Cell Membrane Trafficking Flashcards
Why is membrane trafficking needed?
- Cell compartmentalisations
- Movement of signals
- Modifications
- Retrieval of proteins
What are the two types of membrane trafficking?
- Endocytic
- Exocytic
How are proteins modified?
Addition of oligosaccharide in the ER
Processing in the golgi
What does N and O linked glycosylation do?
Assists folding
Acts as a ligand
What are the advantages of using yeast as a model organism?
- Whole genome is sequenced
- Amenable for study (can be diploid or haploid)
- Limited gene diversity
What are the disadvantages of using yeast as a model organism?
- Limited diversity
- Small
- Not mulitcellular
- Has a cell wall
What is endocytosis?
The invagination of the plasma membrane into the cell producing a vesicle that fuses with endosomes
What was Novick and Shekman 1980’s hypothesis for the yeast experiment to identify membrane trafficking genes?
If proteins were not secreted, the cell would become more dense because of the build up of vesicles.
What are secretory (sec) mutants?
Cells that synthesis the protein but fail to export and secrete it.
How many genes were identified in the 1980 yeast experiment?
23.
Why were not all genes identified in the 1980s yeast experiement?
The test only tested for genes under the effect of temperature.
Only considered transport to the membrane.
How many genes in the 1980 yeast experiment were involved in endocytosis?
5
How is alpha factor and CPY easy to follow?
They are glycosylated and proteolytically cleaved.
What are the possible destinations from the late golgi?
- Membrane
- Early endosome
- Later endosome
- Vacuole
What is a MVB
Multi Vesicular body
