chapter 13.3-13.6 Flashcards
what does PDI do
oxidation/reduction form a disulfide bond, mostly in the lumen of the ER
what does PPI do
rotate side chains into correct formation
what is the unfolded protein response
the presence of unfolded proteins in the rough ER increases transcription of genes that encode ER chaperones and other folding catalysts
BiP can bind to make a signal for more protein chaperones (IreI dimer formation is the signal)
what happens to proteins that can not fold properly
they are retained in the ER for longer time
undergo mannose trimming by ER mannosidases to form GlcNAc
proteins imported into the mitochondrial matrix…
are maintained in an unfolded or partially folded state by bound chaperones (HSC70)
contain a matrix-targeting sequence
what is the general import pore on the outer membrane of the mitochondria
Tom
what is the general import pore on the inner membrane of the mitochondria
Tim
what is the general import pore on the outer membrane of the thylakoid
Toc
what is the general import pore on the inner membrane of the thylakoid
Tic
luminal peroxisomal proteins are synthesized where, contain what, and are incorporated when
on free cytosolic ribosomes, contain a targeting sequence, and are incorporated into the peroxisome post-translationally
how are folded luminal proteins important into the peroxisome
by a system involving cytosolic receptor protein and translocation machinery on the peroxisomal membrane
how are peroxisomal membrane proteins different than luminal proteins
they contain different targeting sequences than peroxisomal matrix proteins and are imported by a different pathway
how are peroxisomal matrix proteins imported
by PTS1 pathway
how are proteins larger than 40kDa transported out of the nucleus
through a large complex nuclear pore complex that requires a nuclear-localization or nuclear-export signal, nuclear transport receptors, Ran G-proteins, and localized Ran-GEFs and GAPS
how are mRNPs transported through the nucleus
by Ran-independent pathways
