Ch 8 - Control of Gene Expression Flashcards
cell memory
the ability of differentiated cells and their descendants to maintain their identity
combinatorial control
describes the way in which groups of transcription regulators work together to regulate the expression of a single gene
differentiation
process by which a pluripotent cell undergoes a progressive coordinated change to a more specialized cell type, brought about by large-scale changes in gene expression
DNA methylation
the enzymatic addition of methyl groups to cytosine bases in DNA; this covalent modification generally turns off genes by attracting proteins that block gene expression
epigenetic inheritance
the transmission of a heritable pattern of gene expression from one cell to its progeny that does not involve altering the nucleotide sequence of the DNA
gene expression
the process by which a gene makes a product that is useful to the cell or organism by directing the synthesis of a protein or an RNA molecule with a characteristic activity
induced pluripotent stem (iPS) cells
somatic cell that has been reprogrammed to resemble and behave like a pluripotent embryonic (ES) cell through the artificial introduction of a set of genes encoding particular transcription regulators
long noncoding RNA
class of RNA molecules more than 200 nucleotides in length that does not encode proteins. often used to regulate gene expression
microRNA (miRNA)
small noncoding RNA that controls gene expression by base-pairing with a specific mRNA to regulate its stability and its translation
positive feedback loop
an important form of regulation in which the end product of a reaction or pathway stimulates continued production or activity; controls a variety of biological processes, including enzyme activity, cell signaling and gene expression
post-transcriptional control
regulation of gene expression that occurs after transcription of the gene has begun; examples include RNA splicing and translational control
promoter
DNA sequence that initiates gene transcription; includes sequences recognized by RNA polymerase and its accessory proteins
regulatory DNA sequence
DNA sequence to which a transcription regulator binds to determine when, where and in what quantities a gene is to be transcribed into RNA
regulatory RNA
RNA molecule that plays a role in controlling gene expression
reporter gene
gene encoding a protein whose activity is easy to monitor experimentally; used to study the expression pattern of a target gene or the localization of its protein product
RNA interference (RNAi)
cellular mechanism activated by double-stranded RNA molecules that results in the destruction of RNAs containing a similar nucleotide sequence. it is widely exploited as an experimental tool for preventing the expression of selected genes (gene splicing)
small interfering RNA (siRNA)
short length of RNA produced from double-stranded RNA during the process of RNA interference. it base-pairs with identical sequences in other RNAs, leading to the inactivation or destruction of the target RNA
transcription regulator
protein that binds specifically to a regulatory DNA sequence to switch a gene either on or off
transcriptional activator
protein that binds to a specific regulatory region of DNA to stimulate transcription of an adjacent gene
transcriptional repressor
protein that binds to a specific regulatory region of DNA to prevent transcription of an adjacent gene
