SUMMARY: Synchronous cultures of prepared by selection of small unbudded cells from an elutriating rotor were used to measure trehalase activity during the cell cycle. After the small cells had been removed from the rotor, the remainder was used to prepare asynchronous control cultures. Both synchronous and control cultures were studied for two cell cycles. In asynchronous cultures the trehalase activity of crude cell lysates rose continuously. In synchronized populations trehalase activity increased from the beginning of budding onwards. However, around the period of cell division the enzyme activity dropped rapidly but transiently by more than 5-fold. The same changes were found during the second budding cycle. Measurements of invertase and glucose-6-phosphate dehydrogenase activities in the same synchronous and asynchronous cultures revealed a continuous increase for both enzymes. Incubation of cell lysates with cAMP-dependent protein kinase before assaying for trehalase resulted in a 2-fold enhancement of enzyme activity in asynchronous control cultures. In synchronized cells this treatment also led to a significant stimulation of trehalase activity, and largely abolished the cell-cycle-dependent oscillatory pattern of enzyme activity. These results suggest that the activity of trehalase during the cell cycle is regulated, presumably at the post-translational level, by a phosphorylation-dephosphorylation mechanism.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error