two and gained two receptor genes. Here we describe the NPY system of a representative of an early diverging lineage among the sarcopterygians, the West Indian Ocean coelacanth Latimeria chalumnae. The coelacanth was found to have retained all seven receptors from the ancestral jawed vertebrate. The receptors display the typical characteristics found in other vertebrates. Interestingly, the coelacanth was found to have the local duplicate of the PYY gene, called pancreatic polypeptide, previously only identified in tetrapods. Thus, this duplication took place very early in the sarcopterygian lineage, before the origin of tetrapods. These findings confirm the ancient complexity of the NPY system and show that mammals have lost more NPY receptors than any other vertebrate lineage. The coelacanth has all three peptides found in tetrapods and has retained the ancestral jawed vertebrate receptor repertoire with neither gains or losses.
|
|
| 7. |
- Larhammar, Dan, et al.
(författare)
-
Unexpected multiplicity of QRFP receptors in early vertebrate evolution
- 2014
-
Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 8, s. 337-
-
Tidskriftsartikel (refereegranskat)abstract
- The neuropeptide QRFP, also called 26RFa, and its G protein-coupled receptor GPR103 have been identified in all vertebrates investigated. In mammals, this peptide-receptor pair has been found to have several effects including stimulation of appetite. Recently, we reported that a QRFP peptide is present in amphioxus, Branchiostoma floridae, and we also identified a QRFP receptor (QRFPR) that mediates a functional response to sub-nanomolar concentrations of the amphioxus peptide as well as short and long human QRFP (Xu et al., submitted). Because the ancestral vertebrate underwent two tetraploidizations, it might be expected that duplicates of the QRFP gene and its receptor gene may exist. Indeed, we report here the identification of multiple vertebrate QRFPR genes. Three QRFPR genes are present in the coelacanth Latimeria chalumnae, representing an early diverging sarcopterygian lineage. Three QRFPR genes are present in the basal actinopterygian fish, the spotted gar. Phylogenetic and chromosomal analyses show that only two of these receptor genes are orthologous between the two species, thus demonstrating a total of four distinct vertebrate genes. Three of the QRFPR genes resulted from the early vertebrate tetraploidizations and were copied along with syntenic neuropeptide Y receptor genes. The fourth QRFPR gene may be an even older and distinct lineage. Because mammals and birds have only a single QRFPR gene, this means that three genes have been lost in these lineages, and at least one of these was lost independently in mammals and birds because it is still present in a turtle. In conclusion, these results show that the QRFP system gained considerable complexity in the early stages of vertebrate evolution and still maintains much of this in some lineages, and that it has been secondarily reduced in mammals.
|
|
| 8. |
- Ocampo Daza, Daniel, et al.
(författare)
-
Evolution of the insulin-like growth factor binding protein (IGFBP) family
- 2011
-
Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 152:6, s. 2278-2289
-
Tidskriftsartikel (refereegranskat)abstract
- The evolution of the insulin-like growth factor binding protein (IGFBP) gene family has been difficult to resolve. The early discovery of IGFBP gene synteny with the HOX (homeobox) gene clusters suggested that IGFBP was quadrupled along with HOX in the ancestral vertebrate chromosome duplications. However, some recent articles have favored independent serial duplications of the IGFBP genes. By combining sequence-based phylogenies and chromosome information from multiple vertebrate species, we conclude that chromosome duplications did indeed expand the IGFBP repertoire. After the ancestral chordate IGFBP gene had undergone a local gene duplication, resulting in a gene pair adjacent to a HOX cluster, chromosome quadruplication of this pair took place in the two basal vertebrate tetraploidizations (2R). Subsequently one gene was lost from two of the four pairs, leading to six IGFBP genes in the fish-tetrapod ancestor. These six genes are presently found in placental mammals. In teleost fishes the situation is more complex: their third tetraploidization (3R) doubled the IGFBP repertoire from six to twelve members whereupon differential losses have occurred. The five sequenced teleost fish genomes retain 9-11 of IGFBP genes. This scenario is supported by the phylogenies of three adjacent gene families, namely the epidermal growth factor receptors (EGFR) and the Ikaros and distal-less (Dlx) transcription factors, in addition to the HOX clusters. The great ages for the IGFBP genes strongly suggest that they evolved distinct functions early in vertebrate evolution.
|
|
| 9. |
- Xu, Bo, et al.
(författare)
-
Characterization of peptide QRFP (26RFa) and its receptor from amphioxus, Branchiostoma floridae
- 2015
-
Ingår i: General and Comparative Endocrinology. - : Elsevier BV. - 0016-6480 .- 1095-6840. ; 210, s. 107-113
-
Tidskriftsartikel (refereegranskat)abstract
- A peptide ending with RFamide (Arg-Phe-amide) was discovered independently by three different laboratories in 2003 and named 26RFa or QRFP. In mammals, a longer version of the peptide, 43 amino acids, was identified and found to bind to the orphan G protein-coupled receptor GPR103. We searched the genome database of Branchiostoma floridae (Bfl) for receptor sequences related to those that bind peptides ending with RFa or RYa (including receptors for NPFF, PRLH, GnIH, and NPY). One receptor clustered in phylogenetic analyses with mammalian QRFP receptors. The gene has 3 introns in Bfl and 5 in human, but all intron positions differ, implying that the introns were inserted independently. A QRFP-like peptide consisting of 25 amino acids and ending with RFa was identified in the amphioxus genome. Eight of the ten last amino acids are identical between Bfl and human. The prepro-QRFP gene in Bfl has one intron in the propeptide whereas the human gene lacks introns. The Bfl QRFP peptide was synthesized and the receptor was functionally expressed in human cells. The response was measured as inositol phosphate (IP) turnover. The Bfl QRFP peptide was found to potently stimulate the receptor's ability to induce IP turnover with an EC50 of 0.28nM. Also the human QRFP peptides with 26 and 43 amino acids were found to stimulate the receptor (1.9 and 5.1nM, respectively). Human QRFP with 26 amino acids without the carboxyterminal amide had dramatically lower potency at 1.3μM. Thus, we have identified an amphioxus QRFP-related peptide and a corresponding receptor and shown that they interact to give a functional response.
|
|
