MRNA localisation ii

jambomber's version from 2015-05-17 13:44

Section 1

Question Answer
What are the caveats to different visualisation approcachesLarg number of stem loops can alter RNA behavious, RnA apatemers are not yetproven in vivo , Beacons are lmited by accesibility of their tagets and flourescent RNAs are x deg by endogenous machinery
Who published paper which investigted RNA movement in nucleus? What did they find?Single particle GFP tracking Trafficking is confined to channels. Docking @ NPC the rate limiting step in export- Reside w/in nuclei for several mins and cross NPC in a matter of seconds
How is Dpb5 activated? What remains unclear?By Gle6 tethered to NPC, Dp5 mutants still have export in drosophila- not essential
Who proposed gene gatingBlöbel
What is the bulk of RNA transported using? What are exceptonsRef/TAP adaptors- Intronless genes- still involves Ref + UAp 56 but unclear why
Why might loc not be that important?Only in a limited number of cases has necessity been demo'ed - disturbing x detectable phenotype
Why is location important- cool exampleMyelin basic protein sticks to membranes- this would cause havoc in the endosomal system
Importance of loc? (4)cost, Gradient est, Spatiotemporal fin tuning. Necessity due to danger
Which RBPs localise Prospero mRNA?Miranda and Staufen
Which organelles are RNAs targetted to?Vimetin and y Actin perinuclear distibution to increase efficeincy of nuclear import. Mit encoded genes loc @ vicinty ie ATP2. Impaired sorting here related to respiratory disease.
Where is transport really long range>>In the vasculature of plams Si and mRNAs - serves as an information pipeline

Section 2

Question Answer
How can mRNA be anchored? Static prelocalisation ie Anchoring of Xcat to the cytoskeleton or multiple rounds of local AT ie Bicoid
What is evidence that dendrite transcripts travel both ways Fmrp adaptor associates with both kinesin and dyenin.
How many mechanisms for localisation exist?5 Diff+entrapment, localised deg. localised syntheisi, polarised nuclear export and Active tranport
How does Xcat 2 move in xenopus?As part of the mitochondrial cloud
Give an example of localised synthessisBeneath the neoromuular jumciton Proximal Myofibril nuclei synthesis deleta and E acetyl choline
Where does polarised export occur?Chlamydo. When deflagelated tubulin B transcripts loclise to polysomes in the cell osterior opposite existing flagelli,
What behaviours do Nuclear hisotries influenceLocalisation, half life and transcription initiation. Mch of what happens in the cytosol is predetermined
What is the best known example of a protein complex which influences an mRNAs destiny?The EJC Heterotertramer associates with mRNA to det tranlatability- ulltimately removed in pioneer round of translation
How is nuture and nature relevant to RNAsNurture = enironment wihtih the nucleus, nature = Primrary sequence elements
Why is oskar loc importantRestricted translation of oskar at the posterior pole is essential for germ line and abdomen formation in the future embryo [
What are the EJC componentseIF4AIII, Barentsz, Mago Nashi and Tsunagi
What is the evidence thatEJC required for loc proper localization of oskar mRNA expressed from an exogenous transgene requires that the transgene contain at least one intron.
Comment on percieved role of EJCWhereas no direct evidence yet exists for involvement of the EJC in localizing other mRNAs in other organisms or cell types, circumstantial evidence may be pointing in that direction. For example, Magoh, Y14 and MLN51 all localize to the dendrites of mammalian hippocampal neurons
What is the advantage of nuclear aquistion of markers? clear advantage of nuclear acquisition of translational inhibitors is the elimination of any potential for premature displacement of mRNP transport and/or regulatory factors by a pioneer round of translation immediately upon nucleocytoplasmic export.