© elsevier, 2011.principles of molecular virology virus gene expression mechanisms by which cells...

Principles of Molecular Virology © Elsevier, 2011.

Virus Gene ExpressionVirus Gene Expression

• Mechanisms by which cells express the information

stored in genes

• Genome coding strategies of different virus groups

• How viruses control gene expression via transcription

and post-transcriptional methods

Principles of Molecular Virology © Elsevier, 2011.

Control of Expression in Control of Expression in Bacteriophage λBacteriophage λ

A simplified genetic map of λ

Principles of Molecular Virology © Elsevier, 2011.

Control of Expression in Control of Expression in Bacteriophage λBacteriophage λ

Principles of Molecular Virology © Elsevier, 2011.

Control of Expression in Control of Expression in Bacteriophage λBacteriophage λ

Principles of Molecular Virology © Elsevier, 2011.

Control of Eukaryote Gene Control of Eukaryote Gene ExpressionExpression

• DNA configuration

• Transcription

• mRNA stability

• Translation

Principles of Molecular Virology © Elsevier, 2011.

Virus Genome Coding StrategiesVirus Genome Coding Strategies

Class I: Double-Stranded DNA:

• Polyomaviruses and Papillomaviruses• Adenoviruses• Herpesviruses • Poxviruses

Principles of Molecular Virology © Elsevier, 2011.

Class II: Single-Stranded DNAClass II: Single-Stranded DNA

Principles of Molecular Virology © Elsevier, 2011.

Class III: Double-Stranded RNAClass III: Double-Stranded RNA

Principles of Molecular Virology © Elsevier, 2011.

Class IV: Single-Stranded Class IV: Single-Stranded (+)sense RNA(+)sense RNA

Principles of Molecular Virology © Elsevier, 2011.

Class V: Single-Stranded (–)sense RNAClass V: Single-Stranded (–)sense RNA

Principles of Molecular Virology © Elsevier, 2011.

Expression of ambisense virus Expression of ambisense virus genomesgenomes

Principles of Molecular Virology © Elsevier, 2011.

Single-Stranded (+)Sense RNA Single-Stranded (+)Sense RNA with DNA Intermediatewith DNA Intermediate

Principles of Molecular Virology © Elsevier, 2011.

Class VII: Double-Stranded DNA Class VII: Double-Stranded DNA with RNA Intermediatewith RNA Intermediate

Hepatitis B virus: Cauliflower mosaic virus:

Principles of Molecular Virology © Elsevier, 2011.

Transcriptional Control of Transcriptional Control of Expression - SV40Expression - SV40

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Transcriptional Control of Transcriptional Control of Expression - Retrovirus LTRsExpression - Retrovirus LTRs

Principles of Molecular Virology © Elsevier, 2011.

Transcriptional Control of Transcriptional Control of Expression - TransactivatorsExpression - Transactivators

Principles of Molecular Virology © Elsevier, 2011.

Post-transcriptional Control of Post-transcriptional Control of Expression - splicing in AdenovirusesExpression - splicing in Adenoviruses

Principles of Molecular Virology © Elsevier, 2011.

Ribosomal FrameshiftingRibosomal Frameshifting

Principles of Molecular Virology © Elsevier, 2011.

SummarySummary

• Control of gene expression is a vital element of virus replication

• Coordinate expression of groups of virus genes results in successive phases of gene expression

• Viruses rely on cis- and trans-acting mechanisms to enhance and coordinate the expression of their genetic information

Principles of Molecular Virology © Elsevier, 2011.

Further ReadingFurther Reading

Alberts, B. (Ed) (2007) Molecular Biology of the Cell, 5th ed. Garland Science, New York. ISBN 0815341067.

Freed, E.O. and Martin, M. (2001) Human immunodeficiency viruses and their replication. In: Fields Virology, 4th ed., Fields, B.N., Knipe, D.M., and Howley, P.M. (Eds.), pp. 1971–2042. Lippincott Williams & Wilkins, Philadelphia, PA. ISBN 07817325

Giedroc, D.P. et al. (2000) Structure, stability and function of RNA pseudoknots involved in stimulating ribosomal frameshifting. Journal of Molecular Biology, 298: 167–185

Kannian, P. and Green, P.L. (2010) Human T Lymphotropic Virus Type 1 (HTLV-1): Molecular Biology and Oncogenesis. Viruses 2(9): 2037-2077. doi:10.3390/v2092037 Latchman, D. (2002) Gene Regulation: A Eukaryotic Perspective. BIOS Scientific, Oxford. ISBN 0748765301

López-Lastra M., et al. (2010) Translation initiation of viral mRNAs. Rev Med Virol. 20(3): 177-195.

Ptashne, M. (2004). A Genetic Switch: Phage Lambda Revisited. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York. ISBN 0879697164

Skalsky, R.L. and Cullen, B.R. (2010) Viruses, microRNAs, and Host Interactions. Annual Review of Microbiology 64: 123-141

Wu, Y. and Marsh, J.W. (2003) Gene transcription in HIV infection. Microbes and Infection, 5: 1023–1027