The Influenza Viruses

1 Genes and Proteins of the Influenza Viruses.- I. Introduction.- A. Structure of the Genome.- II. RNA Segments 1, 2, and 3: The Three Polymerase-Associated Proteins Form a Complex to Transcribe RNA.- A. Three P Proteins.- B. PB1, PB2, and PA Gene Sequences.- C. Functions of the PB1, PB2, and PA Proteins.- D. P Proteins Form a Complex That Migrates to the Cell Nucleus.- E. Influenza B Virus P Proteins and RNA Segments.- F. Influenza C Viruses.- III. RNA Segment 4: Synthesis, Structure, and Function of the Hemagglutinin.- A. General Introduction to the Hemagglutinin.- B. RNA Segment 4 Gene Structure.- C. Three-Dimensional Structure of the Hemagglutinin.- D. Synthesis of HA, Co-translational and Post-translational Modifications, Oligomerization, and the Exocytotic Pathway.- E. Cleavage Activation.- F. Viral Entry and Membrane Fusion.- G. Influenza B Virus Hemagglutinin.- H. Influenza C Virus Glycoprotein.- IV. RNA Segment 5: The Nucleocapsid Protein Forms the Structural Monomer Unit of the Ribonucleoprotein Particles.- A. Structure of RNPs and Involvement in RNA Synthesis.- B. Properties of the Nucleocapsid Protein.- C. Nuclear Transport and Karyophilic Sequences.- D. RNA-Protein Interactions.- E. NP Is a Major Target for Cytotoxic T Lymphocytes.- F. Influenza B Virus NP Gene and Protein.- G. Influenza C Virus NP Gene and Protein.- V. RNA Segment 6: The Neuraminidase.- A. Neuraminidase Function.- B. Structure of Neuraminidase.- C. General Deductions from the Gene Sequence of Influenza A Virus NA.- D. Influenza A Virus Strain Similarities and Differences.- E. N-Terminal Signal Anchor.- F. Three-Dimensional Structure of NA.- G. Influenza B Virus Neuraminidase.- H. Influenza B Virus RNA Segment 6.- I. NB Glycoprotein of Influenza B Virus.- J. Effect of Mutations and Deletions in the Bicistronic mRNA for NB and NA.- K. Influenza C Virus.- VI. RNA Segment 7 of Influenza A Virus: Structure and Synthesis of the Membrane Protein (M1) and an Integral Membrane Protein (M2) from Unspliced and Spliced mRNAs.- A. RNA Segment 7 and Its mRNAs.- B. Membrane Protein (M1).- C. Influenza Virus M2 Protein Structure and Subcellular Localization.- D. Expression of M2 in Eukaryotic Cells from Cloned cDNA.- E. Characterization of a Monoclonal Antibody to the M2 Extracellular Domain.- F. Initial Interaction of M2 with Membranes.- G. Is M2 a Structural Component of Virions?.- H. Function of M2 in Infected Cells.- I. Effect of Amantadine Hydrochloride on M2.- J. Evolution of the Nucleotide Sequence of RNA Segment 7 and the Amino Acid Sequences of M1 and M2.- K. RNA Segment 7 of Influenza B Virus.- L. Membrane Protein of Influenza C Virus.- VII. Influenza A Virus RNA Segment 8: Unspliced and Spliced mRNAs Encode Nonstructural Proteins NS1 and NS2.- A. RNA Segment 8 and Its mRNAs.- B. NS1 Protein.- C. NS2 Protein.- D. RNA Segment 8 of Influenza B Virus: Unspliced and Spliced mRNAs Code for NS1 and NS2.- E. Influenza C Virus RNA Segment 7: Unspliced and Spliced mRNAs Code for NS1 and NS2.- References.- 2 Expression and Replication of the Influenza Virus Genome.- I. Introduction.- II. Viral mRNA Synthesis.- III. Template RNA Synthesis.- IV. Virion RNA Synthesis.- V. Regulation of Viral Gene Expression in Infected Cells.- VI. Interferon-Induced Mx Protein, a Specific Inhibitor of Influenza Virus Replication.- VII. Regulated Splicing of the Viral NS1 and M1 mRNAs.- VIII. Mechanisms for the Selective and Efficient Translation of Influenza Virus mRNAs.- References.- 3 Structure, Function, and Antigenicity of the Hemagglutinin of Influenza Virus.- I. Introduction.- II. Structure of Hemagglutinin.- III. Antigenic Variation.- A. Antigenic Shift.- B. Antigenic Drift.- C. The Importance of Receptor Specificity in Antigenic Change.- IV. Receptor Binding.- A. Structure of the Receptor-Binding Site.- B. The Binding Site of a Receptor-Binding Mutant.- V. Fusion Properties of Hemagglutinin.- A. Acid-Induced Conformational Change of Hemagglutinin.- VI. Conclusions.- Ref