171 research outputs found
Identification of a conserved protein motif in a group of growth factor receptors
AbstractResidues 370–383 (helix C) of the human nerve growth factor receptor (NGF-R) are highly similar to the sequence of the 14 residue wasp toxin, mastoparan. Both regions are predicted to form amphiphilic α-helices, as is the amino-terminal region of the third intracytoplasmic loop (i3) of the β2-adrenergic receptor (β2AR). As both mastoparan and the β2AR i3 interact with G-proteins, it is suggested that helix C of the NGF-R may facilitate interactions with a cytoplasmic protein. A similar structural motif was identified in the cytoplasmic domains of a number of other growth factor receptors, suggesting an important role for this motif in signal transduction mechanisms
Phylogenetic and chromosomal analyses of multiple gene families syntenic with vertebrate Hox clusters
<p>Abstract</p> <p>Background</p> <p>Ever since the theory about two rounds of genome duplication (2R) in the vertebrate lineage was proposed, the Hox gene clusters have served as the prime example of quadruplicate paralogy in mammalian genomes. In teleost fishes, the observation of additional Hox clusters absent in other vertebrate lineages suggested a third tetraploidization (3R). Because the Hox clusters occupy a quite limited part of each chromosome, and are special in having position-dependent regulation within the multi-gene cluster, studies of syntenic gene families are needed to determine the extent of the duplicated chromosome segments. We have analyzed in detail 14 gene families that are syntenic with the Hox clusters to see if their phylogenies are compatible with the Hox duplications and the 2R/3R scenario. Our starting point was the gene family for the NPY family of peptides located near the Hox clusters in the pufferfish <it>Takifugu rubripes</it>, the zebrafish <it>Danio rerio</it>, and human.</p> <p>Results</p> <p>Seven of the gene families have members on at least three of the human Hox chromosomes and two families are present on all four. Using both neighbor-joining and quartet-puzzling maximum likelihood methods we found that 13 families have a phylogeny that supports duplications coinciding with the Hox cluster duplications. One additional family also has a topology consistent with 2R but due to lack of urochordate or cephalocordate sequences the time window when these duplications could have occurred is wider. All but two gene families also show teleost-specific duplicates.</p> <p>Conclusion</p> <p>Based on this analysis we conclude that the Hox cluster duplications involved a large number of adjacent gene families, supporting expansion of these families in the 2R, as well as in the teleost 3R tetraploidization. The gene duplicates presumably provided raw material in early vertebrate evolution for neofunctionalization and subfunctionalization.</p
Concomitant Duplications of Opioid Peptide and Receptor Genes before the Origin of Jawed Vertebrates
Background: The opioid system is involved in reward and pain mechanisms and consists in mammals of four receptors an
Corticotropin-Releasing Hormone (CRH) gene family duplications in Lampreys correlate with two early vertebrate genome doublings
The ancestor of gnathostomes (jawed vertebrates) is generally considered to have undergone two rounds of whole genome duplication (WGD). The timing of these WGD events relative to the divergence of the closest relatives of the gnathostomes, the cyclostomes, has remained contentious. Lampreys and hagfishes are extant cyclostomes whose gene families can shed light on the relationship between the WGDs and the cyclostome-gnathostome divergence. Previously, we have characterized in detail the evolution of the gnathostome corticotropin-releasing hormone (CRH) family and found that its five members arose from two ancestral genes that existed before the WGDs. The two WGDs resulted, after secondary losses, in one triplet consisting of CRH1, CRH2, and UCN1, and one pair consisting of UCN2 and UCN3. All five genes exist in representatives for cartilaginous fishes, ray-finned fishes, and lobe-finned fishes. Differential losses have occurred in some lineages. We present here analyses of CRH-family members in lamprey and hagfish by comparing sequences and gene synteny with gnathostomes. We found five CRH-family genes in each of two lamprey species (Petromyzon marinus and Lethenteron camtschaticum) and two genes in a hagfish (Eptatretus burgeri). Synteny analyses show that all five lamprey CRH-family genes have similar chromosomal neighbors as the gnathostome genes. The most parsimonious explanation is that the lamprey CRH-family genes are orthologs of the five gnathostome genes and thus arose in the same chromosome duplications. This suggests that lampreys and gnathostomes share the same two WGD events and that these took place before the lamprey-gnathostome divergence.Portuguese Foundation for Science and Technology: UIDB/04326/2020info:eu-repo/semantics/publishedVersio
Early vertebrate chromosome duplications and the evolution of the neuropeptide Y receptor gene regions
<p>Abstract</p> <p>Background</p> <p>One of the many gene families that expanded in early vertebrate evolution is the neuropeptide (NPY) receptor family of G-protein coupled receptors. Earlier work by our lab suggested that several of the NPY receptor genes found in extant vertebrates resulted from two genome duplications before the origin of jawed vertebrates (gnathostomes) and one additional genome duplication in the actinopterygian lineage, based on their location on chromosomes sharing several gene families. In this study we have investigated, in five vertebrate genomes, 45 gene families with members close to the NPY receptor genes in the compact genomes of the teleost fishes <it>Tetraodon nigroviridis </it>and <it>Takifugu rubripes</it>. These correspond to <it>Homo sapiens </it>chromosomes 4, 5, 8 and 10.</p> <p>Results</p> <p>Chromosome regions with conserved synteny were identified and confirmed by phylogenetic analyses in <it>H. sapiens, M. musculus, D. rerio, T. rubripes </it>and <it>T. nigroviridis</it>. 26 gene families, including the NPY receptor genes, (plus 3 described recently by other labs) showed a tree topology consistent with duplications in early vertebrate evolution and in the actinopterygian lineage, thereby supporting expansion through block duplications. Eight gene families had complications that precluded analysis (such as short sequence length or variable number of repeated domains) and another eight families did not support block duplications (because the paralogs in these families seem to have originated in another time window than the proposed genome duplication events). RT-PCR carried out with several tissues in <it>T. rubripes </it>revealed that all five NPY receptors were expressed in the brain and subtypes Y2, Y4 and Y8 were also expressed in peripheral organs.</p> <p>Conclusion</p> <p>We conclude that the phylogenetic analyses and chromosomal locations of these gene families support duplications of large blocks of genes or even entire chromosomes. Thus, these results are consistent with two early vertebrate tetraploidizations forming a paralogon comprising human chromosomes 4, 5, 8 and 10 and one teleost tetraploidization. The combination of positional and phylogenetic data further strengthens the identification of orthologs and paralogs in the NPY receptor family.</p
Neuropeptide Y-family peptides and receptors in the elephant shark, Callorhinchus milii confirm gene duplications before the gnathostome radiation
AbstractWe describe here the repertoire of neuropeptide Y (NPY) peptides and receptors in the elephant shark Callorhinchus milii, belonging to the chondrichthyans that diverged from the rest of the gnathostome (jawed vertebrate) lineage about 450 million years ago and the first chondrichthyan with a genome project. We have identified two peptide genes that are orthologous to NPY and PYY (peptide YY) in other vertebrates, and seven receptor genes orthologous to the Y1, Y2, Y4, Y5, Y6, Y7 and Y8 subtypes found in tetrapods and teleost fishes. The repertoire of peptides and receptors seems to reflect the ancestral configuration in the predecessor of all gnathostomes, whereas other lineages such as mammals and teleosts have lost one or more receptor genes or have acquired 1–2 additional peptide genes. Both the peptides and receptors showed broad and overlapping mRNA expression which may explain why some receptor gene losses could take place in some lineages, but leaves open the question why all the known ancestral receptors have been retained in the elephant shark
Schistosomiasis in Tone River Area(Kurzfassen)
Amino acid sequence alignment of the ABLIM family which is one of the gene families that was identified as a neighbouring gene family to the PDE6 catalytic subunit gene family. The sequences were aligned using ClustalO with standard settings within the Seaview 4.5.3 program
Neuropeptide Y receptors (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database
Neuropeptide Y (NPY) receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Neuropeptide Y Receptors [156]) are activated by the endogenous peptides neuropeptide Y, neuropeptide Y-(3-36), peptide YY, PYY-(3-36) and pancreatic polypeptide (PP). The receptor originally identified as the Y3 receptor has been identified as the CXCR4 chemokine recepter (originally named LESTR, [137]). The y6 receptor is a functional gene product in mouse, absent in rat, but contains a frame-shift mutation in primates producing a truncated non-functional gene [83]. Many of the agonists exhibit differing degrees of selectivity dependent on the species examined. For example, the potency of PP is greater at the rat Y4 receptor than at the human receptor [61]. In addition, many agonists lack selectivity for individual subtypes, but can exhibit comparable potency against pairs of NPY receptor subtypes, or have not been examined for activity at all subtypes. [125I]-PYY or [125I]-NPY can be used to label Y1, Y2, Y5 and y6 subtypes non-selectively, while [125I][cPP(1-7), NPY(19-23), Ala31, Aib32, Gln34]hPP may be used to label Y5 receptors preferentially (note that cPP denotes chicken peptide sequence and hPP is the human sequence)
Neuropeptide Y receptors in GtoPdb v.2023.1
Neuropeptide Y (NPY) receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Neuropeptide Y Receptors [158]) are activated by the endogenous peptides neuropeptide Y, neuropeptide Y-(3-36), peptide YY, PYY-(3-36) and pancreatic polypeptide (PP). The receptor originally identified as the Y3 receptor has been identified as the CXCR4 chemokine recepter (originally named LESTR, [139]). The y6 receptor is a functional gene product in mouse, absent in rat, but contains a frame-shift mutation in primates producing a truncated non-functional gene [84]. Three-dimensional structures have been determined for subtype active receptors Y1, Y2 and Y4 [211, 114] and inactive antagonist bound Y1 and Y2 receptors [240, 210]. Many of the agonists exhibit differing degrees of selectivity dependent on the species examined. For example, the potency of PP is greater at the rat Y4 receptor than at the human receptor [62]. In addition, many agonists lack selectivity for individual subtypes, but can exhibit comparable potency against pairs of NPY receptor subtypes, or have not been examined for activity at all subtypes. [125I]-PYY or [125I]-NPY can be used to label Y1, Y2, Y5 and y6 subtypes non-selectively, while [125I][cPP(1-7), NPY(19-23), Ala31, Aib32, Gln34]hPP may be used to label Y5 receptors preferentially (note that cPP denotes chicken peptide sequence and hPP is the human sequence)
QRFP receptor (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database
The human gene encoding the QRFP receptor (nomenclature as agreed by the NC-IUPHAR Subcommittee on the QRFP receptor [16]; QRFPR, formerly known as the Peptide P518 receptor), previously designated as an orphan GPCR receptor was identified in 2001 by Lee et al. from a hypothalamus cDNA library [15]. However, the reported cDNA (AF411117) is a chimera with bases 1-127 derived from chromosome 1 and bases 155-1368 derived from chromosome 4. When corrected, QRFPR (also referred to as SP9155 or AQ27) encodes a 431 amino acid protein that shares sequence similarities in the transmembrane spanning regions with other peptide receptors. These include neuropeptide FF2 (38%), neuropeptide Y2 (37%) and galanin Gal1 (35%) receptors
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