The Togaviridae and Flaviviridae

'1 Comparative and Historical Aspects of the Togaviridae and Flaviviridae.- I. Introduction.- II. Yellow Fever.- A. Early History.- B. Carlos J. Finlay and the Walter Reed Commission.- C. Yellow Fever Commissions of the Rockefeller Foundation.- D. Asibi Virus and the 17D Yellow Fever Vaccine.- III. Early Studies on Viral Encephalitides.- IV. Arthropod-Borne Viruses.- A. Antigenic Relationships among Arboviruses.- B. Serological Groups A and B.- V. Viral Classification and Nomenclature.- VI. Arbovirus Study Group: Togaviruses and Togaviridae.- VII. Non-Arthropod-Borne Togaviruses.- VIII. Contribution of the World Health Organization.- IX. Contribution of the American Committee on Arthropod-Borne Viruses.- X. Impact of Molecular Biology on Viral Classification.- XI. Flaviviridae as a Separate Family.- References.- 2 Alphavirus Structure.- I. Introduction.- II. General Properties.- A. Radial Organization.- B. Glycoprotein Shell.- C. Lipid Bilayer.- D. Core (Nucleocapsid).- E. Hexagonal Glycoprotein Arrays.- III. Virion Assembly.- References.- 3 Structure and Replication of the Alphavirus Genome.- I. Introduction.- II. Structure of the Alphavirus Genome.- A. Physical Structure.- B. Genome Organization.- III. Nonstructural Proteins.- A. Translation and Processing.- B. Opal Codon.- C. Functions of Nonstructural Proteins.- IV. Structural Proteins.- A. Translation and Processing.- B. Functions of Structural Proteins.- C. Mapping of Temperature-Sensitive Mutants.- V. Replication and Transcription of Viral RNA.- A. In Vivo Studies of RNA Replication.- B. In Vitro Studies of RNA Replication.- C. Genetic Studies of Replicase Functions.- D. Host-Cell Proteins as Components of the Viral Replicase.- E. Conserved Sequences in Alphavirus RNAs.- F. Cyclization of Alphavirus RNAs.- G. Alphavirus Defective Interfering RNAs.- VI. Evolution of the Alphavirus Genome.- A. Evolution within the Genus Alphavirus.- B. Codon Usage in Alphaviruses.- C. Evolution within the Family Togaviridae.- D. Relationship of Alphaviruses to Other RNA Viruses.- VII. Concluding Remarks.- References.- 4 Entry of Alphaviruses.- I. Introduction.- II. Attachment.- III. Endocytotic Uptake and Penetration.- A. Cell Biology of Endocytosis.- B. Endocytosis of Viruses.- C. Role of Endosomes in Virus Penetration.- IV. Inhibition of Entry.- A. Lysosomotropic Weak Bases.- B. Carboxylic Ionophores.- C. Monovalent Cations.- D. Temperature Effects.- V. Acid-Dependent Membrane Fusion.- A. Properties of Fusion.- B. Acid-Induced Conformational Change in the Viral Spike Glycoproteins.- C. Mechanism of Fusion.- VI. Conclusion.- References.- 5 Formation and Assembly of Alphavirus Glycoproteins.- I. Glycoprotein Structures and Domains.- II. Biosynthesis of Polypeptides.- III. Glycosylation.- A. Synthesis and Structure of the Oligosaccharide Chains.- B. Role of Glycosylation in Virion Formation.- IV. Fatty Acid Acylation.- V. Proteolytic Formation of E2.- VI. Localization of Glycoproteins to Intracellular Organelles.- VII. Expression of Virus Glycoproteins from Complementary DNAs.- VIII. Assembly and Budding of Virus.- A. Nucleocapsid Formation.- B. Interactions at the Plasma Membrane.- IX. Conclusions and Perspectives.- References.- 6 Defective RNAs of Alphaviruses.- I. Introduction.- II. Identification of Sequences Retained in the Defective Interfering Genomes of Sindbis and Semliki Forest Viruses.- A. Characterization of the Defective Interfering RNAs.- B. Sequence Organization of Defective Interfering RNAs of Sindbis and Semliki Forest Viruses.- C. Expression of Cloned Defective Interfering Genomes.- III. Defective Interfering Particles of Alphaviruses and Persistent Infections.- A. Characteristics of Persistent Infections in Mammalian Systems.- B. Evolution of Sindbis Virus and Its Defective Interfering RNAs during Persistent Infection of Baby Hamster Kidney Cells.- IV. Defective Interfering