Yeast Physiological and Genetic Pathways


Model for GLO1 gene induction under highly osmotic conditions

Click the appropriate protein name to get information about the corresponding protein of the pathway.
This page was kindly provided by Yoshiharu Inoue

See Inoue, Y. et al.
J. Biol. Chem., 273, 2977-2983 (1998)

Speculative model for induction of the GLO1 gene under highly osmotic conditions.

Expression of the HXT11 (hexose transporter), GLK11 (glucokinase), and GPP21 (glycerol-3-phosphate phosphatase) genes has been reported to be enhanced by osmotic stress (Norbeck, J. et al. J. Biol. Chem. 271:13875-13881 (1996), Norbeck, J. and Blomberg, A. J. Biol. Chem. 272:5544-5554 (1997)). The GPD11 gene, which encodes glycerol-3-phosphate dehydrogenase, is under the control of Hog1p. Influx of glucose is increased if S.cerevisiae is exposed to highly osmotic environments, and the glucose is metabolized to dihydroxyacetone phosphate. The Gpd1p catalyzes reduction of dihydroxyacetone phosphate to glycerol 3-phosphate in the presence of NADH, and the Gpp2p catalyzes dephosphorylation of glycerol 3-phosphate to glycerol. On the other hand, methylglyoxal is synthesized from dihydroxyacetone phosphate by methylglyoxal synthase or by beta-elemination in triosephosphate isomerase reaction. The GLO11 gene is expressed by the HOG-MAPK pathway to scavenge methylglyoxal that may be increased by osmotic stress.
FBP, fructose-1,6-bisphosphate; DHAP, dihydrooxyacetone phosphate; G3P, glyceraldehyde 3-phosphate; MG, methylglyoxal; S-LG, S-D-lactoylglutathione; and GSH, glutathione (reduced form).

Generated Wed Feb 18 1998