Control of Gene Expression in Eukaryotic cells

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Control of Gene Expression in Eukaryotic cells
BSCI 420 Lecture 11A Sept. 2002 How may
deaths will it take till we know that to many
people have died? -Bob Dylan 1. Overview 2.
Regulation of individual genes A. Cis-acting
regulatory sequences B. Trans-acting
(Transcription) factors 3. Regulation of
chromatin domains
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1. Overview All Cells of your body (with a few
exceptions) contain the same DNA. So how do
different cells become different? By regulating
gene expression at many different levels a.
Structure of chromatin domains b. Transcription
of individual genes c. Processing of RNA
transcripts d. Transport vs. degradation of
messages e. Translation vs. storage or
degradation of messages f. Activation of
proteins g. Degradation of proteins
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Summary of gene expression in eukaryotes
7. Degraded protein
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The first and major level of control is
transcriptional. Transcriptional control occurs
at 2 levels At the level of A. Individual genes
-or- B. Chromatin domains Individual gene
regulation occurs by the the interaction of 1.
Cis-acting regulatory sequences on DNA and 2.
Trans-acting transcription factors a) Promoters
are 1) A DNA sequence where RNA polymerase binds
to the DNA without transcribing it. 2) Just
upstream from the transcribed sequence 3)
Unidirectional - They orient RNA polymerase in
one direction and send it toward the coding
region of the gene
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RNA polymerase
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Initiation of transcription at a eukaryotic
promoter
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