Term
| differential gene expression |
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Definition
| responsible for creating different cell types, arranging them into their tissues, & coordinating their activity to form the multicellular society we call an individual |
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Term
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Definition
| a structure in eukaryotes created from DNA being wrapped around proteins |
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Term
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Definition
| before transcription can begin in eukaryotes, the stretch of DNA containing the promoter must be released from tight interactions with proteins, so that RNA polymerase can make contact with the promoter |
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Term
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Definition
| the steps required to produce a mature, processed mRNA from a primary RNA transcript |
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Term
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Definition
| particular combinations of histone modifications set the state of chromatin condensation for a particular gene |
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Term
| histone acetyltransferases/HATs |
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Definition
| add acetyl groups to the positively charged lysine residues in histones |
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Term
| histone deacetylases/HDACs |
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Definition
| remove acetyl groups from histones |
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Term
| acetylation of histones usually results in _____ |
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Definition
| decondensed chromatin, a state associated with active transcription |
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Term
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Definition
| patterns of inheritance that are due to something other than differences in DNA sequences |
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Term
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Definition
| a site in DNA where RNA polymerase binds to initiate transcription |
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Term
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Definition
| a conserved sequence that serves as a binding site for proteins needed to start transcription |
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Term
| promoter-proximal elements |
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Definition
| regulatory sequences that are located close to the promoter & bind regulatory proteins |
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Term
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Definition
| regulatory sequences that are far from the promoter & activate transcription |
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Term
| 5 key points about enhancers |
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Definition
1. can be more than 100,000 bases away from the promoter
2. there are many types
3. most genes have more than one
4. usually have binding sites for more than one protein
5. can work even if their normal 5' -> 3' orientation is flipped or are moved to a new location in the vicinity of the gene |
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Term
| transcriptional activators |
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Definition
| regulatory proteins that begin transcription when bound to enhancers |
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Term
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Definition
| regulatory sequences that are similar in structure & share key characteristics with enhancers but work to inhibit transcription |
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Term
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Definition
| regulatory proteins that bind to silencers to shut down transcription |
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Term
| basal transcription factors |
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Definition
| proteins that interact with the promoter & are not restricted to particular genes or cell types |
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Term
| 4 steps: transcription initiation |
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Definition
1. chromatin remodeling
2. exposure of promoter & regulatory sequences
3. assembly of proteins
4. DNA looping allows Mediator to connect DNA-bound activators & basal transcription factors |
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Term
| 4 gene control mechanisms |
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Definition
1. splicing RNAs in various ways
2. modifying the life san of mRNAs
3. altering the rate at which translation is initiated
4. activating or inactivating proteins after translation has occurred |
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Term
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Definition
| macromolecular machines that splice primary RNAs |
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Term
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Definition
| splicing the same primary RNA transcript in different ways to produce different mature mRNAs & thus different proteins |
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Term
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Definition
| when a tiny, single-stranded RNA held by a protein complex binds to a complementary sequence in an mRNA which unleashes either the destruction of the mRNA or a block to the mRNAs translation |
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Term
| 6 steps: RNA interference |
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Definition
1. transcription of a microRNA gene
2. precursor microRNA (miRNA) formed by initial processing of transcript in nucleus
3. double-stranded miRNA formed when enzyme in cytoplasm trims the RNA hairpin into a short double-stranded RNA
4. mature miRNA formed when double-stranded miRNA binds to RISC protein complex & one strand is degraded
5. miRNA, held by RISC, binds to complementary sequence on target mRNA
6. RISC either cuts mRNA or prevents the mRNA from being translated |
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Term
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Definition
| recognizes proteins that have a ubiquitin tag & cuts them into short segments |
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Term
| bacteria VS eukaryotes: chromatin remodeling |
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Definition
b: limited packaging of DNA; remodeling not a major issue in regulating gene expression
e: extensive packaging of DNA; chromatin must be decondensed for transcription to begin |
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Term
| bacteria VS eukaryotes: transcription |
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Definition
b: positive & negative control by regulatory proteins that act as site close to the promoter; sigma interacts with promoter
e: positive & negative control by regulatory proteins that act as sites close to AND far from promoter; mediator required |
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Term
| bacteria VS eukaryotes: RNA processing |
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Definition
b: rare
e: extensive processing; alternative splicing of introns |
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Term
| bacteria VS eukaryotes: mRNA stability |
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Definition
b: rarely used for control
e: commonly used; RNA interference limits the life span or translation rate of many mRNAs |
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Term
| bacteria VS eukaryotes: translation |
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Definition
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Term
| bacteria VS eukaryotes: post-translational modification |
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Definition
| same except eukaryotes also have uibiquitination targets proteins for destruction by proteasome |
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Term
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Definition
| genes that stimulate cell division |
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Term
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Definition
| an allele that promotes cancer development |
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