Selective cytoplasmic organelle and protein targeting has long been thought to constitute the sole determinant of cell polarity and complexity. This view has been changed, however, by the discovery of differential subcellular RNA distribution patterns. Over the past decade it has become clear that selective mRNA sorting and translation contributes to an accumulation of cognate proteins at discrete cellular sites. In this book, various systems are discussed (e.g. Xenopus oocytes, mammalian brain, invertebrate nervous system) in terms of RNA trafficking, RNA-targeting sequences (cis-elements) and RNA-transporting proteins (trans-factors), activity-dependent translational regulation and the significance of the cytoskeleton for neuronal function and plasticity. It also discusses nucleocytoplasmic export of mRNA and viral RNA as another example of subcellular RNA kinesis.

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Localization of mRNAs at Synaptic Sites on Dendrites.- 1 Introduction.- 2 The Machinery for Translation in Dendrites.- 2.1 SPRCs Are Precisely Localized in the Postsynaptic Cytoplasm.- 2.2 SPRCs Are Present at Spine Synapses on Different Neuron Types.- 2.3 SPRCs Are Often Associated with Membranous Organelles in an RER-Like Configuration.- 2.4 SPRCs Are Also Present at Non-Spine Synapses.- 2.5 SPRCs Are Especially Prominent at Developing Synapses.- 3 Types of Proteins That Are Synthesized at SPRCs.- 3.1 Biochemical Studies of Proteins Synthesized by Subcellular Fractions Enriched in Pinched-Off Dendrites.- 3.2 mRNAs in the Dendrites of Neurons in Vivo.- 3.3 Molecular Biological Analyses of the Complement of mRNAs in Isolated Dendrites from Neurons in Vitro.- 3.4 The Search for Novel Dendritic mRNAs.- 4 Activity-Dependent Regulation of mRNA Trafficking in Dendrites.- 4.1 Lessons from the Study of Arc: A Cellular Mechanism for Protein Synthesis-Dependent Synaptic Modification.- 4.2 Post-Translational Processing Within Dendrites.- 5 Signals That Mediate mRNA Routing and Localization.- 5.1 Granules: Supramolecular Packets That May Be Involved in mRNA Transport.- 5.2 mRNA Translocation Mechanisms.- 5.3 Regulation of mRNA Translation at Synapses.- 5.3.1 Studies in Hippocampal Slices 20 5.3.2 Studies in Intact Animals 20 5.3.3 Studies in Synaptoneurosomes.- 6 Conclusion.- References.- Long-Lasting Hippocampal Plasticity: Cellular Model for Memory Consolidation?.- 1 Introduction.- 2 How?.- 2.1 Long-Term Potentiation.- 2.2 Synaptic Tagging and the Variable Persistence of Hippocampal Synaptic Plasticity.- 2.3 Requirements for Cellular Consolidation.- 3 Where?.- 4 When?.- 5 Conclusion.- References.- Neuronal RNA Localization and the Cytoskeleton.- 1 Localization of Cytoskeletal Proteins to Neuronal Processes and Growth Cones.- 2 Regulation of Neuronal mRNA Localization.- 3 Mechanism of mRNA Localization.- 4 mRNA May Be Transported as Particles or Granules.- 5 Future Directions.- References.- Transcription Factors in Dendrites: Dendritic Imprinting of the Cellular Nucleus.- 1 Introduction.- 2 CREB mRNA Is Localized to Neuronal Dendrites.- 3 CREB Protein Is Present in Dendrites.- 4 CREB Protein Moves from the Dendrite to the Cell Nucleus.- 5 Potential Importance of Dendritic CREB in Modulating.- Neuronal Functioning.- 6 Biological Impetus tor Dendritic Imprinting.- References.- RNA Trafficking in Oligodendrocytes.- 1 Introduction.- 2 A2RE Is a cis-Acting RNA Trafficking Determinant.- 3 hnRNP A2 Is a trans-Acting RNA Trafficking Factor.- 4 A2RE/hnRNP A2-Mediated Nuclear Export.- 5 A2RE/hnRNP A2-Mediated Granule Assembly.- 6 A Dual Motor Mechanism for RNA Trafficking on Microtubules.- 7 RNA Trafficking in the Virtual Cell.- 8 The Taxol Paradox.- 9 Negotiating Branch Points.- 10 Translation Regulation.- 11 Summary.- References.- Extrasomatic Targeting of MAP2, Vasopressin and Oxytocin mRNA in Mammalian Neurons.- 1 Introduction.- 2 Microtubule-Associated Protein 2.- 2.1 Dendritic Localization of MAP2 mRNAs.- 2.2 Distribution and Function of MAP2 in Neurons.- 2.3 Characterization of a cis-Acting Dendritic Targeting Element in the MAP2 3' UTR.- 3 Axonal and Dendritic Targeting of VP and OT mRNAs.- 3.1 Axonal mRNA Compartmentalization.- 3.2 Dendritic mRNA Compartmentalization.- 3.3 Molecular Determinants of Subcellular mRNA Targeting.- 4 Final Conclusions and Perspectives.- References.- RNA Transport and Local Protein Synthesis in the Dendritic Compartment.- 1 Introduction.- 2 Differential Subcellular RNA Localization in Neurons.- 2.1 Dendritic RNAs.- 2.2 Synaptic mRNAs.- 2.2.1 Neurotransmitter Receptor mRNAs.- 2.2.2 Non-Neurotransmitter Receptor Synaptic mRNAs.- 2.3 Axonal and Presynaptic mRNAs.- 3 RNA Transport.- 3.1 trans-Acting Factors.- 3.1.1 Translational Factors and Transport Granules.- 3.1.2 Granule Motors.- 3.1.3 mRNA-Specific trans-Acting Factors.- 3.2 cis-Acting Sequences.- 4 Synapse and Local Protein Synthesis Machinery.- 4.1 Ultrastructural Data Suggesting Subsynaptic Protein Synthesis.- 4.2 Immunocytochemical Characterization of the Dendritic Translational Machinery.- 4.3 Biochemical Studies of Translation and Glycosylation Within Dendrites.- 5 Activity-Dependent mRNA Transport and Protein Synthesis.- 5.1 Glutamate Receptor Activation and Calcium Entry.- 5.2 Ca2+-CaMKII Activation and Phosphorylation Pathways.- 5.3 The Neurotrophin Signaling Pathway.- 6 Conclusions and Perspectives.- References.- Neuronal BC1 RNA: Intracellular Transport and Activity-Dependent Modulation.- 1 Evolutionary Relationships.- 2 Intracellular Transport.- 3 Activity-Dependent Regulation.- 4 Outlook.- References.- Nucleocytoplasmic mRNA Transport.- 1 Introduction.- 2 The Export Machinery.- 2.1 Nuclear Pores.- 2.2 Import and Export Receptors.- 2.3 The Role of Ran in the Establishment of Compartment Identity.- 3 Cellular mRNA Export.- 3.1 The Cap Structure.- 3.2 The Poly(A) Tail.- 3.3 hnRNP Proteins.- 3.4 SR Proteins.- 3.5 Visualization of mRNA Export.- 3.6 The Role of Splicing in mRNA Export.- 4 Conclusions.- References.- RNA Localization in Xenopus Oocytes.- 1 Introduction.- 2 The Early Localization Pathway.- 2.1 RNAs That Undergo Localization Along the Early Pathway.- 2.2 cis-Acting Elements.- 2.3 trans-Acting Factors and Cytoskeletal Elements.- 3 The Late Pathway.- 3.1 RNAs That Undergo Localization Along the Late Pathway.- 3.2 cis-Acting Elements.- 3.3 trans-Acting Factors.- 3.4 Cytoskeletal Elements.- 4 The Animal Localization Pathway.- 5 Concluding Remarks.- References.- Local Protein Synthesis in Invertebrate Axons: From Dogma to Dilemma.- 1 Introduction.- 2 mRNA in Axons.- 3 Translocation of mRNA.- 4 Origin of RNA.- 5 Protein Synthesis in Axons.- 6 The Identity of Protein Synthetic Machinery in Axons.- 7 Which Proteins Are Synthesized in Axons?.- 8 Functions of Local Protein Synthesis.- 9 Discussion.- References.- Nucleocytoplasmic RNA Transport in Retroviral Replication.- 1 Introduction.- 2 Retroviral Replication.- 3 RNA Export in Simple versus Complex Retroviruses.- 4 Regulation of HIV-1 Gene Expression: An Overview.- 4.1 How Is Nuclear Retention of Rev-Dependent RNAs Determined?.- 4.2 The HIV-1 Rev-RRE System.- 4.3 CRM1 Is the Cellular Export Receptor for Rev.- 4.4 Other Cellular Factors That Interact with the Rev Protein.- 4.5 Rev/RRE-Like Systems in Other Complex Retroviruses.- 5 CTE: The Constitutive RNA Transport Elements of D-Type Retroviruses.- 5.1 hTAP: A Potential Cellular Export Receptor for CTE.- 5.2 RNA Export in Other Retroviruses and Pararetroviruses.- 6 Summary and Conclusions.- References.