Synthesis of (1-->3)-beta-D-glucan, the major structural component of the yeast cell wall, is synchronized with the budding cycle. Membrane-bound, GTP-stimulated (1-->3)-beta-glucan synthase was dissociated by stepwise treatment with salt and detergents into two soluble fractions, A and B, both required for activity. Fraction A was purified about 800-fold by chromatography on Mono Q and Sephacryl S-300 columns. During purification, GTP binding to protein correlated with synthase complementing activity. A 20-kDa GTP-binding protein was identified by photolabeling in the purified preparation. This preparation no longer required GTP for activity, but incubation with another fraction from the Mono Q column (A1) led to hydrolysis of bound GTP to GDP with a concomitant return of the GTP requirement. Thus, fraction A1 appears to contain a GTPase-activating protein. These results show that the GTP-binding protein not only regulates glucan synthase activity but can be regulated in turn, constituting a potential link between cell cycle controls and wall morphogenesis.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|