Control of Gene Expression 2 Flashcards
(24 cards)
What do microRNAs do?
Non-coding Regulatory RNAs that regulate messenger RNAs via repression or activation of gene activity
They can either degrade RNA or block translation
miRNAs and health
they can change expression profile in disease states
Ex: certain miRNAs can be elevated in stroke or heart disease. Can also be used to identify cancer
How are microRNA causative and responsive?
Causative: Have mutations that cause disease (Ex: Tourette’s Syndrome)
Responsive: Increased miRNA expression down regulates gene in response to disease to limit severity
Where do miRNAs bind?
3’ UT end of mRNA
Detail the steps of microRNA maturation
Originate as a 100 nucleotide precursor
(cropped in nucleus)
Size is cut down to pre-miRNA then processed further to mature miRNA with Dicer outside the nucleus
1 miRNA can impact ____ mRNA
multiple
Tourette’s Syndrome is an example of ____
Causative disease involving miRNA when the SLITRK1 mRNA allows increased miRNA binding therefore it decreases SLITRK1 expression
A proteasome has ____ active ATP sites
six
The ubiquitin complex includes
E1 ubiquitin activating enzyme bound to cysteine with E2 ubiquitin conjugating enzyme and E3 accessory protein ubiquitin ligase
Protein tagged for degradation involves tagging of ____
ubiquitin at lysine on protein via E1
Proteasome inhibitors are used in ____ treatment using ___ as an example.
Multiple myeloma
Bortezomib
Genomic Imprinting
genes are from both mother and father but the expression from single parent gene’s based on gene
Prader WIlli Syndrome
A type of genomic imprinting disorder where there is a paternal deletion on chromosome 15 (15q11-q13) and maternal chromosome 15 not expressed even though present
Hemosiderin
Granules of Ferritin
Where is excess iron stored?
Lungs
Liver
Pancreas
Whether or not ferritin is made is determined by binding of IRP to IRE at ____?
5 prime ferritin mRNA
Whether or not tFe is made is determined by binding of IRP to IRE at ____?
3 prime transferrin receptor mRNA
One of the routes that mRNA can take is silence by joining with ____ to stop translation
RISC
Where does the ubiquitin bind to start tagging for degradation?
Cysteine side chain of E1
What is E3 and what binds to it?
E3 is an accessory ligase protein. Target protein with degradation signal binds to it.
E1 has two roles in protein degradation:
It initiates the formation of the E2E3 complex
It also serves as the transferrer for ubiquitin to the complex
E2E3 complex can be activate in 3 ways
Via ATP phosphorylation
Ligand Binding to E3
Protein subunit addition to E3
Degradation signal can be activated in 3 ways
Phosphorylation
Unmasking of protein signaling site
Creation of destabilizing n-terminus
Clinical features of Prader-WIli Syndrome
Hypogonadism
Short Stature
Obesity
Love to eat
