Overview of Eukaryotic Gene Control Flashcards
What are the 3 RNA Polymerases?
RNA POLYMERASE II - most popular/used
RNA POLYMERASE I
RNA POLYMERASE III
What is RNA Pol I’s use?
Found in the nucleolus, it transcribes only precursor ribosomal RNA (rRNA)
What is RNA Pol II’s use?
It transcribes messenger RNAs (mRNAs) and four small nuclear RNAs (snRNA) that take part in RNA splicing.
What is RNA Pol III’s use?
It transcribes transfer RNA (tRNA), 5S rRNA, and other small stable RNAs including one involved in RNA splicing.
Protein chromatography can separate proteins by…
SIZE - Gel Chromatography (big protein first)
AFFINITY - Antibody-affinity chromatography
CHARGE - Ion-exchange chromatography (Positively charged protein come out first)
How do we isolate a certain protein using liquid chromatography?
1) CHARGE
2) SIZE
3) AFFINITY
This gives you biochemical Quantities that you can work with.
How does alpha-amanitin interfere with RNA synthesis?
Actively highly affect RNA POLYMERASE II.
What are the different sensitivities to alpha-amanitin of RNA Pol I, Pol II and Pol III?
Pol I - NOT SENSITIVE
Pol II - EXTREMELY SENSITIVE
Pol III - SLIGHTLY SENSITIVE
What can be said about a RNA Polymerase II that has a phosphorylated CTD?
They are ACTIVELY TRANSCRIBING.
What is a CTD?
- Part of RNA POL II that regulates its transcriptional activity by phosphorylation and unphosphorylation.
- It also ACTS AS AN ANCHOR FOR OTHER ENZYMATIC ACTIVITIES.
- Made up of 52 NEARLY IDENTICAL REPEATS of Tyr-Ser-Pro-Thr-Ser-Pro-Ser
What does transcription initiation require?
Formation of the PRE-INITIATION COMPLEX.
To what specific concentrations is each RNA Polymerase sensitive to?
Pol I is insensitive to 1μg/ml and 10μg/ml
Pol II is sensitive to 1μg/ml
Pol I is insensitive to 1μg/ml but sensitive to10μg/ml
How can the 3 Eucaryotic RNA Polymerases be distinguished?
By their SENSITIVITY TO ALPHA-AMANITIN
