gene expressions Flashcards
what are the importance of gene expression?
for therapeutic agent dev’t, pathogenic and cancer
what are the 2 levels of regulation?
transcription and translation
what is transcription?
changing amt of mRNA
what is translation for?
regulates mRNa to protein
What are the 2 gene regulation?
positive regulation and negative regulation
what is positive regulation?
an enhancer or activator, increases expression in the presence of a gene regulator
what is negative regulation?
silencer/repressor, decreases regulation when there is a regulator
What is present in the bacteriophage lambda model?
lysogenic, lytic and switch
what is lysogenic?
lambda remains until activated
what is lytic?
already activated inside the host
what are the switch and functions?
cro that repress CI and CI that maintains lysogenic by repressing early lytic
What is an inducible gene?
high regulators, low basal rate
what are constitutive gene?
constant, a housekeeping gene
What is the type A temporal response of a regulatory gene?
gene expression= signal, inducers, present in prokaryotes
What is the type B temporal response of a regulatory gene?
gene expressions short peak= signal, response-desensitization-recovery, pharmacological agents
What is the type C temporal response of a regulatory gene?
gene expression prolong=signal, tissue organ
protein coding genes in prokaryotic gene expression?
operon and cistron
what is operon?
segment of DNA with adjacent genes that is structural, operator and regulatory, the functional unit of transcription and genetic regulation
what is cistron?
genetic unit that code single polypeptide, shortest unit of genetic expression
what is polycistron mRNA?
codes more than one polypeptide eg: lac operon
what is the lac operon model for?
lactose metabolism
LacI
lac operon repressor, negative regulator
CRE
cAMP, CAP, positive regulator
LacZ
B-galactosidase, hydrolyzes B-galactosidase galactose to glucose
LacY
permease
LacA
thiogalactoside transacetylase
Eukaryotic gene transciption
transcriptional, post transcriptional, chromatin, epigenetic
regulation of chromatin
PTMs(postranslational modification)
Protein machinery from PTMs
code writers (catalyse), code readers (recognise, bind and interpret), code eraser (remove)
characteristic of epigenetic
control of gene transcription, behaviors and environment do not change DNA, cis and trans signals
elements of eukaryotic gene transcription
enhancers (promoter site), reporters (modulate gene expression), insulators (prevents enhancers) and LCR (locus control region) which contains clster of genes
what are the motifs of eukaryotic gene transcription
helix turn helix, zinc finger, leucine zipper
helix-turn-helix
symmetric palindrome, high affinity to specific site and low to others
leucine zipper
binds 2-9x
