Gac/Rsm

Question 1

What does Gac stand for?

Answer 1

Global activator of Antibiotic and Cyanide synthesis

Question 2

What is GacS?

Answer 2

A sensor kinase

Question 3

What are the sensor kinases you must know?

Answer 3

GacS
LadS
RetS

Question 4

What does GacS do?

Answer 4

It is autophosphorylated and then phosphorylates GacA

Question 5

Phosphorylated GacA leads to the production of?

Answer 5

Small RNAs

Question 6

What small RNAs?

Answer 6

RsmY and RsmZ

Question 7

What do RsmY and RsmZ do?

Answer 7

They sequester RsmA

Question 8

What is RsmA?

Answer 8

It is a translational repressor

Post-transcriptional regulatory protein

Question 9

When RsmA is free what lifestyle is favoured?

Answer 9

Acute

Question 10

When RsmA is sequestered what lifestyle is favoured?

Answer 10

Chronic

Question 11

How does RsmA prevent translation?

Answer 11

Binds to mRNA which prevents translation from occurring

Question 12

How do the small RNAs sequester RsmA?

Answer 12

They mimic the region RsmA usually binds to and this results in them sequestering RsmA

Question 13

What does the LadS sensor kinase do?

Answer 13

Works in parallel with GacS and promotes chronic infection

Question 14

What does the RetS sensor kinase do?

Answer 14

Works in the opposite fashion to LadS and GacS.

Forms a protein-protein complex with GacS to prevents the small RNAs being produced.

Question 15

RetS favours which lifecycle?

Answer 15

Acute

Question 16

retS mutants lead to?

Answer 16

• Hyperbiofilm phenotype
• Reduced motility
• Low T3SS
• High T6SS
• Higher expression of c-di-GMP