Central Dogma Flashcards
methionine aminopeptidase
removes Met from proteins; overexpressed in cancerous cells
What protein attaches the tRNA to the A site?
EF1 at the expense of one GTP
How many GTPs does it take to charge a tRNA (add aa)
2
What does EF2 do?
moves the new peptide from the A site to the P site, and release the tRNA in the P site, the expense of one GTP
How does heme regulate globin transcription?
Heme inactivates the inhibitor of EF2 - normally a kinase inactivates EF2 but heme prevents that allowing transcription
What are ferritin and transferrin and how are they translationally regulated?
Ferritin - binds to Iron
Transferrin - receptor to bring in iron
Both have IRE’s - iron response elements on their mRNA (sites of regulation)
IRE-BP - binding protein that regulates the two mRNAs
When iron levels are low, IRE-BP stbalizes transferring mRNa to increase translation and blocks intiaition on ferritin by binding to the IRE
When iron levels are high, IRE-BP releases from both allowing for the degradation of transferring mRNA and the translation of ferritin
What is the role of BiP?
It is a chaperone that prevents transmembrne/secretory proteins from accidentally leaving the ER during translation?
What are the steps of N-linked Glycosylation?
N-linked = asaparagine added
- 14 sugar branched oligosaccaride (synthesized in the cytosol and brought in by a oligosaccharyltransferase)
What is a GPI?
an anchor for proteins, the sugars that modify proteins can turn into a an anchor and replace the transmembrane portion of protein
What is calnexin?
chaperone that checks to see if glycopoteins are properly folded, changes in attached sugars by enzymes are also involved
What are mannosidases?
glycoprotein chaperone
How are disulfide bonds formed in the ER lumen?
PDI - protein disulfide isomerases
What do glycosidases and glycotrasnferases do?
modify sugars on proteins in the golgi and ER
What is O-linked glycosylation?
sugar modifications on serine and threonine
What Vesicles are Cathrin coated?
Golgi to membrane and lysosome and endocytosis
What vesicles have a COP coat
Er to golgi and inter golgi
how are vesicles identified?
rab proteins (interact w tethering proteins on target)
KDEL sequence
on resident ER proteins, used to Id what needs to be recycled
M-6-phosphate receptor
used to take hydrolases to the lysosome, used to get cargo and trigger vesicle formation
what protein residues does ubiquitan attach to?
lysine
ER lumen proteins are re-translocated to allow for degradation
sorry not a question plz learn this thx
What is ERAD?
endoplasmic recticulum associated degredation
basically shit (protein folding lol) in the ER gets fucked up or takes too long so ERAD says bye bye bitch and exports it to the cytosol so it can get ubiquitinated and broken down
What is UPR?
Unfolded protein response
When there are too many unfolded proteins the body needs to readjust. It increases the transcription of chaperones and stops mRNA transcription till it gets it shit together. If it cant get it together it tells the cell to die. Sounds like me and my life gr8
What is the difference between and aggregate and an amyloid?
Aggregates are clumps of misoflded proteins where as amyloids are created by a specific alternate folding
