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Khani S, Topel H, Kardinal R, Tavanez AR, Josephrajan A, Larsen BDM, Gaudry MJ, Leyendecker P, Egedal NM, Güller AS, Stanic N, Ruppert PMM, Gaziano I, Hansmeier NR, Schmidt E, Klemm P, Vagliano LM, Stahl R, Duthie F, Krause JH, Bici A, Engelhard CA, Gohlke S, Frommolt P, Gnad T, Rada-Iglesias A, Pradas-Juni M, Schulz TJ, Wunderlich FT, Pfeifer A, Bartelt A, Jastroch M, Wachten D, Kornfeld JW. Cold-induced expression of a truncated adenylyl cyclase 3 acts as rheostat to brown fat function. Nat Metab 2024; 6:1053-1075. [PMID: 38684889 DOI: 10.1038/s42255-024-01033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 03/25/2024] [Indexed: 05/02/2024]
Abstract
Promoting brown adipose tissue (BAT) activity innovatively targets obesity and metabolic disease. While thermogenic activation of BAT is well understood, the rheostatic regulation of BAT to avoid excessive energy dissipation remains ill-defined. Here, we demonstrate that adenylyl cyclase 3 (AC3) is key for BAT function. We identified a cold-inducible promoter that generates a 5' truncated AC3 mRNA isoform (Adcy3-at), whose expression is driven by a cold-induced, truncated isoform of PPARGC1A (PPARGC1A-AT). Male mice lacking Adcy3-at display increased energy expenditure and are resistant to obesity and ensuing metabolic imbalances. Mouse and human AC3-AT are retained in the endoplasmic reticulum, unable to translocate to the plasma membrane and lack enzymatic activity. AC3-AT interacts with AC3 and sequesters it in the endoplasmic reticulum, reducing the pool of adenylyl cyclases available for G-protein-mediated cAMP synthesis. Thus, AC3-AT acts as a cold-induced rheostat in BAT, limiting adverse consequences of cAMP activity during chronic BAT activation.
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Affiliation(s)
- Sajjad Khani
- Institute for Genetics, University of Cologne, Cologne, Germany
- Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Hande Topel
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Novo Nordisk Foundation Center for Adipocyte Signaling (Adiposign), University of Southern Denmark, Odense, Denmark
| | - Ronja Kardinal
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Ana Rita Tavanez
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Novo Nordisk Foundation Center for Adipocyte Signaling (Adiposign), University of Southern Denmark, Odense, Denmark
| | - Ajeetha Josephrajan
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Novo Nordisk Foundation Center for Adipocyte Signaling (Adiposign), University of Southern Denmark, Odense, Denmark
| | | | - Michael James Gaudry
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Philipp Leyendecker
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Nadia Meincke Egedal
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Novo Nordisk Foundation Center for Adipocyte Signaling (Adiposign), University of Southern Denmark, Odense, Denmark
| | - Aylin Seren Güller
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Natasa Stanic
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Novo Nordisk Foundation Center for Adipocyte Signaling (Adiposign), University of Southern Denmark, Odense, Denmark
| | - Phillip M M Ruppert
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | | | | | - Elena Schmidt
- Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Paul Klemm
- Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Lara-Marie Vagliano
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Rainer Stahl
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Fraser Duthie
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Jens-Henning Krause
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany
| | - Ana Bici
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
| | - Christoph Andreas Engelhard
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- Centre for Physical Activity Research, Department of Infectious Diseases, Rigshospitalet, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sabrina Gohlke
- Department of Adipocyte Development and Nutrition, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
| | - Peter Frommolt
- Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Gnad
- Institute of Pharmacology and Toxicology, University Hospital, University of Bonn, Bonn, Germany
| | - Alvaro Rada-Iglesias
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), CSIC/University of Cantabria, Santander, Spain
| | - Marta Pradas-Juni
- Novo Nordisk Foundation Center for Basic Metabolic Research (CBMR), Copenhagen, Denmark
| | - Tim Julius Schulz
- Department of Adipocyte Development and Nutrition, German Institute of Human Nutrition Potsdam-Rehbrücke, Nuthetal, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | | | - Alexander Pfeifer
- Institute of Pharmacology and Toxicology, University Hospital, University of Bonn, Bonn, Germany
| | - Alexander Bartelt
- Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany
- Institute for Diabetes and Cancer (IDC), Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Cardiovascular Research (DZHK), Partner Site Munich Heart Alliance, Munich, Germany
- Department of Molecular Metabolism and Sabri Ülker Center for Metabolic Research, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Martin Jastroch
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Dagmar Wachten
- Institute of Innate Immunity, Medical Faculty, University of Bonn, Bonn, Germany.
| | - Jan-Wilhelm Kornfeld
- Department for Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
- Novo Nordisk Foundation Center for Adipocyte Signaling (Adiposign), University of Southern Denmark, Odense, Denmark.
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Maghsoudi S, Shuaib R, Van Bastelaere B, Dakshinamurti S. Adenylyl cyclase isoforms 5 and 6 in the cardiovascular system: complex regulation and divergent roles. Front Pharmacol 2024; 15:1370506. [PMID: 38633617 PMCID: PMC11021717 DOI: 10.3389/fphar.2024.1370506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 03/11/2024] [Indexed: 04/19/2024] Open
Abstract
Adenylyl cyclases (ACs) are crucial effector enzymes that transduce divergent signals from upstream receptor pathways and are responsible for catalyzing the conversion of ATP to cAMP. The ten AC isoforms are categorized into four main groups; the class III or calcium-inhibited family of ACs comprises AC5 and AC6. These enzymes are very closely related in structure and have a paucity of selective activators or inhibitors, making it difficult to distinguish them experimentally. AC5 and AC6 are highly expressed in the heart and vasculature, as well as the spinal cord and brain; AC6 is also abundant in the lungs, kidney, and liver. However, while AC5 and AC6 have similar expression patterns with some redundant functions, they have distinct physiological roles due to differing regulation and cAMP signaling compartmentation. AC5 is critical in cardiac and vascular function; AC6 is a key effector of vasodilatory pathways in vascular myocytes and is enriched in fetal/neonatal tissues. Expression of both AC5 and AC6 decreases in heart failure; however, AC5 disruption is cardio-protective, while overexpression of AC6 rescues cardiac function in cardiac injury. This is a comprehensive review of the complex regulation of AC5 and AC6 in the cardiovascular system, highlighting overexpression and knockout studies as well as transgenic models illuminating each enzyme and focusing on post-translational modifications that regulate their cellular localization and biological functions. We also describe pharmacological challenges in the design of isoform-selective activators or inhibitors for AC5 and AC6, which may be relevant to developing new therapeutic approaches for several cardiovascular diseases.
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Affiliation(s)
- Saeid Maghsoudi
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada
- Biology of Breathing Group, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Rabia Shuaib
- Biology of Breathing Group, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Ben Van Bastelaere
- Biology of Breathing Group, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
| | - Shyamala Dakshinamurti
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB, Canada
- Biology of Breathing Group, Children’s Hospital Research Institute of Manitoba, Winnipeg, MB, Canada
- Section of Neonatology, Department of Pediatrics, Health Sciences Centre, Winnipeg, MB, Canada
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3
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Miao YD, Quan WX, Dong X, Gan J, Ji CF, Wang JT, Zhang F. Prognosis-related metabolic genes in the development of colorectal cancer progress and perspective. Gene 2023; 862:147263. [PMID: 36758843 DOI: 10.1016/j.gene.2023.147263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 02/10/2023]
Abstract
Colorectal cancer (CRC) is one of the most commonplace malignant tumors in the world. The occurrence and development of CRC are involved in numerous events. Metabolic reprogramming is one of the hallmarks of cancer and is convoluted and associated with carcinogenesis. Lots of metabolic genes are involved in the occurrence and progression of CRC. Study methods combining tumor genomics and metabolomics are more likely to explore this field in depth. In this mini-review, we make the latest progress and future prospects into the different molecular mechanisms of seven prognosis-related metabolic genes, we screened out in previous research, involved in the occurrence and development of CRC.
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Affiliation(s)
- Yan-Dong Miao
- The Cancer Center, Yantai Affiliated Hospital of Binzhou Medical University, The 2nd Medical College of Binzhou Medical University, Yantai 264100, China
| | - Wu-Xia Quan
- Yantai Affiliated Hospital of Binzhou Medical University, The 2nd Medical College of Binzhou Medical University, Yantai 264100, China
| | - Xin Dong
- The Cancer Center, Yantai Affiliated Hospital of Binzhou Medical University, The 2nd Medical College of Binzhou Medical University, Yantai 264100, China
| | - Jian Gan
- Department of Gastroenterology, Yantai Affiliated Hospital of Binzhou Medical University, The 2nd Medical College of Binzhou Medical University, Yantai 264100, China
| | - Cui-Feng Ji
- Yantai Affiliated Hospital of Binzhou Medical University, The 2nd Medical College of Binzhou Medical University, Yantai 264100, China
| | - Jiang-Tao Wang
- Department of Thyroid and Breast Surgery, Yantai Affiliated Hospital of Binzhou Medical University, The 2nd Medical College of Binzhou Medical University, Yantai 264100, China
| | - Fang Zhang
- The Cancer Center, Yantai Affiliated Hospital of Binzhou Medical University, The 2nd Medical College of Binzhou Medical University, Yantai 264100, China.
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Preferential Expression of Ca2+-Stimulable Adenylyl Cyclase III in the Supraventricular Area, Including Arrhythmogenic Pulmonary Vein of the Rat Heart. Biomolecules 2022; 12:biom12050724. [PMID: 35625651 PMCID: PMC9138642 DOI: 10.3390/biom12050724] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 12/10/2022] Open
Abstract
Ectopic excitability in pulmonary veins (PVs) is the major cause of atrial fibrillation. We previously reported that the inositol trisphosphate receptor in rat PV cardiomyocytes cooperates with the Na+-Ca2+ exchanger to provoke ectopic automaticity in response to norepinephrine. Here, we focused on adenylyl cyclase (AC) as another effector of norepinephrine stimulation. RT-PCR, immunohistochemistry, and Western blotting revealed that the abundant expression of Ca2+-stimulable AC3 was restricted to the supraventricular area, including the PVs. All the other AC isotypes hardly displayed any region-specific expressions. Immunostaining of isolated cardiomyocytes showed an enriched expression of AC3 along the t-tubules in PV myocytes. The cAMP-dependent response of L-type Ca2+ currents in the PV and LA cells is strengthened by the 0.1 mM intracellular Ca2+ condition, unlike in the ventricular cells. The norepinephrine-induced automaticity of PV cardiomyocytes was reversibly suppressed by 100 µM SQ22536, an adenine-like AC inhibitor. These findings suggest that the specific expression of AC3 along t-tubules may contribute to arrhythmogenic automaticity in rat PV cardiomyocytes.
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Kleene SJ. Regenerative Calcium Currents in Renal Primary Cilia. Front Physiol 2022; 13:894518. [PMID: 35620606 PMCID: PMC9127361 DOI: 10.3389/fphys.2022.894518] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/18/2022] [Indexed: 11/13/2022] Open
Abstract
Polycystic kidney disease (PKD) is a leading cause of end-stage renal disease. PKD arises from mutations in proteins, one a Ca2+-conducting channel, expressed in the primary cilia of renal epithelial cells. A common hypothesis is that Ca2+ entering through ciliary ion channels may reduce cystogenesis. The cilia have at least two Ca2+-conducting channels: polycystin-2 (PC2) and TRPV4 (transient receptor potential (TRP) cation channel, subfamily V, member 4), but how substantially they can increase intraciliary Ca2+ is unknown. By recording channel activities in isolated cilia, conditions are identified under which the channels can increase free Ca2+ within the cilium by at least 500-fold through regenerative (positive-feedback) signaling. Ca2+ that has entered through a channel can activate the channel internally, which increases the Ca2+ influx, and so on. Regenerative signaling is favored when the concentration of the Ca2+ buffer is reduced or when a slower buffer is used. Under such conditions, the Ca2+ that enters the cilium through a single PC2 channel is sufficient to almost fully activate that same channel. Regenerative signaling is not detectable with reduced external Ca2+. Reduced buffering also allows regenerative signaling through TRPV4 channels, but not through TRPM4 (TRP subfamily M, member 4) channels, which are activated by Ca2+ but do not conduct it. On a larger scale, Ca2+ that enters through TRPV4 channels can cause secondary activation of PC2 channels. I discuss the likelihood of regenerative ciliary Ca2+ signaling in vivo, a possible mechanism for its activation, and how it might relate to cystogenesis.
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Affiliation(s)
- Steven J. Kleene
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, OH, United States
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6
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Members of the KCTD family are major regulators of cAMP signaling. Proc Natl Acad Sci U S A 2022; 119:2119237119. [PMID: 34934014 PMCID: PMC8740737 DOI: 10.1073/pnas.2119237119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2021] [Indexed: 11/18/2022] Open
Abstract
Neuromodulation is pivotal for brain function. One of the key pathways engaged by neuromodulators is signaling via second messenger cAMP, which controls a myriad of fundamental reactions. This study identifies KCTD5, a ubiquitin ligase adapter, as a regulatory element in this pathway and determines that it works by an unusual dual mode controlling the activity of cAMP-generating enzyme in neurons through both zinc transport and G protein signaling. Cyclic adenosine monophosphate (cAMP) is a pivotal second messenger with an essential role in neuronal function. cAMP synthesis by adenylyl cyclases (AC) is controlled by G protein–coupled receptor (GPCR) signaling systems. However, the network of molecular players involved in the process is incompletely defined. Here, we used CRISPR/Cas9–based screening to identify that members of the potassium channel tetradimerization domain (KCTD) family are major regulators of cAMP signaling. Focusing on striatal neurons, we show that the dominant isoform KCTD5 exerts its effects through an unusual mechanism that modulates the influx of Zn2+ via the Zip14 transporter to exert unique allosteric effects on AC. We further show that KCTD5 controls the amplitude and sensitivity of stimulatory GPCR inputs to cAMP production by Gβγ-mediated AC regulation. Finally, we report that KCTD5 haploinsufficiency in mice leads to motor deficits that can be reversed by chelating Zn2+. Together, our findings uncover KCTD proteins as major regulators of neuronal cAMP signaling via diverse mechanisms.
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Urakubo H, Yagishita S, Kasai H, Kubota Y, Ishii S. The critical balance between dopamine D2 receptor and RGS for the sensitive detection of a transient decay in dopamine signal. PLoS Comput Biol 2021; 17:e1009364. [PMID: 34591840 PMCID: PMC8483376 DOI: 10.1371/journal.pcbi.1009364] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 08/18/2021] [Indexed: 12/19/2022] Open
Abstract
In behavioral learning, reward-related events are encoded into phasic dopamine (DA) signals in the brain. In particular, unexpected reward omission leads to a phasic decrease in DA (DA dip) in the striatum, which triggers long-term potentiation (LTP) in DA D2 receptor (D2R)-expressing spiny-projection neurons (D2 SPNs). While this LTP is required for reward discrimination, it is unclear how such a short DA-dip signal (0.5-2 s) is transferred through intracellular signaling to the coincidence detector, adenylate cyclase (AC). In the present study, we built a computational model of D2 signaling to determine conditions for the DA-dip detection. The DA dip can be detected only if the basal DA signal sufficiently inhibits AC, and the DA-dip signal sufficiently disinhibits AC. We found that those two requirements were simultaneously satisfied only if two key molecules, D2R and regulators of G protein signaling (RGS) were balanced within a certain range; this balance has indeed been observed in experimental studies. We also found that high level of RGS was required for the detection of a 0.5-s short DA dip, and the analytical solutions for these requirements confirmed their universality. The imbalance between D2R and RGS is associated with schizophrenia and DYT1 dystonia, both of which are accompanied by abnormal striatal LTP. Our simulations suggest that D2 SPNs in patients with schizophrenia and DYT1 dystonia cannot detect short DA dips. We finally discussed that such psychiatric and movement disorders can be understood in terms of the imbalance between D2R and RGS.
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Affiliation(s)
- Hidetoshi Urakubo
- Integrated Systems Biology Laboratory, Department of Systems Science, Graduate School of Informatics, Kyoto University, Kyoto, Japan
- Section of Electron Microscopy, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
| | - Sho Yagishita
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan
- International Research Center for Neurointelligence (WPI-IRCN), University of Tokyo Institutes for Advanced Study (UTIAS), Tokyo, Japan
| | - Haruo Kasai
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan
- International Research Center for Neurointelligence (WPI-IRCN), University of Tokyo Institutes for Advanced Study (UTIAS), Tokyo, Japan
| | - Yoshiyuki Kubota
- Section of Electron Microscopy, National Institute for Physiological Sciences, Okazaki, Aichi, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, Japan
| | - Shin Ishii
- Integrated Systems Biology Laboratory, Department of Systems Science, Graduate School of Informatics, Kyoto University, Kyoto, Japan
- International Research Center for Neurointelligence (WPI-IRCN), University of Tokyo Institutes for Advanced Study (UTIAS), Tokyo, Japan
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Synthesis and degradation of cAMP in Giardia lamblia: possible role and characterization of a nucleotidyl cyclase with a single cyclase homology domain. Biochem J 2017; 474:4001-4017. [PMID: 29054977 DOI: 10.1042/bcj20170590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 10/17/2017] [Accepted: 10/19/2017] [Indexed: 01/25/2023]
Abstract
Despite its importance in the regulation of growth and differentiation processes of a variety of organisms, the mechanism of synthesis and degradation of cAMP (cyclic AMP) has not yet been described in Giardia lamblia In this work, we measured significant quantities of cAMP in trophozoites of G. lamblia incubated in vitro and later detected how it increases during the first hours of encystation, and how it then returns to basal levels at 24 h. Through an analysis of the genome of G. lamblia, we found sequences of three putative enzymes - one phosphodiesterase (gPDE) and two nucleotidyl cyclases (gNC1 and gNC2) - that should be responsible for the regulation of cAMP in G. lamblia Later, an RT-PCR assay confirmed that these three genes are expressed in trophozoites. The bioinformatic analysis indicated that gPDE is a transmembrane protein of 154 kDa, with a single catalytic domain in the C-terminal end; gNC1 is predicted to be a transmembrane protein of 74 kDa, with only one class III cyclase homology domain (CHD) at the C-terminal end; and gNC2 should be a transmembrane protein of 246 kDa, with two class III CHDs. Finally, we cloned and enriched the catalytic domain of gNC1 (gNC1cd) from bacteria. After that, we confirmed that gNC1cd has adenylyl cyclase (AC) activity. This enzymatic activity depends on the presence of Mn2+ and Ca2+, but no significant activity was displayed in the presence of Mg2+ Additionally, the AC activity of gNC1cd is competitively inhibited with GTP, so it is highly possible that gNC1 has guanylyl cyclase activity as well.
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Bartos DC, Morotti S, Ginsburg KS, Grandi E, Bers DM. Quantitative analysis of the Ca 2+ -dependent regulation of delayed rectifier K + current I Ks in rabbit ventricular myocytes. J Physiol 2017; 595:2253-2268. [PMID: 28008618 DOI: 10.1113/jp273676] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 12/12/2016] [Indexed: 12/25/2022] Open
Abstract
KEY POINTS [Ca2+ ]i enhanced rabbit ventricular slowly activating delayed rectifier K+ current (IKs ) by negatively shifting the voltage dependence of activation and slowing deactivation, similar to perfusion of isoproterenol. Rabbit ventricular rapidly activating delayed rectifier K+ current (IKr ) amplitude and voltage dependence were unaffected by high [Ca2+ ]i . When measuring or simulating IKs during an action potential, IKs was not different during a physiological Ca2+ transient or when [Ca2+ ]i was buffered to 500 nm. ABSTRACT The slowly activating delayed rectifier K+ current (IKs ) contributes to repolarization of the cardiac action potential (AP). Intracellular Ca2+ ([Ca2+ ]i ) and β-adrenergic receptor (β-AR) stimulation modulate IKs amplitude and kinetics, but details of these important IKs regulators and their interaction are limited. We assessed the [Ca2+ ]i dependence of IKs in steady-state conditions and with dynamically changing membrane potential and [Ca2+ ]i during an AP. IKs was recorded from freshly isolated rabbit ventricular myocytes using whole-cell patch clamp. With intracellular pipette solutions that controlled free [Ca2+ ]i , we found that raising [Ca2+ ]i from 100 to 600 nm produced similar increases in IKs as did β-AR activation, and the effects appeared additive. Both β-AR activation and high [Ca2+ ]i increased maximally activated tail IKs , negatively shifted the voltage dependence of activation, and slowed deactivation kinetics. These data informed changes in our well-established mathematical model of the rabbit myocyte. In both AP-clamp experiments and simulations, IKs recorded during a normal physiological Ca2+ transient was similar to IKs measured with [Ca2+ ]i clamped at 500-600 nm. Thus, our study provides novel quantitative data as to how physiological [Ca2+ ]i regulates IKs amplitude and kinetics during the normal rabbit AP. Our results suggest that micromolar [Ca2+ ]i , in the submembrane or junctional cleft space, is not required to maximize [Ca2+ ]i -dependent IKs activation during normal Ca2+ transients.
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Affiliation(s)
- Daniel C Bartos
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Stefano Morotti
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Kenneth S Ginsburg
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, Davis, CA 95616, USA
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10
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Boularan C, Gales C. Cardiac cAMP: production, hydrolysis, modulation and detection. Front Pharmacol 2015; 6:203. [PMID: 26483685 PMCID: PMC4589651 DOI: 10.3389/fphar.2015.00203] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/03/2015] [Indexed: 01/04/2023] Open
Abstract
Cyclic adenosine 3′,5′-monophosphate (cAMP) modulates a broad range of biological processes including the regulation of cardiac myocyte contractile function where it constitutes the main second messenger for β-adrenergic receptors' signaling to fulfill positive chronotropic, inotropic and lusitropic effects. A growing number of studies pinpoint the role of spatial organization of the cAMP signaling as an essential mechanism to regulate cAMP outcomes in cardiac physiology. Here, we will briefly discuss the complexity of cAMP synthesis and degradation in the cardiac context, describe the way to detect it and review the main pharmacological arsenal to modulate its availability.
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Affiliation(s)
- Cédric Boularan
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université Toulouse III Paul Sabatier Toulouse, France
| | - Céline Gales
- Institut des Maladies Métaboliques et Cardiovasculaires, Institut National de la Santé et de la Recherche Médicale, U1048, Université Toulouse III Paul Sabatier Toulouse, France
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Effects of 39 Compounds on Calmodulin-Regulated Adenylyl Cyclases AC1 and Bacillus anthracis Edema Factor. PLoS One 2015; 10:e0124017. [PMID: 25946093 PMCID: PMC4422518 DOI: 10.1371/journal.pone.0124017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 03/09/2015] [Indexed: 12/29/2022] Open
Abstract
Adenylyl cyclases (ACs) catalyze the conversion of ATP into the second messenger cAMP. Membranous AC1 (AC1) is involved in processes of memory and learning and in muscle pain. The AC toxin edema factor (EF) of Bacillus anthracis is involved in the development of anthrax. Both ACs are stimulated by the eukaryotic Ca2+-sensor calmodulin (CaM). The CaM-AC interaction could constitute a potential target to enhance or impair the AC activity of AC1 and EF to intervene in above (patho)physiological mechanisms. Thus, we analyzed the impact of 39 compounds including typical CaM-inhibitors, an anticonvulsant, an anticholinergic, antidepressants, antipsychotics and Ca2+-antagonists on CaM-stimulated catalytic activity of AC1 and EF. Compounds were tested at 10 μM, i.e., a concentration that can be reached therapeutically for certain antidepressants and antipsychotics. Calmidazolium chloride decreased CaM-stimulated AC1 activity moderately by about 30%. In contrast, CaM-stimulated EF activity was abrogated by calmidazolium chloride and additionally decreased by chlorpromazine, felodipine, penfluridol and trifluoperazine by about 20–40%. The activity of both ACs was decreased by calmidazolium chloride in the presence and absence of CaM. Thus, CaM-stimulated AC1 activity is more insensitive to inhibition by small molecules than CaM-stimulated EF activity. Inhibition of AC1 and EF by calmidazolium chloride is largely mediated via a CaM-independent allosteric mechanism.
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12
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Cooper DMF. Store-operated Ca²⁺-entry and adenylyl cyclase. Cell Calcium 2015; 58:368-75. [PMID: 25978874 DOI: 10.1016/j.ceca.2015.04.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 02/06/2023]
Abstract
One of the longest-standing effects of SOCE is in its selective regulation of Ca(2+)-sensitive adenylyl cyclase (AC) activity in non-excitable cells. Remarkably it was this source of Ca(2+) (SOCE) rather than the apparent magnitude of the Ca(2+)-rise that conferred AC responsiveness. The molecular basis for this dependence is now resolved in the case of adenylyl cyclase 8 (AC8). Sensors for Ca(2+) and cAMP targeted to ACs have been particularly useful in dissecting the influences upon and composition of what turn out to be signalling microdomains centred on ACs. A number of physiological processes depend on the regulation by SOCE of ACs, but the issue is under-studied. Here I will expand on these topics and point to some immediate unresolved questions.
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Affiliation(s)
- Dermot M F Cooper
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, United Kingdom.
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13
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Raoux M, Vacher P, Papin J, Picard A, Kostrzewa E, Devin A, Gaitan J, Limon I, Kas MJ, Magnan C, Lang J. Multilevel control of glucose homeostasis by adenylyl cyclase 8. Diabetologia 2015; 58:749-57. [PMID: 25403481 DOI: 10.1007/s00125-014-3445-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/28/2014] [Indexed: 01/22/2023]
Abstract
AIMS/HYPOTHESIS Nutrient homeostasis requires integration of signals generated by glucose metabolism and hormones. Expression of the calcium-stimulated adenylyl cyclase ADCY8 is regulated by glucose and the enzyme is capable of integrating signals from multiple pathways. It may thus have an important role in glucose-induced signalling and glucose homeostasis. METHODS We used pharmacological and genetic approaches in beta cells to determine secretion and calcium metabolism. Furthermore, Adcy8 knockout mice were characterised. RESULTS In clonal beta cells, inhibitors of adenylyl cyclases or their downstream targets reduced the glucose-induced increase in cytosolic calcium and insulin secretion. This was reproduced by knock-down of ADCY8, but not of ADCY1. These agents also inhibited glucose-induced increase in cytosolic calcium and electrical activity in primary beta cells and similar effects were observed after ADCY8 knock-down. Moreover, insulin secretion was diminished in islets from Adcy8 knockout mice. These mice were glucose intolerant after oral or intraperitoneal administration of glucose whereas their levels of glucagon-like peptide-1 remained unaltered. Finally, we knocked down ADCY8 in the ventromedial hypothalamus to evaluate the need for ADCY8 in the central regulation of glucose homeostasis. Whereas mice fed a standard diet had normal glucose levels, high-fat diet exacerbated glucose intolerance and knock-down mice were incapable of raising their plasma insulin levels. Finally we confirmed that ADCY8 is expressed in human islets. CONCLUSIONS/INTERPRETATIONS Collectively, our findings demonstrate that ADCY8 is required for the physiological activation of glucose-induced signalling pathways in beta cells, for glucose tolerance and for hypothalamic adaptation to a high-fat diet via regulation of islet insulin secretion.
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Affiliation(s)
- Matthieu Raoux
- Université de Bordeaux, CNRS UMR 5248, Chimie et Biologie des Membranes et Nano-objets, Batiment B14, Allée Geoffrey St Hilaire, CS90063, F-33615, Pessac, France
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14
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Membranous adenylyl cyclase 1 activation is regulated by oxidation of N- and C-terminal methionine residues in calmodulin. Biochem Pharmacol 2014; 93:196-209. [PMID: 25462816 DOI: 10.1016/j.bcp.2014.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 11/15/2014] [Accepted: 11/17/2014] [Indexed: 12/19/2022]
Abstract
Membranous adenylyl cyclase 1 (AC1) is associated with memory and learning. AC1 is activated by the eukaryotic Ca(2+)-sensor calmodulin (CaM), which contains nine methionine residues (Met) important for CaM-target interactions. During ageing, Met residues are oxidized to (S)- and (R)-methionine sulfoxide (MetSO) by reactive oxygen species arising from an age-related oxidative stress. We examined how oxidation by H2O2 of Met in CaM regulates CaM activation of AC1. We employed a series of thirteen mutant CaM proteins never assessed before in a single study, where leucine is substituted for Met, in order to analyze the effects of oxidation of specific Met. CaM activation of AC1 is regulated by oxidation of all of the C-terminal Met in CaM, and by two N-terminal Met, M36 and M51. CaM with all Met oxidized is unable to activate AC1. Activity is fully restored by the combined catalytic activities of methionine sulfoxide reductases A and B (MsrA and B), which catalyze reduction of the (S)- and (R)-MetSO stereoisomers. A small change in secondary structure is observed in wild-type CaM upon oxidation of all nine Met, but no significant secondary structure changes occur in the mutant proteins when Met residues are oxidized by H2O2, suggesting that localized polarity, flexibility and structural changes promote the functional changes accompanying oxidation. The results signify that AC1 catalytic activity can be delicately adjusted by mediating CaM activation of AC1 by reversible Met oxidation in CaM. The results are important for memory, learning and possible therapeutic routes for regulating AC1.
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15
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Nikolic I, Mitrovic M, Zelen I, Zaric M, Kastratovic T, Stanojevic M, Nenadovic M, Stojanovic T. Inhibitory role of monovalent ions on rat brain cortex adenylyl cyclase activity. J Enzyme Inhib Med Chem 2012; 28:1061-6. [PMID: 22994585 DOI: 10.3109/14756366.2012.712517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Adenylyl cyclases, comprise of a large family of enzymes that catalyze synthesis of the cyclic AMP from ATP. The aim of our study was to determine the effect of monovalent ions on both basal, stimulated adenylate cyclase EC 4.6.1.1 (AC) activity and C unit of AC and on GTPase active G-protein in the synaptic membranes of rat brain cortex. The effect of ion concentration from 30 to 200 mM (1 mM MgCl2) showed dose-dependent and significant inhibition of the basal AC activity, stimulated and unstimulated C unit activity. Stimulation of AC with 5 μM GTPγS in the presence of 50-200 mM of tested salts showed inhibitory effect on the AC activity. From our results it could be postulated that the investigated monovalent ions exert inhibitory effect on the AC complex activity by affecting the intermolecular interaction of the activated α subunit of G/F protein and the C unit of AC complex an inhibitory influence of tested monovalent ions on these molecular interaction.
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Affiliation(s)
- Ivana Nikolic
- Department of Biochemistry, Faculty of medical sciences, University of Kragujevac , Kragujevac , Serbia
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16
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Pharmacological characterization of adenylyl cyclase isoforms in rabbit kidney membranes. Naunyn Schmiedebergs Arch Pharmacol 2011; 383:357-72. [PMID: 21279330 DOI: 10.1007/s00210-011-0600-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 01/07/2011] [Indexed: 10/18/2022]
Abstract
Polycystic kidney disease (PKD) is the most common life-threatening genetic disorder with bilateral cysts caused by increased level of cyclic adenosine 3',5'-monophosphate (cAMP). Since adenylyl cyclases (ACs) catalyze cAMP formation, pharmacological characterization of renal AC isoforms is essential. Therefore, we analyzed differences in activation, inhibition, and regulation of AC isoforms in rabbit cortex and medulla membranes. Glucagon, [8-arginine]vasopressin (AVP) and catecholamines significantly activated cortical AC. However, in medulla only glucagon and AVP activated AC. Under Mg(2+) conditions the profile of cortical membrane AC enzyme kinetics and the inhibitory profile of 2'(3')-O-(N-methylanthraniloyl) (MANT) nucleotides resembled recombinant AC5. In contrast, the K (i) values of MANT nucleotides for medullary membrane AC and its kinetic properties were similar to those of recombinant AC1. Reverse-transcriptase PCR confirmed the presence of AC1 and AC5 in medulla and cortex, respectively. Cortical AC was sensitive to inhibition by Ca(2+), corroborating the importance of AC5. However, Ca(2+)/CaM dependency specific for AC1 was not found in medulla. In conclusion, according to expression, kinetics and inhibition by MANT nucleotides both parts of the kidney differ in their AC isoforms. Whereas Ca(2+)-inhibitable AC5 was confirmed in renal cortex, the initially assumed AC1 activation in medulla could not be confirmed, pointing to the involvement of another AC isoform with some similarity to AC1. Since PKD is characterized by predominant involvement of the collecting duct and the distal nephrons located in renal cortex, AC5 may be the major AC isoform in this part of the kidney where cAMP increases cyst growth. Thus, potent and selective AC5 inhibitors could constitute a novel approach to treat PKD.
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17
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Abstract
Interplay between the signaling pathways of the intracellular second messengers, cAMP and Ca(2+), has vital consequences for numerous essential physiological processes. Although cAMP can impact on Ca(2+)-homeostasis at many levels, Ca(2+) either directly, or indirectly (via calmodulin [CaM], CaM-binding proteins, protein kinase C [PKC] or Gβγ subunits) may also regulate cAMP synthesis. Here, we have evaluated the evidence for regulation of adenylyl cyclases (ACs) by Ca(2+)-signaling pathways, with an emphasis on verification of this regulation in a physiological context. The effects of compartmentalization and protein signaling complexes on the regulation of AC activity by Ca(2+)-signaling pathways are also addressed. Major gaps are apparent in the interactions that have been assumed, revealing a need to comprehensively clarify the effects of Ca(2+) signaling on individual ACs, so that the important ramifications of this critical interplay between Ca(2+) and cAMP are fully appreciated.
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Affiliation(s)
- Michelle L Halls
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, United Kingdom
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18
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Mou T, Masada N, Cooper DMF, Sprang SR. Structural basis for inhibition of mammalian adenylyl cyclase by calcium. Biochemistry 2009; 48:3387-97. [PMID: 19243146 PMCID: PMC2680196 DOI: 10.1021/bi802122k] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Type V and VI mammalian adenylyl cyclases (AC5, AC6) are inhibited by Ca(2+) at both sub- and supramicromolar concentration. This inhibition may provide feedback in situations where cAMP promotes opening of Ca(2+) channels, allowing fine control of cardiac contraction and rhythmicity in cardiac tissue where AC5 and AC6 predominate. Ca(2+) inhibits the soluble AC core composed of the C1 domain of AC5 (VC1) and the C2 domain of AC2 (IIC2). As observed for holo-AC5, inhibition is biphasic, showing "high-affinity" (K(i) = approximately 0.4 microM) and "low-affinity" (K(i) = approximately 100 microM) modes of inhibition. At micromolar concentration, Ca(2+) inhibition is nonexclusive with respect to pyrophosphate (PP(i)), a noncompetitive inhibitor with respect to ATP, but at >100 microM Ca(2+), inhibition appears to be exclusive with respect to PP(i). The 3.0 A resolution structure of Galphas.GTPgammaS/forskolin-activated VC1:IIC2 crystals soaked in the presence of ATPalphaS and 8 microM free Ca(2+) contains a single, loosely coordinated metal ion. ATP soaked into VC1:IIC2 crystals in the presence of 1.5 mM Ca(2+) is not cyclized, and two calcium ions are observed in the 2.9 A resolution structure of the complex. In both of the latter complexes VC1:IIC2 adopts the "open", catalytically inactive conformation characteristic of the apoenzyme, in contrast to the "closed", active conformation seen in the presence of ATP analogues and Mg(2+) or Mn(2+). Structures of the pyrophosphate (PP(i)) complex with 10 mM Mg(2+) (2.8 A) or 2 mM Ca(2+) (2.7 A) also adopt the open conformation, indicating that the closed to open transition occurs after cAMP release. In the latter complexes, Ca(2+) and Mg(2+) bind only to the high-affinity "B" metal site associated with substrate/product stabilization. Ca(2+) thus stabilizes the inactive conformation in both ATP- and PP(i)-bound states.
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Affiliation(s)
- Tung—Chung Mou
- Center for Biomolecular Structure and Dynamics and the Division of Biological Sciences, The University of Montana, Missoula, MT 59812
| | - Nanako Masada
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, United Kingdom
| | - Dermot M. F. Cooper
- Center for Biomolecular Structure and Dynamics and the Division of Biological Sciences, The University of Montana, Missoula, MT 59812
| | - Stephen R. Sprang
- Center for Biomolecular Structure and Dynamics and the Division of Biological Sciences, The University of Montana, Missoula, MT 59812
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19
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Sadana R, Dessauer CW. Physiological roles for G protein-regulated adenylyl cyclase isoforms: insights from knockout and overexpression studies. Neurosignals 2008; 17:5-22. [PMID: 18948702 DOI: 10.1159/000166277] [Citation(s) in RCA: 257] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 04/22/2008] [Indexed: 01/08/2023] Open
Abstract
Cyclic AMP is a universal second messenger, produced by a family of adenylyl cyclase (AC) enzymes. The last three decades have brought a wealth of new information about the regulation of cyclic AMP production by ACs. Nine hormone-sensitive, membrane-bound AC isoforms have been identified in addition to a tenth isoform that lacks membrane spans and more closely resembles the cyanobacterial AC enzymes. New model systems for purifying and characterizing the catalytic domains of AC have led to the crystal structure of these domains and the mapping of numerous interaction sites. However, big hurdles remain in unraveling the roles of individual AC isoforms and their regulation in physiological systems. In this review we explore the latest on AC knockout and overexpression studies to better understand the roles of G protein regulation of ACs in the brain, olfactory bulb, and heart.
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Affiliation(s)
- Rachna Sadana
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
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20
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Willoughby D, Cooper DMF. Organization and Ca2+Regulation of Adenylyl Cyclases in cAMP Microdomains. Physiol Rev 2007; 87:965-1010. [PMID: 17615394 DOI: 10.1152/physrev.00049.2006] [Citation(s) in RCA: 327] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The adenylyl cyclases are variously regulated by G protein subunits, a number of serine/threonine and tyrosine protein kinases, and Ca2+. In some physiological situations, this regulation can be readily incorporated into a hormonal cascade, controlling processes such as cardiac contractility or neurotransmitter release. However, the significance of some modes of regulation is obscure and is likely only to be apparent in explicit cellular contexts (or stages of the cell cycle). The regulation of many of the ACs by the ubiquitous second messenger Ca2+provides an overarching mechanism for integrating the activities of these two major signaling systems. Elaborate devices have been evolved to ensure that this interaction occurs, to guarantee the fidelity of the interaction, and to insulate the microenvironment in which it occurs. Subcellular targeting, as well as a variety of scaffolding devices, is used to promote interaction of the ACs with specific signaling proteins and regulatory factors to generate privileged domains for cAMP signaling. A direct consequence of this organization is that cAMP will exhibit distinct kinetics in discrete cellular domains. A variety of means are now available to study cAMP in these domains and to dissect their components in real time in live cells. These topics are explored within the present review.
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Affiliation(s)
- Debbie Willoughby
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
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21
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Abstract
Based on a variety of single-cell measurements, the notion that cAMP microdomains exist in cells is being increasingly embraced. The cellular and molecular underpinnings of this organization are also steadily being revealed. A dependence of Ca(2+)-sensitive ACs (adenylate cyclases) in HEK-293 cells (human embryonic kidney cells) on capacitative Ca(2+) entry is enforced by their presence in lipid rafts and protein-protein interactions. In these cells, many of the participants in the cAMP cascade, including AC, phosphodiesterase 4, cAMP-dependent protein kinase [PKA (protein kinase A)] and protein phosphatase 2A, are now seen to be involved in higher order assemblies. Moreover, the presence of Na(+)/H(+) exchanger 1 in these domains creates a microclimate, protected against global swings in cellular pH. The Ca(2+)-stimulatable AC8, which is targeted to these regions, can sequester calmodulin for its own regulatory purposes. These devices are a sampling of the multiple layers of organization that are in place -- even in a simple cell -- to ensure faithful and economical communication of the cAMP message.
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Affiliation(s)
- A C L Martin
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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22
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Kamenetsky M, Middelhaufe S, Bank EM, Levin LR, Buck J, Steegborn C. Molecular details of cAMP generation in mammalian cells: a tale of two systems. J Mol Biol 2006; 362:623-39. [PMID: 16934836 PMCID: PMC3662476 DOI: 10.1016/j.jmb.2006.07.045] [Citation(s) in RCA: 241] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 07/15/2006] [Accepted: 07/20/2006] [Indexed: 01/05/2023]
Abstract
The second messenger cAMP has been extensively studied for half a century, but the plethora of regulatory mechanisms controlling cAMP synthesis in mammalian cells is just beginning to be revealed. In mammalian cells, cAMP is produced by two evolutionary related families of adenylyl cyclases, soluble adenylyl cyclases (sAC) and transmembrane adenylyl cyclases (tmAC). These two enzyme families serve distinct physiological functions. They share a conserved overall architecture in their catalytic domains and a common catalytic mechanism, but they differ in their sub-cellular localizations and responses to various regulators. The major regulators of tmACs are heterotrimeric G proteins, which transduce extracellular signals via G protein-coupled receptors. sAC enzymes, in contrast, are regulated by the intracellular signaling molecules bicarbonate and calcium. Here, we discuss and compare the biochemical, structural and regulatory characteristics of the two mammalian AC families. This comparison reveals the mechanisms underlying their different properties but also illustrates many unifying themes for these evolutionary related signaling enzymes.
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Affiliation(s)
- Margarita Kamenetsky
- Department of Pharmacology, Joan and Sanford I. Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Sabine Middelhaufe
- Department of Physiological Chemistry, Ruhr-University, Bochum, Universitätsstraße
| | - Erin M. Bank
- Department of Pharmacology, Joan and Sanford I. Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Lonny R. Levin
- Department of Pharmacology, Joan and Sanford I. Weill Medical College of Cornell University, New York, NY 10021, USA
- Corresponding authors: ;
| | - Jochen Buck
- Department of Pharmacology, Joan and Sanford I. Weill Medical College of Cornell University, New York, NY 10021, USA
| | - Clemens Steegborn
- Department of Physiological Chemistry, Ruhr-University, Bochum, Universitätsstraße
- Corresponding authors: ;
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23
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Cooper DMF, Crossthwaite AJ. Higher-order organization and regulation of adenylyl cyclases. Trends Pharmacol Sci 2006; 27:426-31. [PMID: 16820220 DOI: 10.1016/j.tips.2006.06.002] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 04/26/2006] [Accepted: 06/16/2006] [Indexed: 11/26/2022]
Abstract
There is increasing awareness of the compartmentalization of cAMP signalling--the means by which cAMP levels change in discrete domains of the cell with discrete local consequences. Current developments in understanding the organization of adenylyl cyclases in the plasma membrane are illuminating how the earliest part of cAMP compartmentalization could occur. This review focuses on recent findings regarding three levels of adenylyl cyclase organization--oligomerization, positioning to lipid rafts and participation in multiprotein signalling complexes. This organization, coupled with the role of scaffolding proteins in arranging the downstream effectors of cAMP, helps to identify complexes that greatly facilitate the translation of enzyme activation into local consequences.
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Affiliation(s)
- Dermot M F Cooper
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK.
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24
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Beazely MA, Watts VJ. Regulatory properties of adenylate cyclases type 5 and 6: A progress report. Eur J Pharmacol 2006; 535:1-12. [PMID: 16527269 DOI: 10.1016/j.ejphar.2006.01.054] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Accepted: 01/25/2006] [Indexed: 12/21/2022]
Abstract
Adenylate cyclases (AC) type 5 and 6 comprise the calcium-inhibited family of adenylate cyclase isoforms. Here we review recent discoveries in the regulation of AC5 and AC6 with a focus on posttranslational modifications including glycosylation, nitrosylation, and phosphorylation by the cyclic AMP-dependent protein kinase (PKA), protein kinase C (PKC), and Raf1. We also describe novel signaling interactions such as Galpha(q)-mediated potentiation of AC6 activation. Novel regulators of AC5 and AC6, including small molecules and proteins that physically interact with AC5 and AC6 such as snapin, regulator of G protein signaling 2 (RGS2), protein associated with myc (PAM), and caveolin peptides are discussed. We also describe several recent studies that demonstrate the usefulness of transgenic or adenoviral overexpression of AC5 and AC6 in models for disease states such as cardiovascular hypertrophy. The discovery of novel regulatory mechanisms for AC5 and AC6 and their potential role in crucial physiological processes provide new avenues for research into therapeutic interventions targeting the cyclic AMP pathway.
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Affiliation(s)
- Michael A Beazely
- Department of Physiology, University of Toronto, 1 King's College Circle, Toronto, Canada, ON M5S 1A8.
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25
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Sinha SC, Sprang SR. Structures, mechanism, regulation and evolution of class III nucleotidyl cyclases. Rev Physiol Biochem Pharmacol 2006; 157:105-40. [PMID: 17236651 DOI: 10.1007/112_0603] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cyclic 3',5'-guanylyl and adenylyl nucleotides function as second messengers in eukaryotic signal transduction pathways and as sensory transducers in prokaryotes. The nucleotidyl cyclases (NCs) that catalyze the synthesis of these molecules comprise several evolutionarily distinct groups, of which class III is the largest. The domain structures of prokaryotic and eukaryotic class III NCs are diverse, including a variety of regulatory and transmembrane modules. Yet all members of this family contain one or two catalytic domains, characterized by an evolutionarily ancient topological motif (betaalphaalphabetabetaalphabeta) that is preserved in several other enzymes that catalyze the nucleophilic attack of a 3'-hydroxyl upon a 5' nucleotide phosphate. Two dyad-related catalytic domains compose one catalytic unit, with the catalytic sites formed at the domain interface. The catalytic domains of mononucleotidyl cyclases (MNCs) and diguanylate cyclases (DGCs) are called cyclase homology domains (CHDs) and GGDEF domains, respectively. Prokaryotic NCs usually contain only one catalytic domain and are catalytically active as intermolecular homodimers. The different modes of dimerization in class III NCs probably evolved concurrently with their mode of binding substrate. The catalytic mechanism of GGDEF domain homodimers is not completely understood, but they are expected to have a single active site with each subunit contributing equivalent determinants to bind one GTP molecule or half a c-diGMP molecule. CHD dimers have two potential dyad-related active sites, with both CHDs contributing determinants to each site. Homodimeric class III MNCs have two equivalent catalytic sites, although such enzymes may show half-of-sites reactivity. Eukaryotic class III MNCs often contain two divergent CHDs, with only one catalytically competent site. All CHDs appear to use a common catalytic mechanism, which requires the participation of two magnesium or manganese ions for binding polyphosphate groups and nucleophile activation. In contrast, mechanisms for purine recognition and specificity are more diverse. Class III NCs are subject to regulation by small molecule effectors, endogenous domains, or exogenous protein partners. Many of these regulators act by altering the interface of the catalytic domains and therefore the integrity of the catalytic site(s). This review focuses on both conserved and divergent mechanisms of class III NC function and regulation.
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Affiliation(s)
- S C Sinha
- University of Texas Southwestern Medical Center, Division of Infectious Diseases, Department of Internal Medicine, 5323 Harry Hines Blvd., Dallas 75390-9113, USA.
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26
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Beazely MA, Watts VJ. Galphaq-coupled receptor signaling enhances adenylate cyclase type 6 activation. Biochem Pharmacol 2005; 70:113-20. [PMID: 15885660 DOI: 10.1016/j.bcp.2005.04.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Revised: 04/13/2005] [Accepted: 04/14/2005] [Indexed: 10/25/2022]
Abstract
Calcium signaling robustly inhibits AC6 activity in membrane preparations and in intact cells via capacitative calcium entry (CCE). However, the release of intracellular calcium has not been demonstrated to robustly alter AC6 signaling and activation of Galpha(q)-coupled receptors in tissues that express AC6 enhances cyclic AMP accumulation. To specifically examine the ability of Galpha(q)-coupled receptors to modulate AC6 signaling in intact cells, we used stably transfected HEK-AC6 cells. We demonstrate that AC6 activation is potentiated by activation of endogenous muscarinic receptors expressed in HEK293 cells. Muscarinic receptor activation failed to potentiate the activation of the closely related AC5 isoform. Expression of recombinant Galpha(q)-coupled muscarinic or serotonin receptors, or constitutively active Galpha(q), also potentiated drug-stimulated cyclic AMP accumulation in HEK-AC6 cells. Muscarinic receptor-mediated potentiation of AC6 activation was not due to activation of PKC or modulation of Galpha(i/o)-mediated inhibition of AC6. We demonstrate that calcium chelation or inhibition of calmodulin attenuates the effect of carbachol on AC6 activation. These data support the hypothesis that Galpha(q)-coupled receptor-mediated calcium signaling potentiates AC6 activation in intact cells.
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Affiliation(s)
- Michael A Beazely
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-2091, USA
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27
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Willoughby D, Masada N, Crossthwaite AJ, Ciruela A, Cooper DMF. Localized Na+/H+ exchanger 1 expression protects Ca2+-regulated adenylyl cyclases from changes in intracellular pH. J Biol Chem 2005; 280:30864-72. [PMID: 16002403 DOI: 10.1074/jbc.m414355200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Ca2+-sensitive adenylyl cyclases (ACs) are exclusively regulated by capacitative Ca2+ entry (CCE) in nonexcitable cells. The present study investigates whether this Ca2+-dependent modulation of AC activity is further regulated by local pH changes that can arise beneath the plasma membrane as a consequence of cellular activity. Ca2+ stimulation of AC8 expressed in HEK 293 cells and inhibition of endogenous AC6 in C6-2B glioma cells exhibited clear sensitivity to modest pH changes in vitro. Acid pH (pH 7.14) reduced the Ca2+ sensitivity of both ACs, whereas alkaline pH (pH 7.85) enhanced the responsiveness of the enzymes to Ca2+, compared with controls (pH 7.50). Surprisingly, in the intact cell, the response of AC8 and AC6 to CCE was largely unperturbed by similar changes in intracellular pH (pH(i)), imposed using a weak acid (propionate) or weak base (trimethylamine). A range of hypotheses were tested to identify the mechanism(s) that could underlie this lack of pH effect in the intact cell. The pH sensitivity of CCE in HEK 293 cells is likely to dampen the effects of pH(i) on Ca2+-regulated ACs and may partly explain the discrepancy between in vitro and in vivo data. However, we have found that the Na+/H+ exchanger (NHE), NHE1, is functionally active in these cells, and like AC8 (and AC6) it resides in lipid rafts or caveolae, which may create cellular microdomains where pH(i) is tightly regulated. An abundance of NHE1 in these cellular subdomains may generate a privileged environment that protects the Ca2+-sensitive ACs and other caveolar proteins from local acid shifts.
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Affiliation(s)
- Debbie Willoughby
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
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Valbonesi P, Caselli F, Capuzzo A, Fabbri E. Modulation of adenyl cyclase activity in the gills of Tapes philippinarum. ACTA ACUST UNITED AC 2005; 301:952-60. [PMID: 15562448 DOI: 10.1002/jez.a.101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Adenyl cyclase (AC) plays a pivotal role in cell signaling. The AC system of bivalves has received little attention so far, and our study has been addressed to the characterization of AC properties in the gills of T. philippinarum. The enzyme showed a Km value of 0.77 mM for ATP in the presence of 5 mM Mg2+; in the absence of agonists, it was poorly affected by GTP, while it was stimulated by GTPgammaS and GppNHp up to 14-fold and 4-fold, respectively. Similarly to other invertebrates, the enzyme activity was scarcely stimulated by forskolin. The receptor agonist serotonin (5-HT) significantly stimulated the AC activity, and the pharmacological profile of the 5-HT receptor/s was as follows: (+)butaclamol > dihydroergocryptine > methysergide > prazosin > yohimbine. The AC activity was assessed in vitro in the presence of tributyltin chloride and HgCl2, which reduced the AC activity only at the highest dose tested (10-100 microM). Our data indicate the presence of a membrane-bound AC in gill membranes of T. philippinarum, coupled to Gs proteins and to a specific class of 5-HT receptors. Such receptors show a pharmacological profile slightly different from that reported for 5-HT invertebrate receptors cloned so far.
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Affiliation(s)
- Paola Valbonesi
- University of Bologna, Interdepartment Centre for Research on Environmental Science, 48100 Ravenna, Italy
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Steiner D, Avidor-Reiss T, Schallmach E, Butovsky E, Lev N, Vogel Z. Regulation of adenylate cyclase type VIII splice variants by acute and chronic Gi/o-coupled receptor activation. Biochem J 2005; 386:341-8. [PMID: 15537392 PMCID: PMC1134799 DOI: 10.1042/bj20041670] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Revised: 11/03/2004] [Accepted: 11/10/2004] [Indexed: 11/17/2022]
Abstract
We previously reported that acute agonist activation of G(i/o)-coupled receptors inhibits adenylate cyclase (AC) type VIII activity, whereas agonist withdrawal following chronic activation of these receptors induces AC-VIII superactivation. Three splice variants of AC-VIII have been identified, which are called AC-VIII-A, -B and -C (with AC-VIII-B missing the glycosylation domain and AC-VIII-C lacking most of the C1b area). We report here that AC-VIII-A and -B, but not -C, are inhibited by acute mu-opioid and dopaminergic type D2 receptor activation, indicating that the C1b area of AC-VIII has an important role in AC inhibition by G(i/o)-coupled receptor activation. On the other hand the glycosylation sites in AC-VIII did not play a role in AC-VIII regulation. Although AC-VIII-A and -C differed in their capacity to be inhibited by acute agonist exposure, agonist withdrawal after prolonged treatment led to a similar superactivation of all three splice variants, with no significant change in AC-VIII expression. AC-VIII superactivation was not affected by pre-incubation with a cell permeable cAMP analogue, indicating that the superactivation does not depend on the agonist-induced reduction in cAMP levels. The superactivated AC-VIII-A, -B and -C were similarly re-inhibited by re-application of agonist (morphine or quinpirole), returning the activity to control levels. These results demonstrate marked differences in the agonist inhibition of the AC-VIII splice variants before, but not after, superactivation.
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Key Words
- adenylate cyclase type viii
- camp
- dopamine receptor
- g-protein-coupled receptor
- opiate receptor
- superactivation
- ac, adenylate cyclase
- cho, chinese-hamster ovary
- 8-cpt-camp, 8-(4-chlorophenylthio)-3′,5′-camp
- dmem, dulbecco's modified eagle's medium
- d2 receptor, dopaminergic type 2 receptor
- d2l receptor, long form of the d2 receptor
- fs, forskolin
- ibmx, isobutylmethylxanthine
- ptx, pertussis toxin
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Affiliation(s)
- Debora Steiner
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Tomer Avidor-Reiss
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Ester Schallmach
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Elena Butovsky
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Nirit Lev
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Zvi Vogel
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel
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Crossthwaite AJ, Seebacher T, Masada N, Ciruela A, Dufraux K, Schultz JE, Cooper DMF. The cytosolic domains of Ca2+-sensitive adenylyl cyclases dictate their targeting to plasma membrane lipid rafts. J Biol Chem 2004; 280:6380-91. [PMID: 15574428 DOI: 10.1074/jbc.m411987200] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Lipid rafts are specialized, cholesterol-rich domains of the plasma membrane that are enriched in certain signaling proteins, including Ca(2+)-sensitive adenylyl cyclases. This restrictive localization plays a key role in the regulation of the Ca(2+)-stimulable AC8 and the Ca(2+)-inhibitable AC6 by capacitative calcium entry. Interestingly, AC7, a Ca(2+)-insensitive AC, is found in the plasma membrane but is excluded from lipid rafts (Smith, K. E., Gu, C., Fagan, K. A., Hu, B., and Cooper, D. M. F. (2002) J. Biol. Chem. 277, 6025-6031). The mechanisms governing the specific membrane targeting of adenylyl cyclase isoforms remain unknown. To address this issue, a series of chimeras were produced between the raft-targeted AC5 and the non-raft-targeted AC7, involving switching of their major domains. The AC5-AC7 chimeras were expressed in HEK 293 cells and lipid rafts were isolated from the bulk plasma membrane by either detergent-based or non-detergent-based fractionation methods. Additionally, confocal imaging was used to investigate the precise cellular targeting of the chimeras. Surprisingly, the two tandem six-transmembrane domains of AC5 were not required for localization to lipid rafts. Rather, AC5 localization depended on the complete cytoplasmic loops (C1 and C2); constructs with mixed domains were either retained in the endoplasmic reticulum or degraded. Similar conclusions are drawn for the lipid raft localization of the Ca(2+)/calmodulin-stimulable AC8; again, the C1 and C2 domains are critical. Thus, protein-protein interactions may be more important than protein-lipid interactions in targeting these calcium-sensitive enzymes to lipid rafts.
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Affiliation(s)
- Andrew J Crossthwaite
- Department of Pharmacology, University of Cambridge, Tennis Court Rd., Cambridge, CB2 1PD, United Kingdom
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31
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Kao YY, Lai HL, Hwang MJ, Chern Y. An Important Functional Role of the N Terminus Domain of Type VI Adenylyl Cyclase in Gαi-mediated Inhibition. J Biol Chem 2004; 279:34440-8. [PMID: 15192109 DOI: 10.1074/jbc.m401952200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We show herein that removal of the first 86 amino acids (aa) of the N terminus (designated N) of type VI adenylyl cyclase (ACVI) caused the resultant ACVI mutant (ACVI-DeltaA87) to be more greatly inhibited by a Galpha(i)-coupled receptor or activated Galpha(i) protein. Moreover, in vitro binding of the full-length N and C1a domain (designated C1a), which interacts with Galpha(i), was detected. A truncated N terminus (aa 1-86) also interacted with C1a, suggesting that the C1a-interacting region is located within aa 1-86. Mutation analyses further revealed that N might interact with C1a in the region (aa 434-505) where Galpha(i) is bound. Mutations of two residues (Leu-472 and Val-476) located in this N-binding region of C1a suppressed the interaction between recombinant N and C1a and markedly reduced Galpha(i)-mediated inhibition of ACVI-DeltaA87. Further biochemical analyses of the effect of internal mutations of Leu-472/Val-476 on Galpha(i)-mediated inhibition of wild-type ACVI and ACVI-DeltaA87 suggested that N modulates the Galpha(i)-mediated inhibition of ACVI via binding to C1a when the level of Galpha(i) is low (i.e. around the IC(50) value) and that a more complicated interfering mode results when the level of Galpha(i) is high (i.e. approximately 10- to 20-fold of the IC(50) value). Collectively, data presented herein suggest a novel function of the N terminus of ACVI in Galpha(i)-mediated regulation.
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MESH Headings
- Adenylyl Cyclases/metabolism
- Animals
- Blotting, Western
- CHO Cells
- Catalytic Domain
- Cell Line
- Cell Membrane/metabolism
- Cricetinae
- Dose-Response Relationship, Drug
- Electrophoresis, Polyacrylamide Gel
- GTP-Binding Protein alpha Subunit, Gi2
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- Humans
- Inhibitory Concentration 50
- Leucine/chemistry
- Models, Biological
- Models, Molecular
- Mutagenesis, Site-Directed
- Mutation
- Plasmids/metabolism
- Polymerase Chain Reaction
- Protein Binding
- Protein Conformation
- Protein Isoforms
- Protein Structure, Secondary
- Protein Structure, Tertiary
- Proto-Oncogene Proteins/metabolism
- Rats
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
- Transfection
- Valine/chemistry
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Affiliation(s)
- Yu-Ya Kao
- Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan, ROC
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33
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Cooper DMF. Regulation and organization of adenylyl cyclases and cAMP. Biochem J 2003; 375:517-29. [PMID: 12940771 PMCID: PMC1223734 DOI: 10.1042/bj20031061] [Citation(s) in RCA: 276] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2003] [Revised: 08/07/2003] [Accepted: 08/26/2003] [Indexed: 11/17/2022]
Abstract
Adenylyl cyclases are a critically important family of multiply regulated signalling molecules. Their susceptibility to many modes of regulation allows them to integrate the activities of a variety of signalling pathways. However, this property brings with it the problem of imparting specificity and discrimination. Recent studies are revealing the range of strategies utilized by the cyclases to solve this problem. Microdomains are a consequence of these solutions, in which cAMP dynamics may differ from the broad cytosol. Currently evolving methodologies are beginning to reveal cAMP fluctuations in these various compartments.
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Affiliation(s)
- Dermot M F Cooper
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK.
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Shen Y, Lee YS, Soelaiman S, Bergson P, Lu D, Chen A, Beckingham K, Grabarek Z, Mrksich M, Tang WJ. Physiological calcium concentrations regulate calmodulin binding and catalysis of adenylyl cyclase exotoxins. EMBO J 2002; 21:6721-32. [PMID: 12485993 PMCID: PMC139101 DOI: 10.1093/emboj/cdf681] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Edema factor (EF) and CyaA are calmodulin (CaM)-activated adenylyl cyclase exotoxins involved in the pathogenesis of anthrax and whooping cough, respectively. Using spectroscopic, enzyme kinetic and surface plasmon resonance spectroscopy analyses, we show that low Ca(2+) concentrations increase the affinity of CaM for EF and CyaA causing their activation, but higher Ca(2+) concentrations directly inhibit catalysis. Both events occur in a physiologically relevant range of Ca(2+) concentrations. Despite the similarity in Ca(2+) sensitivity, EF and CyaA have substantial differences in CaM binding and activation. CyaA has 100-fold higher affinity for CaM than EF. CaM has N- and C-terminal globular domains, each binding two Ca(2+) ions. CyaA can be fully activated by CaM mutants with one defective C-terminal Ca(2+)-binding site or by either terminal domain of CaM while EF cannot. EF consists of a catalytic core and a helical domain, and both are required for CaM activation of EF. Mutations that decrease the interaction of the helical domain with the catalytic core create an enzyme with higher sensitivity to Ca(2+)-CaM activation. However, CyaA is fully activated by CaM without the domain corresponding to the helical domain of EF.
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Affiliation(s)
- Yuequan Shen
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Young-Sam Lee
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Sandriyana Soelaiman
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Pamela Bergson
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Dan Lu
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Alice Chen
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Kathy Beckingham
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Zenon Grabarek
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Milan Mrksich
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
| | - Wei-Jen Tang
- Ben-May Institute for Cancer Research, Department of Chemistry, and Committee on Neurobiology, The University of Chicago, Chicago, IL 60637, Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251 and Boston Biomedical Research Institute, Watertown, MA 02472, USA Corresponding author e-mail:
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