chapter 37 Flashcards
gene expression in eukaryotes influenced by what 3 things
- The nuclear membrane, which separates the site of RNA synthesis from
that of protein synthesis. - Complex transcriptional regulation.
- RNA processing, including extensive processing of mRNA precursors.
where is RNA polymerase I located
nucleolus
where is RNA polymerase II located
nucleoplasm
where is RNA polymerase III located
nucleoplasm
what is the cellular transcript of RNA pol I
18S, 5.8S, 28S rRNA
what is the cellular transcript of RNA pol II
mRNA precursors and snRNA
what is the cellular transcript of RNA pol III
tRNA and 5S rRNA
what are cis-acting elements
eukaryotic promoters
what are the common promoters of RNA pol II
- TATA box
- initiator element (Inr)
- downstream core promoter element (DPE)
- CAAT box/GC box
where is the tata box located
between -30 and -100 bp upstream
where is Inr located
-3 and +5 often paired with TATA box
where is DPE located
+28 and +35 works in cooperation with Inr when the TATA box is absent
where are CAAT box/GC box located
-40 and -150 bp upstream
what are enhancer sequences
cis-acting elements that have no promoter activity but can stimulate the effectiveness of promoters even when located thousands of nucleotides from the start site of transcription
what do enhancer sequences do for dummies
stimulate transcription at start sites thousands of bases away
