Part 1
1/Where does transcription happen and what is the outcome?
Where does translation happen and what is the outcome?
1. In the nucleus, leads to RNA
2. In the cytoplasm, leads to protein
What does the insulin receptor do? L11SL12
Allows cells to respond to insulin released into the bloodstream, when activated causes cells to take up glucose for ATP production.
What is miRNA and what does it do?
miRNA is microRNA(small double-stranded RNAS) that interfere with mRNA. They are encoded by genes
They can degrade mRNAs or block translation of mRNAs.
What do chaperones do?
They can either promote or inhibit folding.
What is post transcriptional regulation? And list things that occur post transcription.
PTR is anything that occurs after transcription:
spliceosomes removing introns from the transcript, ubiquitinization of a protein, proteins binding to the 3' UTR, miRNAS bound to mRNA, histone transcriptional, alternative splicing, phosphorylation of a protein by a protein kinase.
Does alternative splicing produce mature mRNA from different genes?
No, produces more than one mature mRNA from the same gene.
What is the RISC complex?
RISC stands for RNA, induced, silencing, complex and is where miRNA is assembled
What are the jobs of Proteasomes? What types of protein do proteasomes degrade?
Proteasome jobs: target mis-folded proteins, clean them up(degrade), and control protein lifespan(regulation of gene expression by regulating protein amount).
What are Exons? What are Introns?
Exons: portion of primary transcript that is retained in mature mRNA(both coding region and UTR).
Introns: portion of primary transcript removed from the mature mRNA. Introns do not contain coding sequences, except in alt. splicing cases.
What regulates alternative splicing? SL16
An RNA binding protein, specifically expressed in muscle cells.
How do miRNAs target specific mRNAs?
Through complementary base pairing
What are the three steps to turning off Fos?
1. Stop new transcription
2. Activate a miRNA to target Fos mRNA
3. Activate a E3 ubiquitin ligase to target Fos protein
What are the three steps to "turning off" a gene?
1. Stop transcribing
2. Degrade mRNA or block translation
3. Degrade or inactivate the protein
What does alternative splicing do?
Makes different proteins of mRNA copies due to different splicing
What RNA processing events in Eukaryotes help stabilize the RNA and helps promote translation?
1. the addition of a "cap" to the 5' end of RNA
2. the addition of poly A "tail" to 3' end of RNA
Why would a cell want to destroy its own mRNA.
Only wants it for a short amount of time or only a little amount.
What is a splicesome?
A larger assembly of proteins & snRNAs. They recognize intron/exon boundaries through RNA-RNA base pairing. They splice out the introns and join the exons together.
What features lead to a longer half-life for the mRNA?
Long 3' poly A-tail, proteins bound to the 3' end of the mRNA to block RNases(RNA degraders) from the transcript.
What is the pathway of miRNA?
1. Get exported from nucleus to cytoplasm
2. Fold and hairpin RNA
3. Process RNA
4. Become miRNA-RISC complex