Effects of amino acids and glucose on adenylate cyclase and cell differentiation of Dictyostelium discoideum☆
[摘要] StarvationtriggersthedifferentiationofDictyosteliumdiscoideumamoebastoaggregationcompetence.Todeterminemorepreciselythenatureofthestarvationsignal,theabilityofvariouscomponentsofthegrowthmediumtoinhibitdifferentiationwasexamined.Changesinadenylatecyclase(theenzymewhichgeneratesthecAMPpulsesbasictothedifferentiationprocess),variousphysiologicalandbiochemicalmarkersofdevelopingcells,andtheabilityofamoebastoformspecificintercellularcontactsweremonitored.Weshowthataminoacidmixturesinhibitcelldifferentiationbypreventingtheincreaseofadenylatecyclaseactivitywhichnormallyoccursduringtheearlyhoursofstarvation.Highconcentrationsofglucosealsoinhibitthedifferentiationprocessbutatalaterstage:Theriseinadenylatecyclasestilloccurswhencellsarestarvedinthepresenceofsugar,buttheenzymedoesnotappeartofunctioninvivo.ExogenouslygeneratedcAMPpulsesarenotabletobypasstheblockexertedbyaminoacidsbutcanbypasstheblockexertedbyglucose.Resultssupportthehypothesisthatthepresenceofaminoacidsinhibitsadenylatecyclasesynthesis,whilethepresenceof3%glucoseblocksendogenousactivationofadenylatecyclase,perhapsasaconsequenceofhighosmoticpressure.
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[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
