Membrane protein trafficking Flashcards
two methods of delivering proteins
signal based and vesicle based
when are proteins translocated into the RER
during their synthesis
how are proteins targeted to the ER
signal sequences
how long are signal sequences
16-30 residues in length
what signal targets secretory proteins to the ER
signal recognition particles
what part of the SRP binds to the hydrophobic amino acids of the signal sequences
p54 subunit
where does SRP direct proteins t
to the ER
what cleaves off the signal sequence
signal peptidase
what does Sec63 do
hydrolyses BiP.ATP
what does a conformational change in BiP causes
binding to incoming polypeptide chain
does posttranslational incorporation into the ER require SRP
no
what are four examples of posttranslational modification
n-linked glycosylation
disulphide bond formation
correct folding
oligomer formation
what does n-linked glycosylation involve
attatchment of sugar molecule oligosaccharide known as glycan to a nitorgen atom
what do disulpide bonds stabilise
tertiary and quaternary structure
what environment does S-S formation require
oxidising
what does oligomer formation form
hemagglutinin
examples of post-translational folding
o-linked glycosylation
proteolytic processing
where does o-linked glycosylation occur
exclusively in the golgi
what is shedding
generation of soluble forms of membrane proteins, proteolytci removal of the extracellular domains of membrane proteins
what carries out shedding
ADAM family
