Showing papers on "Cyclase published in 1977"
TL;DR: It is proposed that continuous GTP hydrolysis at the regulatory guanyl nucleotide site is an essential turn-off mechanism, terminating activation of the adenylate cyclase.
Abstract: Treatment of turkey erthrocyte membranes with cholera toxin caused an enhancement of the basal and catecholamine-stimulated adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] activities. Both of these activities required the presence of GTP. The toxin effect on the adenylate cyclase activity concided with an inhibition of the catecholamine-stimulated guanosinetriphosphatase activity. Inhibition of the guanosinetriphosphatase, as well as enhancement of the adenylate cyclase activity, showed the same dependence on cholera toxin concentrations, and the effect of the toxin on both activities was dependent on the presence of NAD. It is proposed that continuous GTP hydrolysis at the regulatory guanyl nucleotide site is an essential turn-off mechanism, terminating activation of the adenylate cyclase. Cholera toxin inhibits the turn-off guanosinetriphosphatase reaction and thereby causes activation of the adenylate cyclase. According to this mechanism GTP should activate the toxin-treated preparation of adenylate cyclase, as does the hydrolysis-resistant analog guanosine 5'-(beta,gamma-immino)triphosphate [Gpp(NH)p]. Indeed, the toxin-treated adenylate cyclase was maximally activated, in the presence of isoproternol, by either GTP or Gpp(NH)p, while adenylate cyclase not treated with toxin was stimulated by hormone plus GTP to only one-fifth of the activity achieved with hormone plus Gpp(NH)p. Furthermore, the toxin-treated adenylate cyclase activated by isoproterenol plus GTP remained active for and extended period (half-time of 3 min) upon subsequent addition of the beta-adrenergic blocker, propranolol. The native enzyme, however, was refractory to propranolol only if activated by Gpp(NH)p but not by GTP.
683 citations
TL;DR: A model of platelet homeostasis is proposed that suggests platelet aggregation is controlled by a balance between the adenylate cyclase stimulating activity of prostacyclin, and the cAMP lowering activity of PGH2.
650 citations
TL;DR: Comparison of data indicates that adenosine-reactive "P" and "R" sites are present generally and are explained by the presence of both sites on a single adenylate cyclase.
Abstract: The effects of adenosine and adenosine analogs on adenylate cyclases from several tissues have been examined. Two adenosine-reactive sites have been identified: (i) the "R" site, occupancy of which usually leads to activation of cyclase and which requires integrity of the ribose ring for activity, and (ii) the "P" site, which mediates inhibition and requires integrity of the purine ring for activity. Biphasic effects of adenosine are explained by the presence of both sites on a single adenylate cyclase. Comparison of these data with those in the literature indicates that adenosine-reactive "P" and "R" sites are present generally.
540 citations
458 citations
TL;DR: Reconstitution experiments with GTP-binding fractions obtained from isoproterenol-treated membranes suggested that the characteristic synergistic amplification of hormone action by guanylnucleotides is mediated via the guanyl nucleotide binding protein.
412 citations
TL;DR: It is proposed that the active A protomer of choleragen catalyzes the ADP-ribosylation of an arginine, or related amino acid residue in a protein, which is the cyclase itself or is critical to its activation by cholerogen.
354 citations
Book•
01 Jan 1977
TL;DR: The aim of this work is to establish a baseline level of understanding of the enzymatic Formation, Degradation, and Action of Cyclic Nucleotides and the effects of drug and Other Treatments of Animals on the Cyclic AMP-Generating Systems in Brain.
Abstract: 1 Introduction- 2 Enzymatic Formation, Degradation, and Action of Cyclic Nucleotides- 21 Adenylate Cyclases- 211 Regional Distribution of Adenylate Cyclase in Brain- 212 Regional Distribution of Cyclic AMP in Brain- 213 Postdecapitation Changes in Brain Cyclic AMP- 214 Morphological Localization of Cyclic AMP in Brain- 215 Subcellular Distribution of Adenylate Cyclases and Cyclic AMP- 216 Activation and Inhibition of Adenylate Cyclases- 217 Activation by Putative Neurotransmitters- 218 Developmental Changes in Adenylate Cyclases and Cyclic AMP in Brain- 219 Ganglia and Peripheral Neurons- 2110 Cultured Cells- 22 Guanylate Cyclases- 221 Regional Distribution of Guanylate Cyclase and Cyclic GMP in Brain- 222 Subcellular and Morphological Distribution of Guanylate Cyclase in Brain- 223 Activation and Inhibition- 224 Developmental Changes in Guanylate Cyclase and Cyclic GMP in Brain- 225 Ganglia- 23 Phosphodiesterases- 231 Regional Distribution in Brain- 232 Morphological Localization in Brain- 233 Subcellular Distribution in Brain- 234 Multiplicity of Brain Phosphodiesterases- 235 Activation- 236 Inhibitors- 237 Analogs of Cyclic AMP and Cyclic GMP- 238 Developmental Changes in Brain Phosphodiesterases- 239 Strain Differences in Brain Phosphodiesterases- 2310 Ganglia and Peripheral Neurons- 2311 Cultured Cells- 24 Protein Kinases- 241 Cyclic AMP-Dependent Kinases- 242 Cyclic GMP-Dependent Kinases- 25 Phosphoprotein Phosphatases- 251 Regional and Subcellular Distribution in Brain- 252 Activation, Inhibition, and Substrates- 253 Dephosphorylation of Membranal Phosphoproteins- 3 Accumulation of Cyclic Nucleotides- 31 Cyclic AMP in Brain Slices- 311 Rabbit- 312 Guinea Pig- 313 Rat- 314 Mouse- 315 Primates- 316 Pig- 317 Cat- 318 Chicken- 319 Amphibians- 3110 Conversion of Adenine and Adenosine-Labeled Nucleotides to Cyclic AMP- 3111 Release and Uptake of Cyclic AMP- 3112 Effects of Drug and Other Treatments of Animals on the Cyclic AMP-Generating Systems in Brain- 32 Cyclic GMP in Brain Slices- 321 Rabbit- 322 Guinea Pig- 323 Rat- 324 Mouse- 325 Cat- 33 Cyclic AMP in Ganglia and Peripheral Neurons- 331 Vertebrates- 332 Invertebrates- 34 Cyclic GMP in Ganglia and Peripheral Neurons- 341 Vertebrates- 342 Invertebrates- 35 Cyclic Nucleotides in Cells of Neuronal or Glial Origin- 351 Fetal Brain Cells- 352 Neuroma Cells- 4 Functional Role of Cyclic Nucleotides- 41 Enzymatic Processes- 411 Intermediary Metabolism- 412 Membrane Metabolism- 413 Neurotransmitter Metabolism- 414 Cyclases, Phosphodiesterases, and Kinases- 415 Protein Phosphorylation- 416 DNA, RNA, and Protein Synthesis- 42 Cell Morphology, Differentiation, and Growth- 421 Neuroblastoma Cells- 422 Glioma Cells- 423 Hybrid Cells- 424 Fetal Cells- 425 Ganglia and Peripheral Neurons- 426 Role of Microtubules- 427 Trophic Factors- 43 Membrane Phenomena- 431 Central Neurons- 432 Ganglionic Neurons- 433 Peripheral Neurons- 434 Cultured Cells- 44 Levels of Cyclic Nucleotides in Brain- 441 Postdecapitation Changes in Cyclic AMP in Brain- 442 Effects of Drugs and Other Treatments on Levels of Cyclic AMP in Brain- 443 Effects of Drugs and Other Treatments on Levels of Cyclic GMP in Brain- 444 Behavioral Correlations- 445 Clinical Correlations- 45 Central Behavioral and Vegetative Functions- 451 Behavioral Effects- 452 Vegetative Effects- 453 Centrally Active Drugs- Conclusion- References
286 citations
TL;DR: It is suggested that at least two proteins are necessary for adenylate cyclase activity and that one of these is retained in the phenotypically adenYLate Cyclase-deficient variant.
262 citations
TL;DR: It is proposed that activity of adenylate cyclase determines the rate of conversion of the enzyme from one form to the other and that opiates alter the relative abundance of low- and high-activity forms of the enzymes.
Abstract: Reactions mediated by the opiate receptors that inhibit adenylate cyclase (EC 4.6.1.1) are closely coupled to subsequent reactions that gradually increase adenylate cyclase activity of neuroblastoma X glioma NG108-15 hybrid cells. Opiate-treated cells have higher basal-, prostaglandin E1-, and 2-chloroadenosine-stimulated activities than do control cells. However, NaF or guanosine 5'-(beta, gamma-imido)triphosphate abolishes most of the differences in adenylate cyclase activity observed with homogenates from control and opiate-treated cells. Cycloheximide blocked some, but not all, of the opiate-dependent increase in adenylate cyclase activity. These results suggest that the opiate-dependent increase in adenylate cyclase is due to conversion of adenylate cyclase to a form with altered activity. Protein synthesis also is required for part of the opiate effect. We propose that activity of adenylate cyclase determines the rate of conversion of the enzyme from one form to the other and that opiates, by inhibiting adenylate cyclase, alter the relative abundance of low- and high-activity forms of the enzyme.
261 citations
TL;DR: Results suggest that dopamine receptors within the substantia nigra are not located on dopamine cell bodies but are associated with a pathway, containing gamma-aminobutyric acid or substance P, which projects from forebrain structures to the substanta nigra.
Abstract: A dopamine-sensitive adenylate cyclase with characteristics similar to those measured in the striatum is present in the rat substantia nigra. Destruction of dopamine cell bodies by intranigral 6-hydroxydopamine application failed to abolish the response of nigral adenylate cyclase to dopamine. In contrast, brain hemitransection between the striatum and substantia nigra, or a more circumscribed lesion of striatonigral pathways, abolished the dopamine stimulation of adenylate cyclase in the substantia nigra. These results suggest that dopamine receptors within the substantia nigra are not located on dopamine cell bodies but are associated with a pathway, containing gamma-aminobutyric acid or substance P, which projects from forebrain structures to the substantia nigra.
218 citations
TL;DR: To test this hypothesis, four tricyclic antidepressants—representing four different structural types—were tested on the H2 receptor linked to adenylate cyclase in homogenates of the guinea pig hippocampus and cortex.
Abstract: THE observation that cyproheptadine is a competitive antagonist of the histamine H2 receptor linked to adenylate cyclase in brain1 suggested that the chemically similar tricyclic antidepressant drugs may also have this activity. To test this hypothesis, four tricyclic antidepressants—representing four different structural types—were tested on the H2 receptor linked to adenylate cyclase in homogenates of the guinea pig hippocampus and cortex. Both dimaprit and histamine were used as agonists. Dimaprit has potent activity at the H2 receptor with negligible activity at the H1 receptor, that is, less than 0.0001% of that of histamine2.
TL;DR: Murine 3T3-L1 fibroblasts enter a differentiation program subsequent to prolonged maintenance in the confluent state and develop into adipocytes and a totally new control element, adrenocorticotropic hormone responsiveness, was incorporated into the adenylate cyclase system of the adipocytes.
TL;DR: Cyclic AMP may play a crucial role in the regulation of platelet phospholipase acitivity, and this could explain at least in part the inhibition of aggregation caused by substances which, like prostacyclin, raise the levels of cyclicAMP.
TL;DR: A light-activated (5-fold) GTPase which participates in the modulation of photoreceptor phosphodiesterase is found and appears necessary for the reversal of phosphodiestersterase activation in vitro and may play a critical role in the in vivo regulation of light-sensitive phosphodiedterase.
Abstract: We have been studying the mechanism by which light and nucleoside triphosphates activate the discmembrane phosphodiesterase (oligonucleate 5′-nucleotidohydrolase; EC 3141) in frog rod outer segments GTP is orders of magnitude more effective than ATP as a cofactor in the light-dependent activation step GTP and the analogue guanylyl-imidodiphosphate function equally as allosteric activators of photoreceptor phosphodiesterase rather than participating in the formation of a phosphorylated activator Moreover, we have found a light-activated (5-fold) GTPase which participates in the modulation of photoreceptor phosphodiesterase This GTPase activity appears necessary for the reversal of phosphodiesterase activation in vitro and may play a critical role in the in vivo regulation of light-sensitive phosphodiesterase The Km for GTP in the light-activated GTPase reaction is <1 μM The light sensitivity of this GTPase (number of photons required for half-maximal activation) is identical to that of light-activated phosphodiesterase The GTPase action spectrum corresponds to the absorption spectrum of rhodopsin There is, in addition, a light-insensitive GTPase activity with a Km for GTP of 90 μM At GTP concentrations above 5 μM, there is no appreciable activation of GTPase activity by light The substrate Km values for guanylate cyclase, light-activated GTPase, and light-activated phosphodiesterase order an enzyme array that might permit light to simultaneously cause the hydrolysis of both the substrate and product of guanylate cyclase These findings reveal yet another facet of light regulation of photoreceptor/cyclic GMP levels and also provide a striking analogy to the GTP regulation of nonphotoreceptor, hormone-sensitive adenylate cyclase
TL;DR: It is concluded that the activity of the soluble form of guanylate cyclase in cell-free preparations of human platelets can be increased by a lipid-protein interaction involving specific polyunsaturated fatty acids.
TL;DR: It is difficult to reach any firm decision regarding the role of cyclic AMP (or cyclic GMP) in synaptic transmission in the brain, and the development of highly specific inhibitors for adenylate cyclase should provide a firm basis from which to draw conclusions.
Abstract: On the basis of the information presented in this review, it is difficult to reach any firm decision regarding the role of cyclic AMP (or cyclic GMP) in synaptic transmission in the brain. While it is clear that cyclic nucleotide levels can be altered by the exposure of neural tissues to various neurotransmitters, it would be premature to claim that these nucleotides are, or are not, essential to the transmission process in the pre- or postsynaptic components of the synapse. In future experiments with cyclic AMP it will be necessary to consider more critically whether the extracellularly applied nucleotide merely provides a source of adenosine and is thus activating an extracellularly located adenosine receptor, or whether it is actually reaching the hypothetical sites at which it might act as a second messenger. The application of cyclic AMP by intracellular injection techniques should minimize this particular problem, although possibly at the expense of new difficulties. Prior blockade of the adenosine receptor with agents such as theophylline or adenine xylofuranoside may also assist in the categorization of responses to extracellularly applied cyclic AMP as being a result either of activation of the adenosine receptor or of some other mechanism. Ultimately, the development of highly specific inhibitors for adenylate cyclase should provide a firm basis from which to draw conclusions about the role of cyclic AMP in synaptic transmission. Similar considerations apply to the actions of cyclic GMP and the role of its synthesizing enzyme, guanylale cyclase. The use of phosphodiesterase inhibitors in studies on cyclic nucleotides must also be approached with caution. The diverse actions of many of these compounds, which include calcium mobilization and block of adenosine uptake, could account for many of the results that have been reported in the literature.
TL;DR: A novel variant of the S49 mouse lymphoma selected from wild-type cells by growth in medium containing the beta-adrenergic agonist terbutaline and inhibitors of cyclic nucleotide phosphodiesterase, designated as uncoupled (UNC), has been stable for more than 100 generations without exposure to the drugs used for selection.
Abstract: A novel variant of the S49 mouse lymphoma has been selected from wild-type cells by growth in medium containing the beta-adrenergic agonist terbutaline and inhibitors of cyclic nucleotide phosphodiesterase. In contrast to the situation in the wild-type clone, synthesis of adenosine 3':5'-monophosphate (cyclic AMP) is not stimulated by beta-adrenergic agonists or by prostaglandin E1 either in intact variant cells or in membrane preparations of such clones. However, basal and NaF-stimulated activities of adenylate cyclase [ATP pyrophosphate-lyase (cyclizine), EC 4.6.1.1] are normal, enzyme activity is stimulated by guanyl-5'-yl imidodiphosphate [Gpp(NH)p], and intact cells accumulate cyclic AMP when exposed to cholera toxin. Furthermore, variant cell membranes possess ligand-binding activity consistent with the conclusion that a normal or an excessive number of beta-adrenergic receptors is present. Thus, interaction between the hormone-binding and the catalytic moieties of the adenylate cyclase system is lost. This variant phenotype, designated as uncoupled (UNC), has been stable for more than 100 generations without exposure to the drugs used for selection. Such cells should be useful for the elucidation of methanisms of transmission of information from hormone receptors to adenylate cyclase.
TL;DR: The uncoupled and adenylate cyclase-deficient variants of the S49 cell are not complementary and the effects of beta-adrenergic agonists and antagonists on the reconstituted system reproduce those that are characteristic of the wild-type S49 lymphoma cell.
Abstract: Membranes of mouse L cells that contain adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] but lack beta-adrenergic receptors have been solubilized with Lubrol 12A9. Addition of such adenylate cyclase-containing extracts to beta-adrenergic receptor-replete membranes from adenylate cyclase-deficient S49 lymphoma cells results in the production of a catecholamine-sensitive adenylate cyclase system. The effects of beta-adrenergic agonists and antagonists on the reconstituted system reproduce those that are characteristic of the wild-type S49 lymphoma cell. The uncoupled variant of the S49lymphoma contains adenylate cyclase, but donor extracts from this clone fail to reconstitute the hormone-sensitive enzyme activity when added to adenylate cyclase-deficient membranes. Thus, the uncoupled and adenylate cyclase-deficient variants of the S49 cell are not complementary.
TL;DR: Prostacyclin generated by incubation of arachidonic acid, platelets and aortic tissue, causes a rapid and pronounced accumulation of cyclic AMP by intact platelets, as well as stimulation of adenylates cyclase in isolated platelet membranes.
Abstract: PROSTACYCLIN (PGX) (ref. 1) is the name proposed for the metabolic product of a recently discovered enzymic transformation of the prostaglandin endoperoxides PGG2 and PGH2 (refs 2–4). Prostacyclin synthetase, the enzyme which catalyses this conversion, is particularly active in the microsomal fraction of blood vessel walls3,4 although there is evidence that it is also present in the rat stomach fundus3. The prostaglandin endoperoxides, PGG2 and PGH2, have been shown to contract arterial smooth muscle and to cause platelet aggregation5,6, whereas, in contrast, prostacyclin relaxes arterial strips and prevents platelets aggregation3. A biochemical interaction has therefore been postulated to exist between platelets and the blood vessels wall, such that endoperoxides derived from platelets are converted by the vessel wall into prostacylin, which in turn actively prevents the deposition of platelets on the vascular endothelium2,4. In general, agents which inhibit platelet aggregation, such as PGE1, increase cyclic AMP levels, whereas agents causing aggregation lower platelet cyclic AMP levels7. The ability of prostacyclin to rapidly reverse or prevent platelet aggregation suggested that its action on the platelet might, like that of PGE1, be mediated by an increase in cyclic AMP levels. This hypothesis is supported by the experiments detailed here which strongly suggest that prostacyclin generated by incubation of arachidonic acid, platelets and aortic tissue, causes a rapid and pronounced accumulation of cyclic AMP by intact platelets, as well as stimulation of adenylates cyclase in isolated platelet membranes.
TL;DR: The frog erythrocyte membrane provides an excellent model system for the study of beta-adrenergic receptor-adenylate cyclase interactions since it possesses an adenylate Cyclase enzyme which is very responsive to catecholamines.
TL;DR: The evidence suggests that the plasma membrane enzymes, i.e., NADPH oxidase and adenylate cyclase, are controlled, in part, by the intracellular redox potential.
Journal Article•
TL;DR: The structural characteristics necessary for stimulation of octopamine-sensitive adenylate cyclase appear to differ markedly from those required for stimulating of dopamine or beta adrenoceptor-linked adenyate cyclases systems.
Abstract: The pharmacological properties of a cell-free, octopamine-sensitive adenylate cyclase present in homogenates of the brain of the cockroach, Periplaneta americana , have been examined. In accordance with previous reports, octopamine elicited small increases in adenylate cyclase activity in homogenates of both brain and thoracic ganglia. Guanosine 5'-triphosphate, which was routinely included in the assay system, greatly enhanced responses to octopamine, while 5'-guanylylimidodiphosphate greatly increased both basal and octopamine-sensitive adenylate cyclase activities. A variety of phenylethylamines were tested for stimulatory effects upon adenylate cyclase activity in this system: the most potent agonists were found to be octopamine and p -fluorophenylethanolamine. The naturally occurring D(-) isomer of octopamine was over 200 times as potent as the L(+) isomer. A variety of drugs were tested as possible antagonists of the octopamine-sensitive adenylate cyclase; the most potent antagonists were the alpha adrenoceptor antagonist phentolamine and the histamine and 5-hydroxytryptamine antagonist cyproheptadine. A dopamine-sensitive adenylate cyclase was also observed in homogenates of cockroach brain, and was similar to dopamine-sensitive adenylate cyclases in other tissues in its responses to epinine and to the rigid dopamine analogue 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene, and in the stereoselective blockade of responses to dopamine by the potent neuroleptic agent α-flupenthixol. Adenylate cyclase responses to dopamine and octopamine were additive. The structural characteristics necessary for stimulation of octopamine-sensitive adenylate cyclase appear to differ markedly from those required for stimulation of dopamine or beta adrenoceptor-linked adenylate cyclase systems.
ACKNOWLEDGMENTS The authors are grateful to Dr. L. L. Iversen for helpful criticism of the manuscript, and to Miss Susan Gardiner for expert technical assistance.
TL;DR: Findings cast doubt on the notion that uncomplexed ATP is a potent inhibitor and that hormones activate by reducing the affinity of this putative inhibitor.
TL;DR: Evidence for sustained oscillations of the adenylate cyclase activity in signalling cells is presented and it is shown that the oscillating variable is not only transport but also net synthesis of cyclic AMP.
Abstract: As well as acting as a chemotactic factor1 cyclic AMP stimulates cells of Dictyostelium discoideum to differentiate after the end of growth into aggregation-competent cells. These differentiation signals have a temporal pattern : pulses are efficient signals, whereas continuous administration of cyclic AMP may even have an adverse effect2,3. D. discoideum cells can release cyclic AMP spontaneously as reiterated pulses4, and also release cyclic AMP in response to extraneous cyclic AMP pulses5–7, which is important for the transmission of signals in aggregation territories in form of propagated waves8–12. The pulsatile release of cyclic AMP into the extracellular space is preceded by a sharp (about 10-fold) increase of its intracellular concentration within 1 min (ref. 4). This indicates that the oscillating variable is not only transport but also net synthesis of cyclic AMP. The periodic rise of the intracellular cyclic AMP concentration could be due to periodic activation of adenylate cyclase, to inhibition of phosphodiesterase, or to the oscillatory control of both enzymes. We present here evidence for sustained oscillations of the adenylate cyclase activity in signalling cells. No concomitant changes of the ATP concentration, the substrate of adenylate cyclase, were found.
TL;DR: It is suggested that inhibition and activation of fat cell adenylate cyclase by GTP occur through distinct regulatory processes.
TL;DR: It is demonstrated that VIP activates an adenylate cyclase from a synaptosomal fraction of guinea pig brain, and this activation was not potentiated by guanyl triphosphate nucleotides, and was unaffected by α- and β-adrenergic blockers and by atropine.
TL;DR: Guanylate cyclase activity of human platelet homogenates was stimulated by the addition of phospholipase A2 or unsaturated fatty acids such as oleic, vaccenic, linoleic, linolenic, eicosenoic, dithiothreitol, and N-ethylmaleimide, indicating that human platelets are stimulated by uns saturated fatty acid peroxides rather than by fatty acids.
Abstract: Guanylate cyclase [GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2] activity of human platelet homogenates was stimulated by the addition of phospholipase A2 or unsaturated fatty acids such as oleic, vaccenic, linoleic, linolenic, eicosenoic, eicosadienoic, and arachidonic acids. The addition of lipoxidase potentiated the fatty acid-induced stimulation of guanylate cyclase purified by DEAE-cellulose column chromatography. The extent of the stimulation was dependent on the concentration of the oxidized form of these fatty acids (peroxides). Saturated fatty acids such as stearic and arachidic acids had no effect on the guanylate cyclase activity in the presence or absence of lipoxidase, indicating that human plateletguanylate cyclase is stimulated by unsaturated fatty acid peroxides rather than by fatty acids.Hemoglobin prevented the enzyme stimulation produced by low concentrations of fatty acid peroxides, but enhanced stimulation of the enzyme activity with high concentrations of fatty acid peroxides. 2-Mercaptoethanol, dithiothreitol, and N-ethylmaleimide inhibited the guanylate cyclase activities both in the presence and absence of unsaturated fatty acidperoxide. The stimulation of guanylate cyclase activity by unsaturated fatty acid peroxidesis attributed to oxidation of sulfhydryl residues of the enzyme protein.
TL;DR: A new hormone responsiveness can be conferred on an adenylate cyclase system by coupling it to a foreign hormone receptor.
Abstract: A new hormone responsiveness can be conferred on an adenylate cyclase system by coupling it to a foreign hormone receptor. Receptor and enzyme from cells of different species can be compatible with each other.