Intercellular signalling

Arginine is the formamidine donor for creatine synthesis (Figure 31-6) and via ornithine to putrescine, spermine, and spermidine (Figure 31-3) Arginine is also the precursor of the intercellular signaling molecule ni-... 

The production of a female-influencing secretion from the chin gland of male Plethodontid salamander (P. jordani) points to a similar extension of function by the acquisition of female olfactory sensitivity to an intercellular signal protein. Female receptivity is enhanced by a male cytokine-like compound of the interleukin-6 family, in its released form. Rollman et al. (1999) note that pheromonal activity is a previously unrecognised function for cytokines. 

The murine stromal-derived factor-la (SDF-1)/CXCL12 was originally cloned from a cDNA library derived from the bone marrow stromal cell tine ST2 by a method to clone cDNAs that carry specific amino terminal signal sequences, such as those encoding intercellular signaling-transducing molecules... 

Nitric oxide (NO) is an intercellular signaling molecule that can inhibit neuronal energy production (Brorson et al., 1999 Malefic et al., 2004). It has been found that NO donors cause large increases in extracellular adenosine in cultures of forebrain neurons (Rosenberg et al., 2000). These were shown to be caused by NO release, and the accumulation of adenosine was not blocked by probenecid (ENT blocker) or GMP (a blocker of AMP hydrolysis), suggesting that adenosine was likely of intracellular origin. Indeed, it was found that NO donors caused a decrease in intracellular ATP and the inhibition of adenosine kinase activity, possibly due to the rise in adenosine. 

Three phases of receptor-mediated signaling can be identified 178 Four distinct molecular mechanisms that link agonist occupancy of cell-surface receptors to functional responses have been identified 178 Cross-talk can occur between intracellular signaling pathways 179 Signaling molecules can activate gene transcription 181 Nitric oxide acts as an intercellular signaling molecule in the central nervous system 181... 

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