Further studies on the glucose inhibition of β-1,3-glucanohydrolase increase during gut differentiation of sand dollar larvae☆

[摘要] β-1,3-Glucanaseactivityinsanddollarlarvaeappearsat22hrofdevelopment.Thepresenceofglucose,themajorproductofthisenzyme,intheambientseawaterdepressesβ-glucanaseactivity3-fold.Thisglucosedepressionoccursonlyifglucoseispresentduringthetimeofincreaseinβ-glucanaseactivity.Maximumdepressionoccursat10mMglucose;theeffectisnotmimickedbyl-glucoseormethylglucoseanalogs.Theglucoseeffectisreversibleupto32hrofdevelopment,butnotthereafter.Studiesonseaurchinlarvaeshowthatβ-glucanaseactivityfollowsasimilarpatternofincreaseintheseembryos,butisnotaffectedbyexogenousglucose.Thesiteofactionofglucosemaybeatthesynthesisofβ-glucanasemRNA.Iflarvaeareincubatedinglucosefor6hrandactinomycinDissubstitutedforglucose,noincreasedβ-glucanaseactivityoccurs.However,iflarvaeareincubatedincycloheximideandactinomycinDissubstitutedforcycloheximide,increasedβ-glucanaseactivityisobserved.Thusglucosemaybeactingdirectlyontranscriptionoritmaybeaffectingtheturnoverofβ-glucanasemRNA.

[学科分类] 生物科学（综合）