Gene Expression and Regulation Flashcards
Transcriptional control, RNA processing, RNA transport, translational control, mRNA degradation, and protein processing all control ____ ____.
Gene expression
True or false
Some RNAs are not translated into protein. The RNA is the active end product
True
RNA polymerase or DNA polymerase?
1. Active in S phase
2. Exonuclease activity
3. De novo synthesis
- DNA polymerase
- DNA polymerase
- RNA polymerase
_____ DNA region that facilitates transcription initiation. ____ DNA region that signal transcription stop.
Promoter
Terminator
Prokaryotes have one RNA polymerase called a _____. It is made up of the core enzyme plus a sigma factor
Holoenzyme
Transcription factors are needed to access DNA in its _____ form.
Chromatin
A typical RNA polymerase II promoter contains a ____ ____.
TATA box
General transcription factors of RNA polymerase II all starts with ____ in their name and assemble in a step wise fashion to start transcription.
TF
Eukaryotic transcript elongation is coupled with RNA processing. A 5’ _____ is added, ____ are removed, and a _____ is added at the 3’ end.
CAP
Introns
PolyA tail
Different cell types contain the same set of genes but synthesis different sets of _____.
Proteins
General transcription factors bind to ____ promoter sequences such as TATA box, BRE, and DPE.
Activators bind to _____ promoter sequences such as CAAT box, GC box.
Core
Proximal
Activator proteins and repressor proteins bind to specific sequences in the ____ ____ ____.
Distal Promoter Sequences
Gene regulator proteins read DNA on the ____ of the double helix, in the _____ groove.
Outside
Major
Gene regulator proteins carry typical DNA binding motifs such as
1.
2.
3.
- Helix turn helix motif
- Zinc finger motif
- Leucine motif
The _____ _____ uses tryptophan as a ligand to repress genes in the operon of E. coli cells.
Tryptophan repressor (TRP)
TRP repressor can only bind to the operator when it is associated with tryptophan. If there are low levels of tryptophan, the operon is ____. If high levels of tryptophan, the operon is ____.
On
Off
There is dual control of the lac operon.
+glucose +lactose:
+glucose -lactose:
-glucose -lactose:
-glucose +lactose:
Operon is off
Operon is off
Operon is off
Operon is on
_____ ____ are found in eukaryotic cells they are more complex than prokaryotic operon gene regulation. One gene can be controlled by_____ regulatory proteins.
Genetic switches
Dozens or more
The typical order of events for _____ ____ are as follows: gene activator protein binds to chromatin, chromatin remodeling, covalent histone modification, additional activator proteins bound to Gene regulatory region, assembly of pre-initiation complex at the promoter.
Transcription initiation
Gene ____ proteins bind DNA sequences named enhancers. They have a DNA binding domain and an activation domain.
Activator
Repressor proteins often recruit histone ______ or histone ______ _____, in order to promote heterochromatin
Deacetylases
Methyl transferase
______ _____ make DNA more accessible to the transcription machinery such as activators and repressors
HDAC inhibitors
___ _____, for example actinomycin, block transcription elongation in prokaryotes and eukaryotes.
DNA intercalators
antibiotics such as _____ bind only bacterial RNA polymerase
Rifampicin
_____ ______: specifically inhibits RNA polymerase II. It is a common cause of fatal mushroom poisoning (death cap)
Alpha amanitin
Review
_____ _____ is used by cells to control mRNA stability, prevent mRNA translation, promote heterochromatin
RNA interference (RNAi)
miRNA has a ____ and ____, similar to mRNA
CAP
PolyA tail
______ reduces translation by transferring mRNA into P bodies and eventual degradation
Slicing
Dicing uses the ___________ to rapidly degrade mRNA
RNA induced silencing complex (RISC)
______ uses the microprocessor complex, Drosha-Pasha to cleave the polyA tail and CAP from mRNA
Cropping
miRNAs often target _____ of mature mRNA
3’UTRs
______ regulate essential mechanisms, such as embryonic development, cell and tissue, differentiation, carcinogenesis, etc.
miRNAs
There are two general categories of interference RNAs.
1. ______ encode in our genome and often transcribed by RNA polymerase II, SSRNA precursor with stem loop structure
2. _______ generated from exogenous, have long dsRNA precursors
Micro RNAs (miRNAs)
small interfering RNAs (siRNAs)
The goal of ________ is to block translation, and promote mRNA de stabilization/cleavage.
miRNA
______ mostly mediate mRNA cleavage, and are produced in the cytoplasm by Dicer
siRNA
siRNAs use ______ to promote histone, methylation DNA methylation and transcriptional repression
RNA induced transcriptional silencing complex (RITS complex)
Abnormal miRNAs expression is linked to many diseases including:
psychiatric/neurodevelopmental disorders, abnormal heart, development, and heart disease, cancer, and diabetes
Delivery of synthetic siRNA to target cells can knock down or up regulate genes involved in a disease. Use siRNA to block mRNA leading to _____. Use siRNA to block miRNAs leading to ________.
Gene silencing
Gene up regulating
Review
The main types of epigenetic control of gene expression are _____ and _____.
DNA methylation
Chromatin modifications
