scholarly journals Interaction of cAMP with the cell-surface receptor induces cell-type-specific mRNA accumulation in Dictyostelium discoideum.

1986 ◽  
Vol 83 (13) ◽  
pp. 4819-4823 ◽  
Author(s):  
M. Oyama ◽  
D. D. Blumberg
Keyword(s):  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Cell Surface Receptor ◽  
Cell Type ◽  
Mrna Accumulation ◽  
Surface Receptor ◽  
Cell Type Specific ◽  
Specific Mrna

Pharmacological characterization of cyclic AMP receptors mediating gene regulation in Dictyostelium discoideum

1986 ◽  
Vol 6 (7) ◽  
pp. 2402-2408
Author(s):  
B Haribabu ◽  
R P Dottin
Keyword(s):  
Gene Expression ◽  
Cyclic Amp ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Cell Surface Receptor ◽  
Intracellular Camp ◽  
Response Curves ◽  
Pharmacological Characterization ◽  
Surface Receptor ◽  
Extracellular Molecules

Extracellular molecules regulate gene expression in eucaryotes. Exogenous cyclic AMP (cAMP) affects the expression of a large number of developmentally regulated genes in Dictyostelium discoideum. Here, we determine the specificity of the receptor(s) which mediates gene expression by using analogs of cAMP. The order of potency with which these analogs affect the expression of specific genes is consistent with the specificity of their binding to a cell surface receptor and is distinct from their affinity for intracellular cAMP-dependent protein kinase. Dose-response curves with cAMP and adenosine 3',5'-monophosphorothioate, a nonhydrolyzable analog, revealed that the requirement for high concentrations of exogenous cAMP for regulating gene expression is due to the rapid degradation of cAMP by phosphodiesterase. The addition of low concentrations of cAMP (100 nM) or analogs in pulses also regulates gene expression. Both the genes that are positively regulated by exogenous cAMP and the discoidin gene, which is negatively regulated, respond to cAMP analogs to the same degree. Genes expressed in prespore or prestalk cells are also similarly regulated. These data suggest that the effects are mediated through the same receptor. The specificity of this receptor is indistinguishable from that of the well-characterized cell surface cAMP receptor.

scholarly journals Pharmacological characterization of cyclic AMP receptors mediating gene regulation in Dictyostelium discoideum.

1986 ◽  
Vol 6 (7) ◽  
pp. 2402-2408 ◽  
Author(s):  
B Haribabu ◽  
R P Dottin
Keyword(s):  
Gene Expression ◽  
Cyclic Amp ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Cell Surface Receptor ◽  
Intracellular Camp ◽  
Response Curves ◽  
Pharmacological Characterization ◽  
Surface Receptor ◽  
Extracellular Molecules

Extracellular molecules regulate gene expression in eucaryotes. Exogenous cyclic AMP (cAMP) affects the expression of a large number of developmentally regulated genes in Dictyostelium discoideum. Here, we determine the specificity of the receptor(s) which mediates gene expression by using analogs of cAMP. The order of potency with which these analogs affect the expression of specific genes is consistent with the specificity of their binding to a cell surface receptor and is distinct from their affinity for intracellular cAMP-dependent protein kinase. Dose-response curves with cAMP and adenosine 3',5'-monophosphorothioate, a nonhydrolyzable analog, revealed that the requirement for high concentrations of exogenous cAMP for regulating gene expression is due to the rapid degradation of cAMP by phosphodiesterase. The addition of low concentrations of cAMP (100 nM) or analogs in pulses also regulates gene expression. Both the genes that are positively regulated by exogenous cAMP and the discoidin gene, which is negatively regulated, respond to cAMP analogs to the same degree. Genes expressed in prespore or prestalk cells are also similarly regulated. These data suggest that the effects are mediated through the same receptor. The specificity of this receptor is indistinguishable from that of the well-characterized cell surface cAMP receptor.

Regulatory signals affecting a selective loss of mRNA in Dictyostelium discoideum

1989 ◽  
Vol 94 (3) ◽  
pp. 501-509
Author(s):  
H.H. Hassanain ◽  
W. Kopachik
Keyword(s):  
Cyclic Amp ◽  
Cell Surface ◽  
Dictyostelium Discoideum ◽  
Transcript Level ◽  
Cell Surface Receptor ◽  
Cell Contact ◽  
Specific Cell ◽  
Mrna Levels ◽  
Stage Of Development ◽  
Surface Receptor

We identified signals that affect mRNA levels complementary to a gene that is highly expressed in vegetative Dictyostelium discoideum cells. This gene has been cloned as cDNA in the plasmid pcD-D2. The level of transcripts homologous to pcD-D2 fell dramatically in strain XP55 during the aggregation stage of development when cells differentiate on agar. The level, however, did not fall simply as a result of starvation or aggregation-specific cell contact. Rather, before the level is reduced cells must be deprived of amino acids and cyclic AMP administered in amounts and at intervals in pulses to mimic cyclic AMP signal-relay in aggregation. This effect can be blocked either with cyclic AMP-S (a non-hydrolysable cyclic AMP analogue) or adenosine, both of which prevent cyclic AMP binding to the cyclic AMP cell surface receptor. It is also blocked in ‘frigid’ aggregation-deficient mutants HC85 and HC112 known to be defective in a G alpha protein. We conclude that the transcript level is balanced by positive nutritional signals acting against negative signals transduced in part through a cell surface cyclic AMP receptor.

Expression, function, and localization of the REG cell surface receptor

2001 ◽  
Vol 120 (5) ◽  
pp. A18-A19
Author(s):  
B DIECKGRAEFE ◽  
C HOUCHEN ◽  
H ZHANG
Keyword(s):  
Cell Surface ◽  
Cell Surface Receptor ◽  
Surface Receptor

Inhibition of rat ventricular automaticity by adenosine

1985 ◽  
Vol 248 (6) ◽  
pp. H907-H913 ◽  
Author(s):  
L. J. Heller ◽  
R. A. Olsson
Keyword(s):  
Cell Surface ◽  
Cell Surface Receptor ◽  
Chronotropic Effect ◽  
Surface Receptors ◽  
Adenosine Concentration ◽  
Surface Receptor ◽  
Ventricular Automaticity ◽  
Beating Rate ◽  
Chronotropic Effects ◽  
Developed Pressure

This study was designed to characterize adenosine's negative chronotropic effect on ventricular pacemakers. The spontaneous beating rate of isolated, isovolumic rat ventricular preparations perfused with Krebs-Henseleit solution decreased as the adenosine concentration was increased [log M effective concentration 50% (EC50) = -5.22 +/- 0.17]. The lack of effect of propranolol or atropine on this adenosine response eliminates the involvement of endogenous neurotransmitters. Support for the involvement of an external cell surface receptor was provided by findings that theophylline and 8-(4-sulfophenyl)theophylline, an analogue thought to act solely at the cell surface, significantly increased the adenosine log M EC50 to -3.94 +/- 0.22 and -3.61 +/- 0.22, respectively. An increase in spontaneous beating rate induced by theophylline, but not by its analogue, was blocked by the addition of propranolol. The relative chronotropic potency of the adenosine analogues R-PIA, S-PIA, and NECA suggests that the cell surface receptors may be of the Ri type. The negative chronotropic effects of adenosine and its analogues occurred at concentrations that had no effect on the developed pressure of the paced preparation. Electrocardiographic evaluations indicate that at high agonist concentrations, there was an abrupt alteration in electrical properties of the preparation, which could be blocked by theophylline and its analogue.

Sign in / Sign up

Export Citation Format

Share Document