Post-Translational Modifications Flashcards
Which structure of a protein influences folding?
Primary structure
What kind of regions are hidden during folding?
Hydrophobic regions
What can protein misfolding lead to?
- Aggregation
- Perversion
Give an example of when a protein may be misfolded and leads to aggregation
Misfolding of ß-amyloid leads to aggregation forming amyloid plaques in Alzheimer’s
Give an example of when a protein may be misfolded and leads to perversion
Abnormal prion proteins resists protease action
- Then recruits normal prion proteins and proliferates infecting the individual
What is the function of chaperones?
To assist protein folding
Examples of heat shock proteins that are chaperones? Their function?
HSP70 - Assist folding
HSP60 - Help later on to hide hydrophobic regions by encasing
How are incorrectly assembled proteins destroyed?
The hydrophobic regions are exposed then tagged for destruction by ubiquitin
Ubiquitin is attached to a degradation signal so the protein is destroyed by a proteasome
Which protein tags for the destruction of incorrectly assembled proteins?
Ubiquitin
What is ubiquitin attached to?
A degradation signal
What kind of modifications can take place in the ER or cytosol?
Lipidation of proteins
Glycosylation of membrane-bound
What are ubiquinated proteins destroyed by?
Proteasome
What does lipidation modifications of proteins allow?
Lipid anchoring of the protein in cell membrane
What does glycosylation modifications of proteins allow?
Provides protection for membrane-bound and secreted proteins
What is the protein modification of phosphorylation used for?
Regulation of protein interactions
