membrane trafficking Flashcards
exocytosis: summarise the pathway and cellular locations for synthesis, post-translational modification and exocytosis of a secreted protein
examples of intracellular transport
gated (e.g. nuclear import); trans-membrane (e.g. import of new proteins into ER); vesicular transport
pathway of secreted protein
RER → Golgi → plasma membrane
what occurs within the Golgi
post-translational modification (if unassembled or misfolded, enters cytosol for degradation)
what directs the protein to the correct compartment
signal sequence on protein (acts as address label)
where are ribosomes located initially
cytosol common pool
at end of protein synthesis, what happens to the ribosomal subunits
they are released and re-join common pool
where are ribosomes found during protein synthesis
free in cytosol or bound to RER membrane
what proteins do cytosolic ribosomes make
all proteins encoded in nuclear DNA with no signal sequence
what proteins do RER ribosomes make
all proteins to be translocated into RER (secreted and transmembrane); consist of polyribosomes
