Signaling pathways - minutes or hours? - (Feb/02/2012 )

Hi All,

I have a theoretical question. I have seen many articles isolating protein lysates 15-30min after cells were treated with different growth factors (pathway activators) or common biochemical pathway inhibitors, such as LY294002 or PD98059. Some of them then link the alterations in the signalling pathways (e.g. PI3K or MAPK) to processes, such as cell migration, which sometimes take 20 hours to complete, but they do not investigate whether this pathway activation/deactivation is sustained throughout the whole 20h. Is this really a correct thing to do? Can you expect that a brief 15-30min activation of a signaling pathway can trigger behavioral or morphological effects on cells, which would last for 15 hours?

Pathways can be activated/deactivated in few minutes which can lead to effects lasting few hours. Pathways need not be activated the whole time the physiological effect is proceeding.

it depends, at least, of the turn-over of blocked proteins