Migration of Dictyostelium discoideum to the Chemoattractant Folic Acid

Author(s):  
Karl J. Aufderheide ◽  
Chris Janetopoulos
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 ◽  
...  

1983 ◽  
Vol 96 (6) ◽  
pp. 1559-1565 ◽  
Author(s):  
P J Van Haastert

Postvegetative Dictyostelium discoideum cells react chemotactically to gradients of cAMP, folic acid, and pterin. In the presence of a constant concentration of 10(-5) M cAMP cells move at random. They still are able to respond to superimposed gradients of cAMP, although the response is less efficient than without the high background level of cAMP. Cells which are accommodated to 10(-5) M cAMP do not react to a gradient of cAMP if the mean cAMP concentration is decreasing with time. This indicates the involvement of adaptation in the detection of chemotactic gradients: cells adapt to the mean concentration of chemoattractant and respond to positive deviations from the mean concentration. Cells adapted to high cAMP concentrations react normally to gradients of folic acid or pterin. Adaptation to one of these compounds does not affect the response to the other attractants. This suggests that cAMP, folic acid, and pterin are detected by different receptors, and that adaptation is localized at a step in the transduction process before the signals from these receptors coincide into one pathway. I discuss the implications of adaptation for chemotaxis and cell aggregation.


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 ◽  
...  

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.


1977 ◽  
Vol 27 (1) ◽  
pp. 105-114
Author(s):  
B. Wurster ◽  
K. Schubiger

Folic acid is known to be a chemoattractant of pre-aggregation cells of Dictyostelium discoideum. When supplied in pulses, folic acid induces biochemical oscillations and stimulates the development of pre-aggregation to aggregation-competent amoebae. The continuous supply of folic acid has no stimulatory effect. Folic-acid-induced oscillations are accompanied by periodic changes in the cyclic AMP concentration. Pulses of folic acid applied with rhythms between 7 and 11 min efficiently induce oscillations. In contrast, a rhythm of 2 min neither induces oscillations nor suppresses them. Cells start to oscillate with a rhythm of about 8 min. This inherent rhythm is independent of the inducing rhythm. Oscillating cells are less sensitive to folic acid than pre-oscillating ones. They respond only to high concentrations of folic acid which also interact with the oscillating system.


Toxicology ◽  
2002 ◽  
Vol 180 (3) ◽  
pp. 275-292 ◽  
Author(s):  
Jolanta Sroka ◽  
Zbigniew Madeja ◽  
Marta Michalik ◽  
Stanisław Przestalski ◽  
Włodzimierz Korohoda

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