I'm working on retinoic acid-activated signaling pathways and I was wondering how does it activate (stimulate the phosphorilation) of different kinases. For instance, I know it stimulates the fosforilation of p38 as soon as 1 hour after treatment. But how does it do that?, I'm guessing it stimulates the transcription (via RARs) of some kinases that in turn phosphorilate p38. However, this seems not very likely... isn't 1 hour too soon to achieve these effect?.
Anyone knows whether its possible that RA acts DIRECTLY on some kinases?