a protein that binds to a specific regulatory region of dna to permit transcription of an adjacent gene
combinational control
describes the way in which groups of proteins work together in combination to control the expression of a single gene
differentiation
process by which a cell undergoes a progressive change to a more specialized and usually easily recognized cell type
DNA methylation
the enzymatic addition of methyl groups to cytosine bases in DNA. methylation generally turns off genes by attracting proteins that block gene expression
epigenetic inheritance
inherited that is superimposed on the info inherited in the DNA sequence itself. often, info in the form of particular type of chromatin sturcutre (eg a certain pattern of histone modification or DNA methylation)
gene expression
the process by which a gene makes its effect on a cell or organism by directing the synthesis of a protein or a RNA moelcule with a characteristic activity
microRNA
small noncoding RNAs that control gene expression by base-pairing with specific mRNAs to regulate their stability and their translation
positive feedback loop
situation in which the end product of a reaction stimulates its own production
post-transcriptional control
regulation of gene expression that occurs after transcription of the gene has begun; examples are regulation of RNA splicing and other RNA procedssing events, and regulation of translation by microRNA
regulatory DNA sequence
DNA sequence to which a tanspriciotn reulgator binds to determine when, where and in what quanitites a gene is to be transcribed into RNA
reporter gene
introduced gene encoding a protein whose activity is easy to monitor experimentally. it is usually joined to a regulatory sequence, which will then switch on the reporter gene in the normal context in which its own gene is usually expressed
repressor
a protein that binds to a specific regulatory region of DNA to prevent transcription of an adjacent gene
riboswitch
short sequences within some RNAs that change their conformation when specifically bound to small molecules such as metabolites and in this way regulate transcription or translation
RNA interference
cellular mechanism activated by double-stranded RNA molecules that results in the destruction of RNAs containing a similar nucleotide sequence. its widely exploited as an experimental tool for preventing the expression of selected genes (gene silencing.)
small interfering RNA
short lengths of RNA produced from double-stranded RNA during the process of RNA interference. they base-pair with identical sequences in other RNA's, leading to the inactivation or destructio of the target RNA
transcription regulator
protein that binds specifically to a regulatory DNA sequence and is involved in controlling whether a gene is switched on or off