[FMS] CBS - protein targeting Flashcards
name the 3 proteins that are targeted to ER via signal peptide
- Secreted proteins
- Membrane proteins
- Lysosomal proteins
name the 3 cytosolic proteins that are targeted to organelles via other peptide signal
– Mitochondrial proteins
– Nuclear proteins
– Peroxisomal proteins
which part of a protein is synthesised first ?
N terminus and amino end
for what 2 reasons do membrane proteins remain in the ER?
- stop transfer sequences 20-22 aa long
- stop sequence = stops threading = proteins embedded within membrane
protein maturation occurs in the ____ on the ___ face
in the golgi at the trans face
fill in the gaps:
- signal sequence synthesised at the _____
- signal sequence recognised by ______
- SRP binds SRP-receptor on _______
- ______ now bound to ER membrane
- new protein guided through _______ in ER membrane to lumen
- signal sequence cleaved off via ______
- _____ recycled
- signal sequence synthesised at the N-terminus
- signal sequence recognised by signal recognition particule (SRP)
- SRP binds SRP-receptor on ER membrane
- ribosome now bound to ER membrane
- new protein guided through translocation channel in ER membrane to lumen
- signal sequence cleaved off via signal peptidase
- SRP recycled
fill in the gaps:
- ___ golgi are coated with _____ proteins, allowing them to be targeted to specific compartments
- complimentary _____ proteins are present at the destination which ensures correct targetting
- trans golgi are coated with v-snare proteins, allowing them to be targeted to specific compartments
- complimentary t-snare proteins are present at the destination which ensures correct targetting
REMEMBER: Victor comes to Tea (V goes to T)
targeting proteins to the MITCOCHONDRIA happens after ______ but before _____ occurs
happens after TRANSLATION is complete but BEFORE PROTEIN FOLDING occurs
targeting proteins to mitochondria is complexed with chaperone ___
HSP70
targeting to NUCLEUS happens after____ and ____ is complete in ____
after TRANSLATION and FOLDING IS COMPLETED in CYTOPLASM
nuclear proteins contain …
NLS - nuclear localisation signal
pro - lys - lys - lys - arg - lys - val (PKKKRKV) - BASIC
NLS binds …
importin
In the process of targeting to the nucleus, after NLS binds to importin its transported through the nuclear pore using ____ and ____ is hydrolysis need
G-protein RAN + GTP hydrolysis is needed
what performs the opposite of importin?
exportin
lyososomal proteins are synthesised in the ___ and transported to ____
synthesised in ER and transported to TRANS golgi
