Dear Torben et al.,
if you want to know more about the osmolarity response in yeast, try
a Medline search for Mike Gustin. He is working on the MAP kinase
pathway involved in the response to high osmolarity, which is one of the
things you might be interested in. Also, look into Science from last
2-3 months - there was an article about a connection between this
pathway and a 2-component signalling system (sorry - I can't find
the reprint at the moment).