Term
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Definition
Chromosome-->Gene (introns and exons)
Exons+Introns (DNA transcription)--> primary RNA transcript (RNA splicing)-->
mRNA |
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Term
| Flow of Genetic Information |
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Definition
You do not want DNA to go straight to protein because it can be modified.
dsDNA(sense vs. anti-sense)-->ssDNA-->-->mRNA-->protein |
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Term
| Transcription of Prokaryote versus Eukaryote |
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Definition
Eukaryote more complex, post transcriptional modification.
Prokaryote, no post transcriptional modification. |
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Term
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Definition
1)mRNA-template for protein synthesis
2)tRNA-carries AAs to the ribosome
3)rRNA-major component of ribosome and plays a structural and functional role of ribosome. |
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Term
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Definition
1) RNA polymerase I transcribes 18S, 5.8S, and 28S rRNA
2) RNA polymerase II transcribes mRNA and other snRNAs--strongly inhibited by alpha-aminitin, produced by poisonous mushroom Amanita phalloides
3) RNA polymerase III transcribes 5S rRNA and all tRNA |
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Term
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Definition
1) Initiation
RNA polymerase bind to promoter sites on DNA template.
2) Elongation
Complementary nucleotides to the coding DNA strands are added
3) Termination
-Termination signals |
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Term
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Definition
Most simplistic, series of cleavages.
Ribosomal RNA-->preRNA/precursor RNA
takes out the intervening sequences (introns) |
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Term
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Definition
More Complex
Step 1) Cleavage of 5' end by RNase P
Step 2) Add of CCA nucleotide on the 3' end.
Step 3) Intron is removed by Endonuclease activity and ligated to form mature tRNA.
Exonuclease |
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Term
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Definition
most complex.
1) 5' Cap (prevents degradation by protecting end)
2) 3' Polytail (3' cap also needed)
3) Splicing (intron removal, exons ligation)
Stability and correct post-transcriptional processing |
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Term
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Definition
| 7-methylguanosine attached by a triphosphate bridge |
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Term
| 3' Tail of eukaryotic mRNA |
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Definition
Addition to 200 to 300 adenosine groups.
After you have 5' cap, you have cleavage at a recognition site labeled "AAU" followed by three As cleaved by the endonuclease. Adenosines addition are faciliated by ATP. |
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Term
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Definition
| mature mRNA is transported out of nucleus into the cytoplasm and proteins are built based upon code of mRNA. |
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Term
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Definition
3 bases make a codon=Amino Acid, string of AAs make protein.
AUG=start codon |
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Term
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Definition
1) Important determinant of gene expression since amount of time mRNA can be translated determines how much protein is synthesized.
2) Also lets us know how quickly protein synthesis can be shut down after transcription ceases. |
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Term
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Definition
1)regulated decay occurs as a result of coordination interactions between RNA structural component and specific TRANS-acting factor(RNA binding proteins).
2)Different mRNAs can be degraded via distinct pathways while a given mRNA can also be degraded by different, seemingly-redundant pathways, depending upon cellular conditions |
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Term
| mRNA structural components |
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Definition
| Components that keep mRNA stable: 1)5' Cap 2)5'-UTR 3)Protein Coding Region 4)3'-UTR 5)Poly(A) tail |
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Term
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Definition
1) Deadenylation dependent pathway
2) Deadenylation independent pathway
3) Nonsense mediated decay
4) mRNA instability elements (sequences) |
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Term
| Deadenylation-Dependent Pathway |
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Definition
| Poly(A) shortening followed by decapping and EXONucleolytic decay. |
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Term
| Deadenylation-Independent Pathway |
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Definition
ENDOnucelolytic Pathway
FIRST cleave off protein coding region followed by 5' and 3' cleavage. |
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Term
| Nonsense mediated decay(NMD) pathway |
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Definition
| premature stop codon in protein coding region. Transcripts that harbor nonsense codons, unspliced introns, or extended 3'-UTRs are targets for NMD pathway. Deadenylation-INDEPENDENT decapping is followed by 5' degradation. |
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Term
| mRNA instability determinants |
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Definition
sequences that will render mRNA unstable
A+U-Rich elements (AREs) are located in the 3'-UTR region.
Multiple copies of overlapping AUUUA pentamers.
5'-UTR translation-inhibiting Stem-loop structures. |
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Term
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Definition
| Posttranscriptional modification that results in the alteration of the primary nucleotide sequence of RNA transcripts by a mechanism OTHER THAN SPLICING. |
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Term
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Definition
ApoB 48 Intestine (short/truncated form)
ApoB 100 Liver (long form) |
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Term
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Definition
| ApoB100 (liver) removal of amino group through Cytidine Deaminase Editing Complex causes a AA change from C to U, now you have UAA (stop codon) instead of CAA. You now have ApoB48 (in intestine). |
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Term
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Definition
| You have transcriptional RNAs (tRNA and rRNA) as well as small RNAs (siRNA and miRNA) |
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Term
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Definition
are about 20nt long RNAs.
miRNA BINDS TO COMPLEMENTARY mRNA AND THE IMPERFECT miRNA-mRNA duplex REPRESSES TRANSLATION |
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Term
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Definition
1) Implicated in cell death and cell proliferation
2) Change in expression level of miRNAs is associated with dysfunction of their corresponding protein-coding gene targets many of which are involved in initiation and progression of cancer (miRNA is endogenous, present in cell).
Disease state, large expression level of miRNAs. |
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Term
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Definition
Both siRNA and miRNA are formed by DICER.
The DIFFERENCE is siRNAs form a PERFECT complex with mRNA. Once the duplex is formed, it get tagged by an endonuclease called SLICER. |
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Term
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Definition
| Can be custom synthesized to target particular genes/areas (whereas miRNAs are not easy to synthesize) |
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Term
| Short hairpin RNAs (shRNA) |
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Definition
Packaged in a vehicle (vector)--usually recombinant human or non-human virus.
Used in Gene Therapy
Improves efficacy and specificty. |
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