Protein Sorting Mechanisms (4.1) Flashcards
How are intracellular processes separated?
Semipermeable membranes
What is the purpose of compartmentalisation?
Equips the body with different areas to allow for unique building of proteins
Where are proteins synthesised?
On ribosomes in the cytosol or RER
Proteins produced in the cyotosl end up in the?
Cytosol, nucleus, mitochondria, chloroplasts or peroxisome
Proteins produced in the RER end up in?
Entering the ER membrane or transported out of the cell or into endomembrane system organelles
What are the distinct routes of importation into organelles?
Nuclear pores, transport across membranes, transport by vesicles
When does importation occur
post-translationally or co-translationally
What are the sorting signals
Signal peptide or signal patch
What does signal peptide direct to
ER
What does signal patch direct to
Vesicular transport
How were sorting signals shown
Via transfection with GFP
Is traffic through the nuclaer pore bidirectional
Yes
What allows movement through the nuclear pore complex
Nuclear localisation sequence
What is the process of entry to the nucleus
NLS allows recognition by importin and binding; protein-receptor complex binds to nuclear pore filament; complex moves through the nuclear pore; complex interacts with RAN-GTP and dissociates; Importin B is transported to the cytoplasm bound to RAN-GTP (energy is made by RAN-GTP hydrolysis)
What complexes allow entry into mitochondria and chloroplasts?
TIM/TOM; TIC/TOC
