scholarly journals Developmental regulation of calmodulin-dependent adenylate cyclase activity in an insect endocrine gland.

1990 ◽  
Vol 1 (10) ◽  
pp. 771-780 ◽  
Author(s):  
V Meller ◽  
S Sakurai ◽  
L I Gilbert
Keyword(s):  
Adenylate Cyclase ◽  
Developmental Regulation ◽  
Second Messengers ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Prothoracic Gland ◽  
Endocrine Gland ◽  
And Function ◽  
Gs Alpha ◽  
Developmental Switch

The insect prothoracic gland produces ecdysteroids that elicit molting and metamorphosis, and neurohormone stimulation of steroidogenesis by this gland involves both Ca2+ and cyclic adenosine monophosphate second messengers. Prothoracic gland adenylate cyclase exhibits a complex Ca2+/calmodulin (CaM) dependence, a component of which requires an activated Gs alpha for expression. A developmental switch in this system has been identified that correlates with a change in both regulation and function of the gland and involves the loss of sensitivity to extracellular Ca2+ at a time approximately concurrent with the loss of Ca2+/CaM sensitivity by the adenylate cyclase. The extent of cholera toxin activation of gland Gs alpha is lowered before this developmental switch. However, no alterations in Gs alpha levels or mobility are detected, suggesting that Gs alpha interaction with another component in the signaling pathway, perhaps adenylate cyclase itself, produces the apparent Ca2+/CaM dependence and influences the ability of toxin to modify Gs alpha.

Adenylate-cyclase Activity in Obsessive-compulsive Patients

2017 ◽  
Vol 41 (S1) ◽  
pp. S641-S642
Author(s):  
D. Marazziti ◽  
S. Baroni ◽  
F. Mucci ◽  
L. Palego ◽  
A. Piccinni
Keyword(s):  
Adenylate Cyclase ◽  
Second Messengers ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Obsessive Compulsive ◽  
Biological Assays ◽  
Compulsive Disorder ◽  
Healthy Control ◽  
Competing Interest

IntroductionA possible role of second messengers, such as cyclic adenosine monophosphate (cAMP) signalling, in the development of obsessive-compulsive disorder (OCD) has been recently postulated.AimsThe aim of the present study was to explore and to compare the adenylate cyclase (AC) activity in both basal conditions and after the stimulation by isoprenaline (ISO) in platelets of OCD patients and healthy control subjects. The AC activity was measured both in the absence and in the presence of α- and β- adrenoreceptor antagonists.Materials and methodsForty patients were included in the study and compared with healthy volunteers. Biological assays were carried out with a method developed by us.ResultsThe basal AC activity was similar in both groups. The addition of 10 μM ISO enhanced significantly (P < .05) platelet basal AC in both groups. A stimulatory response following ISO in all subjects even without α-antagonists was also observed.DiscussionNo difference in the basal AC activity in platelet membranes of healthy subjects and OCD patients was found. Our findings showed that there is an inhibitory component of ISO effect on platelet AC, due to the agonist interaction with α2 receptors, at its higher concentrations (>1 μM), as well as a condition of supersensitive β-receptors. Our study suggests the presence of cathecolamine system disturbances in OCD.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Light-dependent synthesis of a nucleotide second messenger controls bacterial motility

2021 ◽  
Author(s):  
Jun Xu ◽  
Nobuo Koizumi ◽  
Yusuke V Morimoto ◽  
Ryo Ozuru ◽  
Toshiyuki Masuzawa ◽  
...  
Keyword(s):  
Light Exposure ◽  
Second Messengers ◽  
Random Mutagenesis ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Bacterial Motility ◽  
The Novel ◽  
Flagellar Motors ◽  
And Function

Nucleotide second messengers are universally crucial factors for the signal transduction of various organisms. In prokaryotes, cyclic nucleotide messengers are involved in the bacterial life cycle and function, such as virulence, biofilm formation, and others mainly via gene regulation. Here we show that the swimming motility of a soil bacterium is rapidly modulated by cyclic adenosine monophosphate (cAMP) synthesized upon light exposure. Analysis of a loss-of-photoresponsivity mutant obtained by transposon random mutagenesis determined the novel sensory gene, and its expression in Escherichia coli through codon optimization revealed the light-dependent synthesis of cAMP. GFP labeling showed the localization of the photoresponsive enzyme at the cell poles where flagellar motors reside. The present findings highlight the new role of cAMP that rapidly controls the flagella-dependent bacterial motility and the global distribution of the discovered photoactivated cyclase among diverse microbial species.

Effect of acidosis on PTH-dependent renal adenylate cyclase in phosphorus deprivation: role of G proteins

1990 ◽  
Vol 258 (6) ◽  
pp. F1640-F1649
Author(s):  
E. Bellorin-Font ◽  
R. Starosta ◽  
C. L. Milanes ◽  
C. Lopez ◽  
N. Pernalete ◽  
...  
Keyword(s):  
Metabolic Acidosis ◽  
Adenylate Cyclase ◽  
Maximal Activity ◽  
Phosphate Deprivation ◽  
Adp Ribosylation ◽  
Phosphate Depletion ◽  
Cortical Membranes ◽  
And Function ◽  
Gs Alpha

These studies examine the regulation of adenylate cyclase in renal cortical membranes from phosphate-deprived and phosphate-deprived acidotic dogs. Enzyme stimulation by parathyroid hormone (PTH) was decreased in phosphate deprivation [Vmax 1,578 +/- 169 vs. 2,581 +/- 219 pmol adenosine 3',5'-cyclic monophosphate (cAMP).mg protein-1 x 30 min-1 in controls, P less than 0.01]. Metabolic acidosis further decreased PTH-stimulated activity. Membranes from phosphate-deprived dogs showed a decrease in Gs alpha-content by cholera toxin-dependent ADP-ribosylation (174 +/- 18 arbitrary units vs. 266.4 +/- 13.6 in controls, P less than 0.01). Metabolic acidosis further decreased Gs alpha-content, P less than 0.01. Gi content by pertussis-dependent ADP-ribosylation was also lower in phosphate-deprived and phosphate-deprived acidotic animals. Gs function was examined by its property to protect the catalytic unit from inactivation by N-ethylmaleimide when preincubated with GTP gamma S. In controls, protection of inactivation was 80% of the maximal activity, whereas in phosphate deprivation protection was less than 50%. In conclusion, metabolic acidosis enhances adenylate cyclase resistance to PTH in phosphate deprivation. These alterations are associated with a decrease in the content and function of Gs alpha, suggesting a role of Gs in the renal adaptation to phosphate depletion and acidosis.

scholarly journals Cytochemical methods for the localization of adenylate cyclase. A review and evaluation of the efficacy of the procedures.

1983 ◽  
Vol 31 (1) ◽  
pp. 85-93 ◽  
Author(s):  
L S Cutler
Keyword(s):  
Adenylate Cyclase ◽  
Cyclic Nucleotides ◽  
Cell Biology ◽  
Enzyme System ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cellular Functions ◽  
Cytochemical Localization ◽  
Biochemical Evaluation

The cytochemical procedures for localizing adenylate cyclase have been a source of controversy since their introduction. The importance of cyclic adenosine monophosphate (AMP), the product of adenylate cyclase's action on adenosine triphosphate (ATP), in cell biology is clear. Thus, the ability to localize this enzyme system reliably is an important tool in the study of various cellular functions. This report reviews the literature and presents a biochemical evaluation of the methods for localizing adenylate cyclase. The review and data presented serve to clarify many of the controversies surrounding this important cytochemical procedure. It is evident that although there are problems associated with localizing the enzyme, several valid procedures are currently available for the cytochemical localization of adenylate cyclase. In using these procedures, the effects of fixation and the capture agent on adenylate cyclase activity in the particular tissue being studied should be considered. Only repurified adenylyl imidodiphosphate [App(NH)p] should be used in the incubation medium. If care is taken, the use of these techniques can be of great value in the continued study of the role of cyclic nucleotides in cell biology.

Secondary Messenger Systems in PTSD

2016 ◽  
Author(s):  
Ulrike Schmidt
Keyword(s):  
Second Messengers ◽  
Cyclic Adenosine Monophosphate ◽  
Second Messenger ◽  
Adenosine Monophosphate ◽  
Cyclic Guanosine Monophosphate ◽  
Brain Regions ◽  
Guanosine Monophosphate ◽  
Intracellular Camp ◽  
Post Traumatic Stress ◽  
Secondary Messenger

Second messengers such as cyclic adenosine monophosphate (cAMP), cyclic guanosine monophosphate (cGMP), inositoltriphosphate, and diacylglycerol (DAG) are a prerequisite for the signal transduction of extracellular receptors. The latter are central for cellular function and thus are implicated in the pathobiology of a variety of disorders, such as schizophrenia, bipolar disorder, major depression, and post-traumatic stress disorder (PTSD). This chapter focuses on the involvement of second messenger molecules and their regulators as direct targets in human and animal PTSD and aims to stimulate the underdeveloped research in this field. The synthesis of literature reveals that second messengers clearly play a central role in PTSD-associated brain regions and processes. In particular, pituitary adenylate cyclase-activating polypeptide (PACAP), an important regulator of intracellular cAMP levels, as well as protein kinase c, the major target of DAG, belong to the hitherto most promising PTSD candidate molecules directly involved in second messenger signaling.

scholarly journals A conserved CaM- and radial spoke–associated complex mediates regulation of flagellar dynein activity

2007 ◽  
Vol 179 (3) ◽  
pp. 515-526 ◽  
Author(s):  
Erin E. Dymek ◽  
Elizabeth F. Smith
Keyword(s):  
Mass Spectrometry ◽  
Sequence Similarity ◽  
Second Messengers ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Calcium Sensor ◽  
Wild Type ◽  
Radial Spoke ◽  
Radial Spokes ◽  
Dynein Arms

For virtually all cilia and eukaryotic flagella, the second messengers calcium and cyclic adenosine monophosphate are implicated in modulating dynein- driven microtubule sliding to regulate beating. Calmodulin (CaM) localizes to the axoneme and is a key calcium sensor involved in regulating motility. Using immunoprecipitation and mass spectrometry, we identify members of a CaM-containing complex that are involved in regulating dynein activity. This complex includes flagellar-associated protein 91 (FAP91), which shares considerable sequence similarity to AAT-1, a protein originally identified in testis as an A-kinase anchor protein (AKAP)– binding protein. FAP91 directly interacts with radial spoke protein 3 (an AKAP), which is located at the base of the spoke. In a microtubule sliding assay, the addition of antibodies generated against FAP91 to mutant axonemes with reduced dynein activity restores dynein activity to wild-type levels. These combined results indicate that the CaM- and spoke-associated complex mediates regulatory signals between the radial spokes and dynein arms.

Effect of P1-purinergic agonist on thyrotropin stimulation of H2O2 generation in FRTL-5 and porcine thyroid cells

1994 ◽  
Vol 130 (2) ◽  
pp. 180-186 ◽  
Author(s):  
Ulla Björkman ◽  
Ragnar Ekholm
Keyword(s):  
Adenylate Cyclase ◽  
Primary Culture ◽  
Purinergic Receptor ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Camp Accumulation ◽  
High Concentration ◽  
Thyroid Cells ◽  
H2o2 Generation ◽  
Stimulation Of

Björkman U, Ekholm R. Effect of P1-purinergic agonist on thyrotropin stimulation of H2O2 generation in FRTL-5 and porcine thyroid cells. Eur J Endocrinol 1994;130:180–6. ISSN 0804–4643 Our previous studies have shown that the generation of H2O2 in FRTL-5 thyroid cells is regulated via both the adenylate cyclase/cyclic adenosine monophosphate (cAMP) and Ca2+/phosphatidylinositol pathway: thyrotropin (TSH) stimulates H2O2 generation through both pathways, via the former at a low concentration and via the latter at a high concentration. In porcine thyrocytes in primary culture H2O2 generation is stimulated only via the Ca2+/phosphatidylinositol route. In the present study we explored the effect of a P1-purinergic agonist (phenylisopropyladenosine, PIA) on stimulations induced by TSH and by adenosine triphosphate (ATP), an activator of the Ca2+/phosphatidylinositol cascade via the P2-purinergic receptor. In FRTL- 5 cells, PIA potentiated H2O2 generation stimulated by TSH at 10U/l (but not at 1 U/l), Ca2+ mobilization induced by TSH and Ca2+ mobilization induced by ATP at 1 μmol/l (but not 10 μmol/l). Phenylisopropyladenosine strongly inhibited TSH-induced cAMP accumulation in FRTL-5 cells. In pig thyrocytes, PIA had no effect on H2O2 generation stimulated by TSH or ATP and no effect on ATP-stimulated Ca2+ mobilization. Also, PIA did not inhibit TSH-stimulated cAMP accumulation in pig thyrocytes, and by itselfhad no effecton H2O2 generation or Ca2 + mobilization. Thus, in FRTL-5 cells, but not in porcine thyrocytes, PIA modulates TSH-stimulated H2O2 generation by enhancing the Ca2+/phosphatitylinositol route and inhibiting the adenylate cyclase/cAMP route of the TSH signal. The net result of this modulation apparently depends on the balance between inhibition of the cAMP route and enhancement of the Ca2+ route. This may explain the lack of potentiation observed by 1 U/1 TSH. Ragnar Ekholm, Department of Anatomy, Medicinaregatan 3, S-413 90 Göteborg, Sweden

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