Shared Flashcard Set

Details

Gene Regulation
Plaas
28
Biochemistry
Professional
10/13/2011

Additional Biochemistry Flashcards

 


 

Cards

Term

 

 

 

operons

Definition

 

 

PRO only

physical grouping of related genes

expressed under same conditions

 

may be inducible or repressible

Term

 

 

lac operon

 

structure

type

 

inducer

Definition

 

lac1(repressor)-promoter-operator-structural genes

 

inducible (constitutively off), repressor gene on-->creates repressor protein, which binds operator

 

 

lactose binds repressor protein, changing conformation and preventing it from binding operator

Term

 

 

 

lac operon products

Definition

 

when lactose is present, repressor protein inactivated, and lactose metabolism enzymes are produced:

 

lac permease--transports lactose into cell

beta-galactosidase: cleaves lactose into glucose and galactose, producing E

Term

 

 

 

Trp Operon

type

product

mechanism

Definition

 

 

repressible (constitutively ON)

enzymes necessary for trp synthesis

 

trp is being produced, until tryptophan binds repressor protein, allowing it to bind to operator and turn off gene transcription

 

Term

 

 

promoters

Definition

 

 

DNA seq recognized by transcription factors responsible for determining transcription start site and initiating low levels of transcription

Term

 

 

 

enhancers

Definition

 

 

DNA seq responsible for enhancing transcription levels/ regulating cell- and tissue-specific transcription

 

recognized and bound by specialized transcription factors

Term

 

 

 

response elements

Definition

 

 

 

 

DNA seq that bind transcription factors

 

Term

 

 

 

transcription factor structure

Definition

 

 

DBD: DNA-binding domain

 

TAD: trans-activating domain (binding sites for transcription coregulators)

 

SSD (optional): signal-sensing domain, envtl factors-->up/down regulation

Term

 

 

 

AFs

activation functions

Definition

 

 

binding sites for transcription coregulators on transcription factors

Term

 

 

transcription factors

 

mechanism of action

Definition

 

 

stabilize or block binding of RNA polymerase to DNA

 

catalyze acetylation, deacetylation of histones

 

recruit coactivator/repressor proteins

Term

 

 

 

Zinc finger proteins

Definition

 

 

 

transcription factors

produce loop (via zinc chelation) that binds to DNA

Term

 

 

 

helix-turn-helix proteins

Definition

transcription factors

 

3 alpha helices, joined by curved sections of polypeptide (homeodomain)

 

developmentally important, not produced in post-natal life

Term

 

 

 

 

 

helix-loop-helix proteins

Definition

transcription factors

 

 

need to dimerize to bind to DNA

Term

 

 

 

 

leucine zipper proteins

Definition

 

transcription factors

 

dimerize by means of leucine zipper: alpha helix containing a critical Lys

Term

 

 

 

 

steroid receptors

Definition

transcription factors

 

contain steroid-binding domain, bind steroids which regulate activity

Term

 

 

 

transcription factors are activated by:

Definition

 

envtl signals (stress signals): e.g. heat shock genes

 

hormones and growth factors

Term

 

 

 

Rett syndrome

Definition

 

 

 

neurodevelopmental disorder

 

mutation in MECP2 transcription factor

Term

 

 

 

diabetes, MODY

Definition

Maturity onset diabetes of the young

 

mutations in hepatocyte nuclear factors or insulin promoter factor 1(HNFs or IPF1/Pdx1)

Term

 

 

 

developmental verbal dyspraxia

Definition

 

 

mutations in FOXP2 transcription factor

 

developmental, can't speak

Term

 

 

 

IPEX (autoimmune disease

Definition

 

 

 

FOXP3 transcription factor mutation

Term

 

 

 

 

Li-Fraumeni syndrome

Definition

 

 

p53 transcription factor mutation-->cancers

Term

 

 

 

 

STAT family

Definition

 transcription factors

 

breast cancer

Term

 

 

 

 

 

HOX family

Definition

transcription factor

 

cancers

Term

 

 

 

mRNA and protein regulation

Definition

 

 

mRNA processing, half-life, and translation can be regulated to modify protein expression

 

processing determines translation, since mRNA will not be transported out of nucleus for translation until processing

Term

 

 

 

introns/exons in higher eukaryotes

Definition

 

 

 

higher eukaryotes have larger percentage of genes containing introns, and introns are larger

Term

 

 

 

regulation of mRNA half-life

Definition

 

info found in 3'UTR: AUUUA is signal for early degradation (more times sequence is present, shorter lifespan)

Term

 

 

 

 

poly-A binding protein

Definition

 

 

 

removal-->poly A tail degradation, destabilization of mRNA-ribosome complex

Supporting users have an ad free experience!