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6 Cards in this Set
- Front
- Back
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pos vs. neg controls of gene expression
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both:
-require nucleic acid sequence for the control system(cis-acting element) -require factor that binds to that sequence (trans-acting element) POSITIVE:stim expression of gene NEGATIVE:represses expression |
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transcription factors and repressor prots
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-DNA level gene control
-as cells differentiate they shut off some genes permanently COVALENT modification of histones(mehtylation) and DNA -DNA methylation is associated with gene inactivation -Histone acetylation is assoc. w/ gene activation -Histone methylation also effects gene act. |
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transcription factors
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-many contain DNA binding domain and seperate activation(or repression) domain
transcription act/rep recruit: -co-activators which have histone acetylase activity OR -co-repressors which have histone deacetylase activity |
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more control of gene exp at DNA level
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1)storing inactive gene in heterochromatin which is very compact
2)in euchromatin, altering the ability of the promoter to recruit RNA PolII 3)info recieved from cyto and outside enviro |
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alternative splicing w/ gene regulation
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-use alt. splicing to prod diff prots in diff cells from same gene.
-diff prots that prevent exon recognition or promote it -different promotors on same gene can produce diff mRNAs |
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Post-transcriptional regulation of gene expression
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REGULATE:
1)cap binding protein 2)translation, either by pos or neg controls 3) half-life of an mRNA |
