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20 Cards in this Set
- Front
- Back
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Potential Drug Mechanisms
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-Drugs that permanently destroy/disable genes
-Drugs that destroy RNA message -Drugs that protect RNA message -Drugs that Silence Genes |
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Two mechanisms of ASODN (Antisense oligodeoxynucleotides)
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blocks the DNA translation machinary and form and ODN-RNA complex where the Double-stranded RNA is destroyed by RNase H
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ASODN mechanism
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-Double-stranded RNA destroyed by RNase H
-Also blocks the translation process |
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Salutary Properties of AS Drugs
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Highly Specific
Universally applicable Versatile applicability Verifiable efficacy Rapid development Pharmacologically Predictive |
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The first antisense drug for clinical use
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Vitravene or Fomivirsen (Novartis)
-treats cytomegalovirus (CMV) retinitis in people with AIDS. |
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Diferences between antisense drugs and siRNA Drugs
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Double-stranded RNA,transported into nucleus
- siRNA is double-stranded -Requires cytoplasmic processing by RISC -Ds-siRNA/mRNA destroyed by ribonuclease(versus RNAHase |
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MicroRNAs
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natural antisense oligonucleotides
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Size of MicroRNAs
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Small RNA molecules comprising 21-23 nucleotides
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Varieties of miRNAs
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Some 700 identified miRNAs regulate 30% of human genes
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methyltransferases
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activates Methylation
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Methylation
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promoters for specific genes prevents the binding of the transcriptome to the promotor, hence inhibiting transcription
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histone acetyltransferase
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activates Acetylation
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prevents DNA compaction, resulting in enhanced readiness for transcription
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Acetylation
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histone deacetylase
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deacetylation
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Hydroxymate,benzamide
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Drugs that Inhibit Histone Deacetylase
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Drugs that Inhibit DNA Methylation
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cytidine,5-methylcytidine,
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siRNA Drugs
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-siRNA is double-stranded
-Requires cytoplasmic processing by RISC (RN A-induced silencing complex -Ds-siRNA/mRNA destroyed by ribonuclease |
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how does actylation and deacetylation controlled?
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Acetylation is activated by histone acetyltransferase
and reversed by histone deacetylase |
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What is the significance of acetylation?
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Acetylation prevents DNA compaction, resulting in enhanced readiness for transcription
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What is the significance of acetylation
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ctosine Methylation of promoters for specific genes prevents the binding of the transcriptome to the promotor, hence inhibiting transcription
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