https://mtc.if.ufrgs.br/index.php?action=history&feed=atom&title=JEAN-LOUIS_MARTIEL_AND_ALBERT_GOLDBETER 2026-04-05T10:45:55Z Histórico de revisões para esta página neste wiki MediaWiki 1.39.4 https://mtc.if.ufrgs.br/index.php?title=JEAN-LOUIS_MARTIEL_AND_ALBERT_GOLDBETER&diff=11&oldid=prev 2009-05-04T01:25:38Z

<p>Criou página com &#039;&#039;&#039;&#039;abstract&#039;&#039;&#039; ABSTRACT We analyze a model based on receptor modification for the cAMP signaling system that controls aggregation of the slime mold Dictyostelium discoideum afte...&#039;</p> <p><b>Página nova</b></p><div>'''abstract'''<br /> <br /> ABSTRACT We analyze a model based on receptor modification for the cAMP signaling system that controls<br /> aggregation of the slime mold Dictyostelium discoideum after starvation. The model takes into account both the<br /> desensitization of the cAMP receptor by reversible phosphorylation and the activation of adenylate cyclase that follows<br /> binding of extracellular cAMP to the unmodified receptor. The dynamics of the signaling system is studied in terms of<br /> three variables, namely, intracellular and extracellular cAMP, and the fraction of receptor in active state. Using<br /> parameter values collected from experimental studies on cAMP signaling and receptor phosphorylation, we show that<br /> the model accounts qualitatively and, in a large measure, quantitatively for the various modes of dynamic behavior<br /> observed in the experiments: (a) autonomous oscillations of cAMP, (b) relay of suprathreshold cAMP pulses, i.e.,<br /> excitability, characterized by both an absolute and a relative refractory period, and (c) adaptation to constant cAMP<br /> stimuli. A two-variable version of the model is used to demonstrate the link between excitability and oscillations by<br /> phase plane analysis. The response of the model to repetitive stimulation allows comprehension, in terms of receptor<br /> desensitization, of the role of periodic signaling in Dictyostelium and, more generally, the function of pulsatile patterns<br /> <br /> ===Resumo dos principais tópicos abordados no paper===</div>

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