The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform

Brian Dixon - One of the best experts on this subject based on the ideXlab platform.

  • Molecular cloning and characterization of rainbow trout (Oncorhynchus mykiss) C5a anaphylatoxin receptor
    Immunogenetics, 2003
    Co-Authors: Kazuhiro Fujiki, Roy S. Sundick, Brian Dixon
    Abstract:

    In the course of suppression subtractive hybridization between the cDNA of phytohemagglutinin-stimulated and non-stimulated head kidney cells in rainbow trout ( Oncorhynchus mykiss ), a cDNA clone was obtained that showed most similarity to mammalian receptor for the anaphylatoxin of the fifth complement component (C5aR). The rainbow trout C5aR cDNA contains a 1,679-bp nucleotide sequence that encodes a 350-amino-acid putative protein with 29.0–31.5% identity to mammalian C5aR. Rainbow trout C5aR has seven putative transmembrane domains that are common to mammalian C5aR. A cysteine residue in the second cytoplasmic domain in mammalian C5aR, required for formation of disulfide-linked dimers, is seen in trout C5aR but not in other similar Rhodopsin-Like Receptors. An arginine residue in the fifth transmembrane domain, which is critical for activation of the C5aR by C5a, is also conserved in rainbow trout C5aR. The rainbow trout C5aR gene has a 1.9-kb intron in the position 12 bp upstream of the start codon, which is similar to that seen right after the start codon in human C5aR gene. These results indicate that the clone is a rainbow trout homologue of mammalian C5aR. Southern blot hybridization suggested that C5aR is a single-copy gene. Northern blotting and RT-PCR analyses detected higher amounts of the transcript in head kidney and posterior kidney, but much lower levels in peripheral blood leukocytes and spleen, faint expression in brain and gills, heart, intestine and very faint expression in liver and muscle.

Julie Kniazeff - One of the best experts on this subject based on the ideXlab platform.

  • Class C G protein-coupled Receptors: reviving old couples with new partners
    Biophysics Reports, 2017
    Co-Authors: Thor C. Møller, David Moreno-delgado, Julie Kniazeff
    Abstract:

    G protein-coupled Receptors (GPCRs) are key players in cell communication and are encoded by the largest family in our genome. As such, GPCRs represent the main targets in drug development programs. Sequence analysis revealed several classes of GPCRs: the class A Rhodopsin-Like Receptors represent the majority, the class B includes the secretin-like and adhesion GPCRs, the class F includes the frizzled Receptors, and the class C includes Receptors for the main neurotransmitters, glutamate and GABA, and those for sweet and umami taste and calcium Receptors. Class C Receptors are far more complex than other GPCRs, being mandatory dimers, with each subunit being composed of several domains. In this review, we summarize our actual knowledge regarding the activation mechanism and subunit organization of class C GPCRs, and how this brings information for many other GPCRs.

  • Heptahelical domain of metabotropic glutamate receptor 5 behaves like Rhodopsin-Like Receptors
    Proceedings of the National Academy of Sciences of the United States of America, 2003
    Co-Authors: Cyril Goudet, Florence Gaven, Julie Kniazeff, Martin Cohen-gonsaud, Francine Acher, Laurent Prézeau
    Abstract:

    Although agonists bind directly in the heptahelical domain (HD) of most class-I Rhodopsin-Like G protein coupled Receptors (GPCRs), class-III agonists bind in the extracellular domain of their Receptors. Indeed, the latter possess a large extracellular domain composed of a cysteine-rich domain and a Venus flytrap module. Both the low sequence homology and the structural organization of class-III GPCRs raised the question of whether or not the HD of these Receptors functions the same way as Rhodopsin-Like GPCRs. Here, we show that the HD of metabotropic glutamate receptor 5 (mGlu5) displays the same agonist-independent constitutive activity as the wild-type receptor. Moreover, we show that the noncompetitive antagonist MPEP [2-methyl-6-(phenylethynyl)-pyridine hydrochloride] and the positive allosteric modulator DFB (3,3′-difluorobenzaldazine) act as inverse agonist and full agonist, respectively, on the mGlu5 HD in the absence of the extracellular domain. This finding illustrates that, like Rhodopsin-Like Receptors, the HD of mGluRs can constitutively couple to G proteins and be negatively and positively regulated by ligands. These data show that the HD of mGluRs behave like any other class-I GPCRs in terms of G protein coupling and regulation by various types of ligands.

Kazuhiro Fujiki - One of the best experts on this subject based on the ideXlab platform.

  • Molecular cloning and characterization of rainbow trout (Oncorhynchus mykiss) C5a anaphylatoxin receptor
    Immunogenetics, 2003
    Co-Authors: Kazuhiro Fujiki, Roy S. Sundick, Brian Dixon
    Abstract:

    In the course of suppression subtractive hybridization between the cDNA of phytohemagglutinin-stimulated and non-stimulated head kidney cells in rainbow trout ( Oncorhynchus mykiss ), a cDNA clone was obtained that showed most similarity to mammalian receptor for the anaphylatoxin of the fifth complement component (C5aR). The rainbow trout C5aR cDNA contains a 1,679-bp nucleotide sequence that encodes a 350-amino-acid putative protein with 29.0–31.5% identity to mammalian C5aR. Rainbow trout C5aR has seven putative transmembrane domains that are common to mammalian C5aR. A cysteine residue in the second cytoplasmic domain in mammalian C5aR, required for formation of disulfide-linked dimers, is seen in trout C5aR but not in other similar Rhodopsin-Like Receptors. An arginine residue in the fifth transmembrane domain, which is critical for activation of the C5aR by C5a, is also conserved in rainbow trout C5aR. The rainbow trout C5aR gene has a 1.9-kb intron in the position 12 bp upstream of the start codon, which is similar to that seen right after the start codon in human C5aR gene. These results indicate that the clone is a rainbow trout homologue of mammalian C5aR. Southern blot hybridization suggested that C5aR is a single-copy gene. Northern blotting and RT-PCR analyses detected higher amounts of the transcript in head kidney and posterior kidney, but much lower levels in peripheral blood leukocytes and spleen, faint expression in brain and gills, heart, intestine and very faint expression in liver and muscle.

Laurent Prézeau - One of the best experts on this subject based on the ideXlab platform.

  • Heptahelical domain of metabotropic glutamate receptor 5 behaves like Rhodopsin-Like Receptors
    Proceedings of the National Academy of Sciences of the United States of America, 2003
    Co-Authors: Cyril Goudet, Florence Gaven, Julie Kniazeff, Martin Cohen-gonsaud, Francine Acher, Laurent Prézeau
    Abstract:

    Although agonists bind directly in the heptahelical domain (HD) of most class-I Rhodopsin-Like G protein coupled Receptors (GPCRs), class-III agonists bind in the extracellular domain of their Receptors. Indeed, the latter possess a large extracellular domain composed of a cysteine-rich domain and a Venus flytrap module. Both the low sequence homology and the structural organization of class-III GPCRs raised the question of whether or not the HD of these Receptors functions the same way as Rhodopsin-Like GPCRs. Here, we show that the HD of metabotropic glutamate receptor 5 (mGlu5) displays the same agonist-independent constitutive activity as the wild-type receptor. Moreover, we show that the noncompetitive antagonist MPEP [2-methyl-6-(phenylethynyl)-pyridine hydrochloride] and the positive allosteric modulator DFB (3,3′-difluorobenzaldazine) act as inverse agonist and full agonist, respectively, on the mGlu5 HD in the absence of the extracellular domain. This finding illustrates that, like Rhodopsin-Like Receptors, the HD of mGluRs can constitutively couple to G proteins and be negatively and positively regulated by ligands. These data show that the HD of mGluRs behave like any other class-I GPCRs in terms of G protein coupling and regulation by various types of ligands.

Roy S. Sundick - One of the best experts on this subject based on the ideXlab platform.

  • Molecular cloning and characterization of rainbow trout (Oncorhynchus mykiss) C5a anaphylatoxin receptor
    Immunogenetics, 2003
    Co-Authors: Kazuhiro Fujiki, Roy S. Sundick, Brian Dixon
    Abstract:

    In the course of suppression subtractive hybridization between the cDNA of phytohemagglutinin-stimulated and non-stimulated head kidney cells in rainbow trout ( Oncorhynchus mykiss ), a cDNA clone was obtained that showed most similarity to mammalian receptor for the anaphylatoxin of the fifth complement component (C5aR). The rainbow trout C5aR cDNA contains a 1,679-bp nucleotide sequence that encodes a 350-amino-acid putative protein with 29.0–31.5% identity to mammalian C5aR. Rainbow trout C5aR has seven putative transmembrane domains that are common to mammalian C5aR. A cysteine residue in the second cytoplasmic domain in mammalian C5aR, required for formation of disulfide-linked dimers, is seen in trout C5aR but not in other similar Rhodopsin-Like Receptors. An arginine residue in the fifth transmembrane domain, which is critical for activation of the C5aR by C5a, is also conserved in rainbow trout C5aR. The rainbow trout C5aR gene has a 1.9-kb intron in the position 12 bp upstream of the start codon, which is similar to that seen right after the start codon in human C5aR gene. These results indicate that the clone is a rainbow trout homologue of mammalian C5aR. Southern blot hybridization suggested that C5aR is a single-copy gene. Northern blotting and RT-PCR analyses detected higher amounts of the transcript in head kidney and posterior kidney, but much lower levels in peripheral blood leukocytes and spleen, faint expression in brain and gills, heart, intestine and very faint expression in liver and muscle.