Chapter 4: Protein Sorting and Vesicle Traffic Flashcards
Which organelles can targeting proteins only go INto? Which one can they go in AND out
Only IN: plastids, mitochondria, peroxisomes
in AND out: nucleus
after protein goes to plastid, mitochondria and peroxisomes, it is cut
____________ ___________ requires peptide address labels and sorting machinery, and usually requires crossing at least one membrane.
Protein sorting
In protein sorting, ___________ _____________ act as an address label.
targeting domains
Targeting domains are often located at the ___-_____________ of a protein, but may be present in the C-terminus or elsewhere in the polypeptide.
N-terminus
Most proteins have _________________ surfaces and do NOT readily pass through the hydrophobic lipid bilayer.
hydrophilic
A polypeptide passes through a CHANNEL, and it is assisted by molecular ___________________.
chaperones
____________________ increase the yield of correct tertiary structures but NOT the rate of protein folding.
Chaperones
Targeting of proteins from the cytosol to the compartment surface can occur after protein synthesis is complete (_______-___________________) or during translation on cytoplasmic ribosomes (_________________________).
post-translational; cotranslational
_______-___________ proteins are released in the cytosol and targeted to a variety of destinations
Post-translational
Most proteins destined for the __________________ ______________ (cotranslational) are synthesized on ribosomes bound to the ER.
secretory pathway
ALL nuclear-encoded mRNAs are translated in the _____________.
cytosol
