Regulation of Gene Expression Flashcards
Transcription is initiated
in eukaryotic cells by the
binding of general
_______ to
the proximal
promoter (close to
transcriptional start site)
that aid in the recruitment
of ______
transcription factors, RNA polymerase
Proximal promoter is DNA
sequences located near the
_____ site of transcription
start
general transcription
factors or _______ bind to the promoter sequences or _________ DNA
sequences.
(trans-acting
factors), (cis-acting factors)
cis-acting DNA sequences can be either _____ or _____ DNA sequences
enhancers, silencer
cis acting factors are position independent meaning they can function long distances ______ and _____ of
start site of transcription
upstream, downstream
cis acting factors are orientation independent meaning the sequences are often ______ and can function in both 5’ to 3’ direction and 3’ to 5’ direction
palindromic
a main property of enhancer/silencer DNA sequences (cis-acting DNA sequences) are that they are short DNA sequences (~8 to ~16 bp in length) that function as a ______
double strand
modulation of transcription initiation rates are mediated by sequence specific _______ that bind to specific DNA sequences near individual ______
DNA binding proteins, promoters
______ transcription factors are needed to bind to the gene in order to have an accurate amount of ______
multiple, gene regulation
transacting factors have 4 functional domains which include the ______ domain, ______ domain, ______ domain, and ______ domain
transactivation, DNA binding, ligand binding, dimerization
regulation of transcription is caused by regulating the transcription factors ______ and ______ on the gene and the gene regulatory proteins ate regulated in multiple ways depending on the protein
expression, activity
Co-activators and co-repressors that do not contact DNA but rather interact with _____ that are critical for control of transcription
transcription factors
Some co-activators and co-repressors make direct
contact with the ______ associated with the basal
promoter to regulate initiation of transcription.
general transcription factors
some co-activators and co-repressor make direct contact with the ________ associated with the basal promoter to regulate initiation of
transcription.
general transcription
factors
Dynamic structural changes
to the eukaryotic chromatin is needed for transcriptional regulation of genes because chromatin that is condensed (heterochromatin) is less accessible to ______
RNA polymerase II
chromatin remodeling of euchromatin requires the ______ and _______ of histone which causes the loss of ______ and the recruitment of co-activators complexes are also required in order to be ready for transcription
acetylation, phosphorylation, histone 1
______ of histones (relaxed chromatin) regulates transcription by affecting chromatin compaction and binding of
trans-activating factors to cis-regulatory elements
Acetylation
DNA methylation is the modification of DNA in which methyl groups are added to specific ______ residues in CpG islands
results in ______ of gene transcription
cytosine, long-term repression
DNA methylation disrupts ______ of the transcription machinery
binding
Hypermethylation means that the genes are transcriptionally ____ and disrupts the binding of transcription machinery
inactive
Hypomethylation means that the genes are transcriptionally ____
active
DNA methylation is an important mechanism in ____ control of gene expression
epigenetic
the 4 main points of regulation of gene expression also dictate ______ aka the proteome
protein composition
the 4 points of regulation for the protein include
transcription; initiated by RNA polymerase post-transcription: _______, 3’ end cleavage, RNA editing, and __________
translation: initiation of translation
post-translation: _________, protein targeting, and ________
alternative splicing, mRNA degradation, modification of proteins, protein degradation
Alternative mRNA Splicing is a major mechanism to increase the _____ of proteins produced due to it being able to affect _____ of the mRNA molecule
diversity, any part
specific translational control regulates a subset of mRNAS and is mediated by _______ or long _______ that recognize particular elements present in 5’ untranslated regions of the mRNA
regulatory protein complexes, coding RNAs
global translational control controls acts on general ______ and regulates the translation of most _____
initiation factors, RNA
Global control of translation initiation example includes the _____ of the eIF2-eIF2alpha complex causing it to be inactive and block translation
phosphorylation
4E-BP blocks translation by binding to eIF4G, when 4E-BP is ________ translation is _____
hypophosphorylated, active
lncRNAs anneal to the mRNA and prevent reading which in turn ______
stops translation
IRE-BP controls iron homeostasis by regulating
translation of _______ heavy and light chain mRNA, which encode the subunits of the the iron storage protein. If iron is low, IRE-BP binds and blocks the recruitment for making more _____
ferritin, ferritin
miRNAs are synthesized as a
larger _________ where a short single-stranded molecule of ~22
bases is retained as part of the
RISC complex. The miRNA
guides the RISC complex to
the target mRNA molecule
based on _______
precursor molecules, base pairing
If the RNA-RNA match of mRNA to miRNA is ______, the target mRNA is cleaved and rapidly
degraded
extensive
if the RNA-RNA match is _____ (no more than 7-nucleotides near the 5’ end of the miRNA), translation is inhibited, mRNA destabilized and the mRNA is transferred to P-bodies where it is degraded
limited
post-translational modifications are ______
reversible
Post-translational modifications regulate
_______ and level by altering
confirmation and/or setting up new protein
interactions that mediate ______
protein function, fate
Two major routes for degradation are known:
1. Degradation in ______
2. Degradation in a specific proteasome complex, signaled by ______ of the protein to be degraded
lysosomes, ubiquitination
vesicles containing proteins tagged for destruction fuse with ______
lysosomes
Lining of inner cellular surface of the lysosome is made up of _______ and this
limits lysosomal enzymes to attack
itself
sugar molecules
misfolded proteins are sorted to _____ for their degradation
lysosomes
aggregates produced in Parkinson’s disease disrupt _______
lysosomal function
