Protein Sorting Flashcards
Requirements for protein translocation into organelles
Targetting signal, energy, specific receptor and translocon
Ribosomes and pathways for sorting
Co and Post translational
What is cotranslational
membrane bound
what is post translational
cytosolic
Nuclear pore complex components
cytoplasmic filaments, FG nucleoporins, structural nucleoporins, nuclear basket, terminal ring
What fo FG nucleoporins doe
line NPC channel and from a hydrophobic gel like matrix that regualtes diffusion and transport
How to move proteins for translocation
Use nucleoporins for active transport
Nuclear localisation signalling
Short sequence which is recognised
Examples of NLS
SV40 T antigen (continuous) and Nucleoplamin (bipartit sequence)
Which ones are N-term
ER and mitochondria
ER TS
6-12 hydrohpobic amino acids proceeded with 1 or more basic amino acids
Mito TS
1 side hydro, 1 side homo, helix 20-50 residues
Peroxisome TS
PTS1 signal at C-term, PTS2 at N-term
Nucleus TS
multiples
Importin pathway energy
GTP in particular Ran GTP
How does Importin pathway work
GTP causes conformational change, alpha binds NLS and B interacts with FG
What is the importin parthway
nuclear import pathway
Where are mitochondrial proteins synthesised
cytoplasm
Targetting sequence for mitochondria
MTS
First place proteins travel for mitochondria
First travel into intermembrane space of mitochondria
What chaperones do Mitochondrial proteins have and why
HSP70 which maintain unfolded state
What recognises MTS
TOM 20 and 22 tom stands for outer membrane
What crosses helps move protein when in mitochondiral membrane
Tim 23/17 and Tim 44
When in mitochondrial matrix what happens
HSP70 molecules pull it through and then it is cleaved
