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16 Cards in this Set
- Front
- Back
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What are the general features of a retrovirus?
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Enveloped
(+) RNA Have RNA-dependant DNA polymerase 2 copies of RNA in the capsid |
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What are the known oncogenic tumor viruses? How does transformation occur?
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Oncovirinae: HTLV-1,2,5: T cell leukemia
Rous sarcome virus: solid tumors in chickens Alter cellular growth mechanisms by expressing analogues of cell growth control genes. |
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What structures make up the glycoprotein spike of the retroviruses?
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gp120 and gp41 form the gp160 glycoprotein
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What is the function of gp120?
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binds CD4
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What is the function of gp41?
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promotes cell-virion fusion
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What protein delivers retrovirial cDNA to the nucleus?
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integrase
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What protein processes the polyprotein of retroviruses?
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protease
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How do retroviruses produce and process the viral proteins needed for replication?
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cDNA that is incorporated is transcribed and translated using host machinery.
Protein processed by protease. |
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What is HAART?
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Highly Active Antiretroviral Therapy
RT inhibitors (nucleotide analogues and not) Protease inhibitors Integrase inhibitors |
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What is the origin of HIV?
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Evolved around 1930 from chimpanzees and spread through Africa
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What is the mechanism of RT in retroviruses?
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Makes combo RNA/DNA
Chews up RNA hybrid portion Makes a second strand on original DNA |
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What polyproteins are produced by retroviruses?
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Gag: capsid, matrix, nucleic acid binding proteins
Pol: RT, protease, integrase Env: gp120, gp41 |
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What is the function of LTRs?
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long terminal repeat sequences contain promotors and enhancers that bind cellular transcription factors.
Promote integration into host genome |
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What are the gp120 coreceptors?
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CCR5
CXCR4 |
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Why is antigenic drift of gp120 important?
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impedes immune clearance of the virus, occurs because of RT error rate
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Once gp120 and gp41 are created in the host cell, what happens to them?
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they bud from the ER to the golgi then to the plasma membrane.
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