Controlling protein Action

Question 1

What are some diseases that occur when protein function is lost?

Answer 1

• cancer
• haemophilia
• polycytic kidney disease

Question 2

What is haemophilia?

Answer 2

a genetic deficiency in clotting factor VIII which causes increased bleeding and usually affects males

Question 3

In what ways can protein interactions be controlled?

Answer 3

• expression and degradation
• interaction domains
• localisation
• ligand binding
• protein switches
• protein modifications

Question 4

How can protein activity be controlled by expression and degradation?

Answer 4

• control level of lifetime of protein
• can be controlled by transcription
• level of mRNA and protein can be controlled by regulating degradation

Question 5

How can effector ligand binding affect protein action?

Answer 5

binding of a molecule can induce long range conformation chnages

Question 6

How do interaction domains control protein action?

Answer 6

-intramolecular binding of two interaction domains in the same molecule can inhibition enzyme activity auto inhibition (can be regulated)

Question 7

How does localisation affect enzyme activity?

Answer 7

• multiple proteins involved in a common process are co-located (achieved by modification)
• if two proteins aren’t in the same area of the cell, they can’t interact

Question 8

What are protein switches?

Answer 8

• when some proteins activity/functions and cellular processes don’t run continuously they need to be turned on and off
• usually enzymes that catalyse the hydrolysis of nucleotide phosphate

Question 9

How can protein modifications affect activity?

Answer 9

-modifications can change protein localisation ,activity, interaction and degradation

Question 10

What is hydroxylation?

Answer 10

addition of a single oxygen atom by hydroxylates

Question 11

What maintains a tight regulation of complex pathways?

Answer 11

feedback control