Question

-GLUCOSE GLUCOSE INACTIVATION MIG1 GALA mRNA INDUCTION PATHWAY GALEGAL GALACTOSE 50 X POSITIVE FEEDBACK GAL GAL10 GAL7 GAL2 mRNA 100 X GAL3 Fig. 5. Model for glucose repression of the GAL genes. The numbers shown refer to the effect of glucose at various levels of regulation Thus, GALA is repressed S-fold by MIG1 in the presence of glucose. The MIG/GALA signal is amplified by a GAL80-dependent mechanism that involves down-regulation of the induction pathway. Together, MIGI and GAL80 account for a 50-fold repression of GALI An -2-fold repression of the GAL genes is independent of both MIGI and GAL80, and may reflect the action of other pathways (dashed lines). The final result is a 100-fold repression of the GAL genes by glucose.

Explain each step of the diagram (ie. presence of glucose causes an inhibition of... etc.)

Answer 1

Glucose inhibito Glucose Glucose activate a protein I called MRG 1 MRG 1 MRG1 inhibits the transcription Galt E TAL3 inhibito GAL 80 protein Gal4 (9422 activater GAL3 molein GAL2 protein Gal4 Glucose Minhubits 94480 17 hubitt Gal4 poolein protein MRNA GQL 4) I Galy mRNA gets translated to Gox4 . poolein (5 times) il 1 transcript povoduces peptides Galy other causes the transcription of 5 genes (GALI, GALIO GAL7, GAL2 and GAL) Golio, 7, 2, 3 6411, 10,7,2,3 alhivales AL3 protein activates GAZ puolein GALI GALIO GALI GALZ GALB Transcription of the aforementioned 5 GAL genes is inhibited by MiGa protem MIG1 Glucose activates MiG1 protein LOOX Glucose Sea Anes directly inhibito GAL 1,00 7 2,3 transcriphe