Regulation Of Gene Expression

Front 1

First point at which gene expression can be controlled

Back 1

transcription

Front 2

strength of promotor

Back 2

can vary the amount of gene product made

Front 3

transcriptional activators

Back 3

increase or upregulate transcription by enhancing the interaction between RNA pol and a promoter by binding the RNA pol or binding near the promoter regions upstream of the start site

Front 4

transcriptional repressors

Back 4

decrease or downregulate transcription
bind the operator region and block binding or advancement of the RNApol

Front 5

allosteric proteins

Back 5

proteins whose activity is dependent on binding of a particular small molecule

Front 6

Catabolite activator protein

Back 6

allosteric activator
when glucose is absent cAMP is produced which activates CAP allowing it to facilitate transcription of various sugar utilization pathway genes
known as catabolite repression

Front 7

lac repressor

Back 7

deactivated by a small molecule which binds the operator in front of the genes required for lactose utilization and prevents their transcription in the absence of lactose

Front 8

covalent modification

Back 8

reversible modifications such as phosphoylation that can change the activity of some regulators

Front 9

LexA repressor

Back 9

prevents activation of the SOS DNA repair response
upon dna damage the RecA protein is produced which cleaves LexA
irreversible reaction

Front 10

Sigma factors

Back 10

a component of the RNA pol that provides specificity between the polymerase and the promoter

Front 11

alternate sigma factor

Back 11

allow RNApol to recognize atypical -10 promoter regions thereby limiting transcription of these genes to situations where the alternate sigma factor is produced

Front 12

antitermination

Back 12

rare case in which RNApol may be modified in a way that allows it to ignore termination signals and continue transcription

Front 13

Regulation at level of translation

Back 13

stability of mRNA (nuclease production, mRNA secondary structure, antisense RNAS)
efficiency of ribosome-binding site
antisense RNA

Front 14

Antisense RNA

Back 14

small untranslated RNA that is complementary to the beginning of a particular transcript
binds to the mRNA and prevents translation may also decrease mRNA stability

Front 15

operons

Back 15

consists of two or more genes whose products function together in a particular cellular process

Front 16

regulons

Back 16

multiple individual genes or operons may be under control of the same transcriptional activator or repressor

Front 17

posttranslational modifications

Back 17

reversible ones include phosphoylation, methylation, acetylation
generally work by altering the conformation of the enzyme
irreversible ones include posttranslational processing where a part of a protein is cleaved to activate or inactivate it

Front 18

Bvg

Back 18

Bordetella virulence gene regulon
two-component regulatory which comprises the BvgS/ BvgA proteins. BvgA is a sensor kinase. It transfers the phosphate group to the transcriptional response regulator BvgA which can then bind to promoters of several genes and operons