scholarly journals Chemotaxis to cyclic AMP and folic acid is mediated by different G proteins in Dictyostelium discoideum

1990 ◽  
Vol 96 (4) ◽  
pp. 668-673
Author(s):  
FANJA KESBEKE ◽  
PETER J. M. HAASTERT ◽  
RENÉ J. W. DE WIT ◽  
B. EWA SNAAR-JAGALSKA
Keyword(s):  
Signal Transduction ◽  
Folic Acid ◽  
Cyclic Amp ◽  
G Proteins ◽  
Dictyostelium Discoideum ◽  
Guanylate Cyclase ◽  
Inhibitory Effect ◽  
Sensory Transduction ◽  
Surface Receptors ◽  
Gtpγs Binding

Mutant Frigid A (fgdA) of Dictyostelium discoideum is defective in a functional Ga2 subunit of a G protein and is characterized by a complete blockade of the cyclic AMP-mediated sensory transduction steps, including cyclic AMP relay, chemotaxis and the cyclic GMP response. Folic acid-mediated transmembrane signal transduction was investigated in this mutant; the results show that: (1) cell surface folic acid receptors are present in fgdA mutants. (2) Folic acid induces intracellular responses, including activation of guanylate cyclase and chemotaxis. (3) The inhibitory effect of GTP on folic acid binding to membranes is present. (4) GTPγS binding and highaffinity GTPase are stimulated by folic acid. These data strongly suggest that folic acid receptors are coupled to guanylate cyclase and chemotaxis via a Ga protein that is different from Ga2. The results imply that surface receptors for cyclic AMP and folic acid are coupled to different G proteins.

scholarly journals Cyclic AMP and folic acid mediated cyclic GMP accumulation in Dictyostelium discoideum

FEBS Letters ◽  
1977 ◽  
Vol 79 (2) ◽  
pp. 331-336 ◽  
Author(s):  
José M. Mato ◽  
Peter J.M. Van Haastert ◽  
Frans A. Krens ◽  
Els H. Rhunsburger ◽  
Fred C.P.M. Dobbe ◽  
...  
Keyword(s):  
Folic Acid ◽  
Cyclic Amp ◽  
Dictyostelium Discoideum ◽  
Cyclic Gmp

Identification of a signal transduction response sequence element necessary for induction of a Dictyostelium discoideum gene by extracellular cyclic AMP

1989 ◽  
Vol 9 (11) ◽  
pp. 4660-4669
Author(s):  
J Pavlovic ◽  
B Haribabu ◽  
R P Dottin
Keyword(s):  
Signal Transduction ◽  
Cyclic Amp ◽  
Dictyostelium Discoideum ◽  
Regulatory Element ◽  
Response Sequence ◽  
Base Pairs ◽  
Camp Response Element ◽  
Sequence Element ◽  
Cis Acting ◽  
Gene Coding

The signal transduction pathways that lead to gene induction are being intensively investigated in Dictyostelium discoideum. We have identified by deletion and transformation analysis a sequence element necessary for induction of a gene coding for uridine diphosphoglucose pyrophosphorylase (UDPGP1) of D. discoideum in response to extracellular cyclic AMP (cAMP). This regulatory element is located 380 base pairs upstream of the transcription start site and contains a G+C-rich partially palindromic sequence. It is not required for transcription per se but is required for induction of the gene in response to the stimulus of extracellular cAMP. The cAMP response sequence is also required for induction of the gene during normal development. A second A+T-rich cis-acting region located immediately downstream of the cAMP response sequence appears to be essential for the basal level of expression of the UDPGP1 gene. The position of the cAMP response element coincides with a DNase I-hypersensitive site that is observed when the UDPGP1 gene is actively transcribed.

scholarly journals Oscillations of cyclic nucleotide concentrations in relation to the excitability of Dictyostelium cells

1979 ◽  
Vol 81 (1) ◽  
pp. 33-47 ◽  
Author(s):  
G. Gerisch ◽  
D. Malchow ◽  
W. Roos ◽  
U. Wick
Keyword(s):  
Signal Processing ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Inhibitory Effect ◽  
Camp Concentration ◽  
Surface Receptors ◽  
Camp Generation ◽  
Adenylate Cyclase Activation ◽  
Signal Input ◽  
Extracellular Camp

Aggregating cells of Dictyostelium discoideum are able to release cyclic AMP periodically. The oscillations of cAMP generation are associated with changes in adenylate cyclase activity. Cyclic AMP receptors on the cell surface are functionally coupled to the oscillating system as evidenced by phase shifts that are induced by small pulses of extracellular cAMP. An important element of the oscillating system is the signal processing from surface receptors to the adenylate cyclase. This pathway exhibits adaptation resulting in the suppression of responses to constant, elevated concentrations of cAMP. The signal input for adenylate cyclase activation is, therefore, a change in the extracellular cAMP concentration with time. Oscillations in the absence of detectable changes of intra- or extracellular cAMP concentrations suggest the possibility that there is a metabolic network in D. discoideum cells that undergoes oscillations without coupling to adenylate cyclase. Cyclic GMP concentrations oscillate with a slight phase difference in advance of that of cAMP, suggesting that the two nucleotide cyclases might not be activated by the same mechanism. Elevation of extracellular calcium exerts an inhibitory effect on the accumulation of cAMP and on the second of the two cGMP peaks.

Guanylate Cyclase in Signal Transduction of Dictyostelium Discoideum

1991 ◽  
pp. 497-509 ◽  
Author(s):  
Conchita C. G. M. Schulkes ◽  
Cor D. Schoen ◽  
Jos C. Arents ◽  
Roel van Driel
Keyword(s):  
Signal Transduction ◽  
Dictyostelium Discoideum ◽  
Guanylate Cyclase

scholarly journals Evidence for a messenger function of cyclic GMP during phosphodiesterase induction in Dictyostelium discoideum

1982 ◽  
Vol 152 (1) ◽  
pp. 232-238
Author(s):  
P J van Haastert ◽  
F J Pasveer ◽  
R C van der Meer ◽  
P R van der Heijden ◽  
H van Walsum ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Folic Acid ◽  
Cyclic Amp ◽  
Dictyostelium Discoideum ◽  
Cyclic Gmp ◽  
Close Correlation ◽  
Phosphodiesterase Activity ◽  
Transient Elevation ◽  
Lines Of Evidence ◽  
Stimulation Of

Chemotactic stimulation of vegetative or aggregative Dictyostelium discoideum cells induced a transient elevation of cyclic GMP levels. The addition of chemoattractants to postvegetative cells by pulsing induced phosphodiesterase activity. The following lines of evidence suggest a messenger function for cyclic GMP in the induction of phosphodiesterase: (i) Folic acid and cyclic AMP increased cyclic GMP levels and induced phosphodiesterase activity. (ii) Cyclic AMP induced both cyclic GMP accumulation and phosphodiesterase activity by binding to a rate receptor. (iii) The effects of chemical modification of cyclic AMP or folic acid on cyclic GMP accumulation and phosphodiesterase induction were closely correlated. (iv) A close correlation existed between the increase of cyclic GMP levels and the amount of phosphodiesterase induced, independent of the type of chemoattractant by which this cyclic GMP accumulation was produced. (v) Computer simulation of cyclic GMP binding to intracellular cyclic GMP-binding proteins indicates that half-maximal occupation by cyclic GMP required the same chemoattractant concentration as did half-maximal phosphodiesterase induction.

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