scholarly journals Second messengers and divergent HD-GYP enzymes regulate 3’,3’-cGAMP signaling

2019 ◽  
Author(s):  
Todd A. Wright ◽  
Lucy Jiang ◽  
James J. Park ◽  
Wyatt A. Anderson ◽  
Ge Chen ◽  
...  

ABSTRACT3’,3’-cyclic GMP-AMP (cGAMP) is the third cyclic dinucleotide (CDN) to be discovered in bacteria. No activators of cGAMP signaling have yet been identified, and the signaling pathways for cGAMP have appeared narrowly distributed based upon the characterized synthases, DncV and Hypr GGDEFs. Here we report that the ubiquitous second messenger cyclic AMP (cAMP) is an activator of the Hypr GGDEF enzyme GacB from Myxococcus xanthus. Furthermore, we show that GacB is inhibited directly by cyclic di-GMP, which provides evidence for cross-regulation between different CDN pathways. Finally, we reveal that the HD-GYP enzyme PmxA is a cGAMP-specific phosphodiesterase (GAP) that promotes resistance to osmotic stress in M. xanthus. A signature amino acid change in PmxA was found to reprogram substrate specificity and was applied to predict the presence of non-canonical HD-GYP phosphodiesterases in many bacterial species, including phyla previously not known to utilize cGAMP signaling.

1987 ◽  
Vol 88 (3) ◽  
pp. 379-388
Author(s):  
M.B. Coukell ◽  
A.M. Cameron

Previous studies have suggested that cyclic GMP and/or Ca2+ might function as second messengers in the induction by exogenous cyclic AMP of the cyclic AMP phosphodiesterase (PD) in Dictyostelium discoideum. To assess further the role of Ca2+ in PD induction we examined the effect on this process of a number of putative Ca2+-channel blockers. At relatively low micromolar concentrations, TMB-8, nicardipine, nifedipine, diltiazem and verapamil all altered cell shape and inhibited PD induction in a similar dose-dependent fashion. Concentrations of these drugs that abolished PD induction had no effect on cell viability; however, higher concentrations reduced viability and caused cell lysis. All effects of these compounds on the cells were antagonized at least partially by 5–10 mM-Ca2+. Other cations tested were considerably less effective. Like the organic inhibitors, La3+ also altered cell shape, inhibited PD induction and reduced cell viability at elevated concentrations, but its effect on the cells appeared to be more complex. Inhibition of PD induction by the organic antagonists could not be attributed solely to an impaired uptake of extracellular Ca2+, a reduction of ATP pools in the cells or a direct effect on calmodulin. Concentrations of TMB-8 that inhibited PD induction had little effect on the cyclic GMP response. Therefore, this compound did not inhibit PD induction indirectly by blocking cyclic GMP synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)


Microbiology ◽  
1984 ◽  
Vol 130 (7) ◽  
pp. 1845-1849 ◽  
Author(s):  
A. L. DEVI ◽  
H. D. McCURDY

2006 ◽  
Vol 64 (3a) ◽  
pp. 549-552
Author(s):  
Luciana R. Lopes ◽  
Mario Fernando Prieto Peres ◽  
Kaate R.J. Vanmolkot ◽  
Patrícia R. Tobo ◽  
Eliova Zukerman ◽  
...  

Familial hemiplegic migraine (FHM) is a rare autosomal dominant form of migraine with aura. This disease has been associated with missense mutations in the CACNA1A and ATP1A2 genes. The aim of this study was to identify whether CACNA1A and ATP1A2 are or not related to Brazilian FHM. Here we screened four Brazilian FHM families (total of 26 individuals - 13 affected and 13 asymptomatic or normal) for mutations in both genes. We found an amino acid change in a member of family FHM-D (Arg2206Gly). However since this alteration is not present in all affected individuals and is present in one asymptomatic individual it should be considered a polymorphism. Further studies with additional families will be necessary to reveal the importance of both CACNA1A and ATP1A2 genes on the pathogeneses of FHM in Brazil and to test the third gene (SCN1A) in these FHM families.


2002 ◽  
Vol 205 (4) ◽  
pp. 493-501 ◽  
Author(s):  
U. I. M. Wiehart ◽  
S. W. Nicolson ◽  
R. A. Eigenheer ◽  
D. A. Schooley

SUMMARYFluid secretion by insect Malpighian tubules is controlled by haemolymph-borne factors. The mealworm Tenebrio molitor provides the first known example of antagonistic interactions between endogenous neuropeptides acting on Malpighian tubules. The two corticotropin-releasing-factor (CRF)-related diuretic peptides previously isolated from Tenebrio molitor, Tenmo-DH37 and Tenmo-DH47, were found to stimulate Tenebrio molitor tubules in vitro in a dose-dependent manner with EC50 values of 0.12 nmol l–1 and 26 nmol l–1 respectively. However, no synergistic or additive effect was observed when these two peptides were tested simultaneously. We then investigated antagonism between second messengers: dose–response curves were constructed for stimulation of Tenebrio molitor tubules by cyclic AMP and their inhibition by cyclic GMP. When both cyclic nucleotides were included in the bathing Ringer, the stimulatory effect of cyclic AMP was neutralised by cyclic GMP. Similarly, the stimulatory effect of Tenmo-DH37 was reversed on addition of an antidiuretic peptide (Tenmo-ADF), which was recently isolated from Tenebrio molitor and acts via cyclic GMP. The cardioacceleratory peptide CAP2b, originally isolated from Manduca sexta, also increases intracellular cyclic GMP levels and inhibited fluid secretion by Tenebrio molitor tubules, with an EC50 value of 85 nmol l–1. This inhibitory effect was reversed by Tenmo-DH37. Endogenous diuretic and antidiuretic peptides, effective at low concentrations and acting via antagonistic second messengers, have the potential for fine control of secretion rates in the Malpighian tubules of Tenebrio molitor.


1981 ◽  
Vol 87 (1) ◽  
pp. 198 ◽  
Author(s):  
G. N. Catravas ◽  
S. J. Wright ◽  
P. J. Trocha ◽  
J. Takenaga

1999 ◽  
Vol 77 (6) ◽  
pp. 422-431 ◽  
Author(s):  
Harvey R Weiss ◽  
Gary X Gong ◽  
Michaela Straznicka ◽  
Lin Yan ◽  
James Tse ◽  
...  

We tested the hypothesis that the negative functional effects of cyclic GMP (cGMP) would be greater after increasing cyclic AMP (cAMP), because of the action of cGMP-affected cAMP phosphodiesterases in cardiac myocytes and that this effect would be altered in left ventricular hypertrophy (LVH) produced by aortic valve plication. Myocyte shortening data were collected using a video edge detector, and O2 consumption was measured by O2 electrodes during stimulation (5 ms, 1 Hz, in 2 mM Ca2+) from control (n = 7) and LVH (n = 7) dog ventricular myocytes. cAMP and cGMP were determined by a competitive binding assay. cAMP was increased by forskolin and milrinone (10-6 M). cGMP was increased with zaprinast and decreased by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxilin-1-one (ODQ) both at 10-6 and 10-4 M, with and without forskolin or forskolin + milrinone. Zaprinast significantly decreased percent shortening in control (9 ± 1 to 7 ± 1%) and LVH (10 ± 1 to 7 ± 1%) myocytes. It increased cGMP in control (36 ± 5 to 52 ± 7 fmol/105 myocytes) and from the significantly higher baseline value in LVH (71 ± 12 to 104 ± 18 fmol/105 myocytes). ODQ increased myocyte function and decreased cGMP levels in control and LVH myocytes. Forskolin + milrinone increased cAMP levels in control (6 ± 1 to 15 ± 2 pmol/105 myocytes) and LVH (8 ± 1 to 18 ± 2 pmol/105 myocytes) myocytes, as did forskolin alone. They also significantly increased percent shortening. There were significant negative functional effects of zaprinast after forskolin + milrinone in control (15 ± 2 to 9 ± 1%), which were greater than zaprinast alone, and LVH (12 ± 1 to 9 ± 1%). This was associated with an increase in cGMP and a reduction in the increased cAMP induced by forskolin or milrinone. ODQ did not further increase function after forskolin or milrinone in control myocytes, despite lowering cGMP. However, it prevented the forskolin and milrinone induced increase in cAMP. In hypertrophy, ODQ lowered cGMP and increased function after forskolin. ODQ did not affect cAMP after forskolin and milrinone in LVH. Thus, the level of cGMP was inversely correlated with myocyte function. When cAMP levels were elevated, cGMP was still inversely correlated with myocyte function. This was, in part, related to alterations in cAMP. The interaction between cGMP and cAMP was altered in LVH myocytes.Key words: second messengers, cyclic AMP, cyclic GMP, cardiac myocyte function, cyclic GMP dependent cyclic-AMP phosphodiesterases, left ventricular hypertrophy, dog.


1981 ◽  
Vol 91 (1) ◽  
pp. 287-292 ◽  
Author(s):  
M A Ariano ◽  
A I Matus

The subcellular localization of cyclic GMP and cyclic AMP in the rat caudate-putamen has been studied using horseradish peroxidase immunocytochemistry. Both of the putative neurotransmitter second messengers were visualized in neurons and glial cells at light microscopic resolutions, but not all cells of either category gave detectable staining. This was confirmed at the ultrastructural level where both stained and unstained elements of the same cell type were found within the same field. A striking variation was seen in cyclic nucleotide staining intensity within individual neural and glial cells. Both of the cyclic nucleotides were detected within postsynaptic terminal boutons and within astroglial processes. Cyclic GMP postsynaptic staining was stronger than glial staining, whereas the localization pattern was reversed for cyclic AMP. The synaptic localization of cyclic AMP and cyclic GMP immunoreactivity adds support to the idea that these compounds have an influential role in synaptic function within the striatum.


1986 ◽  
Vol 238 (2) ◽  
pp. 597-604 ◽  
Author(s):  
J S Davis ◽  
L L Weakland ◽  
L A West ◽  
R V Farese

The following studies were conducted to determine whether luteinizing hormone (LH), a hormone which increases cellular levels of cyclic AMP, also provokes increases in ‘second messengers’ derived from inositol lipid metabolism (i.e. inositol phosphates and diacylglycerol). Rat granulosa cells isolated from mature Graafian follicles were prelabelled for 3 h with myo-[2-3H]inositol. LH provoked rapid (5 min) and sustained (up to 60 min) increases in the levels of inositol mono-, bis, and trisphosphates (IP, IP2 and IP3, respectively). Time course studies revealed that IP3 was formed more rapidly than IP2 and IP following LH treatment. The response to LH was concentration-dependent with maximal increases at LH concentrations of 1 microgram/ml. LiCl (2-40 mM) enhanced the LH-provoked accumulation of all [3H]inositol phosphates, presumably by inhibiting the action of inositol phosphate phosphatases. The effectiveness of LH, however, was dependent on the concentration of lithium employed; maximal increases in IP were observed at 10 mM-LiCl, whereas maximal increases in IP2 and IP3 were observed at 20 mM- and 40 mM-LiCl, respectively. The stimulatory effects of LH on inositol phosphate and progesterone accumulation were also compared with changes in cyclic nucleotide levels. LH rapidly increased levels of inositol phosphates, progesterone and cyclic AMP, but transiently reduced levels of cyclic GMP. These results demonstrate that LH increases both cyclic AMP and inositol trisphosphate (and presumably diacylglycerol) in rat granulosa cells. Our findings suggest that two messenger systems exist to mediate the action of LH in granulosa cells.


1983 ◽  
Vol 50 (04) ◽  
pp. 804-809 ◽  
Author(s):  
Torstein Lyberg

SummaryHuman monocytes in vitro respond to various agents (immune complexes, lectins, endotoxin, the divalent ionophore A 23187, 12-0-tetradecanoyl-phorbol 13-acetate [TPA], purified protein derivative [PPD] of Bacille Calmette-Guerin) with an increased synthesis of the protein component of thromboplastin. The effect of cyclic AMP and cyclic GMP on this response has been studied. Dibutyryl-cyclic AMP, prostaglandin E1 and the phosphodiesterase inhibitors 3-butyl-1-methyl-xanthine (MIX) and rac -4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone (Ro 201724), separately and in combination have a pronounced inhibitory effect on the response to immune complexes and PPD, and a moderate effect on the response to endotoxin and lectins. The effect on TPA response and on the response to A 23187 was slight. Dibutyryl-cyclic GMP (1 mM) gave a slight inhibition of the TPA arid IC response, but had essentially no effect on the response to other inducers. The intracellular cAMP level increased when monocytes were incubated with IC, TPA or A 23187 followed by a decrease to basal levels within 1-2 hr, whereas lectin (PHA) and PPD did not induce such changes. The cAMP response to endotoxin varied. Stimulation with IC induced an increase in monocyte cGMP levels, whereas the other stimulants did not cause such changes.


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