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Ferreira J, Levin LR, Buck J. Strategies to safely target widely expressed soluble adenylyl cyclase for contraception. Front Pharmacol 2022; 13:953903. [PMID: 36091839 PMCID: PMC9452739 DOI: 10.3389/fphar.2022.953903] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
In humans, the prototypical second messenger cyclic AMP is produced by 10 adenylyl cyclase isoforms, which are divided into two classes. Nine isoforms are G protein coupled transmembrane adenylyl cyclases (tmACs; ADCY1-9) and the 10th is the bicarbonate regulated soluble adenylyl cyclase (sAC; ADCY10). This review details why sAC is uniquely druggable and outlines ways to target sAC for novel forms of male and female contraception.
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Balbach M, Fushimi M, Huggins DJ, Steegborn C, Meinke PT, Levin LR, Buck J. Optimization of lead compounds into on-demand, nonhormonal contraceptives: leveraging a public-private drug discovery institute collaboration†. Biol Reprod 2021; 103:176-182. [PMID: 32307523 PMCID: PMC7401349 DOI: 10.1093/biolre/ioaa052] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/08/2020] [Accepted: 04/15/2020] [Indexed: 12/20/2022] Open
Abstract
Efforts to develop new male or female nonhormonal, orally available contraceptives assume that to be effective and safe, targets must be (1) essential for fertility; (2) amenable to targeting by small-molecule inhibitors; and (3) restricted to the germline. In this perspective, we question the third assumption and propose that despite its wide expression, soluble adenylyl cyclase (sAC: ADCY10), which is essential for male fertility, is a valid target. We hypothesize that an acute-acting sAC inhibitor may provide orally available, on-demand, nonhormonal contraception for men without adverse, mechanism-based effects. To test this concept, we describe a collaboration between academia and the unique capabilities of a public-private drug discovery institute.
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Affiliation(s)
- Melanie Balbach
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Makoto Fushimi
- Tri-Institutional Therapeutics Discovery Institute, New York, NY, USA
| | - David J Huggins
- Tri-Institutional Therapeutics Discovery Institute, New York, NY, USA.,Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Clemens Steegborn
- Department of Biochemistry, University of Bayreuth, Bayreuth, Germany
| | - Peter T Meinke
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA.,Tri-Institutional Therapeutics Discovery Institute, New York, NY, USA
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
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Dessauer CW, Watts VJ, Ostrom RS, Conti M, Dove S, Seifert R. International Union of Basic and Clinical Pharmacology. CI. Structures and Small Molecule Modulators of Mammalian Adenylyl Cyclases. Pharmacol Rev 2017; 69:93-139. [PMID: 28255005 PMCID: PMC5394921 DOI: 10.1124/pr.116.013078] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Adenylyl cyclases (ACs) generate the second messenger cAMP from ATP. Mammalian cells express nine transmembrane AC (mAC) isoforms (AC1-9) and a soluble AC (sAC, also referred to as AC10). This review will largely focus on mACs. mACs are activated by the G-protein Gαs and regulated by multiple mechanisms. mACs are differentially expressed in tissues and regulate numerous and diverse cell functions. mACs localize in distinct membrane compartments and form signaling complexes. sAC is activated by bicarbonate with physiologic roles first described in testis. Crystal structures of the catalytic core of a hybrid mAC and sAC are available. These structures provide detailed insights into the catalytic mechanism and constitute the basis for the development of isoform-selective activators and inhibitors. Although potent competitive and noncompetitive mAC inhibitors are available, it is challenging to obtain compounds with high isoform selectivity due to the conservation of the catalytic core. Accordingly, caution must be exerted with the interpretation of intact-cell studies. The development of isoform-selective activators, the plant diterpene forskolin being the starting compound, has been equally challenging. There is no known endogenous ligand for the forskolin binding site. Recently, development of selective sAC inhibitors was reported. An emerging field is the association of AC gene polymorphisms with human diseases. For example, mutations in the AC5 gene (ADCY5) cause hyperkinetic extrapyramidal motor disorders. Overall, in contrast to the guanylyl cyclase field, our understanding of the (patho)physiology of AC isoforms and the development of clinically useful drugs targeting ACs is still in its infancy.
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Affiliation(s)
- Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Val J Watts
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Rennolds S Ostrom
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Marco Conti
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Stefan Dove
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
| | - Roland Seifert
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Sciences Center at Houston, Houston, Texas (C.W.D.); Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana (V.J.W.); Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (R.S.O.); Center for Reproductive Sciences, University of California San Francisco, San Francisco, California (M.C.); Institute of Pharmacy, University of Regensburg, Regensburg, Germany (S.D.); and Institute of Pharmacology, Hannover Medical School, Hannover, Germany (R.S.)
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Jaiswal BS, Conti M. Calcium regulation of the soluble adenylyl cyclase expressed in mammalian spermatozoa. Proc Natl Acad Sci U S A 2003; 100:10676-81. [PMID: 12958208 PMCID: PMC196863 DOI: 10.1073/pnas.1831008100] [Citation(s) in RCA: 194] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2003] [Indexed: 11/18/2022] Open
Abstract
In mammals, Ca2+ and HCO3- ions play a critical role in the regulation of sperm function, most likely by regulation of cAMP levels. Mammalian germ cells contain a soluble adenylyl cyclase (sAC) with properties distinct from the well characterized membrane-bound enzymes Here we investigated whether the cyclase expressed in mature spermatozoa has the properties of sAC and whether it is regulated by Ca2+. In addition to an HCO3--dependent activation, the cyclase endogenous to human spermatozoa is stimulated 2- to 3-fold by Ca2+ in a concentration-dependent manner (EC50 approximately 400 nM). In a similar fashion, Ca2+ activates the recombinant rat and human full-length sAC with similar EC50 values. The Ca2+ stimulation was also observed when sAC was activated with HCO3-, was independent of calmodulin, and was associated with an increase in Vmax without changes in Km for ATP-Mg2+. An increase in intracellular Ca2+ by ionophore or by a muscarinic cholinergic receptor agonist increases cAMP in cells transfected with FL-hsAC, but not in mock-transfected cells. Similarly, both Ca2+ and HCO3- stimulate cAMP accumulation in human spermatozoa. These findings provide evidence that human spermatozoa express a cyclase with the properties of sAC and that Ca2+ can substitute for HCO3- in the stimulation of this enzyme, underscoring an important role for sAC in the control of sperm functions.
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Affiliation(s)
- Bijay S Jaiswal
- Division of Reproductive Biology, Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA 94305-5317, USA
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Zippin JH, Levin LR, Buck J. CO(2)/HCO(3)(-)-responsive soluble adenylyl cyclase as a putative metabolic sensor. Trends Endocrinol Metab 2001; 12:366-70. [PMID: 11551811 DOI: 10.1016/s1043-2760(01)00454-4] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Cyclic AMP (cAMP) is an evolutionarily conserved regulator of metabolism. Recently, we identified a novel mammalian source of cAMP - soluble adenylyl cyclase (sAC) - that is regulated directly by bicarbonate ions (HCO(3)(-)). As the concentration of HCO(3)(-) reflects cellular levels of carbon dioxide (CO(2)), energy-generating metabolic processes (which increase intracellular CO(2)) are poised to activate bicarbonate-responsive sAC. This direct link between metabolic activity, sAC and cAMP could represent an evolutionarily conserved mechanism of metabolic feedback regulation.
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Affiliation(s)
- J H Zippin
- Dept of Pharmacology, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA
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Jaiswal BS, Conti M. Identification and functional analysis of splice variants of the germ cell soluble adenylyl cyclase. J Biol Chem 2001; 276:31698-708. [PMID: 11423534 DOI: 10.1074/jbc.m011698200] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In mammalian germ cells, cAMP signaling is dependent on two forms of adenylyl cyclase, the conventional membrane-bound ACIII and a soluble form of adenylyl cyclase (sAC). Recent elucidation of the sAC sequence indicates that this enzyme is phylogenetically distinct from the membrane-bound AC, does not interact with G proteins, and its activity is regulated by bicarbonate ions. Here we have investigated the properties and regulation of this enzyme during spermatogenesis. Two different transcripts encoding a full-length and truncated sAC were identified by reverse transcriptase-polymerase chain reaction and RNase protection analysis. The truncated sAC transcript lacks exon 11 with a premature termination of the open reading frame after the catalytic domain. Reverse transcriptase-polymerase chain reaction with testis RNA from adult mouse and rat of different ages, as well as RNase protection, showed that both transcripts are absent at 11 days of age, appear between 20 and 30 days of age, and are retained in the adult testis. The presence of corresponding proteins in testis, germ cells, and spermatozoa was demonstrated by fast protein liquid chromatography and differential immunoprecipitation with full-length sAC-specific antibodies. Bicarbonate ions activated both sAC forms and increased cAMP levels in germ cells isolated from 25- and 50-day-old rats and adult rats in a concentration-dependent manner. These findings provide evidence that full-length and truncated sAC are generated by alternate splicing. Both forms are active in spermatids, and the bicarbonate present in the seminiferous tubule may be a signal that regulates cAMP levels in these cells.
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Affiliation(s)
- B S Jaiswal
- Division of Reproductive Biology, Department of Gynecology and Obstetrics, Stanford University School of Medicine, Stanford, California 94305-5317, USA
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Buck J, Sinclair ML, Schapal L, Cann MJ, Levin LR. Cytosolic adenylyl cyclase defines a unique signaling molecule in mammals. Proc Natl Acad Sci U S A 1999; 96:79-84. [PMID: 9874775 PMCID: PMC15096 DOI: 10.1073/pnas.96.1.79] [Citation(s) in RCA: 385] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mammals have nine differentially regulated isoforms of G protein-responsive transmembrane-spanning adenylyl cyclases. We now describe the existence of a distinct class of mammalian adenylyl cyclase that is soluble and insensitive to G protein or Forskolin regulation. Northern analysis indicates the gene encoding soluble adenylyl cyclase (sAC) is preferentially expressed in testis. As purified from rat testis cytosol, the active form of sAC appears to be a fragment derived from the full-length protein, suggesting a proteolytic mechanism for sAC activation. The two presumptive catalytic domains of sAC are closely related to cyanobacterial adenylyl cyclases, providing an evolutionary link between bacterial and mammalian signaling molecules.
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Affiliation(s)
- J Buck
- Department of Pharmacology, Joan and Sanford I. Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA
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Young GP, Koide SS, Goldstein M, Young JD. Isolation and partial characterization of an ion channel protein from human sperm membranes. Arch Biochem Biophys 1988; 262:491-500. [PMID: 2452602 DOI: 10.1016/0003-9861(88)90400-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Human sperm cells were fractionated and plasma membrane proteins were separated by molecular gel sieving chromatography (Sephacryl S-200 followed by HPLC). A pore-forming protein was extracted from sperm cell membranes. The partially purified protein migrated with Mr 100,000-110,000, as determined by molecular sieving gel chromatography, and with a Mr 90,000 when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. The channel activity was also extracted with Triton X-114, suggesting a hydrophobic nature for this protein. This protein was incorporated into planar lipid bilayers, resulting in the formation of voltage-dependent ion channels. Single channel fluctuations of 130 pS/unit in 0.1 M NaCl were resolved; however, channels preferentially aggregated in triplets having an open state life-time that persisted for several seconds. The channels studied here were more selective for monovalent cations than anions, but also showed some permeability to anions and larger electrolytes, suggesting a large functional pore diameter. The role of this sperm channel in normal sperm physiology and/or fertilization is presently unclear.
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Affiliation(s)
- G P Young
- Laboratory of Cellular Physiology and Immunology, Rockefeller University, New York, New York 10021
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Smith A, Bugge HP, Berg KA, Møller O, Hansson V. Seasonal changes in testicular structure and function in the blue fox (Alopex lagopus), as quantified by morphometric analysis and measurement of adenylate cyclase activity. INTERNATIONAL JOURNAL OF ANDROLOGY 1986; 9:53-66. [PMID: 3744586 DOI: 10.1111/j.1365-2605.1986.tb00867.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The volume of the blue fox testis showed 5-fold changes during the year, associated with considerable changes in cellular composition. The seminiferous epithelium was maximally regressed in August, when 94% of tubules contained only spermatogonia. By late October, approximately 6 months before the mating season, 40% of tubules contained primary spermatocytes. From the middle of January until the end of April all tubules contained spermatids or more advanced haploid cells. Tubular diameter increased by 73% during testicular re-development, and epithelial height increased 3-fold. Regression to the basal state occurred during May to July. The volume densities of the seminiferous epithelium and of interstitial tissue remained approximately constant throughout the year. Soluble Mn2+-dependent adenylate cyclase activity showed seasonal variations that paralleled those of the haploid germ cell population and testicular volume, whereas somatic cell adenylate cyclase activity was relatively constant.
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Berman MI, Anand-Srivastava MB, Sairam MR. Characterization of gonadotropin-sensitive adenylate cyclase activity in human testis: uncoupling of the receptor-cyclase complex by specific hormonal antagonist. Mol Cell Endocrinol 1985; 42:49-57. [PMID: 2993080 DOI: 10.1016/0303-7207(85)90006-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Basal and gonadotropin stimulated adenylate cyclase activity was assessed in testicular tissues obtained from men (20-80 years). A disparity was observed in the gonadotropin responsiveness of the human testicular adenylate cyclase system to hFSH and hCG stimulation. Of the tissues analyzed, 61% were FSH responsive and 22% showed low response to hCG. Forskolin, a diterpene which activates adenylate cyclase by a receptor independent mechanism, stimulated adenylate cyclase activity in the gonadotropin unresponsive tissues. This suggests that the tissue unresponsiveness is due to an uncoupling of the catalytic subunit of the adenylate cyclase. Several functional properties of the FSH responsive human testicular adenylate cyclase were investigated. hFSH and oFSH stimulated the enzyme activity in a concentration dependent manner. However, the hormone (DG-oFSH) in which 80% of the carbohydrate residues had been removed was inactive, despite its good binding ability to the FSH receptor. hFSH stimulated adenylate cyclase activity was inhibited by DG-oFSH but not by DG-hCG (deglycosylated hCG). The data demonstrates the existence of specific FSH and LH(hCG) receptors in human testicular membranes. The FSH receptors in some tissues are coupled to adenylate cyclase. The link between the FSH receptor and adenylate cyclase may be uncoupled in the presence of the deglycosylated form of oFSH resulting in a loss of hormone response.
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Smith AJ, Jahnsen T, Hansson V. Membrane-bound adenylate cyclase activity in the testis of the blue fox. ARCHIVES OF ANDROLOGY 1985; 14:35-43. [PMID: 3931598 DOI: 10.3109/01485018508987276] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Membrane-bound adenylate cyclase (AC) activity was much higher in the presence of Mn2+ than of Mg2+. The Mn2+-sensitive adenylate cyclase (MnAC) showed a linear rate of activity for at least 60 min. In contrast, the Mg2+-sensitive AC (MgAC) displayed a considerable burst in activity, so that after 90 min of activity it was approximately tenfold higher than at the start of incubation. Guanine nucleotides enhanced MgAC activity; 10(-6) to 10(-5) M of 5'-guanylylimidodiphosphate caused a threefold stimulation. The MgAC could be stimulated by hormones (FSH, hCG, PGE1, isoproterenol, glucagon), the highest activation being achieved with FSH. Increasing levels of ATP produced a concentration-dependent increase in MgAC activity. The apparent affinity of the AC for MgATP increased threefold (Km 0.50-0.15 mM) by raising the free Mg2+ concentration from 0.4 to 10.0 mM. The membrane-bound AC of the blue fox testis is thus regulated by hormones, Mg2+, and guanine nucleotides in a similar manner to ACs in other somatic cells and in testes from other species. The high MnAC activity in membrane particles from these testes probably represents membrane-bound AC activity in germ cells. The burst in MgAC activity during incubation may represent proteolytic activation of membrane-bound germ cell AC, with a gradual appearance of Mg2+ sensitivity.
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Smith AJ, Jahnsen T, Attramadal H, Hansson V. Soluble Mn2+-dependent adenylate cyclase activity in the testis of the blue fox (Alopex lagopus). ARCHIVES OF ANDROLOGY 1984; 12:225-30. [PMID: 6508430 DOI: 10.3109/01485018409161180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Soluble Mn2+-dependent adenylate cyclase (MnAC) activity was found in testicular cytosol from blue foxes castrated during the breeding season. The rate of MnAC activity was approximately constant for 30 min at 35 degrees C and for 2 hr after storage at 25 degrees C. Activity was directly proportional to cytosol protein concentration and was optimal in the physiological pH range. Enzyme activity declined in the presence of an alkylating agent (N-ethyl maleimide, NEM) and was eliminated at a concentration of 1 mM NEM. Low concentrations (0.1-10 mM) of a reducing agent (beta-mercapto ethanol, beta ME) did not increase MnAC activity, whereas a high concentration (100 mM) led to a significant reduction (p less than 0.01) in activity. Substitution of Mn2+ in the assay medium with Mg2+ led to a total loss of enzyme activity, which could not be regained by adding hormones or by preincubation of cytosol for 60 min. The Km for Mn2+ was estimated to be 3.5 mM. The affinity of the enzyme for Mn2+ was not altered by varying the concentration of ATP. In contrast, increasing concentrations of Mn2+ appeared to increase the affinity of the enzyme for MnATP2-. The Km for MnATP2- thus varied from 6 to 18 mM.
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