Post-Translational Modifications Flashcards
Chapter 4
Signal trasnducts requires ____ in some components of the cell in response to an incoming signal.
change
What kind of changes can PTMs provide for the protein?
rapid, specific, and tightly regulated changes
What is the functional consequence of PTM?
it changes the activity of the modified proteins (signaling currency)
What does PTM increase in the function of proteins?
it increases the functional diversity
What kind of modification is this an example of?
phosphorylation
What kind of modification is this an example of?
phosphorylation
What kind of modification is this an example of?
phosphorylation
What kind of modification is this an example of?
acetylation/deacetylation
What kind of modification is this an example of?
N-methylation
What kind of modification is this an example of?
N-methylation
What kind of modification is this an example of?
O-methylation
What kind of modification is this an example of?
Hydroxylation
What does glycosylation affect in proteins?
folding, trafficking, and function
Which type of glycosylation occurs on the hydroxyl group of ser/thr?
O-glycosylation
What type of glycosylation occurs on the amino group of asparagine?
N-glycosylation
polar
The addition of a single N-acetyl gluosamine (GlcNac) to ser/thr on cytosolic and nuclear proteins.
GlcNAcylation
transferase/hydrolase
Examples of simple fatty acids in lipid modification
- myristate
- palmitate
Examples of complex lipid groups in lipid modification
- farnesyl group
- geranylgeranyl group
S-palmitoylation to ____ is more dynamic and may play an active role in signaling.
cystine
What is ubiquitylation?
it is where Gly on ubiquitin interacts with Lys on a protein and binds to the substrate for modification
What is proteolysis?
The final process of protein degredation after ubiquitylation where the protein is degraded into peptide fragments
Describe the process of proteolysis of preproinsulin in the pancreas
1) preproinsulin - A chain, B chain, and C chain
2) proinsulin - Disulfide bonds form between A and B chains
3) insulin - Two disulfide bonds cut out the C chain
What catalyzes the rotation of a proline group about a peptide bond?
peptidyl prolyl cis-trans isomeras (PPIase)
What are some examples of the physical structure which PTMs can change?
- shape
- charge
- hydrophobicity of the surface
global effect on proteins