Constitutively Active Myosin Light Chain Kinase Alters Axon Guidance Decisions in Drosophila Embryos

Developmental Biology

Janice L Fritz¹  Ananda K Seneviratne¹  Mark F.A VanBerkum¹  You-Seung Kim¹ 

[1] Department of Biological Sciences, Wayne State University, Detroit, Michigan, 48202

关键词: Myosin;    Myosin Light Chain Kinase;    Calmodulin;    motility;    axon guidance;    repulsion;    Drosophila;   

DOI  :  10.1006/dbio.2002.0768

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

ConventionalmyosinIIactivityprovidesthemotileforceforaxonoutgrowth,buttoachievedirectionalmovementduringaxonpathwayformation,myosinactivityshouldberegulatedbytheattractiveandrepulsiveguidancecuesthatguideanaxontoitstarget.Here,evidenceforthisregulationisobtainedbyusingaconstitutivelyactiveMyosinLightChainKinase(ctMLCK)toselectivelyelevatemyosinIIactivityinDrosophilaCNSneurons.ExpressionofctMLCKpan-neurallyorinprimarilypCC/MP2neuronscausestheseaxonstocrossthemidlineincorrectly.Thisoccurswithoutalteringcellfatesandissensitivetomutationsintheregulatorylightchains.TheseresultsconfirmtheimportanceofregulatingmyosinIIactivityduringaxonpathwayformation.MutationsinthemidlinerepulsiveligandSlit,oritsreceptorRoundabout,enhancethenumberofctMLCK-inducedcrossovers,butctMLCKexpressionalsopartiallyrescuescommissureformationincommissurelessmutants,whererepulsivesignalsremainhigh.OverexpressionofFrazzled,thereceptorformidlineattractiveNetrins,enhancesctMLCK-dependentcrossovers,butcrossoversaresuppressedwhenFrazzledactivityisreducedbyusingloss-of-functionmutations.TheseresultsconfirmthatproperpathwayformationrequirescarefulregulationofMLCKand/ormyosinIIactivityandsuggestthatregulationoccursindirectresponsetoattractiveandrepulsivecues.

【 授权许可】

Unknown