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Adenylyl Cyclase

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Yoshihiro Ishikawa – One of the best experts on this subject based on the ideXlab platform.

  • direct inhibition of type 5 Adenylyl Cyclase prevents myocardial apoptosis without functional deterioration
    Journal of Biological Chemistry, 2004
    Co-Authors: Kousaku Iwatsubo, Yoshiyuki Toya, Susumu Minamisawa, Takashi Tsunematsu, Masamichi Nakagome, James E Tomlinson, Satoshi Umemura, Robert M Scarborough, Daniel E Levy, Yoshihiro Ishikawa
    Abstract:

    Abstract Adenylyl Cyclase, a major target enzyme of β-adrenergic receptor signals, is potently and directly inhibited by P-site inhibitors, classic inhibitors of this enzyme, when the enzyme catalytic activity is high. Unlike β-adrenergic receptor antagonists, this is a non- or uncompetitive inhibition with respect to ATP. We have examined whether we can utilize this enzymatic property to regulate the effects of β-adrenergic receptor stimulation differentially. After screening multiple new and classic compounds, we found that some compounds, including 1R,4R-3-(6-aminopurin-9-yl)-cyclopentanecarboxylic acid hydroxyamide, potently inhibited type 5 Adenylyl Cyclase, the major cardiac isoform, but not other isoforms. In normal mouse cardiac myocmyocytes, contraction induced by low β-adrenergic receptor stimulation was poorly inhibited with this compound, but the induction of cardiac myocyte apoptosis by high β-adrenergic receptor stimulation was effectively prevented by type 5 Adenylyl Cyclase inhibitors. In contrast, when cardiac myocmyocytes from type 5 Adenylyl Cyclase knock-out mice were examined, β-adrenergic stimulation poorly induced apoptosis. Our data suggest that the inhibition of β-adrenergic signaling at the level of the type 5 Adenylyl Cyclase isoform by P-site inhibitors may serve as an effective method to prevent cardiac myocyte apoptosis induced by excessive β-adrenergic stimulation without deleterious effect on cardiac myocyte contraction.

  • Isoform-targeted regulation of cardiac Adenylyl Cyclase.
    Journal of cardiovascular pharmacology, 2003
    Co-Authors: Yoshihiro Ishikawa
    Abstract:

    Numerous attempts have been made to develop strategies for regulating the intracellular cyclic AMP signal pharmacologically, with an intention to establish either new medical therapeutic methods or experimental tools. In the past decades, many pharmacological reagents have been identified that regulate this pathway at the level of the receptor. G protprotein, Adenylyl Cyclase, cyclic AMP, protein kinase A and phosphodiesterase. Since the cloning of Adenylyl Cyclase isoforms during the 1990s, investigators including ourselves have tried to find reagents that regulate the activity of this enzyme directly in an isoform-dependent manner. The ultimate goal of developing such reagents would be to regulate the cyclic AMP signal in an organ-dependent manner. Ourselves and other workers have reported that such reagents may vary from a simple cation to kinases. In a more recent study, using the results from crystallographic studies and computer-assisted drug design programs, we have identified subtype-selective regulators of Adenylyl Cyclase. Such regulators are mostly based upon forskolin, a diterpene compound obtained from Coleus forskolii, that acts directly on Adenylyl Cyclase to increase the intracellular levels of cyclic AMP. Similarly, novel reagents have been identified that inhibit a specific Adenylyl Cyclase isoform (e.g. type 5 Adenylyl Cyclase). Such reagents would potentially provide a new therapeutic strategy to treat hypertension, for example, as well as methods to selectively stimulate or inhibit this Adenylyl Cyclase isoform, which may be reminiscent of overexpression or knocking out of the cardiac Adenylyl Cyclase isoform by the use of a pharmacological method.

  • Adenylyl Cyclase: A Molecule of Diversity
    Catecholamine Research, 2002
    Co-Authors: Yoshihiro Ishikawa
    Abstract:

    It is now well known that Adenylyl Cyclase is made of multiple subtypes that are divergent in tissue distribution and biochemical characteristics. So far nine subtypes have been cloned and characterized (Hanoune, et al., 2001, Ishikawa, 1997). These subtypes share the common property, i.e., the conversion of ATP to cAMP upon stimulation by Gsα. Other properties such as regulation by Gsγ or calcineurin, however, are different among the subtypes. Further, the tissue distribution of these subtypes is also different. Types I and VIII are localized to neuronal tissues and type V is found in the corpus striatum and the heart. Type IV is found elsewhere. It is thus speculated that each tissue or cell type expresses an unique combination of multiple Adenylyl Cyclase subtypes. In this article, I will summarize the divergent regulation of each Adenylyl Cyclase subtypes from various aspects including that by newly developed pharmacological reagents.

Boris Tabakoff – One of the best experts on this subject based on the ideXlab platform.

  • Immunological assessment of the distribution of Type VII Adenylyl Cyclase in brain
    Brain Research, 1998
    Co-Authors: N Mons, Masami Yoshimura, P L Hoffman, Hiroshi Ikeda, Boris Tabakoff
    Abstract:

    Abstract The localization of the nine identified isoforms of Adenylyl Cyclase in brain has been largely based on determination of patterns of mRNA expression. A polyclonal antibody has now been developed that specifically recognizes Type VII Adenylyl Cyclase. This antibody was used for immunocytochemical analysis of the distribution of Type VII Adenylyl Cyclase in rat brain. Labeling of Type VII Adenylyl Cyclase was observed in several areas, including cerebellum, caudate-putamen, nucleus accumbens, hippocampus and cerebral cortex. In some of these areas, the staining of the Adenylyl Cyclase protein suggested the possibility of presynaptic localization. For example, in situ hybridization showed Type VII Adenylyl Cyclase mRNA concentrated in cerebellar granule neurons. The cerebellar granule cell layer, however, showed little immunostaining, while punctate immunostaining was observed in the molecular layer. These results suggested that protein synthesized in the granule neurons may be targeted to the neuron terminals. Punctate staining in the caudate-putamen, globus pallidus and nucleus accumbens also suggested the possibility of axonal and/or dendritic localization of Type VII Adenylyl Cyclase in these regions. Labeling of the soma of cerebellar Purkinje cells, cortical pyramidal and non-pyramidal cells and interneurons in the cerebellum and hippocampus was also observed. Type VII Adenylyl Cyclase, like the other Adenylyl Cyclase isoforms, has distinct regulatory characteristics, including sensitivity to stimulation by Gsα and G protprotein βγ subunits, modulation by protein kinase C, and high sensitivity to stimulation by ethanol. These characteristics, and the discrete localization of this enzyme, may contribute to its ability to provide signal integration and/or control of neurotransmitter release in particular neurons or brain areas.

  • mu-Opioid receptors inhibit dopamine-stimulated activity of type V Adenylyl Cyclase but enhance dopamine-stimulated activity of type VII Adenylyl Cyclase.
    Molecular pharmacology, 1996
    Co-Authors: Masami Yoshimura, H Ikeda, Boris Tabakoff
    Abstract:

    The introduction of D1A dopamine receptors and mu-opioid receptors into HEK 293 cells that were also transiently transfected with Adenylyl Cyclase cDNA imparted to dopamine and to mu-opioid receptor agonists the ability to modulate the activity of the expressed Adenylyl Cyclase. Dopamine added to cells expressing D1A receptors and type V Adenylyl Cyclase significantly stimulated type V enzyme activity. The concomitant addition of morphine produced a dose-dependent inhibition of dopamine-stimulated type V Adenylyl Cyclase activity. On the other hand, if the HEK 293 cells were transfected with cDNA for type VII Adenylyl Cyclase instead of the type V isoform, morphine stimulated this Adenylyl Cyclase activity beyond the stimulation produced by dopamine. Both the inhibitory and stimulatory effects of morphine were blocked by naloxone or pretreatment of the transfected HEK 293 cells with pertussis toxin. When expressed in the HEK 293 cells, the alpha subunit of transducin, which is considered to be the putative scavenger of the beta gamma subunits of G protproteins, suppressed the stimulatory effect of morphine on type VII Adenylyl Cyclase. We also expressed the Adenylyl Cyclases in cells that were transfected with D1A receptor and G beta 1 and G gamma 2 cDNAs. Dopamine was more efficacious in stimulating type VII Adenylyl Cyclase activity in cells concomitantly transfected with the beta gamma subunit cDNAs than in cells not transfected with these G protprotein subunits. Transfection with beta gamma subunit cDNAs did not affect dopamine stimulation of type V Adenylyl Cyclase activity, and morphine-induced inhibition of type V Adenylyl Cyclase activity was still evident in cells cotransfected with the alpha subunit of transducin. These data support the contention that the effects on type VII Adenylyl Cyclase activity mediated through the G1/G(o) proteins may depend on the actions of the beta gamma subunits. The same is not the case for type V Adenylyl Cyclase. Our data demonstrate that both qualitative and quantitative responses to mu-opioid receptor stimulation depend on the isoform of Adenylyl Cyclase expressed in neurons or other cells of the body.

  • The characterization of a novel human Adenylyl Cyclase which is present in brain and other tissues
    The Journal of biological chemistry, 1995
    Co-Authors: Kaisa Hellevuo, Dermot M.f. Cooper, Masami Yoshimura, N Mons, P L Hoffman, Boris Tabakoff
    Abstract:

    Abstract We characterized a human cDNA clone which encodes a novel Adenylyl Cyclase. Data from Southern and Northern blot analysis, and analysis of sequence similarity with a recently cloned mouse Adenylyl Cyclase (10), indicated that the human Adenylyl Cyclase was a species variant of type VII Adenylyl Cyclase. The sequence of the novel human Adenylyl Cyclase indicated it was a member of the type II Adenylyl Cyclase family, and we compared the regulatory characteristics of the novel human enzyme with those of type II Adenylyl Cyclase. The human type VII and rat type II Adenylyl Cyclases, expressed in human embryonic kidney 293 cells, were activated by prostaglandin E1 (PGE1), but only type VII was activated by isoproterenol. The stimulation of type VII Adenylyl Cyclase by PGE1 and isoproterenol was attenuated by pretreatment of the cells with staurosporine. Phorbol 12,13-dibutyrate synergistically enhanced the stimulation of both type VII and type II enzyme activity by PGE1 and by the constitutively active Gs mutant Gs (Q227L). The human type VII Adenylyl Cyclase activity was unresponsive to capacitatively induced changes in intracellular Ca2+. The functional characteristics of human type VII Adenylyl Cyclase resemble those of the rat type II enzyme, but the enzymes may respond differently to in vivo phosphorylation conditions. While the mRNA for Adenylyl Cyclase type II was found in several brain areas, the message for type VII Adenylyl Cyclase was localized primarily to the cerebellar granule cell layer.

Carmen W. Dessauer – One of the best experts on this subject based on the ideXlab platform.

  • g protein regulated endocytic trafficking of Adenylyl Cyclase type 9
    eLife, 2020
    Co-Authors: Andre M Lazar, Carmen W. Dessauer, Roshanak Irannejad, Tanya A Baldwin, Aparna Sundaram, Silvio J Gutkind, Asuka Inoue, Mark Von Zastrow
    Abstract:

    Cells sense changes in their chemical environment using proteins called receptors. These proteins often sit on the cell surface, detecting molecules outside the cell and relaying messages across the membrane to the cell interior. The largest family of receptors is formed of ‘G protprotein-coupled receptors’ (or GPCRs for short), so named because they relay messages through so-called G protproteins, which then send information into the cell by interacting with other proteins called effectors. Next, the receptors leave the cell surface, travelling into the cell in compartments called endosomes. Researchers used to think that this switched the receptors off, stopping the signaling process, but it is now clear that this is not the case. Some receptors continue to signal from inside the cell, though the details of how this works are unclear. For signals to pass from a GPCR to a G protprotein to an effector, all three proteins need to be in the same place. This is certainly happening at the cell surface, but whether all three types of proteins come together inside endosomes is less clear. One way to find out is to look closely at the location of effector proteins when GPCRs are receiving signals. One well-studied effector of GPCR signaling is called Adenylyl Cyclase, a protein that makes a signal molecule called cAMP. Some G protproteins switch Adenylyl Cyclase on, increasing cAMP production, while others switch it off. To find out how GPCRs send signals from inside endosomes, Lazar et al tracked Adenylyl Cyclase proteins inside human cells. This revealed that a type of Adenylyl Cyclase, known as Adenylyl Cyclase 9, follows receptors as they travel into the cell. Under the influence of active G protproteins, activated Adenylyl Cyclase 9 left the cell surface and entered the endosomes. Once inside the cell, Adenylyl Cyclase 9 generated the signal molecule cAMP, allowing the receptors to send messages from inside the cell. Other types of Adenylyl Cyclase behaved differently. Adenylyl Cyclase 1, for example, remained on the cell surface even after its receptors had left, and did not signal from inside the cell at all. Which cell behaviors are triggered from the membrane, and which are triggered from inside the cell is an important question in drug design. Understanding where effector proteins are active is a step towards finding the answers. This could help research into diseases of the heart, the liver and the lungs, all of which use Adenylyl Cyclase 9 to send signals.

  • g protein regulated endocytic trafficking of Adenylyl Cyclase type 9
    bioRxiv, 2020
    Co-Authors: Andre M Lazar, Carmen W. Dessauer, Mark Von Zastrow, Roshanak Irannejad, Tanya A Baldwin, Aparna Sundaram, Silvio J Gutkind, Asuka Lnoue
    Abstract:

    GPCRs are increasingly recognized to initiate signaling via heterotrimeric G protproteins as they move through the endocytic network, but little is known about how relevant G protprotein effectors are localized. Here we report dynamic trafficking of Adenylyl Cyclase type 9 (AC9) from the plasma membrane to endosomes, while Adenylyl Cyclase type 1 (AC1) remains in the plasma membrane, and stimulation of AC9 trafficking by ligand-induced activation of Gs-coupled GPCRs or Gs. AC9 transits a similar dynamin-dependent early endocytic pathway as activated GPCRs but, in contrast to GPCR trafficking which is regulated by β-arrestin but not Gs, AC9 trafficking is regulated by Gs but not β-arrestin. We also show that AC9, but not AC1, contributes to cAMP production from endosomes. These results reveal dynamic and isoform-specific trafficking of Adenylyl Cyclase in the endocytic network, and a discrete role of a heterotrimeric G protprotein in controlling subcellular location of a relevant effector.

  • Identification of RGS2 and type V Adenylyl Cyclase interaction sites.
    The Journal of biological chemistry, 2003
    Co-Authors: Samina Salim, Srikumar Sinnarajah, John H. Kehrl, Carmen W. Dessauer
    Abstract:

    The production of cAMP is controlled on many levels, notably at the level of cAMP synthesis by the enzyme Adenylyl Cyclase. We have recently identified a new regulator of Adenylyl Cyclase activity, RGS2, which decreases cAMP accumulation when overexpressed in HEK293 cells and inhibits the in vitro activity of types III, V, and VI Adenylyl Cyclase. In addition, RGS2 blocking antibodies lead to elevated cAMP levels in olfactory neurons. Here we examine the nature of the interaction between RGS2 and type V Adenylyl Cyclase. In HEK293 cells expressing type V Adenylyl Cyclase, RGS2 inhibited Galpha(s)-Q227L- or beta(2)-adrenergic receptor-stimulated cAMP accumulation. Deletion of the N-terminal 19 amino acids of RGS2 abolished its ability to inhibit cAMP accumulation and to bind Adenylyl Cyclase. Further mutational analysis indicated that neither the C terminus, RGS GAP activity, nor the RGS box domain is required for inhibition of Adenylyl Cyclase. Alanine scanning of the N-terminal amino acids of RGS2 identified three residues responsible for the inhibitory function of RGS2. Furthermore, we show that RGS2 interacts directly with the C(1) but not the C(2) domain of type V Adenylyl Cyclase and that the inhibition by RGS2 is independent of inhibition by Galpha(i). These results provide clear evidence for functional effects of RGS2 on Adenylyl Cyclase activity that adds a new dimension to an intricate signaling network.

N Mons – One of the best experts on this subject based on the ideXlab platform.

  • Immunological assessment of the distribution of type VII Adenylyl Cyclase in brain.
    Brain research, 1998
    Co-Authors: N Mons, H Ikeda, M Yoshimura, P L Hoffman, B Tabakoff
    Abstract:

    The localization of the nine identified isoforms of Adenylyl Cyclase in brain has been largely based on determination of patterns of mRNA expression. A polyclonal antibody has now been developed that specifically recognizes Type VII Adenylyl Cyclase. This antibody was used for immunocytochemical analysis of the distribution of Type VII Adenylyl Cyclase in rat brain. Labeling of Type VII Adenylyl Cyclase was observed in several areas, including cerebellum, caudate-putamen, nucleus accumbens, hippocampus and cerebral cortex. In some of these areas, the staining of the Adenylyl Cyclase protein suggested the possibility of presynaptic localization. For example, in situ hybridization showed Type VII Adenylyl Cyclase mRNA concentrated in cerebellar granule neurons. The cerebellar granule cell layer, however, showed little immunostaining, while punctate immunostaining was observed in the molecular layer. These results suggested that protein synthesized in the granule neurons may be targeted to the neuron terminals. Punctate staining in the caudate-putamen, globus pallidus and nucleus accumbens also suggested the possibility of axonal and/or dendritic localization of Type VII Adenylyl Cyclase in these regions. Labeling of the soma of cerebellar Purkinje cells, cortical pyramidal and non-pyramidal cells and interneurons in the cerebellum and hippocampus was also observed. Type VII Adenylyl Cyclase, like the other Adenylyl Cyclase isoforms, has distinct regulatory characteristics, including sensitivity to stimulation by Gsalpha and G protprotein betagamma subunits, modulation by protein kinase C, and high sensitivity to stimulation by ethanol. These characteristics, and the discrete localization of this enzyme, may contribute to its ability to provide signal integration and/or control of neurotransmitter release in particular neurons or brain areas.

  • Immunological assessment of the distribution of Type VII Adenylyl Cyclase in brain
    Brain Research, 1998
    Co-Authors: N Mons, Masami Yoshimura, P L Hoffman, Hiroshi Ikeda, Boris Tabakoff
    Abstract:

    Abstract The localization of the nine identified isoforms of Adenylyl Cyclase in brain has been largely based on determination of patterns of mRNA expression. A polyclonal antibody has now been developed that specifically recognizes Type VII Adenylyl Cyclase. This antibody was used for immunocytochemical analysis of the distribution of Type VII Adenylyl Cyclase in rat brain. Labeling of Type VII Adenylyl Cyclase was observed in several areas, including cerebellum, caudate-putamen, nucleus accumbens, hippocampus and cerebral cortex. In some of these areas, the staining of the Adenylyl Cyclase protein suggested the possibility of presynaptic localization. For example, in situ hybridization showed Type VII Adenylyl Cyclase mRNA concentrated in cerebellar granule neurons. The cerebellar granule cell layer, however, showed little immunostaining, while punctate immunostaining was observed in the molecular layer. These results suggested that protein synthesized in the granule neurons may be targeted to the neuron terminals. Punctate staining in the caudate-putamen, globus pallidus and nucleus accumbens also suggested the possibility of axonal and/or dendritic localization of Type VII Adenylyl Cyclase in these regions. Labeling of the soma of cerebellar Purkinje cells, cortical pyramidal and non-pyramidal cells and interneurons in the cerebellum and hippocampus was also observed. Type VII Adenylyl Cyclase, like the other Adenylyl Cyclase isoforms, has distinct regulatory characteristics, including sensitivity to stimulation by Gsα and G protein βγ subunits, modulation by protein kinase C, and high sensitivity to stimulation by ethanol. These characteristics, and the discrete localization of this enzyme, may contribute to its ability to provide signal integration and/or control of neurotransmitter release in particular neurons or brain areas.

  • The characterization of a novel human Adenylyl Cyclase which is present in brain and other tissues
    The Journal of biological chemistry, 1995
    Co-Authors: Kaisa Hellevuo, Dermot M.f. Cooper, Masami Yoshimura, N Mons, P L Hoffman, Boris Tabakoff
    Abstract:

    Abstract We characterized a human cDNA clone which encodes a novel Adenylyl Cyclase. Data from Southern and Northern blot analysis, and analysis of sequence similarity with a recently cloned mouse Adenylyl Cyclase (10), indicated that the human Adenylyl Cyclase was a species variant of type VII Adenylyl Cyclase. The sequence of the novel human Adenylyl Cyclase indicated it was a member of the type II Adenylyl Cyclase family, and we compared the regulatory characteristics of the novel human enzyme with those of type II Adenylyl Cyclase. The human type VII and rat type II Adenylyl Cyclases, expressed in human embryonic kidney 293 cells, were activated by prostaglandin E1 (PGE1), but only type VII was activated by isoproterenol. The stimulation of type VII Adenylyl Cyclase by PGE1 and isoproterenol was attenuated by pretreatment of the cells with staurosporine. Phorbol 12,13-dibutyrate synergistically enhanced the stimulation of both type VII and type II enzyme activity by PGE1 and by the constitutively active Gs mutant Gs (Q227L). The human type VII Adenylyl Cyclase activity was unresponsive to capacitatively induced changes in intracellular Ca2+. The functional characteristics of human type VII Adenylyl Cyclase resemble those of the rat type II enzyme, but the enzymes may respond differently to in vivo phosphorylation conditions. While the mRNA for Adenylyl Cyclase type II was found in several brain areas, the message for type VII Adenylyl Cyclase was localized primarily to the cerebellar granule cell layer.

Masami Yoshimura – One of the best experts on this subject based on the ideXlab platform.

  • Immunological assessment of the distribution of Type VII Adenylyl Cyclase in brain
    Brain Research, 1998
    Co-Authors: N Mons, Masami Yoshimura, P L Hoffman, Hiroshi Ikeda, Boris Tabakoff
    Abstract:

    Abstract The localization of the nine identified isoforms of Adenylyl Cyclase in brain has been largely based on determination of patterns of mRNA expression. A polyclonal antibody has now been developed that specifically recognizes Type VII Adenylyl Cyclase. This antibody was used for immunocytochemical analysis of the distribution of Type VII Adenylyl Cyclase in rat brain. Labeling of Type VII Adenylyl Cyclase was observed in several areas, including cerebellum, caudate-putamen, nucleus accumbens, hippocampus and cerebral cortex. In some of these areas, the staining of the Adenylyl Cyclase protein suggested the possibility of presynaptic localization. For example, in situ hybridization showed Type VII Adenylyl Cyclase mRNA concentrated in cerebellar granule neurons. The cerebellar granule cell layer, however, showed little immunostaining, while punctate immunostaining was observed in the molecular layer. These results suggested that protein synthesized in the granule neurons may be targeted to the neuron terminals. Punctate staining in the caudate-putamen, globus pallidus and nucleus accumbens also suggested the possibility of axonal and/or dendritic localization of Type VII Adenylyl Cyclase in these regions. Labeling of the soma of cerebellar Purkinje cells, cortical pyramidal and non-pyramidal cells and interneurons in the cerebellum and hippocampus was also observed. Type VII Adenylyl Cyclase, like the other Adenylyl Cyclase isoforms, has distinct regulatory characteristics, including sensitivity to stimulation by Gsα and G protein βγ subunits, modulation by protein kinase C, and high sensitivity to stimulation by ethanol. These characteristics, and the discrete localization of this enzyme, may contribute to its ability to provide signal integration and/or control of neurotransmitter release in particular neurons or brain areas.

  • mu-Opioid receptors inhibit dopamine-stimulated activity of type V Adenylyl Cyclase but enhance dopamine-stimulated activity of type VII Adenylyl Cyclase.
    Molecular pharmacology, 1996
    Co-Authors: Masami Yoshimura, H Ikeda, Boris Tabakoff
    Abstract:

    The introduction of D1A dopamine receptors and mu-opioid receptors into HEK 293 cells that were also transiently transfected with Adenylyl Cyclase cDNA imparted to dopamine and to mu-opioid receptor agonists the ability to modulate the activity of the expressed Adenylyl Cyclase. Dopamine added to cells expressing D1A receptors and type V Adenylyl Cyclase significantly stimulated type V enzyme activity. The concomitant addition of morphine produced a dose-dependent inhibition of dopamine-stimulated type V Adenylyl Cyclase activity. On the other hand, if the HEK 293 cells were transfected with cDNA for type VII Adenylyl Cyclase instead of the type V isoform, morphine stimulated this Adenylyl Cyclase activity beyond the stimulation produced by dopamine. Both the inhibitory and stimulatory effects of morphine were blocked by naloxone or pretreatment of the transfected HEK 293 cells with pertussis toxin. When expressed in the HEK 293 cells, the alpha subunit of transducin, which is considered to be the putative scavenger of the beta gamma subunits of G proteins, suppressed the stimulatory effect of morphine on type VII Adenylyl Cyclase. We also expressed the Adenylyl Cyclases in cells that were transfected with D1A receptor and G beta 1 and G gamma 2 cDNAs. Dopamine was more efficacious in stimulating type VII Adenylyl Cyclase activity in cells concomitantly transfected with the beta gamma subunit cDNAs than in cells not transfected with these G protein subunits. Transfection with beta gamma subunit cDNAs did not affect dopamine stimulation of type V Adenylyl Cyclase activity, and morphine-induced inhibition of type V Adenylyl Cyclase activity was still evident in cells cotransfected with the alpha subunit of transducin. These data support the contention that the effects on type VII Adenylyl Cyclase activity mediated through the G1/G(o) proteins may depend on the actions of the beta gamma subunits. The same is not the case for type V Adenylyl Cyclase. Our data demonstrate that both qualitative and quantitative responses to mu-opioid receptor stimulation depend on the isoform of Adenylyl Cyclase expressed in neurons or other cells of the body.

  • The characterization of a novel human Adenylyl Cyclase which is present in brain and other tissues
    The Journal of biological chemistry, 1995
    Co-Authors: Kaisa Hellevuo, Dermot M.f. Cooper, Masami Yoshimura, N Mons, P L Hoffman, Boris Tabakoff
    Abstract:

    Abstract We characterized a human cDNA clone which encodes a novel Adenylyl Cyclase. Data from Southern and Northern blot analysis, and analysis of sequence similarity with a recently cloned mouse Adenylyl Cyclase (10), indicated that the human Adenylyl Cyclase was a species variant of type VII Adenylyl Cyclase. The sequence of the novel human Adenylyl Cyclase indicated it was a member of the type II Adenylyl Cyclase family, and we compared the regulatory characteristics of the novel human enzyme with those of type II Adenylyl Cyclase. The human type VII and rat type II Adenylyl Cyclases, expressed in human embryonic kidney 293 cells, were activated by prostaglandin E1 (PGE1), but only type VII was activated by isoproterenol. The stimulation of type VII Adenylyl Cyclase by PGE1 and isoproterenol was attenuated by pretreatment of the cells with staurosporine. Phorbol 12,13-dibutyrate synergistically enhanced the stimulation of both type VII and type II enzyme activity by PGE1 and by the constitutively active Gs mutant Gs (Q227L). The human type VII Adenylyl Cyclase activity was unresponsive to capacitatively induced changes in intracellular Ca2+. The functional characteristics of human type VII Adenylyl Cyclase resemble those of the rat type II enzyme, but the enzymes may respond differently to in vivo phosphorylation conditions. While the mRNA for Adenylyl Cyclase type II was found in several brain areas, the message for type VII Adenylyl Cyclase was localized primarily to the cerebellar granule cell layer.