Addition of TNFα (100 ng/ml) to MEFs induced a rapid and sharp activation of the SAPK followed by a quick down-regulation.
Thus, the sharp activation of NCE above a certain ligand threshold (while CME nevertheless persists) might regulate the net signalling output, in response to increasing EGF concentrations, in a nonlinear fashion.
The sharp activation of oxidation and phosphorylation in the lamprey liver mitochondria is followed by spawning and death of the animal in the end of spring—in the beginning of summer.
These effects were accompanied by a sharp increase in activation of signal transducer and activator of transcription 3 (STAT3).
For example, the hb shadow enhancer helps produce a sharp boundary of activation by the Bicoid gradient, while its snail (sna) counterpart helps ensure reliable activation under stressful conditions such as high temperatures (Perry et al., 2010, 2011).
Results suggest that younger high performers showed a sharp increase of activation intensity from the lowest to the highest load level (left BAs 44, 45, and 46).
Positive and negative feedback loops within proximal TCR signaling generate a sharp digital activation filter that is necessary for efficient discrimination of antigenic ligands (Altan-Bonnet and Germain, 2005; Das et al., 2009).
In the first stage of boundary formation, cells within the dorsal and ventral compartments of the wing disc signal to one another, forming a sharp stripe of Notch activation at the interface between the two cell populations.
Indeed, the "pan" inhibition of PI3-K activity results in extensive caspase-dependent apoptosis as assessed by ISEL (Fig. 2a, control vs. Ly294002; Fig. 2b, Ly294002) and CASP-3 activity (Fig. 2c, Ly294002), in addition to causing a sharp drop of Akt-1 activation (Fig. 3a, b, Ly294002).
Specifically, they showed a sharp increase in the activation of majority of analyzed markers at 2 h post IR.
