Notes in Protein Synthesis and Degradation

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Status	Last Update	Fields
Published	09/07/2023	The steady state levels of a protein reflect what three things? {{c1::rate of gene transcriptionstability of the mRNAstability of the protein}}
Published	09/07/2023	{{c1::Ribosomes}} are large ribonucleoprotein particles that catalyze the step-wise polymerization of amino acids based on an mRNA template
Published	09/07/2023	A {{c1::polysome}} is multiple ribosomes that reside on a single mRNA
Published	09/07/2023	A {{c1::frameshift mutation}} occurs when bases are inserted or deleted so that the reading frame is shifted
Published	09/07/2023	What is programmed ribosomal frameshifting? {{c1::alternate mechanism of translation, often used by viruses, to merge proteins encoded by two ove…
Published	09/07/2023	What are the subunits of eukaryotic ribosomes? {{c1::60S40S}}
Published	09/07/2023	Each ribosomal subunit contains what two things? {{c1::rRNAprotein}}
Published	09/07/2023	What provides the site of enzymatic activity (peptidyltransferase) in a ribosome?{{c1::28S rRNA}}
Published	09/07/2023	Aminoacyl tRNAs are bound at the {{c1::“A” site}} and through processive (triplet) movement of the ribosome, are transferred to the {{c1::“P” site}} a…
Published	09/07/2023	The area of the charged aminoacyl-tRNA that binds with the mRNA codon is called the {{c1::anticodon}}
Published	09/07/2023	The ribosome moves along the mRNA transcript in the {{c1::5' to 3'}} direction
Published	09/07/2023	What type of bonds are formed between amino acid subunits during translation?{{c1::amide}}
Published	09/07/2023	Protein synthesis occurs in what three discrete biochemical stages? {{c1::initiationelongationtermination}}
Published	09/07/2023	What is mRNA translation? {{c1::protein synthesis catalyzed by ribosomes}}
Published	09/07/2023	During translation, the completed protein is released from the ribosome when one of the three stop codons ({{c1::UAA}}, {{c1::UAG}}, {{c1::UGA}}) is p…
Published	09/07/2023	What are two factors that ensure protein synthesis fidelity? {{c1::elongation factor GTPase "clock"loading of the tRNA synthetase with the correc…
Published	09/07/2023	Met-tRNA is activated by attachment of Met via what?{{c1::the Met COOH group to the 3’ end of tRNA}}
Published	09/07/2023	mRNAs are {{c1::polar}} due to the cap and tail on each transcript
Published	09/07/2023	During initiation of translation, what binds the 5' cap?{{c1::the small ribosomal subunitMethionine-tRNAeIF2-GTP complex}}
Published	09/07/2023	eIF4 is required for what?{{c1::recruitment of initiation complex}}
Published	09/07/2023	What three units does the eIF4 complex contain? {{c1::eIF4E - cap binding proteineIF4G - scaffold proteineIF4A - helicase}}
Published	09/07/2023	What unit of the eIF4 complex binds the 5’ cap?{{c1::eIF4E}}
Published	09/07/2023	What unit of the eIF4 complex is a scaffold protein?{{c1::eIF4G}}
Published	09/07/2023	Which unit of the eIF4 complex is a helicase?{{c1::eIF4A}}
Published	09/07/2023	Once the translation initiation machinery is assembled and cap recognition has occured, the complex scans to find what? {{c1::initiator AUG}}
Published	09/07/2023	Initiator AUG sequences are often surrounded by a what sequece that consists of conserved ribonucleotides?{{c1::Kozak sequence}}
Published	09/07/2023	Where are ribosomal subunits assembled? {{c1::initiator AUG}}
Published	09/07/2023	What do Polio virus and Hepatitis C virus do to block protein synthesis?{{c1::inhibit the initation of translation}}
Published	09/07/2023	What is the effect of viruses that produce a protease that destroys eIF4G?{{c1::blocks host translation initiation}}
Published	09/07/2023	What do IRES (internal ribosome entry site) elements do to hijack host cell translation?{{c1::allow translation initiation and small ribosomal subunit…
Published	09/07/2023	Which human gene contains IRES elements to allow for more efficient translation of chaperone proteins during stress conditions?{{c1::chaperone protein…
Published	09/07/2023	Under stress, {{c1::eIF2A}} can be phosphorylated by {{c2::PERK, GCN2, PKR, and HRI}} to induce a {{c3::protective}} state of global inhibitation of t…
Published	09/07/2023	During the second stage of translation, the growing polypeptide chain bound to the last aminoacyl tRNA sits in which site?{{c1::the P site}}
Published	09/07/2023	When aminoacyl tRNA is initially bound to the A site, it is also bound to what? {{c1::an elongation factor}}
Published	09/07/2023	The amino acid from the aminoacyl tRNA in the A site cannot bind the growing polypeptide chain until what happens?{{c1::the elongation factor is relea…
Published	09/07/2023	What serves a critical role in maintaining fidelity of translation by mediating the release of the elongation factor? {{c1::GTPase}}
Published	09/07/2023	The completed protein is released from the ribosome when what two things happen?{{c1::termination codon appears in the mRNA termination factors b…
Published	09/07/2023	{{c1::Prokaryotic protein synthesis}} is a drug target
Published	09/07/2023	Which antibotic inhibits protein initiation and cause the mRNA to be misread in prokaryotes?{{c1::Streptomycin and other aminoglycoside antibiotics}}
Published	09/07/2023	Which antibotic inhibits the binding of aminoacyl-tRNAs to the 30S subunit of the prokaryotic ribosome?{{c1::Tetracycline}}
Published	09/07/2023	Which antibiotics inhibit the 50S prokaryotic ribosomal subunit and inhibit the formation of the peptide bond?{{c1::chloramphenicol erythromycin}…
Published	09/07/2023	Which antibiotic is an aminoacyl-tRNA analog that gets incorporated into proteins and terminates the chain because it cannot bind the next amino acid?…
Published	09/07/2023	Why is the lifespan of regulatory proteins relatively short?{{c1::allows tight regulation of their steady state levels}}
Published	09/07/2023	Which kind of protein has a relatively long lifespan? {{c1::structural proteins}}
Published	09/07/2023	What are caspases?{{c1::intracellular proteases that function during apoptosis}}
Published	09/07/2023	What are two prominent pathways for protein degredation in mammalian cells? {{c1::caspases ubiquitin-proteasome pathway}}
Published	09/07/2023	What highly conserved, 76 amino acid protein serves as a signal for degradation by the proteasome when covalently attached to lysine on the target pro…
Published	09/07/2023	What provide protected environments for the degradation of ubiquitin-conjugated proteins and efficiently degrade them to small peptides?{{c1::proteaso…
Published	09/07/2023	Unfolding proteins during ubiquitin-proteasome degradation requires what?{{c1::ATP hydrolysis}}
Published	09/07/2023	What protein can de-ubiquitinate other proteins?{{c1::Ubiquitin hydrolases}}
Published	09/07/2023	Regulation of which ubiquitinated proteins are degraded occurs where? {{c1::at the caps of the proteasome}}
Published	09/07/2023	What are the three factors that determine whether a protein will be targetted for degradation?{{c1::N-end ruleaccessibility of the protein to ubiquiti…
Published	09/07/2023	The {{c1::N-end rule}} suggests that protein molecules that begin with certain amino acids are more stable and less likely to be ubiquitinated than pr…
Published	09/07/2023	Peptides produced by proteasomes are {{c1::8-10 amino acids}} long and bind {{c2::MHC (Major Histocompatibility Complex) class I}} proteins
Published	09/07/2023	{{c1::MHC Class I proteins}} are expressed by all cells as peptide binding proteins that are synthesized in the ER
Published	09/07/2023	After a peptide is bound to an MHC class I molecule, it is transported to the {{c1::plasma membrane}} where it is displayed for the immune system
Published	09/07/2023	MHC class I proteins usually display {{c1::self}} peptides but during infection with intracellular pathogen like a virus, they can display {{c2::forei…
Published	09/07/2023	{{c1::Cytomegalovirus}} interferes with MHC class I antigen presentation to avoid immune detection
Status	Last Update	Fields