Fructose 2,6-bisphosphate and trehalose metabolism in Saccharomyces cerevisiae.
1. A regulatory mutant of Saccharomyces (fdp) unable to activate fructose 1,6-bisphosphatase presented a normal response to the glucose and fructose signals as measured by trehalase activation, indicating that the inability of the strain to grow on these sugars is caused by a defect located beyond membrane interactions. 2. In vivo experiments with a mutant strain bearing a phosphoglucoisomerase gene (pgil-delta) deletion showed that activation of trehalase and deactivation of the tehalose-6-phosphate synthase complex occurred to the same extent whether glucose or fructose was used as signal. 3. These results suggest that fructose-2,6-bisphosphate is not involved in the interconversion of forms of the enzymes of trehalose metabolism. Furthermore, when fructose-2,6-bisphosphate was assayed on trehalose synthesizing activity using cell-free extracts and partially purified preparations of the complex, no effect was observed. 4. We conclude that regulation by cAMP fulfills the requirements for control of trehalose levels in Saccharomyces.
Panek
A D
AD
Departamento de Bioquímica, Universidade Federal do Rio de Janerio, Brasil.
Silva
J T
JT
Ferreira-Filho
R
R
Panek
A C
AC
D000242:Cyclic AMP / Q000378:metabolism*; D004187:Disaccharides / Q000378:metabolism*; D004789:Enzyme Activation; D005635:Fructosediphosphates / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D006598:Hexosediphosphates / Q000378:metabolism*; D011494:Protein Kinases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development; D014199:Trehalose / Q000378:metabolism*
D004187:Disaccharides; D005635:Fructosediphosphates; D006598:Hexosediphosphates; C027652:fructose 2,6-diphosphate; D014199:Trehalose; D000242:Cyclic AMP; D011494:Protein Kinases; D005947:Glucose