title: Dynamic interaction between P-bodies and transport ribonucleoprotein particles in dendrites of mature hippocampal neurons.
abstract: The dendritic localization of mRNAs and their subsequent translation at stimulated synapses contributes to the experience-dependent remodeling of synapses and thereby to the establishment of long-term memory. Localized mRNAs are transported in a translationally silent manner to distal dendrites in specific ribonucleoprotein particles (RNPs), termed transport RNPs. A recent study suggested that processing bodies (P-bodies), which have recently been identified as sites of RNA degradation and translational control in eukaryotic cells, may participate in the translational control of dendritically localized mRNAs in Drosophila neurons. This study raised the interesting question of whether dendritic transport RNPs are distinct from P-bodies or whether those structures share significant overlap in their molecular composition in mammalian neurons. Here, we show that P-body and transport RNP markers do not colocalize and are not transported together in the same particles in dendrites of mammalian neurons. Detailed time-lapse videomicroscopy analyses reveal, however, that both P-bodies and transport RNPs can interact in a dynamic manner via docking. Docking is a frequent event involving as much as 50% of all dendritic P-bodies. Chemically induced neuronal activity results in a 60% decrease in the number of P-bodies in dendrites, suggesting that P-bodies disassemble after synaptic stimulation. Our data lend support to the exciting hypothesis that dendritically localized mRNAs might be stored in P-bodies and be released and possibly translated when synapses become activated.
authors.affiliation: Department of Neuronal Cell Biology, Center for Brain Research, Medical University of Vienna, Vienna, Austria.
authors.forename: Manuel
authors.initials: M
authors.lastname: Zeitelhofer
authors.forename: Daniela
authors.initials: D
authors.lastname: Karra
authors.forename: Paolo
authors.initials: P
authors.lastname: Macchi
authors.forename: Marco
authors.initials: M
authors.lastname: Tolino
authors.forename: Sabine
authors.initials: S
authors.lastname: Thomas
authors.forename: Martina
authors.initials: M
authors.lastname: Schwarz
authors.forename: Michael
authors.initials: M
authors.lastname: Kiebler
authors.forename: Ralf
authors.initials: R
authors.lastname: Dahm
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000502:physiology; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology; D002478:Cells, Cultured; D003712:Dendrites / Q000378:metabolism*; D004622:Embryo, Mammalian; D018683:Excitatory Amino Acid Agents / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007211:Indoles; D018613:Microscopy, Confocal / Q000379:methods; D018715:Microscopy, Video / Q000379:methods; D009474:Neurons / Q000166:cytology*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D051381:Rats; D012261:Ribonucleoproteins / Q000378:metabolism*; D014162:Transfection / Q000379:methods
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D018683:Excitatory Amino Acid Agents; C498634:Igf2bp1 protein, rat; D007211:Indoles; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; C492188:Stau2 protein, rat; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D018698:Glutamic Acid; C007293:DAPI; D006861:Hydrogen Peroxide