Cyclic AMP Receptors at the Surface of Aggregating Dictyostelium Discoideum Cells
Two types of cell-surface sites of the cellular slime mold Dictyostelium discoideum are known to react with extracellular cAMP: a cAMP-phosphodiesterase (9, 12, 14) and cAMP-binding sites (6, 7, 10, 13). The latter can be detected by using phosphodiesterase inhibitors such as cGMP (10) or dithiothreitol (6). Both cAMP-phos-phodiesterase and cAMP-binding sites are developmentally regulated exhibiting their maximal activity during aggregation (9, 11). Also, the specificity of binding correlates well with the chemotactic activity of cAMP analogs (8, 11) thus indicating that cAMP-binding to cell-surface receptors is the first step leading to the chemotactic response (1) and to signal relaying (15).
KeywordsScatchard Plot Chemotactic Response Phosphodiesterase Activity cAMP Analog Negative Cooperativity
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- 4.GERISCH, G., MALCHOW, D., HUESGEN, A., NANJUNDIAH, V., ROOS, W. and WICK, U., Proc. ICN-UCLA Symposium on Develop. Biol. (1975) in press.Google Scholar
- 5.GERISCH, G. and MALCHOW, D. , (as cited from W. Roos) Adv. Cyclic Nucleot. Res. (1967) in press.Google Scholar
- 15.SHAFFER, B. M., Adv. Morphogenesis 2 (1962) 109.Google Scholar