Hi yeast enthusiasts,
Now this is getting interesting. Lenore brought up a good point, "What exactly
is a spore?" Maybe, a spore is just a stationary phase cell with a special
cell wall. In Schizosaccharomyces pombe, mutants in PKA are delayed for
germination. PKA is also stimulated by glucose, thus bringing together some of
the themes of this discussion. Also in pombe, adenylate cyclase is stimulated
by glucose through a heterotrimeric G protein, which raises the question "Is
there a glucose receptor?". In S. cerevisiae, glucose also stimulates
adenylate cyclase, but through RAS proteins. I have wondered why no one has
found anything truly upstream of RAS. Does glucose or a derivative regulate
RAS, CDC25, or IRA1 and 2 directly? To bring in another well studied system, I
believe that studies of SUC2 repression by glucose have not identified a
"glucose sensor". Can someone correct me if I am wrong on that point? I
remember that hexokinase II played a role, but I thought that there was some
controversy surrounding the mechanism.
That's all for now.