Cyclic GMP and cyclic AMP changes in response to folic acid pulses during cell development of Dictyostelium discoideum

Wurster, Bernd; Schubiger, Katrin; Brachet, Philippe

doi:10.1016/0045-6039(79)90050-2

Cited by 25 publications

(12 citation statements)

References 25 publications

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“…This observation is interesting in light of the recent reports by Wurster et al [22] that aggregation competent amebae, which have lost chemotactic responsiveness to folic acid [21], still respond physiologically to pulses of folic acid by increasing both intracellular cAMP and cGMP levels. We obtained significantly different results when chemoreception was monitored by the spreading assay.…”

Section: Discussionmentioning

confidence: 64%

Chemoresponsiveness to cAMP and Folic Acid during Growth, Development, and Dedifferentiation in Dictyostelium discoideum

Varnum

Soll

1981

Differentiation

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Section: Discussionmentioning

confidence: 64%

Chemoresponsiveness to cAMP and Folic Acid during Growth, Development, and Dedifferentiation in Dictyostelium discoideum

Varnum

Soll

1981

Differentiation

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“…prespore cells Treatment of vegetative and aggregation-competent cells in suspension with their chemoattractants leads to characteristic changes in light scattering (22,34). Furthermore, the occurrence of this chemotaxis-associated response has been correlated with an increase in intracellular cGMP (9).…”

Section: Light-scattering Changes In Suspensions Of Prestalk Andmentioning

confidence: 98%

Chemotaxis-associated properties of separated prestalk and prespore cells of Dictyostelium discoideum

Mee¹,

Tortolo²,

Coukell³

1986

Biochem. Cell Biol.

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Coukell, M. B. (1986) Chemotaxis-associated properties of separated prestalk and prespore cells of Dictyostelium discoideum. Biochem. Cell Biol. 64, 722-732 During development, prestalk and prespore cells of Dictyostelium discoideum become organized in multicellular structures. This physical association makes it difficult to characterize the two cell types biochemically and physiologically. In the present study, we have separated prestalk and prespore cells from 16-h slugs by the method of Tsang and Bradbury and have examined a number of chemotaxis-associated properties of these cells. When assayed on phosphate-buffered agar under both gradient and nongradient conditions, isolated prestalk cells responded chemotaclically to cAMPand, unexpectedly, to folate andcertain folate derivatives. In contrast, separated prespore cells failed to respond appreciably to any of these compounds. Neither prestalk nor prespore cells of strain HC91 exhibited a CAMP-induced increase in intracellular cGMP. However, a cGMP response was observed in both prestalk and prespore cells of strain NP368, a cGMP phosphodiesterase deficient mutant. Both cell types exhibited comparable CAMP-mediated light-scattering changes and possessed similar levels of surface CAMP-and folatebinding sites. On the other hand, prestalk cells had at least fourfold higher cAMP phosphodiesterase and folate dearninase activities than prespore cells, and a large fraction of both activities was on the cell surface. Therefore, the greater chemotactic response of prestalk cells to cAMP and folate on agar might be due, in part, to their increased capacity to generate a chemoattractant gradient. Results obtained in this study demonstrate that prestalk and prespore cells separated by this procedure can be used in certain physiological as well as biochemical experiments. Mee, J. D., Tortolo, D. M. & Coukell, M. B. (1986) Chemotaxis-associated properties of separated prestalk and prespore cells of Dictyostelium discoideum. Biochem. Cell Biol. 64, 722-732 Au cours du dkveloppement, les cellules prkp6donculaires et pdspores de Dictyostelium discoideum s'organisent en structures multicellulaires. Cette association physique rend difficile la caractkrisation biochimique et physiologique des deux types de cellules. Au cours de cette ttude, utilisant la mtthode de Tsang et Bradbury, nous avons stpark les cellules prtptdonculaires et . les cellules prkspores des agrBgats de 16 h et nous avons examint chez ces cellules un certain nombre de proprittts assocites B la chirniotaxie. Dans les essais sur agar avec tampon phosphate et dans des conditions avec gradient en sans gradient, les cellules pri5p6donculaires isoltes rtpondent chimiotaxiquement au cAMP et, de facon inattendue, au folate et & certains dtrivts du folate.En revanche, les cellules prtspores stpartes ne rtpondent pas de facon appreciable A aucun de ces composts. Le CAMP n'induit pas d'augmentation du cGMP intracellulaire ni dans les cellules prtpCdonculaires ni dans les cellules prtspores de la souche HC91. Cependant, ...

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“…Because bacteria liberate these compounds, this chemotactic system has been considered to be a food-seeking device (2); however, growing evidence suggests that folate may have a role in early development (3,4). Whatever its role, it should be of interest to compare the folate chemotactic system with the cyclic AMP (cAMP) system of aggregating cells.…”

mentioning

confidence: 99%

[3H]Methotrexate as a ligand for the folate receptor of Dictyostelium discoideum.

Nandini-Kishore¹,

Frazier²

1981

Proc. Natl. Acad. Sci. U.S.A.

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Studies of the folate chemotactic receptor ofvegetative Dictyostelium discoideum cells have been hampered by the presence of the degradative enzyme folate deaminase. The diaminopterin compounds aminopterin and methotrexate (MTX) are chemoattractants but are not attacked by the deaminase. [3', 5', 7, 9-3H] Vegetative Dictyostelium discoideum cells are chemotactic to folic acid and pterins (1). Because bacteria liberate these compounds, this chemotactic system has been considered to be a food-seeking device (2); however, growing evidence suggests that folate may have a role in early development (3, 4). Whatever its role, it should be of interest to compare the folate chemotactic system with the cyclic AMP (cAMP) system of aggregating cells. In particular, it seems likely that receptors for both chemoattractants share a common transducer mechanism by which the extracellular signal is coupled to the response of directional motility. A reflection of this general mechanism may be the finding that stimulation of cells in the appropriate stage ofdevelopment with either folate or cAMP results in a transient increase in intracellular cyclic GMP (cGMP) levels (5, 6).Whereas both the cAMP receptor (7, 8) and degradative enzyme (9) 3':5'-cycic-nucleotide phosphodiesterase (cNPDEase, EC 3.1.4.17) of differentiating cells have been well characterized, less is known about the analogous components ofthe folate system. In this vegetative chemotactic system, the degradative enzyme is a pterin deaminase (EC 3.5.4.11) (10,11) with a cellular distribution similar to that of the cNPDEase (7, 9-11). To perform radioligand binding studies with the folate receptor, it is necessary to either inhibit the deaminase or to use a ligand that is not attacked by the enzyme. We and others (11,12) For both methods, cells were suspended at the indicated density (see in 17 mM sodium/potassium phosphate (pH 6.4) at 40C. [3H]MTX was added at 50-70 nM, and a 0.5-ml aliquot periodically was taken for assay. Filtration was on 10-place Hoeffer manifolds with 0.8-,m polycarbonate filters (BioRad), followed by a 1.0-ml wash with cold buffer. For the centrifugation assay, cells were incubated with [3H]MTX for 1.5 min and the 0.5-ml aliquots were layered above 1.0 ml of 12% (wt/vol) polyethylene glycol 6000 in a 1.5-ml polypropylene tube (Bio-Rad) and centrifuged for 30 s in a Beckman Microfuge B at 40C. The filters or the resuspended cell pellets were measured for radioactivity in 10 ml of 3a70 scintillation fluid (Research Products, Elk Grove, IL). Nonspecific binding was determined in the presence of 50 ,uM MTX. Chemotaxis assays were performed and photographed as described (14). The gradient of MIX formed in the 2% (wt/vol) agar well plates was determined by placing 1 AM MIX (containing 200,000 dpm of [3H]MIX) in the center well ofthe plates. After 3 hr ofdiffusion at room temperature, several 3-mm strips ofagar were cut from three plates, cut into 1-mm slices with a gel slicer, and measured for radioactivity. The logarithm ofMIX concentration...

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Cyclic GMP and cyclic AMP changes in response to folic acid pulses during cell development of Dictyostelium discoideum

Cited by 25 publications

References 25 publications

Chemoresponsiveness to cAMP and Folic Acid during Growth, Development, and Dedifferentiation in Dictyostelium discoideum

Chemoresponsiveness to cAMP and Folic Acid during Growth, Development, and Dedifferentiation in Dictyostelium discoideum

Chemotaxis-associated properties of separated prestalk and prespore cells of Dictyostelium discoideum

[3H]Methotrexate as a ligand for the folate receptor of Dictyostelium discoideum.

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