Gene expression during development of Myxococcus xanthus: Pattern of protein synthesis☆

[摘要] ThepatternofproteinsynthesisduringdevelopmentofMyxococcusxanthuswasinvestigated.Thisgram-negativebacteriumhasacomplexlifecyclewhichinvolvesatemporalsequenceofcellularaggregation,moundformation,andmyxosporulation.Atvariousstagesofdevelopment,cellswerepulse-labeledwitha14C-labeledaminoacidmixture.SynthesisofsolubleandmembraneproteinswasthenanalyzedbySDS-polyacrylamidegelelectrophoresis.Ofthe30majorsolubleproteins,atleast25%showedsignificantchangesintheirratesofproductionduringdevelopment.Severalsignificantchangeswerealsofoundinthemembraneproteinsasanalyzedbytwo-dimensionalpolyacrylamidegelelectrophoresis.Themajorproteinssynthesizedduringdevelopmentwereclassifiedintofourdifferenttypes:accumulationproteins,peakproteins,lateproteins,andconstantproteins.ThesynthesisofproteinS,anaccumulationprotein,increasesdramaticallyduringdevelopmenttoamaximumof15%oftotalsolubleproteinsynthesis.Whenmethioninewasaddedtotheculturemedium,cellsdidnotformfruitingbodies.Undertheseconditions,almostalloftheproteinchangesobservedintheearlyandmiddleperiodsofdevelopmentstilloccurred.However,theproductionoflateproteins(e.g.,proteinU)wasnotobserved,suggestingthatmethionineblocksalatestageofdevelopment.Duringglycerolinduction,manyofthechangesinproteinsynthesiswhichnormallyoccurduringdevelopmentwerenotobserved(e.g.,proteinSdidnotaccumulate).TheseresultsindicatethatgeneexpressioninM.xanthusiscomplexandsubjecttotightregulation.

[学科分类] 生物科学（综合）