Wortmannin as a unique probe for an intracellular signalling protein, phosphoinositide 3-kinase.

Wortmannin is a fungal metabolite that so far has been shown to act as a selective inhibitor of phosphoinositide 3-kinase. It can therefore be used to investigate the convergence between two major cellular signalling systems: those involving G-protein-coupled receptors and those involving receptor tyrosine kinases. Importantly, wortmannin can enter intact cells, making whole-cell studies of the above signalling pathways possible.