The ribonucleoprotein nature of the rapidly labeled RNA in the embryonic retina☆

Developmental Biology

P.K. Sarkar¹  A.A. Moscona¹ 

[1] Department of Biology, University of Chicago, Chicago, Illinois 60637 USA

关键词: RNP;    ribonucleoprotein;    mRNP;    messenger ribonucleoprotein;    S15;    15;    000 g supernatant of cell homogenate;    TCA;    trichloroacetic acid;    SDS;    sodium dodecyl sulfate;    EDTA;    ethylene-diaminetetraacetate (disodium salt);   

DOI  :  10.1016/0012-1606(71)90121-7

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Embryonicneuralretinatissueinculturewaspulsedwithuridine-5-3HandtherapidlylabeledRNA-containingparticlesinthecytoplasm,sedimentinginthesubribosomal(20S–70S)andinthepolysomalregion,wereexamined.AlloftherapidlylabeledRNAinthesubribosomalregionwasintheformofRNP,asevidencedbyitsretentiononMilliporefilterswithoutprecipitationwithtrichloroaceticacid.TherapidlylabeledRNAinthesesubribosomalRNPparticleswasnonribosomalincharacteranditssedimentationandotherpropertiesweresimilartothoseofpolysomalmRNA.KineticdatasuggestthattherapidlylabeledRNAfirstappearsinthesubribosomalregionandtheninthepolysomalregion.PolysomalmRNAwasobtainedbydissociatingpolysomeswithEDTAorwithKCl,andthereleasedmessagewasexaminedforthepresenceofprotein.Buoyantdensityanalysesofpolysomesobtainedbyfractionationinsucrosegradients,underconditionsfavoringoptimallabelingofmRNAandminimallabelingofribosomalRNA,showedthatonlyabout50%ofthetotalradioactivitywasrepresentedbythepolysome-boundmessage.TherestwasinnonpolysomalRNPparticleswhichcosedimentedwiththepolysomes.ThenonpolysomalRNPparticleswereresistanttoEDTAandinCsClgradientsbandedinalessdenseregionthanintactordissociatedpolysomes.TheirbuoyantdensitywasverysimilartothatofthesubribosomalRNPparticles,bothcorrespondingtoaproteincontentof55–60%.mRNAreleasedfrompolysomesbytreatmentwithEDTAwasfoundtobeassociatedwithprotein;itbandedatabuoyantdensityof1.51,correspondingtoaproteincontentofabout50%.

【 授权许可】

Unknown